Ahyi submarine volcano (Marianas): possible new volcanic activity

USGS raised the alert level for the submarine volcano due to abnormal seismicity detected in the area by hydroacoustic devices and land-based network devices on neighboring islands.
Seismic stations on Pagan, Sarigan, Anatahan, and Saipan began recording signals starting at 0635 on 24 April believed to be from an undersea volcanic source. Hydroacoustic sensors on Wake Island suggested that the source is at or near Ahyi seamount, although it was possible that the vent is located at one of the other volcanic seamounts in the area.
While conducting coral reef research at Farallon de Pajaros, NOAA divers reported hearing loud explosions and feeling the shock waves. One of the more powerful explosions was felt by the crew as it reverberated through the hull of the ship. On 27 April the Color Code was raised from Unassigned to Yellow. A report issued at 0536 on 30 April noted that seismic activity remained high.
The source of the unusual signals that appeared on 24 April can only be located approximately, and could originate from other seamounts near Ahyi volcano.
For the time being, no other indications of possible volcanic submarine activity have been detected.