Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 11 May – 17 May 2022

Aira – Kyushu (Japan) : JMA reported that a very small eruptive event was recorded at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) during 9-13 May. An eruptive event at 1141 on 15 May generated a plume that rose 1.2 km above the crater rim.

Etna – Sicily (Italy) : INGV reported that at around 1900 on 12 May new vents opened along the N flank of Etna’s Southeast Crater (SEC) and produced ash emissions that rose to 3.5 km (11,500 ft) a.s.l. and drifted SW. Lava flowed from the vents and traveled to the N base of the crater. Lava effusion continued over the next several days, and by 17 May the flow had descended ENE into Valle del Leone, reaching 2,300-2,400 m elevation. Discontinuous Strombolian activity of variable intensities occurred at SEC; during more intense phases ash emissions were visible, though the plumes dissipated rapidly.

Fuego – South-Central Guatemala : INSIVUMEH reported that 2-9 explosions per hour were recorded at Fuego during 10-17 May, generating ash plumes that rose as high as 1.1 km above the crater rim. The ash plumes drifted 10-15 km E, SE, S, and SW causing daily ashfall in areas downwind including Morelia (9 km SW), Panimaché I and II (8 km SW), Santa Sofía (12 km SW), Finca Palo Verde, Finca la Asunción, El Zapote (10 km S), Ceylon, Yucales (12 km SW), El Porvenir (8 km ENE), Alotenángo (8 km ENE), San Miguel Dueñas (10 km NE), San Sebastián, and La Rochela. Daily shock waves rattled structures in communities around the volcano and occasional rumbling was heard. Block avalanches descended the flanks in all directions, but most commonly were visible in the Ceniza (SSW), Seca (W), Trinidad (S), Taniluyá (SW), Honda, and Las Lajas (SE) drainages. Daily explosions ejected incandescent material 100-350 m above the summit.

Great Sitkin – Andreanof Islands (USA) : AVO reported that minor advancement of the lava flows at Great Sitkin indicated continuing slow lava effusion during 10-17 May. Daily elevated surface temperatures were identified in satellite data.

Ibu – Halmahera : PVMBG reported that the eruption at Ibu continued during 11-17 May. Daily gray-and-white ash plumes of variable densities generally rose 200-800 m above the summit and drifted mainly W and N. Eruptive events at 0903 and 1807 on 14 May and at 1759 on 15 May produced ash plumes that rose 0.8-1 km above the summit and drifted W and SW. At 1646 on 16 May dense gray ash plumes rose around 2.5 km and drifted W.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was visible in satellite images during 6-13 May. Explosions on 12 May generated ash plumes that rose as high as 6 km (19,700 ft) a.s.l. by 1120 local time and drifted about 30 km NW. Explosions on 14 May produced ash plumes that rose to 5.7 km (18,700 ft) a.s.l. by 0940 local time and drifted 28 km NE.

Katmai – Alaska : AVO reported that on 13 May strong winds in the vicinity of Katmai and the Valley of Ten Thousand Smokes blew unconsolidated ash SE towards Kodiak Island at an altitude up to 1.8 km (6,000 ft) a.s.l. The ash was originally deposited during the Novarupta eruption in 1912.

Kilauea – Hawaiian Islands (USA) : HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 10-17 May, entering the active lava lake and flowing onto the crater floor. By 10 May the total volume of erupted lava was an estimated 77 million cubic meters, and the lake which had risen a total of 106 m since 29 September 2021. The surface of the lava lake was active all week, though the height of the lake was high and relatively stable. Breakouts of lava occurred along the NE and NW margins of the lake during 10-11 May, and more notably from the E margins the rest of the week.

Lewotolok – Lembata Island : PVMBG reported that the eruption at Lewotolok continued during 10-17 May. An increase in gas emissions along with continuing ash emissions was observed on 14 and 17 May. The ash emissions rose to 1-2.4 km above the summit and drifted W, N, and NE.

Manam – Northeast of New Guinea : The Darwin VAAC reported that during 13-16 May ash plumes from Manam rose to 2.4-3.7 km (8,000-12,000 ft) a.s.l. and drifted NE, SW, and W based on satellite images and weather models.

Merapi – Central Java : BPPTKG reported no significant morphological changes at Merapi’s summit lava dome during 6-12 May, though the height of the dome below the SW rim had increased by around 2 m. As many as 92 lava avalanches traveled a maximum of 2 km, mostly down the Bebeng drainage on the SW flank. Two pyroclastic flows traveled 2 km down the Bebeng drainage. Seismicity remained high.

Pavlof – Alaska Peninsula, Alaska : AVO reported that the eruption at a vent on Pavlof’s upper E flank was ongoing during 10-17 May, and seismic tremor persisted. Daily elevated surface temperatures were identified in satellite images consistent with the effusion of short lava flows on the upper flank.

Reventador – Ecuador : IG reported that a high level of activity continued at Reventador during 10-17 May, though cloudy weather conditions sometimes prevented visual observations, particularly during 14-15 May. Gas-and-ash plumes, often observed multiple times a day as reported by the Washington VAAC, rose as high as 1 km above the summit and drifted mainly NW and W. Incandescence from the crater and incandescent blocks rolling 600 m down the flanks was visible during 10-13 May. During the morning of 17 May a new lava flow descended the NE flank.

Rincon de la Vieja – Costa Rica : On 13 May OVSICORI-UNA reported that 23 small phreatic explosions at Rincón de la Vieja were recorded during the previous week. Eruptive events at 2328 on 10 May and 0700 on 11 May were recorded by the seismic network through darkness and cloudy weather conditions prevented visual confirmation. Tremor levels decreased significantly on 12 May.

Ruapehu – North Island (New Zealand) : On 17 May GeoNet reported that elevated unrest at Ruapehu continued, though at reduced levels. During the previous two weeks the level of volcanic tremor declined from strong to moderate. The lake water temperature decreased from a peak of 41 degrees Celsius on 8 May to 37 degrees Celsius. A gas measurement flight on 13 May confirmed continuing high levels of gas emissions, though at values lower than measured two weeks prior; sulfur dioxide and carbon dioxide flux rates at 179 and 1,658 tonnes per day, respectively. Lake upwelling over the northern vent area was also visible during the overflight.

Sangay – Ecuador : IG reported a high level of activity at Sangay during 10-17 May. Weather clouds and rain often prevented visual and webcam observations of the volcano, though almost daily ash-and-gas plumes were identified in satellite images by the Washington VAAC; plumes rose as high as 1.5 km above the volcano and drifted W. Almost daily, multiple daily thermal anomalies over the volcano were visible in satellite data. The seismic network detected signals indicating lahars or possible lahars during 13-17 May.

Santa Maria – Southwestern Guatemala : INSIVUMEH reported that the eruption at Santa María’s Santiaguito lava-dome complex continued during 10-17 May. Incandescence from Caliente crater and the lava flows on the W and SW flanks was visible nightly and during some early mornings. The lava flows continued to advance in the San Isidro channel, and produced block avalanches from the ends and sides of the flows that descended the S, SW, and S flanks. Ash from these avalanches fell in areas on and around the volcano.

Semeru – Eastern Java : PVMBG reported that the eruption at Semeru continued during 11-17 May. An eruptive event at 0608 on 14 May generated an ash plume that rose 200 m and drifted N. Another event recorded at 0634 on 17 May produced an ash plume that rose 300 m and drifted SW.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that low-level eruptive activity at Semisopochnoi’s North Cerberus cone continued during 10-17 May. Seismicity continued to be elevated with intermittent tremor detected by the seismic network. Several daily explosions were recorded in infrasound and seismic data. Daily low-level ash emissions were visible in clear satellite images and webcam views.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 6-13 May, and lava-dome extrusion continued.

Sinabung – Northwestern Sumatra : During 1 January-17 May gas emissions were frequently visible and detected by instruments; daily averages of sulfur dioxide emissions from passive degassing were below 250 tons per day, though a high value of about 4,000 tons per day was recorded in January, and white plumes of varying densities rose as high as 500 m above the summit. During the previous four months deformation data showed a downward trend and indicated deflation, and the number of deep and shallow volcanic earthquakes signals generally declined. Growth of the SE part of the lava dome continued at a low rate as indicated by low numbers of earthquake signals caused by fluid movement. Avalanches of material were indicated by seismic signals though not visually confirmed.

Stromboli – Aeolian Islands (Italy) : INGV reported that during 9-15 May activity at Stromboli was characterized by ongoing explosions from three vents in Area N (North Crater area) and two vents in Area C-S (South-Central Crater area). During 9-13 May explosions from Area N vents (N1 and N2) averaged 2-4 events per hour; explosions from the N1 vent ejected lapilli and bombs mixed with ash 80-150 m high and those at two N2 vents ejected material less than 80 m high. No explosions occurred at the S1 and C vents in Area C-S; low- to medium-intensity explosions at the two S2 vents occurred at a rate of 0-5 per hour and ejected coarse material 80-150 m high. A sequence of six major explosions occurred at S1 and S2 in Area C-S during 1643-1647 on 13 May. The first, and most energetic, occurred at 1643 and ejected an abundant amount of coarse material 300 m high. The material fell in areas to the E and SE, and at Pizzo Sopra la Fossa (an area atop the volcano about 100 m above the crater terrace). The second explosion was lower in intensity but also ejected coarse material. The third through the sixth explosion all ejected ash. Deposits from the explosions seen during a field visit the next day were found as far at 450 m elevation, and impacts from ballistics were found along the switchbacks up the Liscione between 700 and 830 m elevation. Decimeter to meter-sized bombs were observed near 850 m elevation. Elongated tephra, centimeter to decimeter in size, was seen near Pizzo Sopra la Fossa. The CS vent area had deepened and the vents were elongated towards the central part. After the sequence of explosions on 13 May, through 15 May, explosive activity at N1, N2, and Area C-S was low.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that eruptive activity continued to be recorded at Suwanosejima’s Ontake Crater during 9-16 May. Eruption plumes rose as high as 1 km above the crater rim and material was ejected 400 m above the vent; no explosions were recorded. Ash fell in Toshima village (3.5 km SSW) during 13-16 May.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 11 May – 17 May 2022

Awu – Sangihe Islands : PVMBG had raised the Alert Level for Awu to 2 (on a scale of 1-4) on 12 December 2021 because of a notable increase in the number of both shallow and deep volcanic earthquakes. Since then the number of shallow and deep volcanic earthquakes averaged 8 and 5 events per day, respectively. Gas emissions had not been visible, though weather conditions sometimes prevented views of the volcano. Another significant seismic increase was recorded on 9 May, with 88 shallow events and 147 deep events, and then again the following day with 90 shallow events and 203 deep events. At 1500 on 11 May a white emission was observed rising about 30 m above the crater rim.

