Ahyi Seamount | U.S. Geological Survey
Source: https://www.usgs.gov/volcanoes/ahyi-seamount
Archived: 2026-04-23 17:16
Ahyi Seamount | U.S. Geological Survey
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Ahyi Seamount
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The map displays volcanoes, earthquakes, monitoring instruments, and past lava flows.
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To view an earthquake cross-sectional plot, click "Draw Plot" to start drawing on the map. Once the plot area is selected, click on "View Plot" to view chart or "Clear Plot" to start over.
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Ahyi Seamount
Home
Publications
Connect
Ahyi seamount is a large conical submarine volcano that rises to within 137 m of the sea surface about 18 km SE of the island of Farallon de Pajaros (Uracas) in the northern Marianas.
Quick Facts
Location:
Commonwealth of the Northern Mariana Islands
Latitude:
20.42° N
Longitude:
145.03° E
Elevation:
-75 (m) -246 (f)
Volcano type:
Submarine
Composition:
Andesite - Basalt
Most recent eruption:
2023 CE
Threat Potential:
Very low*
*based on the
National Volcano Early Warning System
Summary
Media
Sources/Usage: Public Domain.
View Media Details
Bathymetric map of Ahyi Seamount.
Ahyi seamount is a large conical submarine volcano that rises to within 75 m of the ocean surface ~18 km SE of the island of Farallon de Pajaros in the northern Marianas. Water discoloration has been observed there, and in 1979 the crew of a fishing boat felt shocks over the summit area, followed by upwelling of sulfur-bearing water. On 24-25 April 2001 an explosive eruption was detected seismically by a station on Rangiroa Atoll, Tuamotu Archipelago. The event was well constrained (± 15 km) at a location near the southern base of Ahyi. An eruption in April-May 2014 was detected by NOAA divers, hydroacoustic sensors, and seismic stations.
July 19, 2019
Volcanic hazards in the Pacific U.S. Territories
Volcanic hazards in the Pacific U.S. Territories
The Commonwealth of the Northern Mariana Islands, Guam, and American Samoa lie along the western side of the famed Pacific Ring of Fire. Here, the processes of active island and submarine volcanoes produce activity both underwater and in the atmosphere that poses potential hazards to the daily lives of residents and travelers. Since 2000, CNMI volcanoes have erupted six times, and one...
Authors
Gabrielle Tepp, Brian Shiro, William W. Chadwick
By
Volcano Hazards Program
,
Volcano Science Center
,
Agrigan
,
Ahyi Seamount
,
Alamagan
,
Anatahan
,
Asuncion
,
Daikoku Seamount
,
East Diamante
,
Esmeralda Bank
,
Farallon de Pajaros
,
Fukujin Seamount
,
Guguan
,
Kasuga 2
,
Maug Islands
,
Ofu-Olosega
,
Pagan
,
Ruby
,
Sarigan
,
South Sarigan Seamount
,
Supply Reef
,
Ta'u Island
,
Tutuila Island
,
Zealandia Bank
,
Subduction Zone Science
July 2, 2019
Hydroacoustic, seismic, and bathymetric observations of the 2014 submarine eruption at Ahyi Seamount, Mariana Arc
Hydroacoustic, seismic, and bathymetric observations of the 2014 submarine eruption at Ahyi Seamount, Mariana Arc
Ahyi seamount, a shallow submarine volcano in the Northern Mariana Islands, began erupting on April 23, 2014. Hydroacoustic eruption signals were observed on the regional Mariana seismic network and on distant hydrophones, and NOAA scuba divers working in the area soon after the eruption began heard and felt underwater explosion sounds. The NOAA crew observed yellow orange bubble mats...
Authors
Gabrielle Tepp, William W. Chadwick, Matthew M. Haney, John J. Lyons, Robert Dziak, Susan Merle, Dave Butterfield, Charles W. Young
By
Volcano Hazards Program
,
Volcano Science Center
,
Ahyi Seamount
October 22, 2018
2018 update to the U.S. Geological Survey national volcanic threat assessment
2018 update to the U.S. Geological Survey national volcanic threat assessment
When erupting, all volcanoes pose a degree of risk to people and infrastructure, however, the risks are not equivalent from one volcano to another because of differences in eruptive style and geographic location. Assessing the relative threats posed by U.S. volcanoes identifies which volcanoes warrant the greatest risk-mitigation efforts by the U.S. Geological Survey and its partners...
