Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 22 June – 28 June 2022

Aira – Kyushu (Japan) : JMA reported that nighttime incandescence at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible during 20-27 June. At 1221 on 27 June an eruptive event produced an ash plume that rose 1.5 km above the crater rim.

Bezymianny – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Bezymianny was identified in satellite images during 17-26 June.

Dukono – Halmahera : Based on satellite and wind model data, the Darwin VAAC reported that during 22-25 and 27 June ash plumes from Dukono rose to 2.1 km (7,000 ft) a.s.l. and drifted N, NW, and W.

Great Sitkin – Andreanof Islands (USA) : AVO reported that the eruption at Great Sitkin continued during 21-28 June. Elevated surface temperatures were identified in satellite images during 26-27 June; weather clouds obscured satellite and webcam views on the other days. Seismicity was low.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was identified in satellite images during 17 and 19-23 June.

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 22-28 June, entering the lava lake and flowing onto the crater floor. The lake remained active all week, and nearly continuous breakouts occurred along the margins.

Krakatau – Sunda Strait : PVMBG reported that at 1712 on 25 June an eruptive event at Anak Krakatau produced a dense black ash plume that rose 400 m above the summit and slowly drifted SW.

Lewotolok – Lembata Island : PVMBG reported that the eruption at Lewotolok continued during 22-28 June. An eruptive event was recorded at 2235 on 24 June by the seismic network, though the event was not visually observed.

Merapi – Central Java : BPPTKG reported that the eruption at Merapi continued during 17-23 June. 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 70 lava avalanches traveled down the Bebeng drainage on the SW flank, reaching a maximum distance of 1.8 km. Seismicity remained high.

Ontakesan – Honshu (Japan) : Inflation and increased seismicity were detected at Ontakesan in February, causing JMA to raise the Alert Level. Inflation ceased in late February and deformation rates had stabilized. Seismicity continued to fluctuate, but decreased in mid-March and volcanic tremor ceased on 19 March. No changes in emissions were observed on 4 June.

Pavlof – Alaska Peninsula, Alaska : AVO reported that the eruption at a vent on Pavlof’s upper E flank was ongoing during 21-28 June, and seismic tremor persisted. Daily elevated surface temperatures identified in satellite images were consistent with the continuing effusion of short (615 m or less) lava flows.

Ruang – Sangihe Islands : An increased number of deep volcanic earthquakes at Ruang in April prompted PVMBG to raise the Alert Level to 2 (on a scale of 1-4). A total of 232 deep volcanic earthquakes were recorded by the seismic network during 1 April-22 June, with just over half of them occurring in early to mid-April. No data was recorded from 18 April through 11 May due to technical difficulties. The network recorded 6-20 events during 11-31 May and just 1-2 events during 1-21 June.

Ruapehu – North Island (New Zealand) : On 28 June GeoNet reported that it had been 10 days since the last notable tremor at Ruapehu and the level remained weak. Lake water temperatures declined to 21 degrees Celsius on 14 June from a high of 40 degrees Celsius recorded in early May; temperatures had increased to 25 degrees Celsius during the previous two weeks. Gas emissions continued to fluctuate based on data collected during overflights and were about 10% less on 23 June than on 13 May, though the sulfur dioxide rate during 24-25 June was comparable to those recorded in mid-May, based on gas measuring equipment recently installed at the volcano. The emission, water temperature and seismic data together indicated continuing moderate levels of unrest. The Volcanic Alert Level remained at 2 (on a scale from 0-5) and the Aviation Color Code remained at Yellow.

Semeru – Eastern Java : PVMBG reported that the eruption at Semeru continued during 22-28 June. Weather clouds prevented visual observations on most days; at 0628 on 24 June an eruptive event produced an ash plume that rose 700 m and drifted SW.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that low-level eruptive activity at Semisopochnoi’s North Cerberus cone continued during 21-27 June. Periods of low-amplitude tremor and a few small low-frequency earthquakes were recorded by the seismic network. Weather clouds often prevented satellite and webcam views; sulfur dioxide emissions were detected in satellite images during 23-24 June and a robust steam plume was visible in webcam images during 25-26 June.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 17-23 June and the eruption characterized by explosions, hot avalanches, and lava-dome extrusion continued. Webcam images recorded explosions on 19 and 21 June that sent ash plumes to 7 and 5 km (23,000 and 16,400 ft) a.s.l., respectively. The ash plumes were visible in satellite images drifting 255 km ENE and 70 km SW during 19-20 and 21 June.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that the eruption at Suwanosejima’s Ontake Crater continued during 20-27 June. Emissions rose as high as 2 km above the crater rim and material was ejected as far as 200 m from the vent.

Whakaari/White Island – North Island (New Zealand) : On 28 June GeoNet reported that activity at Whakaari/White Island had remained at a low level. Observations during an overflight the week before showed that fumaroles active on the crater floor did not contain ash. Gas emission rates had decreased compared to the last observations from mid-May, and the temperature of fumarolic emissions was low at 170 degrees Celsius on 22 June. Visual observations and data collected during the flight, coupled with data from automatically collected monitoring instruments, indicated almost no changes at the volcano in the previous few weeks.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 22 June – 28 June 2022

Bulusan – Luzon (Philippines) : PHIVOLCS reported that unrest continued at Bulusan during 22-28 June. Emissions rose 100-400 m above the summit and drifted NW and W; cloudy weather prevented views of the volcano on 26 June. Sulfur dioxide emissions were 559-751 tonnes per day during 22-26 June. The seismic network recorded 7-65 daily volcanic earthquakes. A small-volume lahar was detected during a thunderstorm, beginning at 1904 on 26 June and lasting for 54 minutes based on seismic and infrasound data. Narrow, channel-confined lahar deposits were seen later along the Calang Creek on the SW flank, in the Cogon barangay.

