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

is adopted.
where:
151
From the equations (2) and (3a) the following relationship is obtained:
S= s 2i~lg r+ rlot + K
1 (4)
4
C' = C2/i; C3 I
C 3
Ki = (C I - B 2 + I),/13
In the griphs which represent equation (4) for different ranges of focal
depth and inte~siLes, the best adjustment of the set of pairs was verified
(i; r I) corresponding to a given earthquake. This work was not carried out
systematically and need; revis ion. ILtmus t be observed that once equation
(/4) is known, this process does not reqnuire tie dcetertmination o i , a parameter
wihich1 is generally unrel iahli ; tis, the anal/sis o1 an carthquake
which has a submarine epicenter, is s implified.
In a general way, iU wa's dpcid',ld to assign an epicenter, even though it
be only of " tentative character, for each one of the event. in this history
of earthquakes; i.fthere is no instrumental epicentcr, nor a study of maps
of isoseismal curves, 'in pticinter was assigned with the coordinates of the
locality which suffered the great:;t intensity.
3.2.2 Time of Origin
All of the time; were converted to G.M.T. It was considered important
to respect the inevitable dii erences between "instrutmental" ard "macroseis ­
mic" times. Such differences are usually in units of minutes and even tens
of minutes (specially, when it is a question of felt earthquakes during the
early hours of the morning and, particu.l.arly, if the information comes from
iural areas).
The time of origin is known only for those events which have been recorded
with inst:ruments.
3.2.3 Maximum Intensities and Tsunamis
'or each locality reported to have been affected by an earthquake, an intensity
was assigned, according to the modified ercalli scale (Brazee ver -
sion). Even though the uncerta inties in the assignment of intensities are
large, it is more convenient to indicate a value, using the best possible criterion,
with the information which one has at the moment, and to indicate at
least, a minimum.
The value indicated as value for the intensity; as the maximum intensity
corresponds to the highest value of the intensities assigned; that it is
to say, there was no intent, in any case, to infer the epicentral intensity