* IGRF values as of 2015.
The Geomagnetism Program has operated an observatory at Puerto Rico since 1903. The current observatory site, consisting of 36 acres in the mountains near Cayey, has been in use since 1965.
- A seismometer for the USGS Global Seismic Network.
- A seismometer for the Puerto Rican Seismic Network.
- CTBTO IMS Auxiliary Seismic Station
- NOAA National Centers for Environmental Information (NCEI) ionosonde