Semisopochnoi volcano news & activity updates:
Semisopochnoi volcano (Alaska) activity update: the seismic unrest continues
Thursday Feb 20, 2020 05:21 AM | BY: MARTIN
Seismic signal from Semisopochnoi volcano as recorded on Adak Island (image: AVO)The Alaska Volcano Observatory (AVO) reported that the seismic unrest continues at the volcano with intermittent, low-level tremor. Tremor bursts lasting from three to twelve minutes every few hours.
Additionally, the seismic station records small explosions on 16 February.
An ash plumes were not visible, though a weather cloud deck persisted between 5,000 ft-15,000 ft (1,500 m-4,600 m) altitude. Weather clouds continued to obscure views of the volcano.
Volcanic Alert Level remains at level 3.
Source: Alaska Volcano Observatory volcano activity update 20 February 2020
Sunday, Feb 16, 2020
The Alaskan Volcano Observatory (AVO) raised the Aviation Colour Code and Alert Level for Semisopochnoi to ORANGE/WATCH due to a significant increase in seismic activity as well as small explosions and tremor bursts, lasting from three to twelve minutes every few hours. No ash plumes have been observed. [more]
Friday, Dec 27, 2019
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. ... [more]
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]