Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the Week 10 February 2021 – 16 February 2021

Aira – Kyushu (Japan) : JMA reported that during 8-15 February incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was often visible nightly. One explosion and five eruptive events generated eruption plumes that rose 1.4-1.5 km above the crater rim and ejected bombs 800-1,100 km away from the crater. The sulfur dioxide emission rate was high, at 2,500 tons per day on 9 February. The Alert Level remained at 3 (on a 5-level scale).

Ebeko – Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 29 January and 1-2 February that sent ash plumes to 3.6 km (11,800 ft) a.s.l. and drifted in multiple directions. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Dukono – Halmahera (Indonesia) : Based on satellite and wind model data and information from PVMBG, the Darwin VAAC reported that during 12-13 February ash plumes from Dukono rose to 1.5-1.8 km (5,000-6,000 ft) a.s.l. and drifted E. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.

Fuego – Guatemala : INSIVUMEH reported that continuous avalanches of material at Fuego during 9-10 February descended the Ceniza (SSW), Seca (W), Trinidad (S), Taniluyá (SW), Las Lajas (SE), and Honda drainages. There were 8-12 explosions per hour, generating ash plumes that rose as high as 1.1 km above the crater rim that drifted 15-20 km W and SE. Ashfall was reported in areas downwind including Santa Sofía, Panimache, Morelia, and Yucales, and shockwaves were audible up to 15 km away. The number of explosions increased to 3-6 per hour during 11-12 February. Ash-and-gas plumes rose to 1.1 km and drifted W and SW, causing ashfall in Sangre de Cristo, Palo Verde, and Yepocapa. Shock waves were felt by nearby residents. Avalanches of material descended the flanks, reaching vegetated areas. During 12-13 February incandescent material was ejected 200 m above the summit and shock waved vibrated local structures. A lava flow had traveled 1 km down the Ceniza drainage, spalling blocks from the flow front that reached vegetated areas. By 14 February the lava flow had lengthened to 1.5 km and a lava flow in the Seca drainage traveled 500 m. During 1020-1023 a series of pyroclastic flows traveled several hundred meters down the Ceniza. Ash plumes from explosions rose 850 m and drifted NE, E, and SE, and caused ashfall in Alotenango, El Porvenir, and Finca La Reunion, in the department of Sacatépequez. During 14-15 February explosions ejected incandescent material 100 m above the summit and rattled nearby structures. Ash plumes rose as high as 450 m and drifted short distances E. Lava flows remained active; they were 800 and 200 m long in the Ceniza and Seca drainages, respectively. Block avalanches from the lava-flow fronts reached vegetated areas. The lava effusion rate had steadily decreased during the late morning of 15 February. During the afternoon explosions, occurring at a rate of 14-30 per hour, produced ash plumes that rose 850-1,050 m above the summit and drifted as far as 50 km E, NE, and N. Ash fell in Porvenir and Alotenango. Activity continued to decrease through the day, characterized by a reduction in the explosion rate, less intense summit incandescence, and low RSAM values. INSIVUMEH declared an end to the effusive eruption phase. Explosions (12-14 per hour) generated ash plumes that rose over 1 km and drifted 130 km N, NE, and E.

Kanlaon – Philippines : PHIVOLCS reported slightly increased seismic activity and volcanic gas flux at Kanlaon. The seismic network recorded 28 volcanic earthquakes during 11-13 February with local magnitudes between 0.7 and 2.2. They were located at shallow depths around 10 km across the N to E portions of the edifice. The sulfur dioxide emission rate on 13 February was 1,130 tonnes per day, the highest value recorded this year; sulfur dioxide emissions had been higher than background levels of 300 tonnes/day since June 2020. Ground deformation data from continuous GPS and tilt measurements indicated slight inflation of the lower and middle flanks since June 2020. Increased seismic activity continued through 16 February; from 0800 on 14 February to 0800 on 16 February there were a total of 59 earthquakes. The Alert Level remained at 1 (on a scale of 0-5) and PHIVOLCS reminded the public to remain outside of the 4-km-radius Permanent Danger Zone.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that activity at Karymsky had decreased; strong explosions were last observed on 2 January and a thermal anomaly was last detected in satellite images on 5 February. The Aviation colour Code was lowered to Yellow (the second lowest level on a four-colour scale) on 11 February and then lowered to Green, the lowest level, on 16 February. Gas-and-steam emissions persisted.