Cleveland – Chuginadak Island (USA) : AVO reported that during 11-17 May elevated surface temperatures over Cleveland were identified in satellite images. No significant seismic or infrasound activity was detected. A continuous sulfur dioxide plume drifted 500 km during 15-16 May.

Krakatau – Sunda Strait : The Darwin VAAC reported that during 10-12 May ash plumes from Anak Krakatau rose to 2.4 km (8,000 ft) a.s.l. and drifted E, N, NW, and W based on satellite images and weather models. On 13 May satellite images showed a narrow ash plume drifting SE and E at an altitude of 2.4 km. Dense steam plume with minor ash content rose to 2.4 km and drifted NE, N, NW, and W during 14-16 May.

Reykjanes – Reykjanes Peninsula : The National Commissioner of the Icelandic Police declared a level of “uncertainty” for the Reykjanes Peninsula on 15 May, noting that the declaration meant that responders and agencies were to review their preparedness plans in response to recent increases in seismicity and deformation. More than 3,000 earthquakes had been detected near Eldvörp in the Reykjanes/Svartsengi volcanic system during the past week. Nine earthquakes above M 3 and two earthquakes above M 4 were recorded during 15-16 May; the largest event was a M 4.3 which was recorded at 1738 on 15 May. The earthquakes were located at depths of 4-6 km. GPS and InSAR data detected inflation W of Thorbjörn during the previous two weeks, likely caused by a magmatic intrusion at 4-5 km depth.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 4 May – 10 May 2022

Aira- Kyushu (Japan) : JMA reported that sulfur dioxide emissions at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) were slightly high at 500 tons per day on 2 May. At 1453 on 3 May an eruption produced a plume that rose 1.1 km above the crater rim. Very small eruptive events were recorded during 6-9 May.

Dukono – Halmahera : Based on satellite and wind model data, the Darwin VAAC reported that during 4-9 May ash plumes from Dukono rose to 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted in multiple directions.

Great Sitkin – Andreanof Islands (USA) : AVO reported that slow lava effusion at Great Sitkin likely continued during 3-10 May; a 5 May satellite image showed that the S flank flow had advanced 15 m. Elevated surface temperatures were identified in satellite data during 6-10 May.

Kavachi – Solomon Islands : Satellite data showed discolored water around Kavachi on 10, 20, 25, and 30 April as well as on 5 May.

Kilauea – Hawaiian Islands (USA) : HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 3-10 May, entering the active lava lake and flowing onto the crater floor. The surface of the lava lake was active all week, though the height of the lake was relatively stable. Daily breakouts occurred along the NE, NW, and S margins of the lake. A short-lived lava flow effused from the W vent and onto the crater floor at around 0700 on 7 May.

Lewotolok – Lembata Island : PVMBG reported that the eruption at Lewotolok continued during 4-10 May. Eruptive events at 1245 on 4 May and 0544 on 6 May produced ash plumes that rose 600 m above the summit and drifted W.

Manam – Northeast of New Guinea : The Darwin VAAC reported that during 3-4 May ash plumes from Manam rose to 2.1 km (7,000 ft) a.s.l. and drifted SE and NW based on information from RVO, satellite images, and weather models. On 6 May ash plumes rose to 1.8 km (6,000 ft) a.s.l. and drifted NW and WNW.

Merapi – Central Java : BPPTKG reported no significant morphological changes at Merapi’s summit lava dome during 29 April-5 May, though the height of the dome below the SW rim had decreased by around 3 m. Based on photo analyses, the volume of the SW lava dome had a volume of 1.52 million cubic meters while the central lava dome was 2.58 million cubic meters. As many as 120 lava avalanches traveled a maximum of 2 km, mostly down the Bebeng drainage on the SW flank. Seismicity remained high.

Nevado del Ruiz – Colombia : On 10 May Servicio Geológico Colombiano’s (SGC) reported that during the previous week the number of seismic signals indicating both rock fracturing and fluid movement at Nevado del Ruiz had increased compared to the week before. Several episodes of drumbeat seismicity were recorded on 5 and 8 May, indicting growth of the lava dome. Some low-temperature thermal anomalies were also identified at Arenas Crater. Gas-and-ash emissions were periodically visible in webcam images. A small ash emission on 3 May caused minor ashfall in the municipalities of Manizales (25 km N), Dosquebradas (40 km W), Santa Rosa, and Pereira (40 km WSW). At 0857 on 9 May an ash plume drifted NW, W, and SW, causing ashfall in Manizales, Villamaría (28 km NW), and Chinchiná (30 km WNW) in the department of Caldas, and in Pereira, Dosquebradas, and Santa Rosa de Cabal (33 km W) in the department of Risaralda.

Pavlof – Alaska Peninsula, Alaska : AVO reported that the eruption at a vent on Pavlof’s upper E flank was ongoing during 3-10 May, though weather conditions sometimes prevented visual observations. Seismic tremor persisted. Daily elevated surface temperatures were identified in satellite images and almost daily steam emissions were recorded in webcam images. The lava flow from the E vent was 500 m long by 8 May.

Rincon de la Vieja – Costa Rica : On 5 May OVSICORI-UNA reported an average of two daily phreatic explosions at Rincón de la Vieja during the previous week. The events did not eject material outside of the crater and produced steam plumes that rose no higher than 200 m above the crater rim. A phreatic explosion at 1650 on 6 May produced a steam plume that rose 500 m. A few phreatic explosions and several steam emissions were recorded on 7 May. Several steam emissions were also recorded on 8 May.

Ruapehu – North Island (New Zealand) : On 11 May GeoNet reported that elevated unrest at Ruapehu continued during the previous week, consisting of lake water heating, volcanic gas output, and strong volcanic tremor. The lake water temperature continued to rise, peaking at 41 degrees Celsius. Steam plumes were visible rising from the lake; an overflight confirmed that they were caused by a combination of the warming lake and atmospheric conditions, with no eruptive activity. Tremor levels declined but remained high. A gas measurement flight on 4 May confirmed high levels of gas emissions with sulfur dioxide and carbon dioxide flux rates at 260 and 1,970 tonnes per day, respectively. Lake upwelling over the central and northern vents areas was also visible during multiple overflights. The sustained carbon dioxide and sulfur gas emissions, along with high tremor levels, continue to indicate that magma is driving this period of heightened unrest.

Sabancaya – Peru : Instituto Geofísico del Perú (IGP) reported moderate levels of activity at Sabancaya during 2-8 May with a daily average of 53 explosions. Gas-and-ash plumes rose as high as 3 km above the summit and drifted N, NE, E, and SE. As many as five thermal anomalies originating from the lava dome in the summit crater were identified in satellite data. Minor inflation continued to be detected near Hualca Hualca (4 km N).

Semeru – Eastern Java : PVMBG reported that the eruption at Semeru continued during 3-10 May. Ash plumes visible on 5, 7, and 9 May were rising 400-700 m above the summit and drifting mainly SW.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that low-level eruptive activity at Semisopochnoi’s North Cerberus cone continued during 3-10 May. Seismicity continued to be elevated with intermittent tremor detected by the seismic network. Several daily explosions were recorded during 8-10 May. Weather clouds obscured views of the volcano, though daily minor, low-level ash emissions were seen in webcam views. A pilot reported a low-level eruption cloud on 9 May.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 29 April-6 May, and lava-dome extrusion continued.

Stromboli – Aeolian Islands (Italy) : INGV reported that during 2-8 May activity at Stromboli was characterized by ongoing explosions from three vents in Area N (North Crater area) and two vents in Area C-S (South-Central Crater area). Explosions from Area N vents (N1 and N2) averaged 3-6 events per hour; explosions from the N1 vent ejected lapilli and bombs mixed with ash 80-150 m high and those at two N2 vents ejected material less than 80 m high. N2 produced weak and occasional spattering. No explosions occurred at the S1 and C vents in Area C-S; low-intensity explosions at the two S2 vents occurred at a rate of 1-5 per hour and ejected coarse material no higher than 80 m.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that eruptive activity continued to be recorded at Suwanosejima’s Ontake Crater during 2-9 May. Eruption plumes rose as high as 1.3 km above the crater rim; no explosions were recorded. Crater incandescence was occasionally visible during 2-6 May and ash fell in Toshima village (3.5 km SSW).

Whakaari/White Island – North Island (New Zealand) : On 9 May GeoNet reported that activity at Whakaari/White Island remained at a low level based on observations and data collected during an overflight conducted on 27 April. Gas-and-steam emission temperatures were up to 111 degrees Celsius, down from 16 March highs of 288 degrees Celsius. Geysering activity at one of the water-saturated vents was observed. Satellite data indicated minor uplift in the active vent area. Seismicity was low.

Wolf – Isla Isabela (Galapagos) : On 5 May IG reported that the eruption at Wolf’s SE flank was over. The eruption began at 2320 on 6 January from an approximately 8-km-long radial fissure, trending NW-SE, that had at least five active vents. Lava flows from the vents traveled SE then E, covering an area of more than 30 square kilometers. The maximum length of the flow field was 18.5 km, with the farthest-reaching flow stopping 150-200 m from the coastline. The highest levels of heat, sulfur dioxide emissions, seismicity, and deformation were recorded in the early days of the eruption. Sulfur dioxide emissions had been absent for the previous 30 days.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 4 May – 10 May 2022

Cleveland – Chuginadak Island (USA) : On 10 May AVO raised the Aviation Color Code and the Volcano Alert Level for Cleveland to Yellow and Advisory, respectively, noting that elevated surface temperatures and sulfur dioxide emissions were identified in satellite data during the past few days.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was visible in satellite images during 29 April-6 May. Explosions on 4 May generated ash plumes that rose as high as 3.2 km (10,500 ft) a.s.l. and drifted about 60 km SW.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 27 April – 3 May 2022

Aira – Kyushu (Japan) : JMA reported that a very small eruptive event was recorded at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) on 2 May.

