DGAR Seismic Station
1.
Background
The U.S. National Science Foundation has provided funds to the Incorporated Research Institutions for
Seismology (IRIS), a consortium of US universities, to construct and manage the Global Seismographic Network
(GSN), a data collection facility of over 130 seismic stations worldwide. Data collected from GSN stations are
used for research on earthquakes and Earth structure, and have applications in earthquake hazard mitigation
and nuclear test monitoring. IRIS has subcontracted with UCSD’s Project IDA to deploy and operate
approximately one-third of the GSN.
UCSD approached the U.S. Navy in 1997, and through them, the B.I.O.T. government, for permission to install a
GSN seismic station on the island of Diego Garcia, B.I.O.T. Permission was granted in 1998, and UCSD personnel
visited Diego Garcia to review possible sites on the island to house GSN instrumentation. After a site on the
grounds of the USAF GEODSS installation was selected and approved by the B.I.O.T., UCSD contacted the U.S.
Navy Support Facility, Diego Garcia, (NAVSUPPFAC) for construction of a vault on the GEODSS grounds to house
the seismic instruments.
The vault was completed in August 2003. Project IDA personnel arrived on Diego Garcia toward the latter part of
January 2004 to install the seismic equipment and the DGAR seismic station became operational on the 2nd of
February.
2. Scope
UCSD requests the assistance for the following activities in support of the Global Seismographic Station seismic
equipment now installed at GEODSS on Diego Garcia:
1. Check normal system operation each week and contact UCSD immediately if equipment fails or if
abnormal conditions are observed.
2. Verify STS-2 seismometer mass position each month, or as requested by UCSD, and adjust as
required.
3. Check for water accumulation in the vault once per month.
4. Respond to questions from UCSD regarding the state of the UCSD seismographic equipment,
computers, and communications links.
5. Perform non-routine checks or diagnostic procedures on the UCSD equipment, including the sensors,
recording system, power system, or real-time computer equipment, as requested by UCSD.
6. Replace components of the UCSD equipment as specified by UCSD with spare parts sent from the
United States.
7. Return all removed, replaced, or spare UCSD equipment to the United States, as requested by UCSD.
8. Provide "on call" logistical support for periodic visits of UCSD personnel (estimated to be every 24
months). Assist in arranging air transport of IDA personnel to Diego Garcia.
Based upon past experience at this and other stations, we estimate that a non-specialist electronics technician
could perform tasks 1-4 in a total time of 1-2 hours per month. The same person would spend 8-16 hours per
year performing tasks 5-8. I am uncertain how much effort is required to arrange air transport.