* IGRF values as of 2015.
The Guam observatory was established in 1957. The observatory is situated on property owned by the U.S. Air Force according to terms of an agreement with the USGS and the Geomagnetism Program.
- A seismometer for the USGS Global Seismic Network.
- CTBTO IMS Auxiliary Seismic Station
- The Guam observatory is part of the 210 Magnetic Meridian Array.