USGS Volcano Notice - DOI-USGS-NMI-2026-04-23T20:38:55+00:00

NORTHERN MARIANAS VOLCANOES
No definitive signs of unrest were detected at any Northern Mariana Island volcanoes during the past week.

Monitoring of Northern Mariana Islands Volcanoes

Typhoon Sinlaku has caused extensive destruction to the infrastructure on the island of Saipan. All data feeds from seismic and acoustic sensors on the island are now unavailable, and there are no ground-based instruments to detect significant explosive activity in the region, should it occur. It is unclear when connections to these sensors will be restored.

The USGS will continue to monitor satellite images and distant hydroacoustic and seismic sensors for any signs of volcanic activity in the CNMI. This level of monitoring can detect significant volcanic activity but cannot provide advance warning of eruptions.

Due to a lack of geophysical monitoring on any of the volcanic islands, the following volcanoes have alert levels of UNASSIGNED: Anatahan, Sarigan, Farallon de Pajaros, Supply Reef, Maug, Asuncion, Agrigan, Pagan, Almagan, and Guguan.