Shishaldin volcano (Alaska, USA): weekly volcanic activity report 23 October-29 October 2019
Thu, 31 Oct 2019, 10:0010:00 AM | BY: MARTIN
Seismicity and infrasound signals were consistent with low level eruptive activity and a steam plume was persistent.
Lava filled the crater and overflowed the north crater rim (image: Sentinel 2)
By 23 October lava had filled the crater and during 23-24 October overflowed the north crater rim. A 200 m long lava flow on the north flank melted snow and caused a lahar which traveled 2.9 km and stopped at about 1,230 m elevation. A smaller lava flows caused a 1 km long lahar to descend the northeast flank. Spatter accumulated around the crater rim and melted snow.
On 25 October AVO noted that trace ash deposits had extended at least 8.5 km SE.
During 26-29 October continued low level eruptive activity. Seismicity remained elevated with periods of high amplitude tremor.
27-28 October were recorded small explosions. A satellite image from 28 October showed a 850 m long SWIR anomaly on the northwest flank from a lava flow. A central spatter cone was visible. Spatter deposits on the snow at the upper flanks was evident and tephra deposits extended about 2.5 km north. The lahar on the northwest flank branched extensively at lower elevations and was at least 5 km long.
The Aviation Color Code remained at Orange and the Volcano Alert Level remained at watch.
Source: Smithsonian / USGS Weekly Volcanic Activity Report 23 October-29 October 2019
Wed, 30 Oct 2019, 06:00
Shishaldin volcano (Fox Islands, USA) - Smithsonian / USGS Weekly Volcanic Activity Report for 30 October-5 November 2019 (New Activity / Unrest)
AVO reported that by 28 October two stalled lava flows extended as far as 1.8 km down Shishaldin's NW flank, lahars had traveled at least 4 km down the NW flank, and trace ash deposits on the N flank were identified in satellite images. Activity paused during 29-30 October but resumed on 31 October. Numerous small explosions were detected by the local seismic network during 31 October-1 November and incandescence was visible in webcam images. ... Read all
Thu, 24 Oct 2019, 21:19
Satellite data is now showing that the deep summit crater has been filled and lava is starting to flow over the rim with spatter from Strombolian explosions also being deposited. This melted some of the thick ice sending a lahar halfway down the north flank. Elevated seismicity continues. Read all