AVO reported that low-level unrest continued at Semisopochnoi during 30 May-6 June. Seismicity remained low and few earthquakes were detected. Minor steam emissions were occasionally visible in webcam images on 31 May and 2 and 4 June.
AVO reported that low-level unrest continued at Semisopochnoi during 30 May-6 June. Seismicity remained low and few earthquakes were detected. Minor steam emissions were occasionally visible in webcam images on 31 May and 2 and 4 June.
On 17 May AVO reported that eruptive activity at Semisopochnoi had declined during the previous week, though seismicity remained slightly elevated and low-level steaming continued from Mount Young. Ash emissions had last occurred on 5 May leaving minor deposits on the NW flank of Mount Young's N crater. The Aviation Color Code was lowered to Yellow (the second lowest level on a four-color scale) and the Volcano Alert Level was lowered to Advisory (the second highest level on a four-level scale).
Semisopochnoi volcano (image: AVO)
The Alaska Volcano Observatory (AVO) reported a decreased activity at the volcano over the past week.
AVO reported that low-level unrest continued at Semisopochnoi during 9-16 May. Weather clouds mostly obscured satellite and webcam views. Volcanic tremor was detected during 9-10 May; there was no evidence of explosive or earthquake activity in the geophysics data during the rest of the week.
AVO reported that low-level unrest continued at Semisopochnoi during 2-9 May, though it was seismically quiet for the most part, with only occasional small earthquakes. Cloudy weather often obscured satellite views. Steam emissions from the N crater of Mount Young were visible in partially clear webcam images during 3-6 May.
AVO reported that low-level unrest continued at Semisopochnoi during 26 April-2 May. Seismicity was at low levels, and a few small local earthquakes were recorded during 28-29 April. Daily minor steam emissions were seen rising from Mount Young, though cloudy weather sometimes prevented webcam and satellite views.
AVO reported that low-level unrest continued at Semisopochnoi during 18-25 April. Daily periods or bursts of tremor and occasional low-frequency earthquakes were detected during the week. Small explosions were detected in seismic and infrasound data during 18-19 and 24-25 April.
Wed, 19 Apr 2023, 14:00
AVO reported that low-level unrest continued at Semisopochnoi during 12-18 April. No eruptive activity was observed, though some weak seismicity was recorded. Cloudy weather often prevented webcam and satellite views during most of the week.
Read allWed, 12 Apr 2023, 14:00
AVO reported that low-level unrest continued at Semisopochnoi during 5-11 April. An extensive low-altitude steam plume drifted more than 400 km during 4-6 April and was likely related to volcanic emissions but did not appear to contain ash. Several small explosions were detected on 5 April, and periods of seismic tremor and local earthquakes were recorded during 5-6 April, but seismicity was quiet during the rest of the week.
Read allWed, 5 Apr 2023, 14:00
AVO reported that low-level unrest continued at Semisopochnoi during 28 March-4 April. Steam emissions from the N crater of Mount Young were visible in webcam images during 29-30 March; weather clouds obscured webcam and satellite views during most of the week. Minor seismic and infrasound signals were recorded during 31 March-1 April that may or may not have been related to activity at N crater.
Read allWed, 29 Mar 2023, 14:00
AVO reported that low-level unrest continued at Semisopochnoi during 22-28 March. Steam emissions from the N crater of Mount Young were visible during 22 and 26-27 March. No explosive activity was detected in seismic or infrasound data.
Read allWed, 22 Mar 2023, 15:00
AVO reported that low-level ash emissions from the N crater of Semisopochnoi's Mount Young were observed in several web camera images during 18-19 March. Small explosions and volcanic tremor had also resumed. Ash emissions were not detected in satellite images, though on 18 March a robust steam-and-gas plume was visible drifting 150 km from the N crater.
Read allMon, 20 Mar 2023, 03:56
Abundant degassing from the north crater of Mount Young at Semisopochnoi volcano yesterday (image: AVO)
The Alaska Volcano Observatory raised the alert level to "Orange", as low-level ash emissions have continued from the north crater of Mount Young at the volcano over the past 24 hours.
Read allThu, 16 Mar 2023, 11:00
AVO reported that low-level ash emissions from the N crater of Semisopochnoi's Mount Young were observed in several web camera images during 18-19 March. Small explosions and volcanic tremor had also resumed. Ash emissions were not detected in satellite images, though on 18 March a robust steam-and-gas plume was visible drifting 150 km from the N crater.
Read allThu, 23 Feb 2023, 03:00
AVO reported that seismicity at Semisopochnoi's Mount Young was low during 14-21 February, and steam emissions were visible in webcam images almost daily. On 22 February the Aviation Color Code was lowered to Yellow (the second lowest level on a four-color scale) and the Volcano Alert Level was lowered to Advisory (the second highest level on a four-level scale). AVO noted that no significant tremor, ash emissions, or explosive activity had been recorded since late January.
Read allWed, 15 Feb 2023, 15:00
AVO reported that eruptive activity at Semisopochnoi's Mount Young continued during 7-14 February. Seismicity was low, and a few local earthquakes were recorded during 7-8 February. Steam emissions were visible in webcam images almost daily though views were often cloudy.
Read allWed, 8 Feb 2023, 15:00
AVO reported that eruptive activity at Semisopochnoi's Mount Young continued during 1-7 February. Seismicity was elevated and daily weak tremor was recorded. Minor steam emissions were visible in webcam images during 3-7 February.
Read allWed, 1 Feb 2023, 15:00
AVO reported that eruptive activity at Semisopochnoi's Mount Young was ongoing during 24-31 January. Seismicity was elevated and daily weak tremor was recorded. Minor steam emissions were visible in webcam images on 24 January and 29-30 January.
Read allWed, 25 Jan 2023, 15:00
AVO reported that eruptive activity at Semisopochnoi's Mount Young was ongoing during 17-24 January. Seismicity was elevated with daily small local earthquakes and occasional weak tremor. Minor steam emissions were visible in webcam images during 17-19 January; no activity was identified in cloudy satellite views during the rest of the week.
Read allWed, 18 Jan 2023, 15:00
AVO reported that eruptive activity at Semisopochnoi's Mount Young was ongoing during 10-17 January. Seismicity was elevated with small local earthquakes and weak tremor. Minor steam emissions were visible in webcam images during 11 and 16-17 January.
Read allWed, 11 Jan 2023, 15:00
AVO reported that eruptive activity at Semisopochnoi's Mount Young, formerly Mount Cerberus, was ongoing during 4-10 January. Daily minor steam emissions were visible in webcam views. Seismicity was above background levels; low-level explosive activity was detected in geophysical data during 4-5 January with elevated seismicity and infrasound signals observed on local stations.
Read allWed, 4 Jan 2023, 15:00
AVO reported that fresh ash deposits on the flanks of Semisopochnoi's Mount Cerberus were visible in webcam images during 27-28 December, indicating that activity at the N crater had resumed on 27 December. The deposits extended about 1 km from the vent. Ash plumes were not visible in satellite and webcam images, though a persistent steam plume rising as high as 2.5 km (5,000 ft) a.s.l. may have been carrying minor amounts of ash.
Read all