Authors
John W. Ewert, Angela K. Diefenbach, David W. Ramsey
By
Volcano Hazards Program
,
Volcano Science Center
,
Agrigan
,
Ahyi Seamount
,
Alamagan
,
Anatahan
,
Asuncion
,
Belknap
,
Black Butte Crater Lava Field
,
Black Rock Desert Volcanic Field
,
Blue Lake Crater
,
Carrizozo Lava Flow
,
Cascade Range Weekly Update
,
Cinnamon Butte
,
Clear Lake Volcanic Field
,
Coso Volcanic Field
,
Crater Lake
,
Craters of the Moon Volcanic Field
,
Daikoku Seamount
,
Davis Lake Volcanic Field
,
Devils Garden Lava Field
,
Diamond Craters Volcanic Field
,
Dotsero Volcanic Center
,
East Diamante
,
Esmeralda Bank
,
Farallon de Pajaros
,
Fukujin Seamount
,
Glacier Peak
,
Guguan
,
Haleakalā
,
Hell's Half Acre Lava Field
,
Hualālai
,
Indian Heaven Volcanic Field
,
Jordan Craters Volcanic Field
,
Kama‘ehuakanaloa
,
Kasuga 2
,
Kīlauea
,
Lassen Volcanic Center
,
Long Valley Caldera
,
Mammoth Mountain
,
Markagunt Plateau Volcanic Field
,
Maug Islands
,
Mauna Kea
,
Mauna Loa
,
Medicine Lake
,
Mono Lake Volcanic Field
,
Mono-Inyo Craters
,
Mount Adams
,
Mount Bachelor
,
Mount Baker
,
Mount Hood
,
Mount Jefferson
,
Mount Rainier
,
Mount Shasta
,
Mount St. Helens
,
Newberry
,
Ofu-Olosega
,
Pagan
,
Red Hill-Quemado Volcanic Field
,
Ruby
,
Salton Buttes
,
San Francisco Volcanic Field
,
Sand Mountain Volcanic Field
,
Sarigan
,
Soda Lakes
,
South Sarigan Seamount
,
Supply Reef
,
Ta'u Island
,
Three Sisters
,
Tutuila Island
,
Ubehebe Craters
,
Uinkaret Volcanic Field
,
Valles Caldera
,
Wapi Lava Field
,
Weekly Update
,
West Crater Volcanic Field
,
Yellowstone
,
Zealandia Bank
,
Zuni-Bandera Volcanic Field
View All
Quick Facts
Location:
Commonwealth of the Northern Mariana Islands
Latitude:
20.42° N
Longitude:
145.03° E
Elevation:
-75 (m) -246 (f)
Volcano type:
Submarine
Composition:
Andesite - Basalt
Most recent eruption:
2023 CE
Threat Potential:
Very low*
*based on the
National Volcano Early Warning System
Volcanoes Hazards Program Links
Assess
Prepare
Forecast
Activity
Products
Observatories
About
Was this page helpful?
Skip to main content
Official websites use .gov
A
.gov
website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A
lock (
)
or
https://
means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Ahyi Seamount
Find U.S. Volcano
Filters
Learn More
The map displays volcanoes, earthquakes, monitoring instruments, and past lava flows.
Get Help
Earthquake Plots
To view an earthquake cross-sectional plot, click "Draw Plot" to start drawing on the map. Once the plot area is selected, click on "View Plot" to view chart or "Clear Plot" to start over.
Map Layers
Earthquake Colors
Earthquake Depth Units
Earthquake Time Units
Results
Filters
Learn More
The map displays volcanoes, earthquakes, monitoring instruments, and past lava flows.
Get Help
Earthquake Plots
To view an earthquake cross-sectional plot, click "Draw Plot" to start drawing on the map. Once the plot area is selected, click on "View Plot" to view chart or "Clear Plot" to start over.
Settings
Map Layers
Earthquake Colors
Earthquake Depth Units
Earthquake Time Units
x
Map Legend
x
Map Legend
Results
Ahyi Seamount
Home
Publications
Connect
Ahyi seamount is a large conical submarine volcano that rises to within 137 m of the sea surface about 18 km SE of the island of Farallon de Pajaros (Uracas) in the northern Marianas.
Quick Facts
Location:
Commonwealth of the Northern Mariana Islands
Latitude:
20.42° N
Longitude:
145.03° E
Elevation:
-75 (m) -246 (f)
Volcano type:
Submarine
Composition:
Andesite - Basalt
Most recent eruption:
2023 CE
Threat Potential:
Very low*
*based on the
National Volcano Early Warning System
Summary
Media
Sources/Usage: Public Domain.
View Media Details
Bathymetric map of Ahyi Seamount.
Ahyi seamount is a large conical submarine volcano that rises to within 75 m of the ocean surface ~18 km SE of the island of Farallon de Pajaros in the northern Marianas. Water discoloration has been observed there, and in 1979 the crew of a fishing boat felt shocks over the summit area, followed by upwelling of sulfur-bearing water. On 24-25 April 2001 an explosive eruption was detected seismically by a station on Rangiroa Atoll, Tuamotu Archipelago. The event was well constrained (± 15 km) at a location near the southern base of Ahyi. An eruption in April-May 2014 was detected by NOAA divers, hydroacoustic sensors, and seismic stations.
July 19, 2019
Volcanic hazards in the Pacific U.S. Territories
Volcanic hazards in the Pacific U.S. Territories
The Commonwealth of the Northern Mariana Islands, Guam, and American Samoa lie along the western side of the famed Pacific Ring of Fire. Here, the processes of active island and submarine volcanoes produce activity both underwater and in the atmosphere that poses potential hazards to the daily lives of residents and travelers. Since 2000, CNMI volcanoes have erupted six times, and one...