Ambae – Vanuatu : On 28 April the Vanuatu Meteorology and Geo-Hazards (VMGD) reported that the cone in Ambae’s Lake Voui continued to produce steam and ash emissions.

Ambrym – Vanuatu : The Vanuatu Meteorology and Geo-Hazards Department (VMGD) reported that incandescence from Ambrym’s Benbow Crater was visible during 25 January-3 February from a lava flow that had effused from a new vent on the NW part of the crater floor. Recent observations indicated that gas and ash was no longer being emitted from the crater, and seismicity had decreased and stabilized.

Dukono – Halmahera : Based on satellite and wind model data, the Darwin VAAC reported that during 27-29 April and 2-3 May ash plumes from Dukono rose to 2.1 km (7,000 ft) a.s.l. and drifted E, NE, N, and NW.

Great Sitkin – Andreanof Islands (USA) : AVO reported that slow lava effusion at Great Sitkin likely continued during 27 April-3 May; no significant seismic activity was detected and weather clouds obscured webcam and satellite views.

Kilauea – Hawaiian Islands (USA) : HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 26 April-3 May, entering the active lava lake and flowing onto the crater floor. Roiling and spattering in the SE part of the lake was visible during 26-27 April. The surface of the lava lake was active all week, and the height of the lake fluctuated; the lake occasionally overflowed the rim, sending lava onto the crater floor. Daily breakouts occurred along the margins of the crater rim.

Lewotolok – Lembata Island : PVMBG reported that the eruption at Lewotolok continued during 26 April-4 May. Daily white-and-gray ash plumes rose 50-600 m above the summit and drifted in multiple directions. Images of the volcano showed incandescent material being ejected above the crater rim.

Manam – Northeast of New Guinea : The Darwin VAAC reported that on 1 May ash plumes from Manam rose to 2.7 km (9,000 ft) a.s.l. and drifted SE and ESE based on information from RVO, satellite images, and weather models. During 2-3 May low-level ash emissions rose to 2.1 km (7,000 ft) a.s.l. and drifted ESE.

Merapi – Central Java : BPPTKG reported that the eruption at Merapi continued during 22-28 April. The heights and morphologies of the SW lava dome and the central lava dome were unchanged from the previous week, and seismicity remained at high levels. As many as 102 lava avalanches traveled a maximum of 2 km, mostly down the Bebeng drainage on the SW flank.

Pavlof – Alaska Peninsula, Alaska : AVO reported that the eruption at a vent on Pavlof’s upper E flank was ongoing during 26 April-3 May, though weather conditions sometimes prevented visual observations. Seismic tremor persisted and elevated surface temperatures were identified in satellite images almost daily. A short lava flow had descended the E flank during 26-28 April and was about 500 m long. Steaming from the active vent was visible during 30 April-2 May.

Semeru – Eastern Java : PVMBG reported that the eruption at Semeru continued during 26 April-3 May. Almost daily ash plumes were visible rising 300-700 m above the summit that drifted W, SW, and E. Ash plumes were recorded at 0523 and 0557 on 28 April, 0502 and 0649 on 29 April, 0621 on 30 April, 0704 on 2 May, and 0922 on 3 May. A pyroclastic flow from the end of the lava flow descended the SE flank at 0630 on 1 May and produced ash plumes that rose as high as 500 m above the summit.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that low-level eruptive activity at Semisopochnoi’s North Cerberus cone continued during 26 April-3 May. Tremor continued to be detected by the seismic network. Weather clouds obscured views of the volcano on most days, though occasional views during 27-29 May revealed new ash deposits on the flanks.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 22-29 April, and lava-dome extrusion continued.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that eruptive activity continued to be recorded at Suwanosejima’s Ontake Crater during 25 April-2 May. Eruption plumes rose as high as 800 m above the crater rim and crater incandescence was occasionally visible. One explosion, recorded in Toshima village (3.5 km SSW), generated an ash plume that rose 1.3 km and into weather clouds.

Wolf – Isla Isabela (Galapagos) : IG reported that thermal anomalies over Wolf were periodically identified in satellite images during 26 April-3 May, indicating active lava flows.

Yasur – Vanuatu : On 28 April Vanuatu Meteorology and Geohazards Department (VMGD) reported that activity at Yasur continued at a high level of “major unrest,” as defined by the Alert Level 2 status (the middle level on a scale of 0-4). Ash-and-gas emissions and loud explosions continued to be recorded, with bombs falling in and around the crater.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 27 April – 3 May 2022

Batu Tara – Komba Island : PVMBG issued VONAs noting recent increased gas emissions at Batu Tara but no confirmed eruptions. Ground-based observers reported that at 1453 and 1617 on 28 April gas emissions rose 1-1.2 km above the summit and drifted W. At 0054 on 2 May gas emissions rose 500 m and drifted W.

Gaua – Banks Islands (Vanuatu) : On 28 April the Vanuatu Meteorology and Geo-Hazards Department (VMGD) reported ongoing steam-and-gas emissions from Gaua’s Mt. Garet, and warned visitors that they may notice a sulfur odor near the cone. On 3 May local villages, especially in Naveto in the NE part of the island, heard a loud explosion and then saw a dense ash plume rising from Mt. Garet during 0900-0930.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was visible in satellite images on most days during 22-29 April. Explosions during 21-22 April produced ash plumes that rose as high as 5 km (16,400 ft) a.s.l. and drifted around 95 km E and SE. Explosions at 1410 on 28 April, local time, generated an ash plume that rose to 10 km (32,800 ft) a.s.l., was about 5 x 7 km at it’s top, and drifted WNW. The Aviation Color Code was raised to Red (the highest level on a four-color scale). By 1550 the ash cloud had spread to 28 x 34 km in size and had drifted almost 290 km WNW at an altitude of 9 km.

Krakatau – Sunda Strait : PVMBG reported that only white gas plumes rose above Anak Krakatau during 27 April-4 May. Satellite images acquired on 27 April and 2 May showed incandescent lava flows in and around the crater and advancing into the sea.

Ruapehu – North Island (New Zealand) : On 2 May GeoNet reported that elevated unrest at Ruapehu continued during the previous week, consisting of lake water heating, volcanic gas output, and strong volcanic tremor. Variable tremor levels were characterized by bursts of strong tremor and short periods of weaker tremor. The lake water temperature had risen to 38 degrees Celsius. During an overflight scientists observed reduced upwelling in the lake over the Northern vents and additional upwelling over the main Central Vent, indicating that it was at least partially unblocked. A sulfur dioxide flux of 390 tonnes per day was measured during a flight on 28 April, the sixth highest amount since 2003. The sustained carbon dioxide and sulfur gas emissions, along with high tremor levels, continue to indicate that magma is driving this period of heightened unrest. At around 0945 on 3 May a steam plume was visible slowly rising as high as 1.5 km above the crater rim; it dissipated by 1030. The plume was not accompanied by seismic or acoustic signals, and weather conditions favored cloud formation. Scientists on an overflight that afternoon observed active upwelling and a slightly higher lake level, similar to observations the previous day. The lake temperature had risen to 39 degrees Celsius. Results from lake water chemistry analysis showed no indication that magma was interacting with the hydrothermal system beneath the lake.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 20 April – 26 April 2022

Aira – Kyushu (Japan) : JMA reported that very small eruptive events at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) were recorded during 18-25 April. Crater incandescence was periodically visible at night. The sulfur dioxide emissions were slightly high at 1,300 tons per day on 19 April but then dropped to 500 tons per day on 22 April.

Davidof – Aleutian Islands (USA) : AVO lowered both the Aviation Color Code and the Volcano Alert Level for Davidof to Unassigned on 21 April, noting that the earthquake swarm which began in January had declined in the previous few weeks. It is unknown if the swarm was due to tectonic processes or volcanic unrest. The level “Unassigned” means that there is not sufficient instrumentation on the volcano for AVO to characterize a base level of activity; the closest seismometer was on Little Sitkin (15 km E).

Dukono – Halmahera : Based on satellite and wind model data, the Darwin VAAC reported that during 21-23 and 25 April ash plumes from Dukono rose to 2.1 km (7,000 ft) a.s.l. and drifted in multiple directions.

Fuego – South-Central Guatemala :INSIVUMEH reported that 2-10 explosions per hour were recorded at Fuego during 21-25 April, generating ash plumes that rose as high as 1.3 km above the crater rim. The ash plumes mainly drifted as far as 15 km SE, S, and SW causing daily ashfall in areas downwind including Morelia (9 km SW), Panimaché I and II (8 km SW), Santa Sofía (12 km SW), El Porvenir (8 km ENE), Sangre de Cristo (8 km WSW), Finca Palo Verde, Finca la Asunción, El Zapote (10 km S), San Pedro Yepocapa (8 km NW), Ceylon, San Andrés Osuna, and La Rochela. Shock waves rattled structures in communities around the volcano on most days and occasional rumbling was heard. Block avalanches descended the flanks in all directions, but most commonly were visible in the Ceniza (SSW), Seca (W), Trinidad (S), Taniluyá (SW), Honda, and Las Lajas (SE) drainages, often reaching vegetated areas. Explosions ejected incandescent material 100-350 m above the summit during 21-24 April.

Great Sitkin – Andreanof Islands (USA) : AVO reported that slow lava effusion at Great Sitkin continued during 20-26 April, and very low seismicity persisted.

Ibu – Halmahera : PVMBG reported that the eruption at Ibu continued during 22-26 April. Daily dense gray ash plumes generally rose 400-1,500 m above the summit and drifted W and NE, though at 0948 on 25 April ash plumes rose up to 3 km above the summit and drifted W.

