USGS Volcano Notice - DOI-USGS-HVO-2022-08-26T17:39:34-07:00

HVO/USGS Volcanic Activity Notice

Volcano: Ofu-Olosega (VNUM #244010)

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

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

Issued: Friday, August 26, 2022, 4:18 PM HST
Source: Hawaiian Volcano Observatory
Notice Number: 2022/H392
Location: S 14 deg 10 min W 169 deg 37 min
Elevation: 2096 ft (639 m)
Area: American Samoa

Volcanic Activity Summary:

Ofu-Olosega Islands volcano has been ruled out as the source of the ongoing Manuʻa Islands earthquake swarm. Data from seismometers installed in the Manuʻa Islands this week confirms that the ongoing earthquake activity is related to Taʻū Island volcano and not Ofu-Olosega. Accordingly, the USGS is lowering the volcano alert level to NORMAL and the aviation color code to GREEN for Ofu-Olosega. Taʻū Island remains at ADVISORY/YELLOW.

Due to the closeness of the Ofu-Olosega Islands to Taʻū Island, residents of Ofu-Olosega could still be significantly affected by events that may take place on or around Taʻu Island. The earthquake swarm is still ongoing, and people on Ofu-Olosega are likely to feel shaking from future events. Residents of Ofu-Olosega can now find updates on relevant hazards and other important information in the Daily Reports for Taʻū Island. Possible hazards that could impact residents of Ofu-Olosega include shaking related to strong, damaging earthquakes, local tsunamis or large waves related to underwater volcanic activity or landslides, and/or ash and gas from volcanic eruptions.

USGS scientists continue to monitor the earthquake swarm with six microseismometers placed on Tutuila, Taʻū, and Olosega Islands and two more sensitive seismometers on Taʻū and Ofu Islands. We are working to bring a third advanced seismometer online on eastern Ta’u Island.

To keep receiving information about the ongoing earthquake crisis in American Samoa, subscribe to the Volcano Notification Service (https://volcanoes.usgs.gov/vns2/)
and select Taʻū Island from the volcano list.

Samoan and English language alert level and color code definitions: (PDF download, 57.68 kb) https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/media/files/VOLCANO%20AVIATION%20CODES%20AND%20ALERT%20LEVELS.pdf

Recent Observations:
[Volcanic cloud height] Unknown
[Other volcanic cloud information] Unknown

Remarks:

Hazards

It is unclear if this earthquake swarm at Taʻū will escalate to a volcanic eruption on or near Taʻū Island. An eruption could pose significant hazards to residents of American Samoa; these hazards include volcanic gases, volcanic ash, low-level localized explosions of lava, lava flows, earthquake shaking, and tsunami. Volcanic gas and ash travel with the wind, and ocean disturbances may be felt across the Manu’a Islands.

Report what you feel and see.

Residents can assist USGS and NWS monitoring efforts by noting and reporting accurate times when they feel earthquake shaking or notice other changes that might be related to volcanic activity to either the NOAA Pago Pago National Weather Service Office (https://www.weather.gov/ppg/wsopagooffice) or the American Samoa EOC in Pago Pago (684-699-3800).

Contacts:

HVO, askHVO@usgs.gov—best contact for regular reporting and questions.
Ken Hon, HVO Scientist in Charge, USGS khon@usgs.gov
Natalia Deligne, American Samoa Lead Responding Scientist, USGS ndeligne@usgs.gov

Next Notice:

A new VAN will be issued if conditions change significantly or alert levels are modified. While a VAN is in effect, daily scheduled updates are posted at https://www.usgs.gov/programs/VHP/volcano-updates#hvo. Search for past statements here: https://volcanoes.usgs.gov/hans2/search.