Chikurachki – Paramushir Island (Russia) : KVERT reported that a thermal anomaly over Chikurachki was identified on 21 June and an explosive eruption occurred on 24 June. Explosions recorded during 0730-2100 on 24 June (local time) produced ash plumes that rose to 4.5 km (14,800 ft) a.s.l. A 14 x 30 km ash cloud was visible in satellite images at 0850 drifting 25 km SE. A VONA issued at 1445 on 25 June (local time) stated that only gas-and-steam emissions were rising from the volcano and that the Aviation Color Code was lowered to Yellow. The ash cloud from the explosive phase had drifted about 790 km SE. Satellite images on 26 June indicated no additional explosions; gas-and-steam emissions persisted.

Ebeko – Paramushir Island (Russia) : KVERT reported that moderate activity at Ebeko continued according to volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E. Explosions generated ash plumes that rose up to 2.5 km (8,200 ft) a.s.l. and drifted S, SE, and NE during 18 and 22-23 June. A thermal anomaly over the volcano was identified in satellite images on 22 June. At 1510 local time on 24 June an ash plume was observed drifting 5 km SE at an altitude of 2.5 km (8,200 ft) a.s.l..

San Cristobal – Sierra de los Marrabios : According to a news article, INETER reported that at 0751 on 26 June a moderate explosion at San Cristóbal produced a gas-and-ash plume that rose 1.5 km above the crater rim and drifted WSW. A minor amount of ash fell in the communities of La Grecias 3 and Las Grecias 4 (12 km WSW), and the city of El Viejo (18 km WSW). RSAM data spiked during the explosion and then returned to normal levels afterwards.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 15 June – 21 June 2022

Bezymianny – Central Kamchatka (Russia) : KVERT reported that eruptive activity at Bezymianny that continued during 10-17 June was characterized by strong fumarolic emissions, lava-dome incandescence, and hot avalanches. A daily thermal anomaly was also identified in satellite images.

Chiles-Cerro Negro – Colombia-Ecuador : Recent increased seismicity began in May. Earthquakes were first felt on 12 June by residents near the border of Colombia and Ecuador, in the indigenous reservations of Chiles, Panán, and Mayasquer (Colombia), and in Tufiño (Ecuador). Seismicity continued, and from 0205 on 12 June to 0832 on 14 June there were 260 events clustered in two zones, in the S part of CCNVC (at depths of less than 6 km below the CCNVC summit) and about 9 km SE beneath Caldera de Potrerillos (at depths of 7-9 km). The earthquake swarm activity was similar to other swarms recorded since 2013. A trend of inflation at a rate of approximately 28 mm/year has been recorded since 2016 (the beginning of deformation monitoring) through the end of 2020, when the deformation stabilized. Neither inflation nor deflation was detected during the beginning of 2020 or in 2021. Inflation was again detected in March and was continuing at a rate of 32 mm/year. Data from hydrothermal sites around CCNVC showed variations from previous measurements in gas data, and conductivity, temperature, pH, and morphology of a few of the hot spring locations, though they were a result of changes to the hydrothermal systems and not increased volcanic activity.

Cleveland – Chuginadak Island (USA) : AVO reported that during 15-21 June elevated surface temperatures over Cleveland were sometimes identified in satellite images, reflecting the continuing emissions of hot gases. Weather clouds sometimes prevented views of the volcano. Crater subsidence in the summit crater was detected during the previous several weeks. Sulfur dioxide emissions were detected on 15 and 21 June.

Dukono – Halmahera : Based on satellite and wind model data, the Darwin VAAC reported that during 16-21 June ash plumes from Dukono rose to 2.1 km (7,000 ft) a.s.l. and drifted NW and W.

Etna – Sicily (Italy) : INGV reported that during 13-19 June gas emissions rose from Etna’s Southeast Crater (SEC) and Bocca Nuova Crater (BN); the emissions from BN were dense and voluminous on 13 June and drifted SSW. Lava effusion from the vent located at about 2,700 m elevation, along the fissure that had opened on 29 May, had slowed by 13 June and stopped by that evening. Lava continued to erupt from a vent along the 7 June fissure, located at the base of the N wall of the Valle del Bove, advancing to 1,760 m elevation by 14 June. Effusion ceased overnight during 15-16 June.

Great Sitkin – Andreanof Islands (USA) : AVO reported that the eruption at Great Sitkin continued during 8-14 June. Elevated surface temperatures were identified in satellite data almost daily, consistent with lava effusion; weather clouds sometimes obscured satellite and webcam views. Seismicity was low with several small local earthquakes detected by the seismic network.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was identified in satellite images during 10-11 and 15-17 June.

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 14-22 June, entering the lava lake and flowing onto the crater floor. The surface of the lava lake was continuously active all week, and nearly continuous breakouts occurred along the margins. The lake level was variable in response to cycles of inflation and deflation. By 17 June the total volume of erupted lava was an estimated 93 million cubic meters, and the lake which had risen a total of 120 m since 29 September 2021.

Krakatau – Sunda Strait : PVMBG reported that several eruptive events at Anak Krakatau were recorded during 15-17 June. Eruptions at 0636, 1337, and 2119 on 15 June, 1241 on 16 June, and 0042 and 1839 on 17 June produced dense gray-to-black ash plumes that rose 300-600 m above the summit and drifted N, SW, and S. A few of the webcam images posted with the reports showed ejected incandescent material.

Lewotolok – Lembata Island : PVMBG reported that the eruption at Lewotolok continued during 14-22 June. An eruptive event at 1501 on 16 June produced a white-to-gray ash plume that rose about 700 m above the summit and drifted W and NW. Another event at 1127 on 17 June generated a dense gray ash plume that rose about 1 km and drifted W.

Merapi – Central Java : BPPTKG reported that the eruption at Merapi continued during 10-16 June. 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 58 lava avalanches traveled down the Bebeng drainage on the SW flank, reaching a maximum distance of 1.8 km. Seismicity remained high.

Pavlof – Alaska Peninsula, Alaska : AVO reported that the eruption at a vent on Pavlof’s upper E flank was ongoing during 14-21 June, and seismic tremor persisted. Daily elevated surface temperatures identified in satellite images were consistent with the continuing effusion of short (500 m or less) lava flows.

