“SIGNS of unrest at Ahyi seamount have diminished and nothing indicative of submarine volcanic activity has occurred for at least four weeks,” according to the United States Geological Survey.
“Hydroacoustic detection of underwater volcanic activity has been negligible since early April 2023 and satellite observations of discolored water near the seamount were last noted in late March 2023,” USGS added.
“Starting mid-October 2022, hydroacoustic sensors at Wake Island, 2,270 km. (1,410 miles) east of Ahyi, began recording signals consistent with activity from an undersea volcanic source. In collaboration with the Laboratoire de Geophysique in Tahiti, a combined analysis of the hydroacoustic signals and data from seismic stations located at Guam and Chichijima Island, Japan, confirmed that the source of this activity was at or near Ahyi seamount,” USGS stated.
However, it added, hydrophone signals indicative of submarine volcanic activity are no longer detected.
Due to the apparent absence of activity, the aviation color code is being lowered from “yellow” — which indicates volcanic activity — to “unassigned,” and the alert level is being lowered from “advisory” to “unassigned,” USGS stated.
Ahyi seamount is a large conical submarine volcano that rises to within 137 meters of the sea surface about 18 km. southeast of Farallon de Pajaros or Uracas Island in the Northern Islands, and is about 600 km. north of Saipan.