Subscribe to these messages: https://volcanoes.usgs.gov/vns2/
Summary of volcanic hazards from eruptions: https://www.usgs.gov/observatories/hvo/hazards
Recent earthquakes in Hawaiʻi (map and list): https://www.usgs.gov/observatories/hvo
Volcanoes of American Samoa: https://www.usgs.gov/observatories/hvo/volcanoes-american-samoa
Explanation of Volcano Alert Levels and Aviation Color Codes: https://www.usgs.gov/programs/VHP/volcanic-alert-levels-characterize-conditions-us-volcanoes

(1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA)
(2) Issued:	(20220827/0218Z)
(3) Volcano:	Ofu-Olosega (VNUM #244010)
(4) Current Color Code:	GREEN
(5) Previous Color Code:	YELLOW
(6) Source:	Hawaiian Volcano Observatory
(7) Notice Number:	2022/H392
(8) Volcano Location:	S 14 deg 10 min W 169 deg 37 min
(9) Area:	American Samoa
(10) Summit Elevation:	2096 ft (639 m)
(11) Volcanic Activity Summary:	Ofu-Olosega Islands volcano has been ruled out as the source of the ongoing Manuʻa Islands earthquake swarm. Data from seismometers installed in the Manuʻa Islands this week confirms that the ongoing earthquake activity is related to Taʻū Island volcano and not Ofu-Olosega. Accordingly, the USGS is lowering the volcano alert level to NORMAL and the aviation color code to GREEN for Ofu-Olosega. Taʻū Island remains at ADVISORY/YELLOW. Due to the closeness of the Ofu-Olosega Islands to Taʻū Island, residents of Ofu-Olosega could still be significantly affected by events that may take place on or around Taʻu Island. The earthquake swarm is still ongoing, and people on Ofu-Olosega are likely to feel shaking from future events. Residents of Ofu-Olosega can now find updates on relevant hazards and other important information in the Daily Reports for Taʻū Island. Possible hazards that could impact residents of Ofu-Olosega include shaking related to strong, damaging earthquakes, local tsunamis or large waves related to underwater volcanic activity or landslides, and/or ash and gas from volcanic eruptions. USGS scientists continue to monitor the earthquake swarm with six microseismometers placed on Tutuila, Taʻū, and Olosega Islands and two more sensitive seismometers on Taʻū and Ofu Islands. We are working to bring a third advanced seismometer online on eastern Ta’u Island. To keep receiving information about the ongoing earthquake crisis in American Samoa, subscribe to the Volcano Notification Service (https://volcanoes.usgs.gov/vns2/) and select Taʻū Island from the volcano list. Samoan and English language alert level and color code definitions: (PDF download, 57.68 kb) https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/media/files/VOLCANO%20AVIATION%20CODES%20AND%20ALERT%20LEVELS.pdf
(12) Volcanic cloud height:	Unknown
(13) Other volcanic cloud information:	Unknown
(14) Remarks:	Hazards It is unclear if this earthquake swarm at Taʻū will escalate to a volcanic eruption on or near Taʻū Island. An eruption could pose significant hazards to residents of American Samoa; these hazards include volcanic gases, volcanic ash, low-level localized explosions of lava, lava flows, earthquake shaking, and tsunami. Volcanic gas and ash travel with the wind, and ocean disturbances may be felt across the Manu’a Islands. Report what you feel and see. Residents can assist USGS and NWS monitoring efforts by noting and reporting accurate times when they feel earthquake shaking or notice other changes that might be related to volcanic activity to either the NOAA Pago Pago National Weather Service Office (https://www.weather.gov/ppg/wsopagooffice) or the American Samoa EOC in Pago Pago (684-699-3800).
(15) Contacts:	HVO, askHVO@usgs.gov—best contact for regular reporting and questions. Ken Hon, HVO Scientist in Charge, USGS khon@usgs.gov Natalia Deligne, American Samoa Lead Responding Scientist, USGS ndeligne@usgs.gov
(16) Next Notice:	A new VAN will be issued if conditions change significantly or alert levels are modified. While a VAN is in effect, daily scheduled updates are posted at https://www.usgs.gov/programs/VHP/volcano-updates#hvo. Search for past statements here: https://volcanoes.usgs.gov/hans2/search.