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# NERSL -- The National Energy Research Seismic Library

### August 1994

*"More than one billion dollars has been invested by various industrial sectors in acquiring and processing the seismic data that is now a part of the NERSL collection.  While these data reside in vaults, the tape medium they are stored on deteriorates, and the data are not available to the public.  The cost to rescue these data and to store them on a permanent medium that is easily distributed for use is about one tenth of one percent of the original cost of acquisition.  These data that would otherwise be lost forever are valuable in research, education, and exploration."
Nick Zihlman, U.S. Geological Survey

**The U.S. Geological Survey (USGS) formed NERSL in 1989 to collect seismic data that were at risk for disposal.**
The intent is to have the geophysical and petroleum industries donate seismic data in digital form, accompanied by relevant documentation, to the National Energy Research Seismic Library so that the data might be made available to the public.  Today, about 20,000 magnetic tapes of various densities are stored in the NERSL vault, about one third of which are from the **National Petroleum Reserve - Alaska** (NPRA), and about half of which represent marine seismic profiling off the U.S. east coast.  **USGS workers transcribe seismic data onto CD-ROM for release to the public domain.**
Compact disc-read only memory (CD-ROM) is a storage technology that was pioneered by the music industry.  Huge sums of money have been invested in this technology; for this reason, USGS researchers think that it is likely to be useable for several decades.  CD-ROM is inexpensive to produce and the user makes a relatively small investment in hardware.  The discs can also store large quantities of data and information while remaining small and easily transportable.  USGS scientists have released four seismic products on CD-ROM.  The pilot NERSL disc included seismic data in final stacked form from marine and land studies.  The second release included a grid of 29 seismic lines from NPRA in industry-standard SEG-Y format.  The third disc was prepared in cooperation with the Department of Energy'sMorgantown Energy Technology Center, and included results of deep seismic studies from the Pacific northwest.  The fourth release is a 39-disc set of field data and reports from the **International Phase of Ocean Drilling** (IPOD).**Rapidly-deteriorating IPOD seismic data were rescued by USGS workers.**
Testing revealed that data on the original field tapes were deteriorating.  Although there were some sections of the tapes where magnetic oxide had fallen off, only about 0.2 percent of the data were actually lost due primarily to heroic data-reconstruction efforts.  Usually, this kind of damage results in data losses approaching 20 percent.  To prevent further losses, the original 631 magnetic tapes were compressed and transferred to 183 new tapes, and eventually to 39 CD-ROM's.  This data set, a 3400-kilometer long multichannel seismic-reflection profile extending from Cape Hatteras, North Carolina, to the rift valley of the Mid-Atlantic Ridge, was collected in a 1974 effort jointly sponsored by the USGS and the National Science Foundation'sDeep Sea Drilling Project (DSDP).**USGS researchers expect to release whole-Earth data sets on CD-ROM.**
The purpose of this effort is to provide investigators with the opportunity to study an area in complete detail where data are available.  The pilot case is the NPRA data base which includes a large variety of information.  The largest volume of NPRA data placed on CD-ROM is digital seismic, but other data sets may include geologic maps, topography, rock core images, digital well logs, as well as gravity and magnetic data.  The digital seismic data will be available in industry-standard format, and will include 79 seismic lines collected between 1974 and 1980, forming an approximate north-south and east-west grid covering the NPRA.  Digital well log data from wells near the seismic data will be included.  Public-domain display and manipulation software will also be included with the data.For More Information:Dr. F.N. ZihlmanU.S. Geological SurveyMS 960Denver Federal CenterDenver, CO  80225
Email: zihlman@usgs.gov

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This USGS Fact Sheet can be found at <URL:http://energy.usgs.gov/factsheets/NERSL/nersl.html>Maintained by L. Friedrich  Last updated 23-Sept-1997*