Kavachi – Solomon Islands : Satellite data showed discoloured water around and to the SW of Kavachi on 25 January. Discoloured water was not obviously visible in 20 January images; weather clouds prevented views of the area in images through 14 February.

Kilauea – Hawaiian Islands (USA) : HVO reported that a vent on the inner NW wall of Kilauea’s Halema`uma`u Crater continued to supply the lava lake during 10-16 February. The western part of the lake deepened from 215 m to around 217 m and the lake surface actively overturned at “plate” boundaries. The W end of the lava lake was perched by 3 m above the distal margin of recent overflows. A series of surficial cracks separated the W part of the lake from the stagnant E part. Lava spillovers just N of the inlet of lava sporadically flowed around the NW margin of the perched lake. Gas jetting at two locations above the W vents and two bursts of spatter were observed during 9-10 February. The sulfur dioxide emission rate was 1,600 and 1,100 tons/day on 10 and 12 February, respectively. During 15-16 February a few lava flows were visible along the N and E margins of the E part of the lake.

Klyuchevskoy – Central Kamchatka (Russia) : KVERT reported that activity at Klyuchevskoy notably decreased, with the eruption likely ending on 8 Febryary. The temperature of the thermal anomaly identified in satellite images abruptly dropped on 7 February, and the magnitude of volcanic tremor decreased during 7-8 February and continued to decline through 12 February. Strombolian activity was not visible at night during 11-12 February. The Aviation colour Code was lowered to Yellow (the second lowest level on a four-colour scale) on 12 February. The Tokyo VAAC reported that re-suspended ash was identified in satellite images during 12-13 February. On 15 February an ash plume rose to 5.2 km (17,000 ft) a.s.l. and drifted NE.

Lewotolo – Lomblen Island (Indonesia) : PVMBG reported that the eruption at Lewotolo continued during 9-15 February. Gray-and-white ash plumes rose 400-1,000 m above the summit and drifted E and SE. Strombolian explosions ejected material 500 m SE on 13 February. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 4 km away from the summer crater.

Pacaya – Guatemala : INSIVUMEH reported that a during 9-10 February Strombolian explosions at Pacaya’s Mackenney Crater ejected material 200-300 high and away from the crater. Ash clouds occasionally rose as high as 650 m and drifted 10 km W and SW. A 1.3-km-long lava flow was active on the S flank; block avalanches from the front of the lava flow descended 200 m. Activity increased around 1600 on 10 February. Strombolian explosions ejected incandescent material 500 m above the crater rim and produced gas-and-ash plumes that drifted W. Ashfall was reported in the villages of El Patrocinio (about 5 km W) and El Rodeo (4 km WSW). During 11-12 February material was ejected 300-500 m above the crater. Ash plumes rose 950 m and drifted N, causing ashfall in San Francisco de Sales (5 km N), San Jose Calderas, and Concepción el Cedro (9 km NNW). Seismic data recorded pulses of increased activity during the morning of 12 February and again around 1400 on 13 February. Explosions ejected material 300-500 m above the crater. Ash-and-gas plumes rose almost 500 m and drifted 6 km W, N, and NE, causing ashfall in Santa Elena Barillas (6 km ENE), Mesillas Bajas (5 km NE), and Mesillas Altas. Another pulse of activity was recorded at 1145 on 14 February. Material was ejected as high as 250 m. Ash plumes rose less than 400 m and drifted 5 km E. A 650-m-long lava flow in the SSW flank was active on 15 February. Explosions continued to ejected material as high as 250 m above the vent.

