A small explosion occurred on August 17 in Suwanosejima, in the Ryulyu volcanic arc. According to reports, ash emissions reached up to 2,133 m above sea level.
An eruption was reported by the JMA on August 18, 2020 around 8 p.m. at Suwanosejima; it was accompanied by a plume of gas and ash which rose to 1,200 meters above the crater, then dissipated towards the south
Source: JMA & Copernicus / Sentinel-2
The main plume of the crater, white and gray, with a moderate to thick intensity, is observed this August 18 at about 2000 meters from the summit of Sinabung.
At the level of seismicity, we distinguish :
- 6 blast earthquakes, with an amplitude of 12 to 45 mm and a duration of 22 to 73 seconds.
- 32 low frequency earthquakes, with an amplitude of 2 to 15 mm, and the duration of the earthquake was 7 to 16 seconds.
- 4 local tectonic earthquakes, with an amplitude of 4-34 mm, S-P 1.6-3 seconds and a long earthquake of 11-29 seconds.
- 3 distant tectonic earthquakes, with an amplitude of 5-13 mm, S-P 28.4-31 seconds and a long earthquake of 86-696 seconds.
- 4 episodes of continuous tremor with an amplitude of 0.5 to 60 mm, dominating 10 mm.
The activity level is at 3 / siaga, with a red aviation code.
Sources: PVMBG, Magma Indonesia and VAAC Darwin.
Sinabung - time-lapse 18.08.2020 - Doc. PVMBG via Volcano YT
Two violent earthquakes off Bengkulu rocked the Indonesian island of Sumatra. The 6.8 and 6.9 magnitude earthquakes occurred at 5:23 a.m. local / 10:23 p.m. GMT and 5:29 a.m. local / 10:29 p.m. GMT on August 18, 2020, as reported by monitoring stations.
No tsunami warning has been issued, nor an assessment of the damage caused by these earthquakes.
They have to do with the subduction of the Indo-Australian plate under the Sunda plate.
The Manna seismic station, south of Bengkulu, recorded 2 earthquakes of M greater than 6 on 08/18/2020.
An earthquake of M 6.6 struck Masbate Island on August 18, 2020 at 8:30 a.m. local / 12:03 a.m. GMT in the Philippines. It was followed by strong aftershocks.
We deplore one death and dozens of wounded; much damage to homes is due to its shallow depth and power.
The origin is tectonic.
Sources: USGS Earthquake Hazards - EMSC - Local Observatory