catalogo de terremotos para america del sur catalog of earthquakes ...

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A third area of emphasis has been the referencing of all data included in
the catalog in as thorough a manner as pnossih.e. This includes primarily the
source code given for hypocenter data and tr source codes for all magnitudes
listed. Complete referencing for these parameters pa'n"Kea a necessary key
for additional examination and .va~uaticn in the future, and thus these
catalogs can serve an a tasis for future research.
Several problems ,'u'nencon:tered during the compilation of the
catalogs. The first of these was irtegrating data received in many varying
formats, without introducing additionai data processing errors. Another
problem was encountorad in assiyfni!'. events to countries. When the individual
countries worked on the catalog, thepi covered a tcnlr aphic block delineated by
latitude and longitude coordinates and not by political boundaries. These
blocks overlapped between difrerent countries. in compiling the composite
catalog for all of South Ame"ica, it was important Lo eliminate the
duplication of cvents resulting from combining the individual country
catalogs. This required defining some arbitrary boundaries between countries
and assigoin r Qach event to L oingle country. 'n order to do this we
digitized a map prc~uced by the U.S. Defense Mapp!ng Agency (U.S. Defense
Mapping Agency) and used a computer program which provided consistent
assignment of events to oiffereyt countries based on these digitized
boundaries. he assignment of evants to countr.es remains as only an
approximat in unsd for ourposes Cf organizirng the catalog into regions.
Because thq editi Li 'as orT'gnived by cou ntry, the possibility exists that
sore evnrts have maer Olatd a, left cn of the catalog if different
sources provi;dng rather diffryn, lociat icns were u-ed by different
countries. For example, iH Colombia preferred a location by Gutenberg and
Richter which was located in Ecuador and Ecuador used a location determined