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Ahyi Seamount

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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: 
Latitude: 20.42° N
Longitude: 145.03° E
Elevation: -137 (m) -449 (f)
Volcano type: Submarine 
Composition: Andesite - Basalt
Most recent eruption: 2014 CE
Threat Potential: Low/Very Low*

Summary

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. Water discoloration has been observed over the submarine volcano, and in 1979 the crew of a fishing boat felt shocks over the summit area of the seamount followed by upwelling of sulfur-bearing water. On April 24-25, 2001 an explosive submarine eruption was detected seismically from a seismic station on Rangiroa Atoll, Tuamotu Archipelago. The event was well constrained (+/- 15 km) at a location near the southern base of Ahyi; the summit of the seamount lies within the location uncertainty. Ahyi submarine volcano is seen in a bathymetric view looking from the NE with two times vertical exaggeration. Image courtesy of Susan Merle (Oregon State University/NO‘A‘ā Vents Program). From the Smithsonian Global Volcanism Program.