San Cristobal – Nicaragua : The Washington VAAC reported that on 14 February an ash cloud from San Cristóbal rose to 2.3 km (7,500 ft) a.s.l. and drifted SW based on satellite data, webcam images, and weather models. A thermal anomaly was also identified.

San Miguel – El Salvador : SNET stated that San Miguel’s seismic network recorded long-lasting and continuous periods of volcanic tremor that began on 7 February and continued through 14 February. Discrete earthquakes from minor rock fracturing were also detected. RSAM values fluctuated between 25 and 75 units, below normal values around 150 units.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 5-12 February. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Sinabung – Indonesia : PVMBG reported that the eruption at Sinabung continued during 10-16 February, though weather conditions sometimes prevented visual confirmation. Dense white plumes rose as high as 1 km above the summit and drifted in multiple directions. During 12-14 February pyroclastic flows traveled as far as 2 km down the E and SE flanks. Avalanches descended 500-1,500 m down the E, SE, and S flanks. The Alert Level remained at 3 (on a scale of 1-4), with a general exclusion zone of 3 km and extensions to 5 km in the SE sector and 4 km in the NE sector.

Soufriere St. Vincent – St. Vincent : University of the West Indies Seismic Research Centre (UWI-SRC) and National Emergency Management Organisation (NEMO) reported that the lava dome in Soufrière St. Vincent’s main crater continued to grow during 10-16 February. Gas-and-steam continued to rise from the top of the dome as well as along the contact of the old and new domes. The dome also grew taller and spread laterally to the NW and SE. By 12 February the it was 90 m tall, 618 m long, 232 m wide, and had an estimated volume of 6.83 million cubic meters. Four additional seismometers were installed, strengthening the seismic network. NEMO reminded the public to avoid the volcano and that descending into the crater remained extremely dangerous. The Alert Level remained at Orange (the second highest level on a four-colour scale).

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that incandescence at Suwanosejima’s Ontake Crater was occasionally visible at night during 5-12 February. Intermittent eruptive events produced ash plumes that rose as high as 1.2 km above the crater rim and ejected bombs 500 m away from the crater. Ashfall was reported in Toshima village (4 km SSW). The Alert Level remained at 2 (on a 5-level scale).

Taal – Luzon (Philippines) : PHIVOLCS reported that geochemical data collected from Taal’s Main Crater lake indicated a continuous acidification of the water from pH 2.79 to 1.59 between January 2020 and February 2021. A maximum temperature of 77.1 degrees Celsius was unseasonably high, and carbon dioxide/hydrogen sulfide gas flux ratios were consistent with shallow magma degassing. Tilt data indicated minor deflation around Main Crater, though minor inflation was consistently recorded across the Taal region as indicated by analysis of GPS data, InSAR, and microgravity changes. A total of 68 relatively weak tremor signals were detected during 13-15 February; 50 of those were recorded during 0500-1500 on 15 February. The events on 15 February ranged in duration from two to five minutes and occurred at depths less than 1 km. The depth and location of the earthquakes suggested increased hydrothermal activity beneath Taal Volcano Island. Increased seismic activity continued through 16 February; from 0800 on 15 February to 0800 on 16 February there were a total of 98 earthquakes. The Alert Level remained at 1 (on a scale of 0-5) and PHIVOLCS strongly recommended no entry onto the island, and the Main Crater and the Daang Kastila fissure (along the walking trail) was strictly prohibited.

Villarrica – Chile : SERNAGEOMIN reported that dense gas emissions were observed in Villarrica’s webcam images rising 700 m above the summit on 10 February. Long-period (LP) events were recorded by the seismic network at 1146 and 1156 on 16 February. Ash emissions associated with the earthquakes rose 160 m and drifted NW and 280 m and drifted NE, respectively. The Alert Level remained at Yellow, the second lowest level on a four-colour scale. ONEMI maintained an Alert Level Yellow (the middle level on a three-colour scale) for the municipalities of Villarrica, Pucón (16 km N), Curarrehue, and the commune of Panguipulli, and the exclusion zone for the public of 500 m around the crater.

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