Semisopochnoi volcano news & activity updates:
Semisopochnoi volcano (Alaska): weekly volcanic activity report 18-24 Dec 2019
Friday Dec 27, 2019 10:31 AM | BY: MARTIN
Semisopochnoi volcano covered by clouds from satellite (image: Sentinel 2)
The Alaska Volcano Observatory (AVO) reported that ash plumes reached 5,000 ft (1,500 m) altitude and drifted about 15 km SE on 14 and 17 December.
Seismic signal from Semisopochnoi volcano as recorded on Adak Island (image: AVO)
During 17-20 December seismicity was characterized by tremor bursts and small explosions, though cloudy weather conditions prevented visual confirmation.
Elevated seismicity was recorded on 21 December.
Nothing significant was detected during 22-24 December.
The Aviation Color Code remained at Orange.
Source: Smithsonian / USGS Weekly Volcanic Activity Report 18-24 Dec 2019
Saturday, Dec 07, 2019
An eruption is probably occurring at the volcano. The Alaska Volcano Observatory (AVO) detected seismic signals of strong volcanic tremor, probably corresponding to the arrival of magma in the summit vent, but the nature of the eruption itself is unclear: ... [more]
Thursday, Nov 21, 2019
The U.S. Geological Survey Alaska Volcano Observatory (AVO) noted that weak seismicity levels continue. No eruptive activity has been detected by regional infrasound data, and no anomalous activity was observed in cloudy satellite data over the past day. [more]
Monday, Sep 23, 2019
Seismicity at the volcano has decreased over the past few weeks with no observations of seismic tremor since September 15. ... [more]
Wednesday, Aug 07, 2019
AVO reported that during 31 July-6 August seismicity at the volcano remained elevated and was characterized by periods of weak, continuous tremor and discrete low-frequency earthquakes. Satellite images were mostly cloudy, though a possible steam plume was visible during 5-6 August. ... [more]
Saturday, Jul 06, 2019
Yesterday, the Alaska Volcano Observatory raised the alert level of the volcano due to an increase in seismicity above background levels. ... [more]