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.
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).
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.
by Harold Bolton (Albuquerque Seismic Lab)