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| Titel |
Seismicity at the northeast edge of the Mexican Volcanic Belt (MVB) and activation of an undocumented fault: the Peñamiller earthquake sequence of 2010-2011, Querétaro, Mexico |
| VerfasserIn |
A. Clemente-Chavez, A. Figueroa-Soto, F. R. Zúñiga, M. Arroyo, M. Montiel, O. Chavez |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1561-8633
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| Digitales Dokument |
URL |
| Erschienen |
In: Natural Hazards and Earth System Science ; 13, no. 10 ; Nr. 13, no. 10 (2013-10-14), S.2521-2531 |
| Datensatznummer |
250085531
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| Publikation (Nr.) |
 copernicus.org/nhess-13-2521-2013.pdf |
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| Zusammenfassung |
The town of Peñamiller in the state of Querétaro, Mexico, is located at
the northeast border of the seismogenic zone known as the Mexican Volcanic
Belt (MVB), which transects the central part of Mexico with an east–west
orientation. In the vicinity of this town, a sequence of small earthquakes occurred during
the end of 2010 and beginning of 2011. Seismicity in the continental regimen
of central Mexico is not too frequent; however, it is known that there are
precedents of large earthquakes (Mw magnitude greater than 6.0) occurring in
this zone. Three large earthquakes have occurred in the past 100 yr: the
19 November 1912 (MS = 7.0), the 3 January 1920 (MS = 6.4), and the 29 June 1935
(MS = 6.9) earthquakes. Prior to the instrumental period, the earthquake
of 11 February 1875, which took place near the city of Guadalajara, caused
widespread damage. The purpose of this article is to contribute to the
available seismic information of this region. This will help advance our
understanding of the tectonic situation of the central Mexico MVB
region.
Twenty-four shallow earthquakes of the Peñamiller seismic sequence of
2011 were recorded by a temporary accelerograph network installed by the
Universidad Autónoma de Querétaro (UAQ). The data were analyzed in order to
determine the source locations and to estimate the source parameters. The
study was carried out through an inversion process and by spectral analysis.
The results show that the largest earthquake occurred on 8 February 2011 at
19:53:48.6 UTC, had a moment magnitude Mw = 3.5, and was located at
latitude 21.039° and longitude −99.752°, at a depth of
5.6 km. This location is less than 7 km away in a south-east direction from
downtown Peñamiller. The focal mechanisms are mostly normal faults with
small lateral components. These focal mechanisms are consistent with the
extensional regimen of the southern extension of the Basin and Range (BR)
province. The source area of the largest event was estimated to have a
radius of 0.5 km, which corresponds to a normal fault with azimuth of
174° and an almost pure dip slip. Peak ground acceleration (PGA)
was close to 100 cm s−2 in the horizontal direction. Shallow
earthquakes induced by crustal faulting present a potential seismic risk and
hazard within the MVB, considering the population growth. Thus, the necessity
to enrich seismic information in this zone is very important since the risk
at most urban sites in the region might even be greater than that posed by
subduction earthquakes. |
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