Kilauea – Hawaiian Islands (USA) : HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 19-26 April, entering an active lava lake and flowing onto the crater floor. The surface of the lava lake was active all week, and the height of the lake fluctuated; the lake occasionally overflowed the rim, sending lava onto the crater floor. Daily breakouts occurred along the N, NE, E, and S parts of the crater.

Langila – New Britain (Papua New Guinea) : The Darwin VAAC reported that on 24 April an ash plume from Langila rose 2.1 km (7,000 ft) a.s.l. and drifted SW. The plume had dissipated within 5.5 hours.

Lewotolok – Lembata Island : PVMBG reported that the eruption at Lewotolok continued during 19-26 April. Daily white-and-gray ash plumes rose 50-400 m above the summit and drifted W, NW, and E.

Merapi – Central Java : BPPTKG reported that the eruption at Merapi continued during 15-21 April. The heights and morphologies of the SW lava dome and the central lava dome were unchanged from the previous week, and seismicity remained at high levels. As many as 150 lava avalanches traveled a maximum of 2 km mostly down the Bebeng drainage on the SW flank. One pyroclastic flows traveled 2 km SW down the Bebeng.

Pavlof – Alaska Peninsula, Alaska : AVO reported that the eruption at a vent on Pavlof’s upper E flank was ongoing during 20-26 April, though weather conditions sometimes prevented visual observations. Seismic tremor persisted and daily elevated surface temperatures were identified in satellite images.

Popocatepetl – Mexico : CENAPRED reported that the eruption at Popocatépetl continued during 19-26 April. Each day there were 6-27 steam-and-gas emissions that rose from the crater and drifted mainly SW. The plumes sometimes contained ash. Incandescence from the crater was sometimes visible at night. Two minor explosions were recorded at 0152 and 0559 on 21 April.

Rincon de la Vieja – Costa Rica : OVSICORI-UNA reported that a small eruptive event at Rincón de la Vieja was recorded at 0618 on 25 April, though it was not visible due to weather conditions. Another small event was recorded at 0156 on 26 April; the plume was not visible due to conditions.

Sabancaya – Peru : Instituto Geofísico del Perú (IGP) reported moderate levels of activity at Sabancaya during 18-24 April with a daily average of 37 explosions. Gas-and-ash plumes rose as high as 2.3 km above the summit and drifted N, NE, SE, and S. As many as 10 thermal anomalies originating from the lava dome in the summit crater were identified in satellite data. Minor inflation continued to be detected near Hualca Hualca (4 km N).

Santa Maria – Southwestern Guatemala : INSIVUMEH reported that the eruption at Santa María’s Santiaguito lava-dome complex continued during 21-25 April. Incandescence from Caliente crater and the lava flows on the W and SW flanks was visible nightly and early mornings. Avalanches of blocks descended the W and SW flanks of Caliente. The lava flows continued to advance, traveling as far as 2.5 km in the San Isidro channel, and produced block avalanches from the ends and sides of the flows that descended the S, SW, and S flanks. Ash from these avalanches fell in areas around the volcano and a sulfur odor was also occasionally noticed.

Semeru – Eastern Java : PVMBG reported that the eruption at Semeru continued during 19-26 April. Almost daily ash plumes were visible rising 200-600 m above the summit that drifted N, S, SW, and W. Cloudy weather sometimes prevented visual observations.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that low-level eruptive activity at Semisopochnoi’s North Cerberus cone continued during 19-26 April. Periods of seismic tremor were occasionally detected and small explosions were recorded in seismic data during 19-20 April. Minor, low-level, plumes with low ash content were visible in webcam images through each day during 19-20 April, with occasional more energetic ash plumes. Weather cloud cover often hindered webcam and satellite views during the rest of the week.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 15-22 April, and lava-dome extrusion continued. Explosions during 15-16 April produced ash plumes that rose as high as 5 km (16,400 ft) a.s.l. and drifted about 75 km SE.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that eruptive activity continued to be recorded at Suwanosejima’s Ontake Crater during 18-25 April. Eruption plumes rose as high as 1.5 km above the crater rim; no explosions were recorded.

Wolf – Isla Isabela (Galapagos) : IG reported that thermal anomalies over Wolf were periodically identified in satellite images during 19-26 April, though were absent on several of the days. Lava advancement was identified in images during 19-21 April; no surface activity was visible the rest of the week.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 20 April – 26 April 2022

Edgecumbe – Southeastern Alaska (USA) : AVO stated that a seismic swarm beneath Kruzof Island near Edgecumbe that began at about 0200 on 11 April had declined to background levels by 22 April. The swarm prompted an in-depth analysis of satellite data which spanned the last 7.5 years. The data showed that a broad area of uplift, about 17 km in diameter, was located about 2.5 km E of Edgecumbe. The uplift began in August 2018 and deformed at a rate of up to 8.7 cm per year in the center of the area, totaling 27 cm of uplift; the deformation was ongoing. Retrospective analysis of seismic data revealed that earthquakes started occurring in 2020, though the recent swarm was unusual. The deformation and seismic data together suggested magma movement beneath the volcano, consistent with an intrusion at about 5 km below sea level.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was visible in satellite images during 15-22 April. Explosions during 17-19 and 21 April generated ash plumes that rose as high as 7.5 km (24,600 ft) a.s.l. and drifted 500 km NE. SE, and E. A powerful explosion at 0805 on 20 April (local time) generated ash plumes that rose as high as 11 km (36,100 ft) a.s.l. and drifted more than 2,000 km NE. Ashfall was reported in the territory of the Kronotsky Reserve (Semyachinsky, Valley of Geysers), 50 km NE, and at Cape Nalychevo, 100 km S. Explosions continued through the day; ash plumes rising to 5 km (16,400 ft) a.s.l. were visible in satellite images at 1500, local time. The previous ash plume was about 505 x 130 km and drifted NE, S, and SE at an altitude of 8.7 km (28,500 ft) a.s.l.

Krakatau – Sunda Strait : PVMBG reported that the eruption at Anak Krakatau had intensified. Dense white, gray, and black ash plumes rose as high as 1 km above the summit and drifted SW during 17-19 April. Strombolian activity was first observed on 17 April; that same day that sulfur dioxide emissions increased to 181.1 tons per days from 28.4-68.4 tons per day recorded during 14-15 April. A dense gray-black ash plume rose around 800 m above the summit at 0621 on 21 April and drifted E. At 0049, 0145, 0237, and 1730 on 22 April dense gray-to-black ash plumes rose 500-1,500 m above the summit and drifted SW. Incandescent material was occasionally ejected above the vent. Sulfur dioxide emissions notably increased to 9,219 tons per day on 23 April. That same day, at around 1219, lava flowed into the sea and produced a white steam plume at the entry point. Ash plumes were taller on 23 April, rising to 3 km above the summit at 0608, 1200, and 2020, with SSW, S, and SE drifts. The plumes continued to be characterized as dense, and white, gray, and black in color.

Purace – Colombia : Observatorio Vulcanológico y Sismológico de Popayán, Servicio Geologico Colombiano (SGC), reported that during 19-25 April the number and magnitudes of earthquakes at Puracé was similar to the previous week. Signals included 72 volcano-tectonic (VT) events, indicating rock fracturing, along with 207 long-period (LP) events and 14 low-energy tremor pulses, indicating fluid movement. Data from the GNSS (Global Navigation Satellite System) geodetic network continued to show inflation on the centimeter scale. Sulfur dioxide emissions were lower than the previous week, with values of 937-992 tonnes per day, and gas plumes drifted NW. During a field visit on 22 April scientists observed no changes to the crack near Puracé and Curiquinga volcanoes, and no visible gas emissions. Additional cracks, oriented NW-SE, were observed, in addition to volcanic ash deposits that were likely emplaced on 29 March.

Ruapehu – North Island (New Zealand) : On 26 April GeoNet reported that elevated unrest at Ruapehu had been ongoing for the past five weeks, characterized by lake water heating, volcanic gas output, and strong volcanic tremor. Tremor levels fluctuated the past week but represented a record for the longest and strongest tremor episode ever recorded at the volcano. The lake water temperature remained at 37 degrees Celsius, indicating a substantial amount of heat from magma at a shallow depth (0.5-2 km), though water chemistry showed no change based on sampling during 31 March-15 April.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 6 April – 12 April 2022

Aira – Kyushu (Japan) : JMA reported that very small eruptive events at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) were recorded during 11-18 April. Crater incandescence was periodically visible at night.

Asosan – Kyushu (Japan) : JMA reported that no eruptions had been recorded at Asosan after the end of the last eruption in October 2021. Crater incandescence, which had been occasionally visible since December 2021, was absent beginning on 27 February. Deflation began around 27 February but stabilized in April. Observations of the crater from 17 March revealed that it had deepened, compared to pre-eruption conditions, and that water had returned. Sulfur dioxide emissions had increased to 1,600 tons per day on 25 March, but four observations made during 29 March-12 April showed values in the range of 800-1,200 tons per day. Though these values were higher than those measured in September 2021, before the eruption, they represented a decreasing trend. During a field visit on 7 April scientists observed white emissions rising from Nakadake Crater and gray pools of hot water on the crater floor. A hot spring was active on the S side of the pools. The area of the water represented about 40 percent of the crater floor and the water temperature was 71 degrees Celsius.

Dukono – Halmahera : Based on satellite and wind model data, the Darwin VAAC reported that during 13-18 April ash plumes from Dukono rose to 2.1 km (7,000 ft) a.s.l. and drifted NE, E, SE, and S.

Great Sitkin – Andreanof Islands (USA) : AVO reported that slow lava effusion at Great Sitkin continued during 13-19 April, based on high-resolution satellite data. Weather clouds prevented visual observations on most days. Very low seismicity persisted.