Reventador – Ecuador : IG reported that a high level of activity continued at Reventador during 14-22 June, 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 1.7 km above the summit and drifted mainly NW and W. Incandescence from the crater was often visible at night or during the early morning.

Ruapehu – North Island (New Zealand) : On 20 June GeoNet reported continuing unrest at Ruapehu. Tremor levels had been characterized as weak to moderate for the previous three weeks but increased for a brief period. Levels increased sharply during the evening of 17 June, fluctuated between moderate and strong levels on 18 June, and then decreased to weak levels by 19 June. Lake water temperatures continued to decline, reaching 22 degrees Celsius.

Sangay – Ecuador : IG reported a high level of activity at Sangay during 14-22 June. Daily ash-and-gas plumes were identified in webcam images, and seen in satellite images by the Washington VAAC. Plumes rose as high as 2.4 km above the volcano and drifted W and SW; ashfall was reported in Retén Ichubamba (35 km WNW) and Chauzán San Alfonso (40 km W) during 14-16 June. Almost every day multiple thermal anomalies over the volcano were visible in satellite data. Weather clouds sometimes obscured views of the volcano.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that low-level eruptive activity at Semisopochnoi’s North Cerberus cone continued during 14-21 June. Periods of weak tremor were recorded by the seismic network. Weather clouds often prevented satellite and webcam views; minor steam emissions were visible in one clear webcam image on 17 June.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 10-17 June and explosions, hot avalanches, and lava-dome extrusion continued. A daily thermal anomaly was identified in satellite images. Webcam images recorded explosions on 10 June that sent ash plumes to 6.5 km (21,300 ft) a.s.l. The ash plumes were visible in satellite images drifting 130 km SE. At 0847 on 20 June (local time) explosions were recorded in webcam images. Ash plumes rose to 7 km (23,000 ft) a.s.l. and drifted 10 km E.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that the eruption at Suwanosejima’s Ontake Crater continued during 13-20 June. Crater incandescence was visible at night. Emissions rose as high as 1.6 km above the crater rim and material was ejected as far as 300 m from the vent.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 15 June – 21 June 2022

Bulusan – Luzon (Philippines) : PHIVOLCS reported that unrest continued at Bulusan during 15-21 June. Emissions, sometimes voluminous, rose 100-500 m above the summit and drifted NW, WSW, and SW. Daily sulfur dioxide emissions were 660-1,255 tonnes per day. During 0500-2345 on 20 June the seismic network recorded 65 volcanic earthquakes, including one low-frequency volcanic earthquake; most of the events were weak and shallow.

Ebeko – Paramushir Island (Russia) _ KVERT reported that small phreatic bursts were visible at Ebeko during 11-15 June along with periodic, moderate explosions that generated ash up to 2.5 km (8,200 ft) a.s.l.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 8 June – 14 June 2022

Aira – Kyushu (Japan) : JMA reported that nighttime incandescence at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible during 6-13 June. Very small eruptive events were recorded during 6-10 June.

Bezymianny – Central Kamchatka (Russia) : KVERT reported that eruptive activity at Bezymianny was characterized by strong fumarolic emissions, lava-dome incandescence, and hot avalanches continued during 4-9 June. A daily thermal anomaly was identified in satellite images.

Dukono – Halmahera : Based on satellite and wind model data, the Darwin VAAC reported that during 8-14 June ash plumes from Dukono rose to 2.1 km (7,000 ft) a.s.l. and drifted NW, W, and SW.

Erta Ale – Ethiopia : On 2, 7, and 12 June infrared satellite data showed two thermal anomalies of variable intensities in Erta Ale’s S pit crater.

Etna – Sicily (Italy) : INGV reported that during 6-12 June explosive activity at Etna’s Southeast Crater (SEC) produced sporadic and minor ash emissions that rapidly dispersed. The fissure located at the upper part of the Valle del Bove, between 2,700 and 2,900 m elevation, continued to produce lava flows at a variable rate. The flows were most active between 2,000 and 2,100 m elevation but overall were visibly cooling during the week. Flows from the fissure that had opened on 7 June at the base of the N wall of the Valle del Bove, at 1,979 m elevation, had traveled 170 m and were also cooling. A new fissure with three active vents opened on 11 June around 1,900 m elevation. Lava effusion was slow, and the flow only traveled a few tens of meters.

Great Sitkin – Andreanof Islands (USA) : AVO reported that the eruption at Great Sitkin continued during 8-14 June. Elevated surface temperatures were identified in satellite data almost daily, consistent with lava effusion. Seismicity was low.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was identified in satellite images during 4-9 June.

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 8-14 June, entering the lava lake and flowing onto the crater floor. The surface of the lava lake was continuously active all week, and the lake level was relatively stable. Nearly-continuous breakouts of lava occurred along the margins of the lake. The sulfur dioxide emission rate was approximately 1,900 and 1,350 tonnes per day on 8 and 10 June, respectively.

Lewotolok – Lembata Island : PVMBG reported that the eruption at Lewotolok continued during 8-14 June. Daily white-and-gray emissions rose as high as 1 km above the summit and drifted in multiple directions. The summit crater was often incandescent, and a 200-m-long lava flow was active W of the summit.

Merapi – Central Java : BPPTKG reported that the eruption at Merapi continued during 3-9 June. 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 75 lava avalanches, reaching a maximum distance of 2 km, traveled down the Bebeng drainage on the SW flank. Seismicity remained high.

Pavlof – Alaska Peninsula, Alaska : AVO reported that the eruption at a vent on Pavlof’s upper E flank was ongoing during 8-14 June, and seismic tremor persisted. Daily elevated surface temperatures identified in satellite images were consistent with the continuing effusion of short (500 m or less) lava flows. Diffuse, low-level ash emissions were visible in webcam images on 13 June.

Popocatepetl – Mexico: CENAPRED reported that the eruption at Popocatépetl continued during 7-14 June. Each day there were 9-36 steam-and-gas emissions that rose from the crater and drifted in multiple directions.

