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Report on Ahyi (United States) — 28 December-3 January 2023


Ahyi

Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 28 December-3 January 2023
Managing Editor: Sally Sennert.

Please cite this report as:

Global Volcanism Program, 2022. Report on Ahyi (United States) (Sennert, S, ed.). Weekly Volcanic Activity Report, 28 December-3 January 2023. Smithsonian Institution and US Geological Survey.

Weekly Report (28 December-3 January 2023)

Ahyi

United States

20.42°N, 145.03°E; summit elev. -75 m

All times are local (unless otherwise noted)


Unrest continued to be detected at Ahyi Seamount during 28 December 2022-3 January 2023. Daily signals possibly indicating explosions were detected by hydrophone sensors on Wake Island (2,270 km E of Ahyi). No activity was visible in mostly cloudy satellite images. The Aviation Color Code remained at Yellow (the second lowest level on a four-color scale) and the Volcano Alert Level remained at Advisory (the second lowest level on a four-level scale).

Geological Summary. 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.

Source: US Geological Survey