Kilauea – Hawaiian Islands (USA) : HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 12-19 April, entering an active lava lake and flowing onto the crater floor. The surface of the lava lake was active all week, and the height of the lake fluctuated. Flows occasionally overtopped perched levees. At 2315 on 10 April a flow emerged from the S side on the vent that covered areas along the southwest and western margins, and was active through 14 April. Breakouts along the N, NE, and S parts of the crater were visible during 14-19 April.

Lewotolok – Lembata Island : PVMBG reported that the eruption at Lewotolok continued during 12-19 April. Daily white-and-gray ash plumes rose as high as 50-500 m above the summit and drifted W, NW, and E.

Manam – Northeast of New Guinea : The Darwin VAAC reported that on 18 April ash plumes from Manam rose to 13.7 km (45,000 ft) a.s.l. and drifted N based on information from RVO, satellite images, and weather models. Ash had dissipated by 1540. At 2000 an ash plume was visible in a satellite image through a break in weather cloud cover drifted NE at an altitude of 4.9 km (16,000 ft) a.s.l. Ash had dissipated by 0830 on 19 April.

Merapi – Central Java : BPPTKG reported that the eruption at Merapi continued during 8-14 April. The volumes of the SW lava dome and the central lava dome were unchanged from the previous week, and seismicity remained at high levels. As many as 112 lava avalanches originating from two areas on the SW dome traveled a maximum of 2 km down the Bebeng drainage on the SW flank.

Pavlof – Alaska Peninsula, Alaska : AVO reported that the eruption at a vent on Pavlof’s upper E flank was ongoing during 12-19 April, though weather conditions sometimes prevented visual observations. Seismic tremor persisted and elevated surface temperatures were identified in satellite images almost daily. Steam emissions were seen rising above the summit in webcam images on 16 April.

Reventador – Ecuador : IG staff observed high levels of activity at Reventador during a field visit from 4 to 7 April, and noted sporadic emissions with moderate ash content. They viewed the volcano with a thermal camera and saw an active lava flow on the upper NNE flank, producing rock avalanches as it advanced. The flow was 1.7-2 km long and effused from a vent about 200 m below the summit on the NNE flank. Two inactive and cooling flows were located adjacent to the active flow. Activity continued to be high during 12-19 April, though cloudy weather conditions frequently prevented visual observations. Steam, gas, and ash plumes, often observed multiple times a day with the webcam or reported by the Washington VAAC, rose as high as 1 km above the summit crater and drifted W and NW. Crater incandescence was visible most nights and early mornings; incandescent material was visible descending the flanks during 13-14 April.

Sangay – Ecuador : IG reported that the eruption at Sangay continued at a high level, with lava flows effusing from the Ñuñurcu, Central, and Norte vents. Explosions originated from a western vent that reactivated in late 2021, and from Central vent. The Norte vent, on the N flank, had opened on 2 December 2021. Activity levels were slightly higher during 4-6 April, characterized by a higher rate of lava effusion and a satellite-detected thermal anomaly at the Norte vent on 4 April, along with a diffuse but continuously-emitted volcanic cloud that rose 1.7 km above the crater rim and drifted up to 650 km W during 5-6 April. Low-frequency tremor was also recorded during 5-6 April. Even though the eruption plume drifted notably farther than average distances recorded during 2019-2022, only minor ashfall was reported in Chauzán San Alfonso (40 km W, in Guamote canton, Chimborazo province). During 12-18 April weather clouds and rain often prevented visual and webcam observations of the volcano, though daily ash-and-gas plumes were identified in satellite images by the Washington VAAC or in webcam views; plumes rose less than 2 km above the volcano and drifted W and NW. Minor ashfall was reported in Chauzán San Alfonso. The seismic network detected signals indicating descending lahars during 12-13 and 15 April.

Semeru – Eastern Java : PVMBG reported that the eruption at Semeru continued during 13-19 April. Daily ash plumes were visible rising 300-400 m above the summit and drifted N and S, even though cloudy weather sometimes prevented visual observations. The Alert Level remained at 3 (on a scale of 1-4). The public was warned to stay at least 500 m away from Kobokan drainages within 17 km of the summit, along with other drainages originating on Semeru, including the Bang, Kembar, and Sat, due to lahar, avalanche, and pyroclastic flow hazards.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that low-level eruptive activity at Semisopochnoi’s North Cerberus cone continued during 12-19 April. Periods of seismic tremor were detected daily and occasional small explosions were recorded in seismic and regional infrasound data on most days. Weather cloud cover often hindered webcam and satellite views; minor, low-level ash plumes were visible in webcam images during 16-19 April.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 8-15 April, and lava-dome extrusion continued. Explosions on 9 April produced ash plumes that rose as high as 12 km (39,400 ft) a.s.l. and drifted more than 2,000 km NE during 9-10 April. Explosions during 13-14 April generated ash plumes that rose to 6-6.5 km (19,700-21,300 ft) a.s.l. and drifted 80-110 km SW and S.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that eruptive activity continued to be recorded at Suwanosejima’s Ontake Crater during 11-18 April. One explosion produced an eruption plume that rose as high as 2.7 km above the crater rim. Ashfall was reported in Toshima village (3.5 km SSW) and in other areas as far as 5 km away. No explosions were recorded during 15-18 April, though emissions rose 1.1 km.

Wolf – Isla Isabela (Galapagos) : IG reported that the eruption at Wolf continued during 13-18 April. Lava flows continued to advance towards the coast based on thermal data; satellite images showed minor advancement during 11-16 April and the end of the flow near the coastline.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 13 April – 19 April 2022

Bezymianny – Central Kamchatka (Russia) : KVERT reported that the effusive eruption at Bezymianny continued during 8-15 April, along with incandescence at the lava dome, avalanches descending the SE flank, and steam-and-ash emissions. A daily thermal anomaly over the dome was identified in satellite images.

Edgecumbe – Southeastern Alaska (USA) : AVO stated that a seismic swarm beneath Kruzof Island near Edgecumbe began at about 0200 on 11 April, and by 15 April several hundred earthquakes had been recorded. The number of events was unusual for that volcano. The magnitudes were generally M 1.7 or smaller, though a M 2.8 was detected on 11 April. The events were located at depths of less than 10 km, though the exact locations were difficult to constrain due to the lack of a local seismic network on the island; the closest station was in Sitka, 25 km E. The source of the swarm was unknown, and related either to tectonic processes or volcanic unrest, or a combination of both.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was visible in satellite images on 9 and 11-12 April; the volcano was quiet or obscured by clouds on the other days during 8-15 April. Explosions produced ash plumes that rose to 6 km (19,700 ft) a.s.l. and drifted SSW, based on satellite data acquired at 0810 on 20 April, local time. Explosions continued and within an hour produced larger ash plumes that rose 9.8-10 km (32,100-32,800 ft) a.s.l. and drifted almost 30 km NE.

Poas – Costa Rica : OVSICORI-UNA reported that submarine fumaroles in the S part of Poás’s Boca A lake and subaerial fumaroles along the E margins continued to produce low-temperature gas emissions during 13-19 April. The lake water continued to convect, and was light gray in color, since the phreatic explosion that had occurred on 6 April at “Orange Fumarola” located in a fumarolic field along the inner N crater wall. For a period of time on 17 April a gas monitoring station in Coronado measured a higher concentration of sulfur dioxide aerosols, between 8.5 and 17.6 micrograms of gas per cubic meter of ambient air, which was higher than the daily average of 6.7. Some residents reported respiratory discomfort such as sneezing, coughing, and shortness of breath.

Krakatau – Sunda Strait : PVMBG reported that several ash emissions from Anak Krakatau were visible in webcam images and described by observers during 15 and 17-19 April. The ash plumes were variably whitish gray, gray, and black, with all but one characterized as dense. Events at 0327, 1034, and 1837 on 15 April produced ash plumes that rose 0.7-1 km above the summit and drifted SW. Ash plumes at 0925, 1830, and 2215 on 17 April rose 500-800 m above the summit and drifted SW; Strombolian activity produced the ash plume at 1830. On 18 April events at 0358, 0419, 0714, 1246, 1330, and 1558 generated ash plumes that rose as high as 2 km and drifted SW. Ash plumes were visible on 19 April, rising 50-500 m above the summit and drifting SE and NE.

Ruang – Sangihe Islands : PVMBG reported that at least 121 deep volcanic earthquakes at Ruang were recorded during 1-16 April, though the number of those events began to increase on 7 April. No visible changes to the crater were noted, but weather conditions sometimes prevented views. Seismicity significantly changed on 16 April, characterized by 50 deep volcanic earthquakes, two local tectonic earthquakes, and four felt earthquakes.

Ruapehu – North Island (New Zealand) : On 20 April GeoNet reported that elevated unrest at Ruapehu had continued during the previous week. Scientists observed upwelling in the lake over the N vent area and visible sulfur slicks on the lake’s surface during an observation flight. The lake water temperature had stabilized at 37 degrees Celsius and continued to be medium gray in color. The lake observations were within normal ranges for a typical heating cycle. Tremor levels remain elevated, though, representing the longest period of tremor recorded over the previous 20 years.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 6 April – 12 April 2022

Aira – Kyushu (Japan) : JMA reported that incandescence at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible at night during 4-11 April. Very small eruptive events were recorded on 6 and 9 April.

Dukono – Halmahera : Based on satellite and wind model data, the Darwin VAAC reported that during 7-12 April ash plumes from Dukono rose to 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted NE and NW.

Great Sitkin – Andreanof Islands (USA) : AVO reported that slow lava effusion at Great Sitkin continued during 5-12 April and very low seismicity persisted. The lava flows on the S, W, and N flanks had advanced up to 10 m during 2-8 April, and elevated surface temperatures identified in satellite images during 8-10 April indicated continuing effusion. Steaming from the vent and flow field was occasionally identified in satellite images.

Heard – Kerguelen Plateau : Satellite images of Heard Island’s Big Ben volcano showed thermal anomalies of varying intensity over Mawson Peak (the summit area) and on the NW flank during the previous month. Weather clouds prevented views of the volcano for 11 of the 14 acquisitions during 11 March-13 April. On 11 March a small thermal anomaly at the peak was visible along with a larger anomaly over a vent or multiple vents about 1 km W; the larger anomaly was elongated NE-SW, suggesting a lava flow. Multiple anomalies in the same areas were visible on 31 March and 13 April.