Authors
Gabrielle Tepp, Brian Shiro, William W. Chadwick
By
Volcano Hazards Program
,
Volcano Science Center
,
Agrigan
,
Ahyi Seamount
,
Alamagan
,
Anatahan
,
Asuncion
,
Daikoku Seamount
,
East Diamante
,
Esmeralda Bank
,
Farallon de Pajaros
,
Fukujin Seamount
,
Guguan
,
Kasuga 2
,
Maug Islands
,
Ofu-Olosega
,
Pagan
,
Ruby
,
Sarigan
,
South Sarigan Seamount
,
Supply Reef
,
Ta'u Island
,
Tutuila Island
,
Zealandia Bank
,
Subduction Zone Science
July 2, 2019
Hydroacoustic, seismic, and bathymetric observations of the 2014 submarine eruption at Ahyi Seamount, Mariana Arc
Hydroacoustic, seismic, and bathymetric observations of the 2014 submarine eruption at Ahyi Seamount, Mariana Arc
Ahyi seamount, a shallow submarine volcano in the Northern Mariana Islands, began erupting on April 23, 2014. Hydroacoustic eruption signals were observed on the regional Mariana seismic network and on distant hydrophones, and NOAA scuba divers working in the area soon after the eruption began heard and felt underwater explosion sounds. The NOAA crew observed yellow orange bubble mats...
Authors
Gabrielle Tepp, William W. Chadwick, Matthew M. Haney, John J. Lyons, Robert Dziak, Susan Merle, Dave Butterfield, Charles W. Young
By
Volcano Hazards Program
,
Volcano Science Center
,
Ahyi Seamount
October 22, 2018
2018 update to the U.S. Geological Survey national volcanic threat assessment
2018 update to the U.S. Geological Survey national volcanic threat assessment
When erupting, all volcanoes pose a degree of risk to people and infrastructure, however, the risks are not equivalent from one volcano to another because of differences in eruptive style and geographic location. Assessing the relative threats posed by U.S. volcanoes identifies which volcanoes warrant the greatest risk-mitigation efforts by the U.S. Geological Survey and its partners...
Authors
John W. Ewert, Angela K. Diefenbach, David W. Ramsey
By
Volcano Hazards Program
,
Volcano Science Center
,
Agrigan
,
Ahyi Seamount
,
Alamagan
,
Anatahan
,
Asuncion
,
Belknap
,
Black Butte Crater Lava Field
,
Black Rock Desert Volcanic Field
,
Blue Lake Crater
,
Carrizozo Lava Flow
,
Cascade Range Weekly Update
,
Cinnamon Butte
,
Clear Lake Volcanic Field
,
Coso Volcanic Field
,
Crater Lake
,
Craters of the Moon Volcanic Field
,
Daikoku Seamount
,
Davis Lake Volcanic Field
,
Devils Garden Lava Field
,
Diamond Craters Volcanic Field
,
Dotsero Volcanic Center
,
East Diamante
,
Esmeralda Bank
,
Farallon de Pajaros
,
Fukujin Seamount
,
Glacier Peak
,
Guguan
,
Haleakalā
,
Hell's Half Acre Lava Field
,
Hualālai
,
Indian Heaven Volcanic Field
,
Jordan Craters Volcanic Field
,
Kama‘ehuakanaloa
,
Kasuga 2
,
Kīlauea
,
Lassen Volcanic Center
,
Long Valley Caldera
,
Mammoth Mountain
,
Markagunt Plateau Volcanic Field
,
Maug Islands
,
Mauna Kea
,
Mauna Loa
,
Medicine Lake
,
Mono Lake Volcanic Field
,
Mono-Inyo Craters
,
Mount Adams
,
Mount Bachelor
,
Mount Baker
,
Mount Hood
,
Mount Jefferson
,
Mount Rainier
,
Mount Shasta
,
Mount St. Helens
,
Newberry
,
Ofu-Olosega
,
Pagan
,
Red Hill-Quemado Volcanic Field
,
Ruby
,
Salton Buttes
,
San Francisco Volcanic Field
,
Sand Mountain Volcanic Field
,
Sarigan
,
Soda Lakes
,
South Sarigan Seamount
,
Supply Reef
,
Ta'u Island
,
Three Sisters
,
Tutuila Island
,
Ubehebe Craters
,
Uinkaret Volcanic Field
,
Valles Caldera
,
Wapi Lava Field
,
Weekly Update
,
West Crater Volcanic Field
,
Yellowstone
,
Zealandia Bank
,
Zuni-Bandera Volcanic Field
View All
Quick Facts
Location:
Commonwealth of the Northern Mariana Islands
Latitude:
20.42° N
Longitude:
145.03° E
Elevation:
-75 (m) -246 (f)
Volcano type:
Submarine
Composition:
Andesite - Basalt
Most recent eruption:
2023 CE
Threat Potential:
Very low*
*based on the
National Volcano Early Warning System
Volcanoes Hazards Program Links
Assess
Prepare
Forecast
Activity
Products
Observatories
About
Was this page helpful?