Accession Number : ADA267841


Title :   A Geological and Geophysical Information System for Eurasia


Descriptive Note : Semiannual technical rept. no. 3, 30 Oct 92-30 Apr 93,


Corporate Author : CORNELL UNIV ITHACA NY INST FOR THE STUDY OF THE CONTINENTS


Personal Author(s) : Fielding, Eric J ; Barazangi, Muawia ; Isacks, Bryan L


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a267841.pdf


Report Date : 29 Jun 1993


Pagination or Media Count : 16


Abstract : Topography and heterogeneous crustal structure have major effects on the propagation of regional seismic phases. We are collecting topographical, geological, and geophysical datasets for Eurasia into an information system that can be accessed via Internet connections. Now available are digital topography, satellite imagery, and data on sedimentary basins and crustal structure thicknesses. We are expanding the scope of our information system to include data on the Middle East and North Africa. Under the auspices of several other ongoing projects at Cornell we have collected a very large literature collection, satellite imagery and some detailed datasets, especially in Syria and Morocco. New datasets for Eurasia include maps of depth to Moho beneath Europe and Scandinavia. We have created regularly spaced grids of the crustal thickness values from these maps that can be used to create profiles of crustal structure. These profiles can be compared by an analyst or an automatic program with the crustal seismic phases received along the propagation path to better understand and predict the path effects on phase amplitudes, a key to estimating magnitudes and yields, and for understanding variations in travel-time delays for phases such as Pn, important for improving regional event locations. The gridded data could also be used to model propagation of crustal phases in three dimensions. In the near future, we will be making new databases from the Middle East and North Africa available via the Internet. We encourage ARPA and Air Force researchers to contact us about gaining access to our databases at these computer mail addresses: eric/geology.cornell.edu -or- fielding/seismo.css.gov.


Descriptors :   *INFORMATION SYSTEMS , *SEISMIC DATA , *SEISMIC WAVES , *GEOGRAPHY , *EURASIA , *BASINS(GEOGRAPHIC) , *GEOLOGICAL SURVEYS , DATA BASES , SYRIA , EUROPE , MODELS , PATHS , DEPTH , PROFILES , AMPLITUDE , AFRICA , GEOPHYSICS , NUCLEAR EXPLOSION DETECTION , MAPS , EARTH CRUST , YIELD , ARTIFICIAL SATELLITES , WAVE PROPAGATION , MOROCCO , MOHOROVICIC DISCONTINUITY , NORTH AFRICA , TRAVEL TIME , SEDIMENTATION , AUTOMATIC , VARIATIONS , PHASE , TOPOGRAPHY , GRIDS , MIDDLE EAST , THICKNESS , AIR FORCE


Subject Categories : Information Science
      Geology, Geochemistry and Mineralogy
      Seismology
      Nuclear Weapons


Distribution Statement : APPROVED FOR PUBLIC RELEASE