Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the Week 24 February 2021 – 2 March 2021

Aira – Kyushu (Japan) : JMA reported that during 22 February-1 March incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible nightly. Three explosions and four non-explosive events generated eruption plumes that rose as high as 2.6 km above the crater rim and ejected bombs 0.6-1.3 km away from the crater. The Alert Level remained at 3 (on a 5-level scale).

Dukono – Halmahera (Indonesia) : PVMBG reported that during 23-28 February ash plumes from Dukono rose 100-500 m above the summit and drifted SE and E. Weather conditions prevented visual observations during 1-2 March. 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.

Ebeko – Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 19-26 February that sent ash plumes to 3.6 km (11,800 ft) a.s.l. and drifted E and SE. Ashfall was reported in Severo-Kurilsk on 20 February and a thermal anomaly was identified in satellite images that same day. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego – Guatemala : INSIVUMEH reported that 5-15 explosions were recorded per hour during 23 February-2 March at Fuego, generating ash plumes as high as 1.1 km above the crater rim. Shock waves rattled buildings around the volcano. Block avalanches descended the Ceniza (SSW), Seca (W), Trinidad (S), Taniluyá (SW), Las Lajas (SE), and Honda drainages, often reaching vegetated areas. Ashfall was reported on most days in several areas downwind including Morelia (9 km SW), Panimaché I (8 km SW), Santa Sofía (12 km SW), El Porvenir (8 km ENE), and San Pedro Yepocapa (8 km NW). Incandescent material was ejected 100-400 m above the summit almost daily. Curtains of old ash deposits remobilized by strong winds were observed during 26-27 February.

Ibu – Halmahera (Indonesia) : PVMBG reported that during 24 February-2 March gray-and-white ash plumes from Ibu rose 200-800 m above the summit and drifted in multiple directions. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to stay at least 2 km away from the active crater and 3.5 km away on the N side.

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 24 February-2 March. The depth of the western part of the lake deepened from 217 to 219 m. Lava effused from a submerged vent and rapidly developed a thin crust as it flowed E towards the main stagnant island. The crust occasionally overturned at “plate” boundaries, and lava rarely overflowed onto the sloped margins of the lake. The E half of the lake remained solidified; the crusted area expanded towards the W. The sulfur dioxide emission rate was 700-1,100 tons/day during 25-26 February and 1 March.

Kirishimayama – Kyushu (Japan) : JMA lowered the Alert Level for Kirishimayama to 1 (on a scale of 1-5) on 1 March. The number of volcanic earthquakes had increased in late December 2020 but then began to decline in January 2021 and continued the downward trend through February. No other observation data showed signs of unrest.

Lewotolo – Lomblen Island (Indonesia) : PVMBG reported that the eruption at Lewotolok continued during 24 February-2 March; weather conditions sometimes hindered visual observations. Gray-and-white ash plumes rose 100-700 m above the summit and drifted N, E, SE, and W. 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.

Merapi – Central Java (Indonesia) : BPPTKG reported that the 2021 lava dome just below Merapi’s SW rim and the new lava dome in the summit crater both continued to grow during 19-25 February. The 2021 lava-dome volume was an estimated 618,700 cubic meters on 25 February, with a growth rate of about 13,600 cubic meters per day. A total of three pyroclastic flows traveled 1.9 km down the SW flank. One of the three, recorded at 1652 on 25 February, was followed by minor ashfall in Kali Tengah Lor, Kali Tengah Kidul, Deles, and Tlukan. The Alert Level remained at 3 (on a scale of 1-4), and the public were warned to stay 5 km away from the summit.

Raung – Eastern Java (Indonesia) : PVMBG reported that daily gray ash plumes rose 200-1,200 m above Raung’s summit during 24 February-2 March. Ash plumes were sometimes dense and drifted mainly N, E, and S. 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.

Sangay – Ecuador : IG reported a high level of activity at Sangay during 24 February-2 March. Seismicity was characterized by 3-254 daily explosions, long-period earthquakes, and signals indicating emissions. Weather clouds often prevented visual observations of the volcano, but the Washington VAAC recorded almost daily ash plumes that rose as high as 1.5 km above the summit and drifted mainly NW, W, and SW. A seismic station possibly recorded a lahar on 25 February.

Santa Maria – Guatemala : INSIVUMEH reported that during 23 February-2 March explosions at Santa María’s Santiaguito lava-dome complex generated ash plumes that rose as high as 1 km above the complex. Collapses of blocky lava from the Caliente dome sent avalanches mainly down the SW flank, often reaching the base of the complex. Minor pyroclastic flows were occasionally generated. Ash plumes drifted W and SW, often causing minor ashfall around the volcano.

Semeru – Eastern Java (Indonesia) : The Darwin VAAC reported that during 24-25 February ash plumes from Semeru rose to 4-4.3 km (13,000-14,000 ft) a.s.l. and drifted SE based on satellite images. PVMBG noted that weather conditions prevented visual observations during 24 February-2 March. The Alert Level remained at 2 (on a scale of 1-4), with a general exclusion zone of 1 km and extensions to 4 km in the SSE sector.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 19-26 February. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

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 24 February-2 March. The rate of growth was variable, though overall slow. Gas emissions continued to damage vegetation in the summit area as well as on the SW flank. The monitoring teams replaced a camera and continue to improve the seismic and GPS networks. The Alert Level remained at Orange (the second highest level on a four-colour scale).

Suwanosejima – Ryukyu Islands (Japan) : JMA reported intermittent eruptive events at Suwanosejima’s Ontake Crater during 19-26 February. These events produced ash plumes that rose as high as 1.8 km above the crater rim and ejected bombs 200 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).

from WordPress https://ift.tt/2MNlTVF