AVO/USGS Volcanic Activity Notice

Volcano: Trident (VNUM #312160)

Current Volcano Alert Level: NORMAL
Previous Volcano Alert Level: ADVISORY

Current Aviation Color Code: GREEN
Previous Aviation Color Code: YELLOW


Issued: Wednesday, October 19, 2022, 2:06 PM AKDT
Source: Alaska Volcano Observatory
Notice Number: 2022/A1190
Location: N 58 deg 14 min W 155 deg 6 min
Elevation: 3599 ft (1097 m)
Area: Alaska Peninsula

Volcanic Activity Summary:

The swarm of earthquakes that began on August 24, 2022, beneath Trident Volcano has subsided and seismic tremor has not been observed since September 30, 2022. Occasional local earthquakes continue to be detected at background levels. Due to this decrease in activity and the absence of other signs of unrest, we are lowering the Aviation Color Code to GREEN and the Volcano Alert level to NORMAL.

Should activity increase, AVO will issue further notices. AVO monitors Trident with a local network of seismometers, a webcam, remote sensing data, and regional infrasound and lightning networks. To view current monitoring data, see https://avo.alaska.edu/activity/Trident.php 

Recent Observations:
[Volcanic cloud height] none
[Other volcanic cloud information] none
[Ballistics] none
[Lava flow/dome] none
[Lava flow] none

Remarks:

Trident Volcano is one of the Katmai group of volcanoes located within Katmai National Park and Preserve on the Alaska Peninsula. Trident consists of a complex of four cones and numerous lava domes, all andesite and dacite in composition, that reach as high as 6,115 ft above sea level. An eruption beginning in 1953 constructed the newest cone, Southwest Trident, and four lava flows on the flank of the older complex. This eruption continued through 1974 and produced ash (an initial plume rose to 30,000 ft asl), bombs, and lava at various times. Fumaroles remain active on the summit of Southwest Trident and on the southeast flank of the oldest, central cone. Trident is located 148 km (92 miles) southeast of King Salmon and 440 km (273 miles) southwest of Anchorage.

Contacts:

Michelle Coombs, Scientist-in-Charge, USGS, mcoombs@usgs.gov, (907) 786-7497

David Fee, Coordinating Scientist, UAFGI, dfee1@alaska.edu, (907) 378-5460

Next Notice:

A new VAN will be issued if conditions change significantly or alert levels are modified. While a VAN is in effect, regularly scheduled updates are posted at http://www.avo.alaska.edu.

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.

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(1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA)
(2) Issued:	(20221019/2206Z)
(3) Volcano:	Trident (VNUM #312160)
(4) Current Color Code:	GREEN
(5) Previous Color Code:	YELLOW
(6) Source:	Alaska Volcano Observatory
(7) Notice Number:	2022/A1190
(8) Volcano Location:	N 58 deg 14 min W 155 deg 6 min
(9) Area:	Alaska Peninsula
(10) Summit Elevation:	3599 ft (1097 m)
(11) Volcanic Activity Summary:	The swarm of earthquakes that began on August 24, 2022, beneath Trident Volcano has subsided and seismic tremor has not been observed since September 30, 2022. Occasional local earthquakes continue to be detected at background levels. Due to this decrease in activity and the absence of other signs of unrest, we are lowering the Aviation Color Code to GREEN and the Volcano Alert level to NORMAL. Should activity increase, AVO will issue further notices. AVO monitors Trident with a local network of seismometers, a webcam, remote sensing data, and regional infrasound and lightning networks. To view current monitoring data, see https://avo.alaska.edu/activity/Trident.php
(12) Volcanic cloud height:	none
(13) Other volcanic cloud information:	none
(14) Remarks:	Trident Volcano is one of the Katmai group of volcanoes located within Katmai National Park and Preserve on the Alaska Peninsula. Trident consists of a complex of four cones and numerous lava domes, all andesite and dacite in composition, that reach as high as 6,115 ft above sea level. An eruption beginning in 1953 constructed the newest cone, Southwest Trident, and four lava flows on the flank of the older complex. This eruption continued through 1974 and produced ash (an initial plume rose to 30,000 ft asl), bombs, and lava at various times. Fumaroles remain active on the summit of Southwest Trident and on the southeast flank of the oldest, central cone. Trident is located 148 km (92 miles) southeast of King Salmon and 440 km (273 miles) southwest of Anchorage.
(15) Contacts:	Michelle Coombs, Scientist-in-Charge, USGS, mcoombs@usgs.gov, (907) 786-7497 David Fee, Coordinating Scientist, UAFGI, dfee1@alaska.edu, (907) 378-5460
(16) Next Notice:	A new VAN will be issued if conditions change significantly or alert levels are modified. While a VAN is in effect, regularly scheduled updates are posted at http://www.avo.alaska.edu.

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