Kadovar – Northeast of New Guinea : Based on satellite and wind model data, the Darwin VAAC reported that on 8 April an ash plume from Kadovar rose to an altitude of 1.5 km (5,000 ft) a.s.l. and drifted SE.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was visible in satellite images on 3 and 5-6 April; the volcano was quiet or obscured by clouds on the other days during 1-8 April.

Katmai – Alaska : AVO reported that on 8 April strong winds in the vicinity of Katmai and the Valley of Ten Thousand Smokes blew unconsolidated ash SE towards Kodiak Island at an altitude up to 2.4 km (8,000 ft) a.s.l. The ash was originally deposited during the Novarupta eruption in 1912.

Kilauea – Hawaiian Islands (USA) : HVO reported that lava effusion from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater continued at variable rates during 5-12 April. Lava from a vent flowed into the active W part of the lava lake, which comprised about 2.3 percent of the total crater floor’s surface, and onto the crater floor. The surface of the lava lake was active all week, and the height of the lake fluctuated. Numerous ooze outs of lava were visible along the lake’s NW, NE, E, and SE margins; a more substantial ooze-out at the N margin was active during 6-7 April. A small outbreak at the W vent was visible overnight during 8-9 April. Just after 2300 on 10 April a flow emerged from the S side on the vent that covered areas along the southwest and western margins through 12 April.

Lewotolok – Lembata Island : The eruption at Lewotolok continued during 5-12 April according to PVMBG. Daily white-and-gray ash plumes with variable densities rose as high as 500 m above the summit and drifted E, NW, and W. Photos posted by PVMBG showed nighttime crater incandescence and incandescent material being ejected.

Merapi – Central Java : BPPTKG reported no significant morphological changes at Merapi’s summit lava dome during 1-7 April. Based on photo analyses, the volume of the SW lava dome was 1.7 million cubic meters while the central lava dome was 2.6 million cubic meters. Seismicity remained at high levels. As many as 144 lava avalanches originating from the SW dome traveled a maximum of 2 km down the Bebeng drainage on the SW flank. A single pyroclastic flow traveled 1.5 km down the SW flank.

Nevado del Ruiz – Colombia : Servicio Geológico Colombiano’s (SGC) reported that at 1713 on 11 April a seismic signal at Nevado del Ruiz was recorded along with an ash, gas, and steam plume. The plume rose almost 3.3 km above the summit and drifted N, causing minor ashfall around the volcano as reported by Parque Nacional Natural Los Nevados staff. It was also visible in webcam images and from the city of Manizales, 28 km NW.

Pavlof – Alaska Peninsula, Alaska : AVO reported that the eruption at a vent on Pavlof’s upper E flank was ongoing during 5-12 April, and seismic tremor persisted. Elevated surface temperatures were identified in satellite images almost daily. Possible minor lava effusion was visible in satellite images on 6 April, and a few small explosions were recorded each day during 6-9 April. Low-level ash emissions were visible in webcam and satellite images during 6-7 April, and satellite images captured ash and pyroclastic flow deposits extending at most 1.5 km from the vent and short lava flows on 9 April. Steam emissions from the vent were visible during 8-10 April.

Rincon de la Vieja – Costa Rica : OVSICORI-UNA reported that a small eruptive event at Rincón de la Vieja was recorded at 0136 on 6 April, though the event was not visible due to poor visibility. Two small phreatic eruptions were recorded on 7 April at 1141 and 1323, based on webcam data. The resulting plumes rose 1,000 m and 500 m above the crater, respectively.

Sabancaya – Peru : Instituto Geofísico del Perú (IGP) reported moderate levels of activity at Sabancaya during 4-10 April with a daily average of 52 explosions. Gas-and-ash plumes rose as high as 2.5 km above the summit and drifted E, SE, and S. Three thermal anomalies originating from the lava dome in the summit crater were identified in satellite data. Minor inflation continued to be detected near Hualca Hualca (4 km N).

Semeru – Eastern Java : PVMBG reported that the eruption at Semeru continued during 5-12 April. Ash plumes rose 0.4-1 km above the summit during 6 and 8-12 April and drifted N. NW, and SW.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that low-level eruptive activity at Semisopochnoi’s North Cerberus cone continued during 6-12 April. Periods of seismic tremor were detected daily and occasional small explosions were recorded on most days in seismic and regional infrasound data. Partly-to-mostly-cloudy webcam views and occasional satellite images showed daily short-lived ash bursts and more continuous steam emissions. Steam plumes drifted as far as 70 km SW during 6-7 April. A low-level steam plume drifted more than 100 km at altitudes less than 1.5 km (5,000 ft) a.s.l. during 7-8 April. A low-level ash plume drifted up to 80 km WNW on 8 April. Local ash deposits were occasionally visible.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 2-8 April. The lava dome continued to grow and strong fumarolic activity, incandescence, and avalanches accompanied this activity.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that eruptive activity continued to be recorded at Suwanosejima’s Ontake Crater during 4-8 April. Two explosions produced eruption plumes that rose as high as 3.3 km above the crater rim and ejected blocks as far as 500 m from the crater. Ashfall was reported in Toshima village (3.5 km SSW). No eruptive activity was noted during 9-11 April, though emissions rose 700 m.

Wolf – Isla Isabela (Galapagos) : IG reported that the eruption at Wolf continued during 5-12 April. Minor sulfur dioxide emissions were recorded during 5-6 April. Thermal data captured and mapped on 6 April indicated that lava flows were getting closer to the coast; daily thermal alert counts, as many as around 154, indicated active and advancing lava flows during the rest of the week.

Yasur – Vanuatu : The Wellington VAAC reported that during 9 and 11-12 April ash-and-steam emissions from Yasur were intermittently visible in webcam and satellite images rising 0.9-1.8 km (3,000-6,000 ft) a.s.l. and drifting SE.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 6 April – 12 April 2022

Bezymianny – Central Kamchatka (Russia) : KVERT reported that a daily thermal anomaly over Bezymianny was visible in satellite images during 2-8 April. Strong fumarolic activity, incandescence at the lava dome, and avalanches were also reported.

Poas – Costa Rica : OVSICORI-UNA reported that on 6 April at 0240 a phreatic explosion from a vent called “Orange Fumarola” located in a fumarolic field along the inner N crater wall at Poás generated a plume that rose 500 m above the crater rim. Activity lasted for three minutes. The event caused a small landslide that modified the vent. Some of the material from the landslide was deposited in a narrow strip about 100 m into the Boca A lake. Stirred sediment was visibly moving in convection cells, turning the lake water from green to a uniform milky gray color as the sediment mixed into the water. Subaerial fumarolic vents at the E and S parts of the lake more vigorously emitted gasses following the event and remained at that level at least through 12 April. Convection in the lake also continued. OVSICORI-UNA noted that satellite data acquired the day before the explosion showed a total of 500 tons of sulfur dioxide released from both Poás and Turrialba.

Purace – Colombia : On 29 March Observatorio Vulcanológico y Sismológico de Popayán, Servicio Geologico Colombiano (SGC), reported that the number of earthquakes at Puracé had increased during the previous few weeks, and were characterized by volcano-tectonic (VT) events, indicating rock fracturing, and long-period (LP) and volcanic tremor (TR) events, indicating fluid movement. The number of events notably increased on 28 March, with 479 VT, 183 (LP), and 119 (TR) events in total. The magnitudes of events abruptly increased the next day; the largest event was a M 3.3 recorded at 1214 on 29 March. Two fractures opened on 29 March, each about 40 m long, and produced gas emissions detected by satellite; ash was reported by observers in the area. The fractures were located along Coconucos Volcanic Chain, between Puracé Volcano and Curiquinga Volcano. The Alert Level was raised to Yellow (the second lowest on a four-color scale) on 30 March. Seismicity continued to be elevated through 4 April. The earthquakes were low magnitude, and located about 800 m SE of Puracé and beneath Curiquinga, at depths of 2 km on average. The number of events signifying fluid movement was increasing. GNSS (Global Navigation Satellite System) geodetic network and DInSAR (Differential Interferometry by Synthetic Aperture Radar) showed inflation on the millimeter scale. Sulfur dioxide and carbon dioxide emissions increased, based on satellite and ground-based sampling data, and a fumarole on the N flank of Puracé intensified and produced a strong sulfur odor. Significant unrest continued during 5-11 April. The seismic network recorded a total of 2,077 earthquakes, consisting of 248 VT events, 1,759 LP events, 37 low-energy TR events, and 31 hybrid events. Millimeter-scale inflation persisted, and sulfur dioxide emissions averaged 1,800 tonnes per day.

Ruapehu – North Island (New Zealand) : On 12 April GeoNet reported that unrest at Ruapehu had intensified during the previous week, characterized by increased gas emissions, elevated tremor, and increasing crater lake water temperatures. Tremor levels were elevated but had declined from the peak reached during 6-7 April. Higher levels of gas emissions were confirmed during an overflight on 11 April; a peak carbon dioxide value was the second highest ever recorded at Ruapehu. Lake temperatures continued to slowly climb and reached 38 degrees Celsius. The lake water was gray in color and had area of upwelling over the N vents; sulfur slicks on the lake’s surface were visible. GeoNet noted that temperature and modeled heat input to the lake were within typical ranges for a heating cycle, though the elevated tremor levels and gas emissions suggested that magma was interacting with the geothermal system.

