- Volcanic History Overview: Supply Reef is a conical submarine volcano in the northern Mariana Islands that rises to within 8 m of the sea surface. The andesitic seamount lies about 10 km NW of the Maug Islands, the emergent summit of a submarine volcano that is joined to Supply Reef by a low saddle at a depth of about 1800 m. Supply Reef was mapped as Quaternary; living corals on the crater rim suggest that the volcano is either dormant or extinct (Corwin, 1971). Several submarine eruptions have been detected by sonar signals originating from points very approximately located at distances of 15-25 km NW of Supply Reef. From the Smithsonian Global Volcanism Program.
- Location: Mariana Islands, Mariana Islands
Elevation: -8 m
Recent Eruption: 1989
- Hazard Assessments: Sako, M. K.; Trusdell, F. A.; Koyanagi, R. Y.; Kojima, George; Moore, R. B., 1995, Volcanic investigations in the Commonwealth of the Northern Mariana Islands, April to May 1994, USGS Open-File Report 94-705.
- Link to monitoring data: NMI Web Site
Volcanic Alert Level: UNASSIGNED Aviation Color Code: UNASSIGNED