Ruapehu – North Island (New Zealand) : On 14 June GeoNet reported that unrest at Ruapehu continued to decline. During the previous week volcanic tremor levels were weak, but remained above background levels recorded since 2013. Lake water temperatures had dropped to 23 degrees Celsius, which corresponded to the long-term average heat flow. Relatively high sulfur dioxide and carbon dioxide measurements were recorded in mid-May, but weather conditions prevented gas measurement flights after that time.

Semeru – Eastern Java : PVMBG reported that the eruption at Semeru continued during 8-14 June. VONAs were issued for a few eruptive events (recorded at 0547 on 10 June, 0546 on 11 June, 0521 on 13 June, and at 0546 on 14 June) that produced ash plumes that rose 200-500 m above the summit and drifted in multiple directions.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that low-level eruptive activity at Semisopochnoi’s North Cerberus cone continued during 7-14 June. Seismicity remained elevated with intermittent tremor and occasional explosions. Minor ash emissions rising to low altitudes (less than 1.5 km (5,000 ft) a.s.l.) were visible in webcam images on most days; weather clouds sometimes prevented satellite and webcam views.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 4-9 June and explosions, hot avalanches, and lava-dome extrusion continued. A daily thermal anomaly was identified in satellite images.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that the eruption at Suwanosejima’s Ontake Crater continued during 6-13 June. Crater incandescence was visible at night. One explosion was recorded during 6-10 June, producing a plume that rose 2 km above the crater rim and ejecting material 300 m away from the vent. During 10-13 June eruption plumes rose as high as 1.5 km above the crater rim and material was ejected as far as 300 m from the vent.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 8 June – 14 June 2022

Bulusan – Luzon (Philippines) : PHIVOLCS reported that increased seismicity at Bulusan began at 0500 on 9 June, characterized by a total of 45 volcanic earthquakes, including two low-frequency events. Most of the events were low magnitude and shallow. A phreatic eruption was detected at 0337 on 12 June. Plumes were not visible in webcam images due to darkness, but residents of Inlagadian (Casiguran municipality) briefly saw incandescence at the base of a plume. In data from seismic and infrasound instruments the event was classified as an explosion-type earthquake which lasted about 18 minutes. An explosion was felt by residents within 5 km, including in the barangays of Añog (Juban) and Inlagadian. Rumbling was heard in Sitio Bagong Barrio, and in barangays of Santa Lourdes (Barcelona), Inlagadian and San Juan (Casiguran), Bentuco (Gubat), and Añog, Calateo, and Puting Sapa (Juban). Sporadic ash emissions began to be observed at 0430. At daybreak emissions were visible rising from six vents: Blackbird Crater (the main crater), three explosion pits in the summit crater, and two vents on the NW and N sides of the summit. Steam, gas, and ash plumes rose 400-750 m above the summit and drifted several kilometers NW. Ash carried by winds fell in areas as far as 50 km NW, in Sorsogon City and Palanas, Pilar, Sorsogon Province, across Sorsogon Bay, and as far as Anislag, Daraga, Albay. Ash on the upper NW flanks was visible, and several barangays in the municipalities of Casiguran, Juban, and Magallanes experienced minor ashfall. Emissions continued throughout the day. According to a news article more than 11,000 people (at least 2,800 families) in Juban evacuated, and flights in and out of the Bicol International Airport were cancelled. After the eruption gas emissions rose from the main crater and, for the first time this year, from the NW summit vent.

Krakatau – Sunda Strait : PVMBG reported that an eruptive event at Anak Krakatau was recorded at 1159 on 8 June, producing a dense white-to-gray ash plume that rose about 500 m above the summit and drifted SW. At 1304 a dense gray ash plume rose around 500 m and drifted S.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 1 June – 7 June 2022

Bezymianny – Central Kamchatka (Russia) : KVERT reported that after a notable explosive eruption phase occurred at Bezymianny on 28 May (local date), eruptive activity characterized by strong fumarolic emissions, lava-dome incandescence, and hot avalanches continued through 3 June.

Dukono – Halmahera : Based on satellite and wind model data, and information from ground observers, the Darwin VAAC reported that during 1-7 June ash plumes from Dukono rose to 2.4 km (8,000 ft) a.s.l. and drifted NE, NW, W, and SW.

Etna – Sicily (Italy) : INGV reported that during 30 May-5 June the fissure located at the upper part of Etna’s Valle del Bove, between 2,700 and 2,900 m elevation, continued to produce lava flows at a variable rate. The flows branched and overlapped, reaching 1,900 m elevation by 5 June. Strombolian activity at Southeast Crater (SEC) varied in intensity and frequency, producing ash emissions that drifted SSE; the most intense activity occurred during 1-3 June. Ash plumes rose to around 5 km (16,400 ft) a.s.l. and drifted S on 3 June. On 7 June a new fissure opened at the base of the N wall of the Valle del Bove, in the Serracozzo area, at 1,900-1,950 m elevation. The fissure produced a lava flow that traveled a few tens of meters.

Great Sitkin – Andreanof Islands (USA) : AVO reported that the eruption at Great Sitkin continued during 31 May-7 June, though weather clouds sometimes hindered observations. Surface temperatures were occasionally identified in satellite data, consistent with lava effusion. A few small earthquakes were detected on a few of the days.

Ibu – Halmahera : PVMBG reported that the eruption at Ibu continued during 31 May-7 June. Daily gray-and-white ash plumes of variable densities generally rose 200-800 m above the summit and drifted in multiple directions. An eruptive event at 1116 on 6 June produced a dense gray ash plume that rose 4 km above the summit and drifted W.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was identified in satellite images during 27 May-3 June.

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 31 May-7 June, entering the lava lake and flowing onto the crater floor. The surface of the lava lake was continuously active all week, and the lake level was relatively stable, dropping and then rising 6 m. Nearly-continuous breakouts of lava occurred along the margins of the lake.

Lewotolok – Lembata Island : PVMBG reported that the eruption at Lewotolok continued during 1-7 June. Daily white-and-gray emissions rose as high as 1.3 km above the summit and drifted in multiple directions. The summit crater was often incandescent, and the lava flow on the E flank was incandescent during 1-4 June, based on photos in the reports.