Taal – Luzon (Philippines) : PHIVOLCS lowered the Alert Level for Taal to 2 (on a scale of 0-5) on 9 April, noting a significant decrease in activity during the previous two weeks. Sulfur dioxide emissions were high during the first three weeks of March, peaking at 21,211 tonnes per day on 16 March, but dropped on 3 April to an average of 240 tonnes per day; the flux again decreased to 103 tonnes per day on 8 April, the lowest number recorded since unrest began in 2021. During 26 March-9 April only 86 small-magnitude and imperceptible volcanic earthquakes had been recorded, and by 31 March background tremor associated with shallow hydrothermal activity had ceased. Electronic tilt monitoring on Taal Volcano Island, continuous Global Positioning System (GPS) data, and InSAR analysis of Sentinel-1 satellite data indicated continuing deflation of Taal, particularly on the SE flank. Diffuse plumes from the lake had also decreased in frequency, though they rose 600-900 m above the surface during 10-12 April. Sulfur dioxide emissions were below instrumental detection limits on 11 April.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 30 March – 5 April 2022

Aira – Kyushu (Japan) : JMA reported that very small eruptive events were recorded at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) during 29 March through 4 April. After 2 April, incandescence was observed at night with a high-sensitivity surveillance camera.

Ambae – Vanuatu : On 31 March the Vanuatu Meteorology and Geo-Hazards (VMGD) reported that explosions at the cone in Ambae’s Lake Voui continued to produce steam and ash emissions. Wet tephra that was also ejected from the cone during this activity remained within the caldera. Light ashfall was reported in nearby villages.

Ambrym – Vanuatu : On 31 March the Vanuatu Meteorology and Geo-Hazards Department (VMGD) reported that nighttime crater incandescence from Ambrym’s Benbow Crater was no longer visible, though steam emissions persisted.

Bezymianny – Central Kamchatka (Russia) : KVERT reported that a daily thermal anomaly over Bezymianny was visible in satellite images during 26 March through 1 April. Strong fumarolic activity, incandescence at the lava dome, and avalanches were also reported. Dome collapses were detected on 25 and 31 March and ash clouds rose to 4 km (13,000 ft) a.s.l., expanding 40 km E and 20 km SW, respectively.

Dukono – Halmahera : Based on satellite and wind model data, the Darwin VAAC reported that during 29 March through 4 April ash plumes from Dukono rose to 2.1 km (7,000 ft) a.s.l. and drifted SE, S, E, and ENE.

Fuego – South-Central Guatemala : INSIVUMEH reported that 4-8 explosions per hour were detected at Fuego during 30 March through 5 April, generating gas-and-ash emissions that rose to 4.9 km (16,000 ft) a.s.l. and drifted as far as 30 km NW, W, SW, and S. Block avalanches descended the Las Lajas (SE), Seca (W), Ceniza (SSW), Taniluyá (SW), Trinidad (S), Honda, and Santa Teresa drainages. At night, incandescence was observed up to 150 m above the crater. Fine ashfall was reported in Panimaché I and II (8 km SW), Morelia (9 km SW), Santa Sofía (12 km SW), Finca Palo Verde, Yepocapa (8 km NW), El Porvenir (8 km ENE), and Sangre de Cristo (8 km WSW). Shock waves from the explosions and rumbling sounds rattled local structures. Based on satellite and wind model data, the Washington VAAC reported that during 29 March through 4 April ash plumes from Fuego rose to 4.9 km (16,000 ft) a.s.l. and drifted SE, E, SW, S, WNW, WSW.

Great Sitkin – Andreanof Islands (USA) : AVO reported that slow lava effusion at Great Sitkin continued during 30 March through 5 April and low seismicity persisted. Cloud cover prevented views of the volcano most of the week, but slow lava effusion continued; minor flow fronts advanced from the W and S lobes, as well as the E margin.

Ibu – Halmahera : PVMBG reported that the eruption at Ibu continued during 25-31 March. On 30 March at 1048 an ash plume rose 1 km above the summit that drifted S. Roughly 58 avalanches traveled 100-400 m N and NW. The Alert Level remained at a 2 (on a scale of 1-4), and the public was warned to stay at least 2 km away from the active crater and 3.5 km away on the N side.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was visible in satellite images during 24-26 March. The volcano was either quiet or obscured by clouds on the other days during 27 March through 1 April.

Kavachi – Solomon Islands : Satellite data showed discolored water around Kavachi on 31 March. The discolored water fanned out to the S over a short distance, though it was not clearly observed due to cloudy weather.

Kikai – Ryukyu Islands (Japan) : JMA reported that eruptive activity continued to be recorded at Satsuma Iwo-jima, a subaerial part of Kikai’s NW caldera rim, during 29 March through 4 April. White gas-and-steam plumes rose 1 km above the crater rim. Surveillance cameras observed nightly incandescence.

Kilauea – Hawaiian Islands (USA) : HVO reported that lava effusion from vents in the lower W wall of Kilauea’s Halema`uma`u Crater continued at variable rates during 30 March through 5 April. Lava from a vent flowed into the active W part of the lava lake and onto the crater floor. Numerous and sustained ooze outs of lava along the lake’s margins; effusion along interior surface fractures persisted during the week but showed decreasing activity. On 31 March a hornito that was forming on the E side of the lake exhibited spattering throughout the day. HVO noted that by 29 March about 64 million cubic meters of lava had been erupted since the current eruption began, raising the crater floor by 96 m (315 ft). The sulfur dioxide emission rate was approximately 3,100 tons/day, based on measurements made on 31 March. During 2-5 April continued ooze outs were occurring along the E half of the crater floor and NW margin, but at a decreased rate, and crustal overturning occurred occasionally on the NW margin.

Kirishimayama – Kyushu (Japan) : JMA reported a high number of volcanic earthquakes just below Shinmoedake (Shinmoe peak, a stratovolcano of the Kirishimayama volcano group). On 31 March the number of volcanic earthquakes increased below Ebino Kogen (located on the NW flank of the Karakunidake stratovolcano, about 5 km NW of Shinmoedake). Fumarolic plumes continued to rise from a fissure on the W flank.

Krakatau – Sunda Strait : PVMBG reported that the eruption at Anak Krakatau continued during 25-31 March. On 1326 on 30 March an eruption that lasted 96 seconds generated a gray-black ash plume that rose 700 m above the summit and drifted NE based on webcam images. White gas-and-steam emissions rose 25-100 m above the summit.

Lewotolok – Lembata Island : The eruption at Lewotolok continued during 25-31 March according to PVMBG. White-and-gray emissions rose 50-500 m above the summit and drifted W and NW. Ash emissions rose 200-500 m above the summit. On 31 March at 1204 an ash plume rose 800 m above the summit and drifted NW according to a ground observer.

Merapi – Central Java : BPPTKG reported no significant morphological changes at Merapi’s summit lava dome during 25-31 March, though the height of the dome below the SW rim had increased by 4 m. Based on photo analyses, the volume of the SW lava dome had a volume of 1.7 million cubic meters while the central lava dome was 2.6 million cubic meters. Seismicity remained at high levels. As many as 118 lava avalanches originating from the SW dome traveled a maximum of 2.5 km down the Bebeng drainage on the SW flank. On 28 March two pyroclastic flows were recorded on a seismogram that descended 2.5 km SW, one of which occurred at 1509. On 1 April a pyroclastic flow at 1500 descended 1.5 km down the SW flank. Based webcam, satellite, and wind data, the Darwin VAAC reported re-suspended ash that rose to 100 m (300 ft) a.s.l. As many as 37 avalanches were detected, but the distance and direction were not observed.

Nevados de Chillan – Central Chile : Based on satellite and webcam data, isolated ash pulses from Nevados de Chillán were reported by the Buenos Aires VAAC during 31 March that rose to 4.9 km (16,000 ft) a.s.l. and drifted N and NNE. Intermittent hotspots were observed in satellite imagery on 1 April.

Pavlof – Alaska Peninsula, Alaska : AVO reported that weak eruptive activity was ongoing at Pavlof during 30 March through 4 April, and seismic tremor persisted. Weak explosive activity was detected during 31 March and 2-3 April with low-level plumes visible in the mornings, though satellite and webcam views were mostly obscured by clouds. During 3-4 April elevated surface temperatures were detected in satellite images despite the cloudy weather.

Popocatepetl – Mexico : CENAPRED reported that the eruption at Popocatépetl continued during 30 March through 5 April. Each day there were 11-29 diffuse gas-and-steam emissions with ash rising from the crater and drifting S, E, NE, and SE. Based on webcam, satellite and wind models, the Washington VAAC reported ash plumes that rose to 7.3 km (24,000 ft) a.s.l. that drifted E and SE. A moderate explosion was recorded at 2022 on 29 March, resulting in light ashfall in San Pedro Benito Juárez, a municipality of Atlixco. Three volcano-tectonic (VT) earthquakes were recorded on 30 March at 1129, 1146, and 1514. Intermittent VT earthquakes continued during the week.

Reventador – Ecuador : IG reported that a high level of activity continued at Reventador during 30 March through 5 April, though cloudy weather conditions sometimes prevented visual observations. Gas-and-ash plumes, often observed multiple times a day with the webcam or reported by the Washington VAAC, rose as high as 4.6 km (15,000 ft) a.s.l. and drifted mainly NW, W, and SW. As many as 68 daily explosions were detected, in addition to long-period (LP) and emission tremors. Daily thermal anomalies were also reported. On clear weather nights, incandescence could be observed in the upper part of the E flank of the volcano. Blocks were recorded rolling 400 m below the crater on all flanks during 4 April, in addition to the incandescence in the crater.

Rincon de la Vieja – Costa Rica : OVSICORI-UNA reported that 10 eruptive events at Rincón de la Vieja had been recorded since 15 March, one of which was detected on 27 March. Between 28 and 29 March a swarm of long-period earthquakes were detected. On 4 April at 1042 an eruption that lasted 1.5 minutes produced a plume, but the height was not observed due to weather conditions.

Ruapehu – North Island (New Zealand) : On 28 March and 5 April GeoNet reported that unrest continued at Ruapehu with elevated levels of tremor and increasing crater lake water temperatures from 32 degrees Celsius to 36 degrees Celsius.

Sangay – Ecuador : IG reported that the eruption at Sangay continued during 30 March through 5 April. Weather clouds and rain often prevented visual and webcam observations, though daily gas-and-ash plumes that rose to 6.7 km (22,000 ft) a.s.l. and drifted W, SW, WSW, and NW were identified in satellite images by the Washington VAAC or in webcam views. As many as 96 daily explosions were detected along with frequent long-period events and emission tremors. Daily thermal anomalies were also visible in satellite data. Incandescent material was visible on the flanks in webcam imagery on clear weather days.

