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USGS Volcano Notice - DOI-USGS-AVO-2023-05-31T11:05:06-08:00
ALASKA VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Wednesday, May 31, 2023, 11:13 AM AKDT (Wednesday, May 31, 2023, 19:13 UTC)
GREAT SITKIN (VNUM #311120)
52°4'35" N 176°6'39" W, Summit Elevation 5709 ft (1740 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE
Slow eruption of lava is continuing at Great Sitkin Volcano, producing a thick lava flow within the summit crater. Seismicity remains low over the last day with a few local earthquakes detected. Slightly elevated surface temperatures were observed in partly cloudy satellite views over the past day.
An eruption of lava began at Great Sitkin Volcano in July 2021 and has continued to slowly erupt since, but no explosive events have occurred. An explosive event occurred in May 2021, before the current eruption of lava. The volcano is monitored by local seismic and infrasound sensors, satellite data, webcams, and regional infrasound and lightning networks.
ANIAKCHAK (VNUM #312090)
56°54'21" N 158°12'32" W, Summit Elevation 4400 ft (1341 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW
Local seismic stations are currently offline. No activity was observed in cloudy satellite and webcam images.
The current period of seismic unrest began in October 2022. Increases in seismic activity have been detected previously at other similar volcanoes, with no subsequent eruptions. We expect additional shallow seismicity and other signs of unrest, such as gas emissions, elevated surface temperatures, and additional surface deformation to precede any future eruption, if one were to occur.
AVO monitors Aniakchak with a local network, which currently consists of one functional local seismometer and several regional seismometers, as well as satellite remote sensing data and regional infrasound and lightning networks.
SEMISOPOCHNOI (VNUM #311060)
51°55'44" N 179°35'52" E, Summit Elevation 2625 ft (800 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW
There was no evidence of explosive activity in the geophysics data over the past day. Seismicity remains low with a few earthquakes detected. No unusual activity was observed in satellite views. Minor steam emissions were detected in occasional clear web camera views of the summit.
Small eruptions producing minor ash deposits within the vicinity of the active north crater of Mount Young and ash clouds usually under 10,000 ft (3 km) above sea level have characterized recent periods of eruption since 2018. Additional ash-producing events could occur again with little warning.
Semisopochnoi volcano is monitored by local seismic and infrasound sensors, satellite data, webcams, and regional infrasound and lightning networks.
TAKAWANGHA (VNUM #311090)
51°52'1" N 178°1'37" W, Summit Elevation 4754 ft (1449 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW
No significant earthquake activity was detected over the last day and clouds obscured all satellite and webcam images.
Increases in seismic activity have been detected previously at Takawangha volcano and other similar volcanoes, with no subsequent eruptions. We expect additional shallow seismicity and possibly other signs of unrest, such as gas emissions, elevated surface temperatures, and additional surface deformation to precede any future eruption, if one were to occur.
Takawangha volcano and Tanaga Volcano are monitored with a local seismic and infrasound network, regional infrasound and lightning detection networks, and satellite data. Tanaga Volcano is about 5 miles (8 km) west of Takawangha volcano on Tanaga Island.
TANAGA (VNUM #311080)
51°53'2" N 178°8'35" W, Summit Elevation 5925 ft (1806 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW
No significant earthquake activity was detected over the last day and clouds obscured all satellite and webcam images.
Increases in seismic activity have been detected previously at Tanaga Volcano and other similar volcanoes, with no subsequent eruptions. We expect additional shallow seismicity and possibly other signs of unrest, such as gas emissions, elevated surface temperatures, and additional surface deformation to precede any future eruption, if one were to occur.
Tanaga Volcano and Takawangha volcano are monitored with a local seismic and infrasound network, regional infrasound and lightning detection networks, and satellite data. Takawangha volcano is about 5 miles (8 km) east of Tanaga Volcano on Tanaga Island.
TRIDENT (VNUM #312160)
58°14'3" N 155°6'9" W, Summit Elevation 3599 ft (1097 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW
Earthquake activity remains elevated at Trident Volcano. No other activity was observed in partly cloudy satellite data and webcam images.
The current period of seismic unrest began on August 24, 2022. Increases in seismic activity have been detected previously at Trident Volcano and other similar volcanoes, with no subsequent eruptions. We expect additional shallow seismicity and other signs of unrest, such as gas emissions, elevated surface temperatures, and surface deformation, to precede any future eruption if one were to occur.
AVO monitors Trident Volcano with a local network of seismometers, a webcam, remote sensing data, and regional infrasound and lightning networks.
CONTACT INFORMATION:
Aaron Wech, Acting Scientist-in-Charge, USGS awech@usgs.gov (907) 786-7497
David Fee, Coordinating Scientist, UAFGI dfee1@alaska.edu (907) 378-5460
The Alaska Volcano Observatory is a cooperative program of the U.S. Geological Survey, the University of Alaska Fairbanks Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys.