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About
the IRIS/USGS Data Collection Center
The IRIS/USGS Data Collection Center is operated by the United States
Geological Survey at the Albuquerque Seismic Lab (ASL) in Albuquerque,
New Mexico. ASL is located on the Isleta Indian Reservation adjacent
to the south boundary of Kirtland Air Force Base about 15 miles
southeast of Albuquerque. IRIS has had a relationship with ASL since
1988.
History
When the Laboratory opened in 1961 the assigned functions were to
develop and test seismic instrumentation, to support a small network
of domestic Coast & Geodetic Survey and cooperating observatories,
and to operate a seismological observatory. During the 1960s ASL
became heavily engaged in field experiments and aftershock studies
as well, but these activities ceased after the transfer to the USGS.
The three original functions, very much expanded in the case of
the network operations, continue to be important functions of the
Laboratory. One major additional activity that spun off from global
network operations is the processing and distribution of digital
data collected from network stations. (learn
more about the history of ASL)
Data
Collection
With the advent of digital recording in the early 1970s, it became
necessary to establish a DCC at ASL specifically for the digital
data. Originally designed to review and process tapes from a 10-station
global network, the capacity, complexity, and functionality of the
DCC have been greatly expanded over the years. In the early years,
the ASL DCC archived and distributed digital data in the form of
copies of the station tapes. This was awkward for the data user
because several different formats came into use as the networks
expanded and it was necessary to mount tapes containing two weeks
of data from each station in order to process a specific event.
In 1980, ASL began distributing network day tapes. Each day tape
contained 26 hours of concurrent data from all of the stations in
the digital network, making it mucheasier for a researcher to access
event data. Later, in order to deal with a proliferation of recording
formats, the USGS, with the concurrence of IRIS and the FDSN, developed
a Standard for Exchange of Earthquake Data (SEED). The SEED format
is being used for recording data at the new GSN field stations and
has been adopted worldwide for distribution of data. The SEED format
also specifies a method of data compression that substantially reduces
the quantity of data that must be archived and distributed. The
methods of distributing digital data to the data users has also
evolved. The ASL DCC has become a data 'wholesaler', rather than
a data 'retailer'. The DCC distributes network data to a number
of data centers - like the IRIS DMC - that now provide custom data
services to individual users. The future of the ASL DCC will revolve
around the collection, verification and distribution of live data
sent from the individual stations via satellite and the Internet.
(Learn more about
data distribution)
Learn
more about other Data Collection Centers.
Submitted
by Harold Bolton, Albuquerque
Seismic Lab
For more information or comments contact 
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