Manam – Northeast of New Guinea : The eruption at Manam was ongoing. The Darwin VAAC reported that during 1-3 and 5 June ash plumes rose to 2.4-3 km (8,000-10,000 ft) and drifted NW, W, and SW, based on satellite and webcam images and information from RVO.

Merapi – Central Java : BPPTKG reported that the eruption at Merapi continued during 27 May-2 June. 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 101 lava avalanches, reaching a maximum distance of 1.8 km, traveled down the Bebeng drainage on the SW flank. One pyroclastic flow also traveled 1.8 km down the Bebeng drainage. Seismicity remained high.

Pagan – Mariana Islands (USA) : The U.S. Geological Survey reported that a possible sulfur dioxide emission from Pagan was detected on 31 May. The Aviation Color Code and the Volcano Alert Level remained at Unassigned. There are no ground-based instruments, so Pagan is monitored with satellite imagery, distal geophysical data, and mariner reports.

Pavlof – Alaska Peninsula, Alaska : AVO reported that the eruption at a vent on Pavlof’s upper E flank was ongoing during 31 May-7 June, and seismic tremor persisted. A short lava flow from the vent was observed during 31 May-1 June, and daily elevated surface temperatures identified in satellite images during the remainder of the week were consistent with continuing activity.

Rincon de la Vieja – Costa Rica : OVSICORI-UNA reported continuing eruptive activity at Rincón de la Vieja characterized by small phreatic explosions. A minor emission was possibly recorded on 4 June, though it could not be visually confirmed due to darkness. An eruptive event at 0804 on 6 June produced a steam plume that rose about 3 km above the summit. Sulfur dioxide from the plume was detected by an instrument located to the S. Another event was recorded at 1204 later that day, though a plume was not visible due to weather conditions.

Ruapehu – North Island (New Zealand) : On 7 June GeoNet reported that elevated unrest at Ruapehu continued, though at reduced levels. During the previous week volcanic tremor levels had decreased from moderate to weak, and lake water temperatures had declined to 28 degrees Celsius. Weather conditions prevented gas measurement flights during the previous few weeks.

Sabancaya – Peru : Instituto Geofísico del Perú (IGP) reported moderate levels of activity at Sabancaya during 30 May-6 June with a daily average of nine explosions. Gas-and-ash plumes rose as high as 1.5 km above the summit and drifted E and SE. As many as six 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 1-7 June. A few eruptive events (recorded at 0701 and 0710 on 1 June, and at 1306 on 6 June) produced ash plumes that rose 300-500 m above the summit and drifted N, W, and SW. Occasionally on the other days white plumes rose 100-600 m and drifted in multiple directions.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that low-level eruptive activity at Semisopochnoi’s North Cerberus cone continued during 31 May-6 June. Seismicity remained elevated with intermittent tremor; one explosion was recorded during 31 May-1 June and multiple small explosions were recorded during 4-6 June. Weather clouds mostly prevented satellite and webcam views. Minor ash emissions rising to low heights were visible in webcam images during 6-7 June.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 27 May-3 June; explosions, hot avalanches, and lava-dome extrusion continued.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 1 June – 7 June 2022

Bulusan – Luzon (Philippines) : At 1037 on 5 June a phreatic eruption at Bulusan produced a gray steam-rich plume, somewhat visible through weather cloud cover, that rose at least 1 km above the summit and drifted W. The event lasted about 17 minutes and was visible from Juban (Sorsogon Province). Ashfall was reported in Puting Sapa, Añog, Guruyan, Catanusan, Buraburan, Bacolod, and Sangkayon in Juban, and Bolos in Irosin, Sorsogon Province. Residents of Añog, Guruyan, and Catanusan also reported rumbling sounds and a sulfur odor. PHIVOLCS raised the Alert Level to 1 (on a scale of 0-5) and reminded the public not to enter the 4-km-radius Permanent Danger Zone (PDZ) nor the 2 km Extended Danger Zone (EDZ) on the SE flank. After the eruption gas emissions rose from the main crater and, for the first time this year, from the NW summit vent.

Reykjanes – Reykjanes Peninsula : On 2 June IMO reported that the rate of uplift on the Reykjanes Peninsula had significantly decreased, and seismicity had been declining, with only about 150 earthquakes recorded the previous day. The Aviation Color Code was lowered to Green because the data indicated no magma movement.

Ulawun – New Britain (Papua New Guinea) : RVO reported that at 0820 on 2 June a small eruption at Ulawun produced dense gray ash plumes that rose about 3 km above the summit and drifted NW. The elevated activity lasted 10-15 minutes. Minor ashfall was reported in areas downwind, including in Ulamona Mission and on Lolobau Island. Seismicity increased during the event, then dropped back to lower levels. Diffuse white plumes were visible rising from the summit the next day.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 25 May – 31 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 23-30 May. Crater incandescence was visible at night during 23-27 May.

Ambae – Vanuatu : On 27 May the Vanuatu Meteorology and Geo-Hazards (VMGD) reported that the cone in Ambae’s Lake Voui continued to produce steam and ash emissions.

Dukono – Halmahera : Based on satellite and wind model data, the Darwin VAAC reported that during 26-28 and 30-31 May ash plumes from Dukono rose to 2.1-2.7 km (7,000-9,000 ft) a.s.l. and drifted in multiple directions.

Etna – Sicily (Italy) : INGV reported that during 23-29 May activity at Etna’s Southeast Crater (SEC) was characterized by intermittent Strombolian activity and occasional ash emissions. At 0805 on 29 May a fissure opened in the upper part of the Valle del Bove. Two vents along the fissure, located at 2,850 and 2,730 m elevation, produced slow-moving lava flows that had advanced E to 2,090 m elevation by the next day. During an aerial survey conducted on 30 May scientists observed a series of about four arc-shaped fractures on the E flank of SEC, between 3,000 and 3,200 m elevation, and unstable and slumped material which had moved downslope.

