Publication Date:
2018-02-16
Description:
In the last two decades, several studies addressed the revaluation and
homogenization of the Italian instrumental seismic catalog, but all of them refer to the
time interval from 1981, that is, the starting year of the Catalogo Strumentale dei
Terremoti Italiani (CSTI). At the time, the CSTI was conceived as the continuation
of the catalog of the Progetto Finalizzato Geodinamica (PFG) but, over time, the PFG
catalog was almost totally forgotten, and presently it is even difficult to obtain because
it is not provided by any website. In this work, we integrate a genuine copy of PFG,
with additional locations from the bulletins of the Istituto Nazionale di Geofisica
(ING, now known as INGV) and of the International Seismological Centre (ISC) and
with local magnitudes from two couples of Wood–Anderson (WA) seismometers
operational in Italy in the 1970s and 1980s, mostly derived from a careful scrutiny
of paper bulletins of the Osservatorio Geofisico Sperimentale (OGS) and of the ING.
We restrict our analysis to the time interval from 1960 to 1980 because, based on
various evidence, we can infer that within such period most instrumental magnitudes
reported by the PFG catalog are reasonably coherent with the Richter’s definition.
Magnitudes provided by WA stations and other data sources are calibrated with
respect to Mw by general orthogonal regressions. The final catalog from 1960 to 1980
contains 8536 earthquakes, of which we compute a true or proxy Mw magnitude with
related uncertainty for 6407. The analysis of the frequency–magnitude distribution
indicates completeness for about Mw ≥4:0. This work extends the time coverage
of the Italian instrumental catalog to about 55 yrs before the present, allowing the
statistical study of some important seismic periods that occurred, for example, in
1962 (Irpinia), 1968 (Belice Valley), 1976 (Friuli), 1979 (Umbria), and 1980 (Irpinia).
Description:
Published
Description:
481–492
Description:
4IT. Banche dati
Description:
JCR Journal
Keywords:
local magnitude
;
magnitude homogenization
;
04.06. Seismology
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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