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

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is provided for four, magnitude valu.f. The first is an mb magnitude, followed
h'y a M magnitude. The other two may be additiontl mb or M s magnitudes, other
s
reported magnitudes, magnitudes derived from intenilty data, or magnitudes
converted from one :Jagnitude scale to another (for example, an M s magnitude
converted from an mb magnitmde).
All intensities listed are in either the ModifLed Mercalli (MM) scale
(Wood and Neuman, 1931) or the MSK scale (Medvedev and Sponheuer, 1969).
Compilation
The compilation of the catalogs was undertaken in two parts. One was the
instrumental catalog beginning just after 1900. The second was the historical
catalog beginning with the earliest known event for each country and
continuing to the present. In the present century the Listorical data
supplement the instrumental data. The instrumental cata-.og was compiled using
data from international sources and from local instrumental data. The
international data were supplied primarily through compilations and
publications of the U.S. Geological Survey (USGS), the U.S. National Oceanic
and Atmospheric Administration (NOAA), and the International 7eismological
Centre (ISC). The primary sources included in the USGS, NOA and ISC
compilations of data and the dates covered by them are as fellows:
G-R Gutenberg and Richter (19541) 1906-1(50
ISS International Seismological Summary 1918-1963
CGS U.S. Coast and Geodetic Survey 1933-1973
BCI Bureau Central International de
Seismologie 1951-1960
ISC International Seismological Centre 1964-present
GS U.S. Geological Survey 1973-present