Fuego – South-Central Guatemala : INSIVUMEH reported that 2-9 explosions per hour were recorded at Fuego during 24-31 May, generating ash plumes that rose as high as 1.1 km above the crater rim. The ash plumes drifted as far as 30 km in multiple directions, causing ashfall on most days in areas downwind including La Soledad (11 km N), Chimaltenango (21 km NNE), Parramos, Yepocapa (8 km N), Quisaché, Santa Isabel, La Rochela, El Zapote (10 km S), and La Trinidad (S). Ashfall was probable but not reported on three of the days. Daily shock waves rattled structures in communities around the volcano and occasional rumbling was heard. Block avalanches descended the upper 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. Explosions ejected incandescent material 100-400 m above the summit on most days. Lahars descended the Ceniza and El Jute (SE) drainages during 27-28 May.

Gaua – Banks Islands (Vanuatu) : On 27 May Vanuatu Meteorology and Geo-Hazards (VMGD) reported that steam emissions continued to be emitted at Gaua based on satellite images and local observers. The steam plumes may have contained volcanic gases.

Great Sitkin – Andreanof Islands (USA) : AVO reported that the eruption at Great Sitkin continued during 24-31 May, though weather clouds sometimes hindered observations. Almost daily elevated surface temperatures were identified in satellite data, consistent with lava effusion, and satellite images during 28-29 May showed that the lava field had expanded. Steam emissions were occasionally visible.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was identified in satellite images during 20 and 23-27 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 24-31 May, entering the lava lake and flowing onto the crater floor. The surface of the lava lake was continuously active all week, though the height of the lake was high and relatively stable. Nearly-continuous breakouts of lava occurred along the NW and W margins of the lake.

Kuchinoerabujima – Ryukyu Islands (Japan) : The number of volcanic earthquakes had decreased to low levels. The report noted that sulfur dioxide emissions had continued to remain low, and that no changes in temperature or the extent of the geothermal areas around the crater were observed.

Lewotolok – Lembata Island : PVMBG reported that the eruption at Lewotolok continued during the month of May. White, gray, and black plumes rose as high as 1.2 km above the summit crater, and white-and-gray plumes rose 100-500 m. Lava flows were active on the crater floor. On 31 May lava flow breached the E crater rim and traveled 500 m E, towards the Jontona Village, located 4 km E of the summit.

Manam – Northeast of New Guinea : The Darwin VAAC reported daily ash plumes at Manam during 25-29 May. At 0720 on 25 May an ash plume rose to 2.4 km (8,000 ft) a.s.l. and drifted W, and dissipated within 30 minutes. Ash plumes rose to 2.1 km (7,000 ft) a.s.l. and drifted NW during 25-26 May. An eruptive event, observed at 0657 on 27 May by RVO and webcam images, produced an ash plume that rose to 2.4 km a.s.l. based on webcam views; weather clouds prevented satellite views of the emissions. On 28 May an ash plume rose to 2.1 km a.s.l. and drifted NE. A thermal anomaly over the volcano was visible following the emission. On 29 May diffuse ash plumes rose to 2.1-2.4 km a.s.l. and drifted in multiple directions.

Merapi – Central Java : BPPTKG reported that the eruption at Merapi continued during 20-26 May. 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 144 lava avalanches traveled a maximum of 2 km down the Bebeng drainage on the SW flank. Three 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 24-31 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 E flank. An active flow that was 650 m long was visible in satellite images during 28-29 May.

Rincon de la Vieja – Costa Rica : OVSICORI-UNA reported that several small phreatic explosions at Rincón de la Vieja were recorded during 25-28 May. A phreatic explosion at 1730 on 25 May produced minor ashfall on local plants located on the upper flanks. Weather conditions often prevented views of plumes.

Santa Maria – Southwestern Guatemala : INSIVUMEH reported that the eruption at Santa María’s Santiaguito lava-dome complex continued during 23-31 May. Incandescence from Caliente crater and the lava flows on the W and SW flanks was visible nightly and during some early mornings. Avalanches of incandescent blocks descended the W, SW, and S flanks of Caliente. 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. The lava flow was 3.3 km long by 27 May. Cement-like lahars descended the Cabello de Ángel drainage (a tributary of Nimá I on the SE flank) during 27-28 May, carrying tree trunks, branches, and blocks up to 1 m in diameter.

Semeru – Eastern Java : PVMBG reported that the eruption at Semeru continued during 24-31 May. Several eruptive events (recorded at 0553 and 0627 on 28 May, at 0819 on 29 May, and at 0529 on 30 May) produced ash plumes that rose 300-600 m above the summit and drifted N and SW.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that low-level eruptive activity at Semisopochnoi’s North Cerberus cone continued during 24-31 May. Seismicity continued to be elevated with intermittent tremor and several daily explosions recorded by infrasound and seismic instruments. Weather clouds often prevented satellite and webcam views; sporadic ash emissions were visible during 27-28 May and likely occurred on other days as well. Sulfur dioxide emissions were detected during 27-29 May, and elevated surface temperatures were identified during 28-29 May.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 20-27 May, and lava-dome extrusion continued.

Stromboli – Aeolian Islands (Italy) : INGV reported that during 23-29 May activity at Stromboli was characterized by ongoing explosions from four vents in Area N (North Crater area) and three vents in Area C-S (South-Central Crater area). During most of the week explosions from Area N vents (N1 and N2) averaged 3-6 events per hour; explosions from the N1 vent ejected lapilli and bombs 80-150 m high, and minor gas emissions and weak spattering was visible at N2 vents. No explosions occurred at the S1 and C vents in Area C-S (except for on 25 May); low- to medium-intensity explosions at the two S2 vents occurred at a rate of 0-4 per hour and ejected coarse material 80-150 m high. At 1611 on 25 May a high-energy explosive event occurred at the N vent in S2, ejecting material beyond the area viewed by the Pizzo webcam, located about 250 m elevation. A second explosion, recorded at 1612 at the C vent, ejected course material 80 m high.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that 33 explosions were recorded at Suwanosejima’s Ontake Crater during 23-30 May. Eruption plumes rose as high as 1.9 km above the crater rim and material was ejected 500 m above the vent. Crater incandescence was visible at night. Ash fell in Toshima village (3.5 km SSW) during 23-27 May. The Alert Level remained at 3 and the public was warned to stay 2 km away from the crater.