Kikai – Ryukyu Islands (Japan) : JMA reported that eruptive activity continued to be recorded at Satsuma Iwo-jima, a subaerial part of Kikai’s NW caldera rim, during 29 March through 4 April. White gas-and-steam plumes rose 1 km above the crater rim. Surveillance cameras observed nightly incandescence.

Santa Maria – Southwestern Guatemala : INSIVUMEH reported that the eruption at Santa María’s Santiaguito lava-dome complex continued during 30 March through 5 April. Incandescence from Caliente crater and the lava flows on the W and SW flanks were visible during the night and early morning, accompanied by weak-to-moderate block-and-ash avalanches along its path down the W, SW, and S flanks that reached the base of the dome. The avalanches generated ash plumes that drifted W. Fine ashfall occurred near the volcano on 3 April, including in San Marcos (8 km SW) and Loma Linda Palajunoj (7 km SW). The smell of sulfur was sometimes detected in Las Marias.

Semeru – Eastern Java : PVMBG reported that the eruption at Semeru continued during 25-31 March. Activity included a pyroclastic flow, ash plumes that rose 300-700 m and drifted mainly N and NW, and gas-and-steam emissions reaching 200-300 m above the summit. Ground observers, webcam images, and satellite data detected ash plumes that rose to 4.3 km (14,000 ft) a.s.l. and drifted N and W, according to MAGMA Indonesia and the Darwin VAAC. Avalanches were reported on 1 April. On 3 April a strong thermal anomaly was detected in infrared satellite imagery.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that low-level eruptive activity at Semisopochnoi’s North Cerberus cone continued during 30 March-4 April. Periods of seismic tremor and occasional small explosions were detected daily in seismic and regional infrasound data. Daily minor ash emissions rose no higher than 3 km (10,000 ft) a.s.l. and occasional steam emissions were visible in webcam and satellite images; clouds sometimes prevented satellite views.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 26 March through 1 April. The lava dome continued to grow and strong fumarolic activity, incandescence, and avalanches accompanied this activity.

Sirung – Pantar Island : PVMBG reported that white emissions rose 10-50 m above the summit of Sirung and drifted NE, E, and SE. Seismicity was relatively low and showed a consistent decrease since July 2021.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that eruptive activity continued to be recorded at Suwanosejima’s Ontake Crater during 29 March through 4 April. As many as 122 explosions were recorded, and crater incandescence was visible nightly. Eruption plumes rose as high as 2.8 km above the crater rim and ejected blocks as far as 900 m from the crater. Ashfall was reported in Toshima village (3.5 km SSW).

Taal – Luzon (Philippines) : PHIVOLCS reported that hot volcanic fluids circulated and upwelled in Taal’s Main Crater lake during 30 March through 6 April, producing plumes that rose as high as 2 km above the lake’s surface and drifted SW. Sulfur dioxide emissions averaged 265-7,856 tonnes/day during the week. Tremor events persisted daily until 5 April. Three phreatomagmatic bursts from the Main Crater were detected at 1039, 1047, and 1055, based on seismic data and webcam images, which produced plumes 500-900 m tall that drifted SW.

Telica – Sierra de los Marrabios : Based on webcam images, the Washington VAAC reported that on 29 March ash emissions at Telica rose as high as 1.5 km (5,000 ft) a.s.l. and drifted W.

Whakaari/White Island – North Island (New Zealand) : On 4 April GeoNet reported that the ash emissions at Whakaari/White Island had not been observed since late February 2022; gas temperatures had declined to below 300 degrees Celsius.

Wolf – Isla Isabela (Galapagos) : IG reported that the eruption at Wolf continued during 30 March through 5 April. Daily thermal alert counts, as many as around 145, indicated active and advancing lava flows.

Yasur – Vanuatu : On 31 March the Vanuatu Meteorology and Geohazards Department (VMGD) reported that activity at Yasur continued at a high level of “major unrest.” 

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 30 March – 5 April 2022

Agung – Bali : Based on ground reports, satellite imagery, and wind model data, the Darwin VAAC reported that during 3 April an ash plume from Agung rose to 3.7 km (12,000 ft) a.s.l.

Poas – Costa Rica : OVSICORI-UNA reported that on 6 April at 0242 a phreatic explosion was detected at the N wall crater wall at Poás, generating a plume that rose 500 m above the crater. Activity lasted for three minutes.

Purace – Colombia : The Popayán Observatory, part of the Servicio Geologico Colombiano (SGC) reported that there was an increase in the number of volcano-tectonic earthquakes associated with rock fractures at Puracé. On 28 March, 479 volcanic tremors, 183 long-period (LP), and 119 volcanic tremor (TR) events were detected. Seismicity was detected 800 m SE from the crater at average depths of 2 km. An earthquake that occurred at 1214 on 29 March had a magnitude of 3.3. That same day, two cracks approximately 40 m long produced gas-and-steam emissions.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 23 March – 29 March 2022

Aira – Kyushu (Japan) : JMA reported that very small eruptive events were recorded at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) during 21-28 March.

Dukono – Halmahera : Based on satellite and wind model data, the Darwin VAAC reported that during 26-28 March ash plumes from Dukono rose to 2.4 km (8,000 ft) a.s.l. and drifted SE, E, and ENE.

Great Sitkin – Andreanof Islands (USA) : AVO reported that slow lava effusion at Great Sitkin continued during 22-29 March and very low seismicity persisted. Cloud cover prevented views of the volcano most of the week; one satellite image acquired on 24 March showed slow expansion of the flow field.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was visible in satellite images during 22-23 March. The volcano was either quiet or obscured by clouds on the other days during 18-25 March.

Kilauea – Hawaiian Islands (USA) : HVO reported that lava effusion from vents in the lower W wall of Kilauea’s Halema`uma`u Crater continued at variable rates during 22-29 March. Lava from a vent flowed into the active W part of the lava lake and onto the crater floor. Numerous and sustained ooze outs of lava along the lake’s margins and interior seams persisted during the week. HVO noted that by 17 March about 58 million cubic meters of lava had been erupted since the current eruption began.

Kirishimayama – Kyushu (Japan) : JMA reported an increase in volcanic earthquakes just below Shinmoedake (Shinmoe peak, a stratovolcano of the Kirishimayama volcano group). A total of 21 events were recorded during 26-27 March, prompting JMA to raise the Alert Level to 2 (on a scale of 1-5) on 27 March. Volcanic earthquakes continued to be recorded during 27-28 March. A two-minute-period of volcanic tremor began to be recorded at 1624 on 28 March. Minor deflation first recorded in December 2021 was ongoing. Fumarolic plumes continued to rise no higher than 100 m from a fissure on the W flank.

Merapi – Central Java : BPPTKG reported no significant morphological changes at Merapi’s summit lava dome during 18-24 March, but the height of the dome below the SW rim had increased by 4 m. Seismicity remained at high levels; the intensity of the signals had increased compared to the previous week. As many as 51 lava avalanches originating from the SW dome traveled a maximum of 2 km down the Bebeng drainage on the SW flank. Six pyroclastic flows traveled as far as 2.5 km. Minor ashfall was reported in the Selo District.

Pavlof – Alaska Peninsula, Alaska : AVO reported that the eruption at a vent on Pavlof’s upper E flank was ongoing during 22-29 March, and seismic tremor persisted. Elevated surface temperatures were identified in satellite images on most of the days and were consistent with minor lava effusion. Cloud cover sometimes prevented webcam and satellite views of the summit area; sulfur dioxide emissions were visible in satellite images during 24-26 March. Two small explosions were detected in local and regional infrasound data during 23-24 March and one was recorded during 26-27 March.

Rincon de la Vieja – Costa Rica : OVSICORI-UNA reported that several eruptive events at Rincón de la Vieja were recorded during 22-26 March, though none were visible due to weather conditions. A one-minute-long event was recorded at 0350 on 22 March. A series of pulses occurred over a 20-minute period, at 0140, 0146, and 0159 on 23 March, with additional small events at 1045, 1339, 1939, and 2244. According to the Washington VAAC a possible ash emission was visible in satellite images at 1420 drifting W at an altitude of 2.7 km (9,000 ft) a.s.l. OVSICORI-UNA noted that a series of small eruptive events were recorded during 0129-0140 on 25 March. A small eruption with possible two separate pulses was recorded on 26 March.

Semeru – Eastern Java : PVMBG reported that the eruption at Semeru continued during 22-29 March. Daily eruptive events produced ash plumes recorded by observers that rose 0.2-1.8 km above the summit and drifted mainly N, NW, and W. The Alert Level remained at 3 (on a scale of 1-4). The public was warned to stay at least 500 m away from Kobokan drainages within 17 km of the summit, along with other drainages originating on Semeru, including the Bang, Kembar, and Sat, due to lahar, avalanche, and pyroclastic flow hazards.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that low-level eruptive activity at Semisopochnoi’s North Cerberus cone continued during 22-29 March. Periods of seismic tremor and occasional small explosions were detected daily in seismic and regional infrasound data. Daily minor ash emissions and occasional steam emissions were visible in webcam and satellite images; clouds sometimes prevented satellite views.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 18-25 March.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that eruptive activity continued to be recorded at Suwanosejima’s Ontake Crater during 21-28 March. As many as 42 explosions were recorded, and crater incandescence was visible nightly. Eruption plumes rose as high as 2.3 km above the crater rim and ejected blocks as far as 800 m from the crater. Ashfall was reported in Toshima village (3.5 km SSW).

Telica – Sierra de los Marrabios : Based on webcam images, the Washington VAAC reported that on 25 March ash emissions at Telica rose as high as 1.5 km (5,000 ft) a.s.l. and drifted SW.

Wolf – Isla Isabela (Galapagos) : IG reported that the eruption at Wolf continued during 22-29 March. Daily thermal alert counts, as many as around 200, indicated active and advancing lava flows on the SSE flank.