| definition |
-
Incorporated Research Institutions
for Seismology
IRIS
IRIS Data Management Center: "http://www.iris.washington.edu/HTM/dms.htm"
IRIS Headquarters: "http://www.iris.edu/"
General Overview
The Incorporated Research Institutions for Seismology (IRIS) is a consortium of
73 universities with research programs in seismology. The major source of
funding for IRIS is the National Science Foundation. IRIS is composed of three
principal programs. The Global Seismographic Network (GSN) is charged with
deploying a new network of permanent stations distributed around the world.
The Program for Array Seismic Studies of the Continental Lithosphere (PASSCAL)
has developed a new line of portable seismographic recording systems that can
be used for recording a wide variety of seismographic data, and the Data
Management System (DMS) is charged with managing the data generated by the
PASSCAL and GSN programs and to effectively distribute these data to the
seismological community.
The Global Seismographic Network: The GSN has developed two lines of
standardized stations employing very-broadband (VBB) sensor technology. Network
operating facilities are now in place at the U.S. Geological Survey Albuquerque
Seismological Laboratory and the IRIS/IDA group at Scripps Institution of
Oceanography of the University of California, San Diego.
Through the US/USSR Joint Seismic Program, a cooperative
effort of IRIS, the U.S. Geological Survey, and the
Institute of Physics of the Earth in Moscow, funded through
the Air Force, at least 13 stations are to be established
in the Soviet Union. IRIS operated this program because
of its direct contribution to the goal of establishing
near-uniform global coverage of digital seismic stations
and its role in fostering new experiments in array and
network seismology and data telemetry using state-of-the-art
instrumentation.
The Program for Array Studies: PASSCAL has developed a line of 6-channel,
standardized, portable dataloggers to serve as the backbone of the national
capability. The first of several planned Instrument Centers has been
established at the Lamont-Doherty Geological Observatory, and with 90
dataloggers now in place. The instruments have been used in a variety of
experiments since the first delivery in August, 1989.
Prototypes for a second line of compatible, less expensive 3-channel
dataloggers have been ordered. These are expected to play a major role in
experiments where number and density of sensors are critical, and support
individual investigators and educational programs.
The rapid deployment of PASSCAL instruments following
the 17 October Loma Prieta Earthquake has emphasized the
role of portable instruments in providing badly needed
capabilities for dense deployment and rapid response
within the National Earthquake Hazard Reduction Program.
Field experiments during the past year have demonstrated
the capability of these instruments in several very
different applications: (1)Recording of offshore airgun
shots in a crustal refraction profile; (2)Recording of
teleseisms on a 1500 km array of 3-component stations;
(3)Participation in teleseismic studies of crustal structure
in Kenya; (4)Testing of a tight 2-D array for monitoring the
propagation of high frequency regional phases; (5)Rapid
response deployment of instruments for recording aftershocks
of the Loma Prieta earthquake.
Workstations for field support and data management of
PASSCAL data have been developed, based on SUN hardware.
These computers are incorporated routinely as an essential
part of PASSCAL data acquisition programs.
The formidable practical difficulties of managing portable instruments and data
flow in the field have been greatly reduced by the standardization of hardware
and software, and the existence of a central support organization.
The Data Management System: The IRIS Data Management System manages data flow
and data quality from the data Collection Centers (DCC) to the archive,
followed by distribution to the scientific community. It consists of nodes for
data collection at Albuquerque Seismological Laboratory and the University of
California, San Diego and a central archive at the University of Texas, Austin.
Through Internet, it extends to the data users and to European users via the
ORFEUS data center in the Netherlands. The archive is unique in the world in
its commitment to handling continuous data streams at 20 sps. It has been
functional for over six months, and is now handling user requests in excess of
the estimates made in a 1986 design study for the steady-state load on a fully
implemented GSN. The DMS has also been designated as the first data center of
the Federation of Digital Broadband Seismographic Networks, an international
organization of countries that operate broadband recording stations.
Through dial-up and telemetry facilities at certain GSN
sites, the DMS downloads major event waveforms in near
real-time, and provides this information to the community
through the GOPHER software interface.
Special datasets from important earthquakes and from field
deployments of PASSCAL instruments have been compiled and
are distributed upon request.
The DMS is a focus for the support and distribution of
application and utility software.
Cooperating Agencies and Organizations: These programs have been carried out
through the participation of a variety of agencies and research institutions,
and of many individual scientists from the member Universities.
The U.S. Geological Survey (USGS) is a partner with
IRIS in the implementation of the GSN. IRIS members
of the IRIS University network operate stations and
networks in cooperation with the USGS U.S. National
Network and the national Earthquake Hazards Reduction
Program.
Internationally, IRIS is a member of the Federation of
Digital Seismographic Networks, in which national
programs for deployment of VBB digital instrumentation
are coordinated.
USGS provides earthquake information and digital data
that complement the continuous data archive and
distribution services of the IRIS DMS.
The Eurasian Seismic Studies Program (ESSP) involves
the cooperation of the USGS, the (Soviet) Institute
of Physics of the Earth, the Defense Advanced Research
Projects Agency (DARPA), and a number of University
participants.
IRIS facilities are implemented through subcontract to
Universities. At present, such efforts are in place at
the University of California, San Diego, the University
of Texas, Austin, Columbia University, and the University
of California, Berkeley.
Oversight and Management: Governance of IRIS is in the hands of Committee
members from the research community, and management through a small staff with
headquarters in Arlington, Virginia. Each member institution has one
representative on the IRIS Board of Directors, which has legislative control of
the Consortium. The Executive Committee, representing the Board of Directors,
makes overall policy, and Program Standing Committees provide regular input
by the research community into the operations of the programs.
Contact: IRIS
Incorporated Research Institution for Seismology
1200 New York Ave. NW, Suite 800
Washington, DC 20005
webmaster@dmc.iris.washington.edu
Access: "http://www.iris.edu/"
|