Yasur – Vanuatu : On 27 May Vanuatu Meteorology and Geohazards Department (VMGD) reported that activity at Yasur continued at a high level of “major unrest”. 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 25 May – 31 May 2022

Bezymianny – Central Kamchatka (Russia) : KVERT reported that the eruption at Bezymianny continued, characterized by strong fumarolic emissions, lava-dome incandescence, explosions, and hot avalanches. Seismicity increased during 23-28 May. Multiple and notable collapses of hot avalanches on the E flank produced ash plumes that rose to 4-5 km (13,100-16,400 ft) a.s.l. and drifted 70-320 km in multiple directions. Activity significantly increased on 28 May, local time. According to Kamchatka Volcanological Station (Volkstat), observers saw ash plumes from Bezymianny rising over Klyuchevsky volcano around lunchtime. The plume altitudes gradually increased and late in the evening a large, strong, explosive event occurred; ash plumes rose to 11 km (36,100 ft) a.s.l. and drifted E. According to KVERT satellite data showed ash plumes rising 10-12 km (32,800-39,400 ft) a.s.l. and drifting ESE at 1920. The Aviation Color Code was raised to Red (the highest level on a four-color scale). By 2010 the ash plumes had risen to 15 km (49,000 ft) a.s.l., and previous ash emissions had drifted 365 km SE. Volkstat observers noted that activity began to decline by about 2020 and plume altitudes did not exceed 6 km (19,700 ft) a.s.l. and drifted SE. Ash plumes continued to be emitted, though they rose no higher than 5 km based on webcam views. Two ash plumes were identified in satellite images; the first was drifting 212 km SE at an altitude of 9.5 km (31,200 ft) a.s.l. and the second was drifting 650 km SE at unspecified altitudes. On 29 May at 1000 gas-and-steam plumes with some ash were visible in webcam images rising as high as 4.5 km a.s.l. and drifting 45 km SE. Satellite images showed that the large ash cloud from the day before had drifted 1,635 km SE.

Cleveland – Chuginadak Island (USA) : AVO reported that during 24-31 May daily elevated surface temperatures over Cleveland were identified in satellite images, along with plumes of steam and sulfur dioxide gas. Crater subsidence in the summit crater was detected during 26-27 May.

Dempo – Southeastern Sumatra : PVMBG reported that at 0154 on 31 May a phreatic eruption at Dempo produced ashfall in areas within 5 km, including Pagar Alam Utara district (E) and North Dempo District. Ash deposits were as thick as 1 mm.

Yakedake – Honshu (Japan) :On 24 May, a report noted that the number of small volcanic earthquakes with epicenters near the summit began increasing around 2300 the day before. The report also noted that minor inflation near the summit was continuing. Daily small volcanic earthquakes continued to be counted through 31 May.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 18 May – 24 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 16-23 May. Crater incandescence was visible at night. At 0900 on 17 May an eruptive event produced a plume that rose 1.5 km above the crater rim. That same day the sulfur dioxide rate was slightly high at 1,700 tons per day.

Dukono – Halmahera : Based on satellite and wind model data, the Darwin VAAC reported that during 17-20 May ash plumes from Dukono rose to 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted W and NW. The plumes on 17 May drifted 185 km W.

Etna – Sicily (Italy) : INGV reported that at around 1900 on 12 May a new vent opened along the N flank of Etna’s Southeast Crater (SEC) at an elevation of 3,250 m, and produced ash emissions that rose to 3.5 km (11,500 ft) a.s.l. and drifted SW. Small pyroclastic flows descended the flank. Lava effused from the vent and traveled N and NE into the snowy Valle del Leone, where lava blocks that rolled onto the snow caused steam plumes. The lava flow slowly advanced during 13-22 May, reaching 2,300-2,400 m elevation by 17 May. Discontinuous Strombolian activity of variable intensities occurred at SEC; ash emissions were visible during more intense phases, though the plumes dissipated rapidly. A new lava flow emerged from the vent on the N flank at around 2300 on 17 May and traveled N and NE alongside the previous lava flow. During fieldwork conducted on 18 May, scientists observed that lava had reached an elevation of 2,700 m in the Valle del Leone. A new vent opened on the N flank of SEC by 1730 on 20 May, at 3,250 m elevation, just NW of the previous vent. The vent produced a small lava flow that curved N and NE, joining the previous flow. By 21 May lava flows were not advancing below the summit area, at elevations of 2,700-2,800. Strombolian activity of varying intensity continued at SEC; periodic ash emissions generated ashfall in areas as far as Catania. At 2305 on 21 May a pyroclastic flow from the 20 May vent traveled 700 m NNE. Ash emissions intensified during 0300-0400 on 22 May. By that evening, lava flows from the 12 May vent had ceased and the 20 May vent produced short lava flows.

Fuego – South-Central Guatemala : INSIVUMEH reported that on 23 May lahars descended Fuego in the Las Lajas drainage (SE), the Ceniza drainage (SSW), and the Honda drainage (E); all three lahars carried fine material along with tree trunks, branches, and blocks as large as 1.5 m in diameter.

Great Sitkin – Andreanof Islands (USA) : AVO reported that the eruption at Great Sitkin continued during 17-24 May. Almost daily elevated surface temperatures were identified in satellite data, consistent with lava effusion. Steam emissions were visible during 23-24 May.

Ibu – Halmahera : PVMBG reported that the eruption at Ibu continued during 17-24 May. Daily gray-and-white ash plumes of variable densities generally rose 200-1,500 m above the summit and drifted in multiple directions.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that during 13-20 May daily explosions at Karymsky generated ash plumes that rose 3-9.5 km (9,800-31,200 ft) a.s.l. and drifted more than 450 km in various directions. A thermal anomaly over the volcano was visible in satellite images during 13-14 and 17-19 May.

Katmai – Alaska : AVO reported that on 20 May strong winds in the vicinity of Katmai and the Valley of Ten Thousand Smokes blew unconsolidated ash WNW 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 17-24 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 high and relatively stable. Breakouts of lava occurred along the E, N, NW, and W margins of the lake.

Lewotolok – Lembata Island : PVMBG reported that the eruption at Lewotolok continued during 17-24 May. Daily white steam plumes were visible rising 50-800 m above the summit and drifted multiple directions. White-and-gray emissions were visible on 19 and 21 May rose as high as 500 m above the summit and drifted SE, W, and NW.

Manam – Northeast of New Guinea : The Darwin VAAC reported that during 17-19 May ash plumes from Manam rose to 2.4 km (8,000 ft) a.s.l. and drifted NW and W based on satellite images and weather models.

Merapi – Central Java : BPPTKG reported that the eruption at Merapi continued during 13-19 May. 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 82 lava avalanches traveled a maximum of 2 km, mostly down the Bebeng drainage on the SW flank. One pyroclastic flow traveled 2.5 km down the Bebeng drainage. Seismicity remained high.

Nevados de Chillan – Central Chile : SERNAGEOMIN reported low levels of activity at Nevados de Chillán during 1-15 May. The area of the lava dome on the floor of Nicanor Crater was 1,626 square meters, similar to measurements from March (1,665 square meters); deformation measurements indicated that extrusion had ceased. Crater incandescence was sometimes visible; thermal anomalies were identified in satellite images on 3, 5, 8, 10, 13, and 15 May. There were 217 explosions in the active crater recorded by the seismic network. The explosions mainly produced steam, though the plumes occasionally contained tephra. Material from explosive activity accumulated in the NE part of the crater. An energetic explosion on 16 May produced an ash plume that rose 900 m and pyroclastic flows that descended the SE, NE, and W flanks as far as 400 m. Seismicity remained at moderate levels. Sulfur dioxide emissions averaged 466 ± 54 tons per day, peaking at 802 tons per day on 7 May. An explosion was recorded on 21 May.

Pavlof – Alaska Peninsula, Alaska : AVO reported that the eruption at a vent on Pavlof’s upper E flank was ongoing during 17-24 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.

Rincon de la Vieja – Costa Rica : OVSICORI-UNA reported that a few small phreatic explosions at Rincón de la Vieja were recorded during the previous week. A phreatic explosion at 1343 on 18 May produced a steam-and-gas plume that rose 200 m above the crater rim. At 1710 on 19 May an eruptive event produced a gas-and-steam plume that rose 100 m above the summit. More small eruptive events at 0251 and 0443 on 21 May were recorded by seismic and infrasound instruments.

Ruapehu – North Island (New Zealand) : On 24 May GeoNet reported that elevated unrest at Ruapehu continued, though at reduced levels. During the previous week the levels of volcanic tremor further declined, were variable, but remained above normal. The lake water temperature decreased from a peak of 41 degrees Celsius on 8 May to 30 degrees Celsius, showing a cooling trend. 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 were at 179 and 1,658 tonnes per day, respectively; data from new instruments confirmed that these levels remained elevated.

Semeru – Eastern Java : PVMBG reported that the eruption at Semeru continued during 17-24 May. White plumes were occasionally visible rising 100-700 m above the summit. Several eruptive events (recorded at 0525 on 19 May, at 0552 on 20 May, at 0525 on 21 May, at 0632 on 22 May, and at 0624 on 23 May) produced ash plumes that rose 200-500 m above the summit and drifted S and SW.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that low-level eruptive activity at Semisopochnoi’s North Cerberus cone continued during 17-24 May. Seismicity continued to be elevated with intermittent tremor and several daily explosions recorded by infrasound and seismic instruments. Low-level ash emissions were visible in clear satellite images and webcam views; clouds sometimes obscured views towards the end of the week. A sulfur dioxide plume drifted 240 km N during 17-18 May, and sulfur dioxide emissions were detected during 23-24 May.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 13-20 May, and lava-dome extrusion continued.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that eruptive activity continued to be recorded at Suwanosejima’s Ontake Crater during 16-23 May. Eruption plumes rose as high as 1.9 km above the crater rim and material was ejected 400 m above the vent. Ash fell in Toshima village (3.5 km SSW) and in other areas within 5 km. Three explosions were recorded during 20-23 May and crater incandescence from the crater was visible at night.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 18 May – 24 May 2022

Bezymianny – Central Kamchatka (Russia) : On 24 May KVERT reported that the effusive eruption at Bezymianny continued, characterized by strong fumarolic emissions, lava-dome incandescence, and hot avalanches. Notable hot avalanches descended the E flank. Gas-and-steam plumes with some ash content drifted 30 km NW on 24 May and 25 km NE on 25 May, at altitudes of 3-4.5 km (9,800-14,800 ft) a.s.l.

Cleveland – Chuginadak Island (USA) : AVO reported that during 17-24 May almost daily elevated surface temperatures over Cleveland were identified in satellite images. Daily sulfur dioxide emissions were visible, and steam plumes rose from the crater during 22-24 May. A series of small, local earthquakes were detected on 18 May.

Krakatau – Sunda Strait : The Darwin VAAC reported that on 18 May a diffuse ash plume from Anak Krakatau rose to 2.4 km (8,000 ft) a.s.l. and drifted WNW based on satellite images and weather models. On 19 May a dense steam plume with diffuse ash rose to 2.4 km and drifted N.

Reykjanes – Reykjanes Peninsula : IMO reported an ongoing seismic swarm and uplift on the Reykjanes Peninsula, indicative of a magma intrusion. Satellite data analysis indicated that 4-4.5 cm of uplift occurred during 27 April-21 May centered just NW of Mt. Thorbjorn. Magma was accumulating at depths of 4-5 km, and the intrusion was possibly 7-8 km long. During 22-23 May about 400 earthquakes were recorded; a M 3 earthquake was recorded at 1113 on 22 May and a M 3.5 earthquake was recorded at 0715 on 23 May, both were located about 3 km E of Mt. Thorbjorn.

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.