Publication Date:
2017-04-04
Description:
Accepted for publication in Journal of Geophysical Researches. Copyright (2010) American Geophysical Union
Description:
Two critical items in the energetic budget of a seismic province are the strain rate, which is measured geodetically on the Earth’s surface, and the yearly number of earthquakes exceeding a given magnitude. Our study is based on one of the most complete and recent seismic catalogs of Italian earthquakes and on the strain rate map implied by a multi-year velocity solution for permanent GPS stations. For 36 homogeneous seismic zones, we used the appropriate Gutenberg Richter relation based on the seismicity catalog to estimate a seismic strain rate, which is the strain rate associated with the mechanical work due to a co-seismic displacement. The volume storing most of the elastic energy is associated with the long-term deformation of each seismic zone, and therefore, the seismic strain rate is inversely proportional to the static stress drop. The GPS-derived strain rate for each seismic zone limits the corresponding seismic strain rate, and an upper bound for the average stress drop is estimated. These results demonstrated that the implied regional static stress drop ranged from 0.1 to 5.7 MPa for catalog earthquakes in the moment magnitude range [4.5–7.3]. These results for stress drop are independent of the “a” and “b” regional parameters and heat flow but are very sensitive to the assumed maximum magnitude of a seismic province. The data do not rule out the hypothesis that the stress drop positively correlates with the time elapsed after the largest earthquake recorded in each seismic zone.
Description:
The research was supported by Project S1 2007-2009 of Istituto Nazionale di Geofisica e Vulcanologia and Dipartimento della Protezione Civile, Rome.
Description:
In press
Description:
1.9. Rete GPS nazionale
Description:
3.1. Fisica dei terremoti
Description:
4.2. TTC - Modelli per la stima della pericolosità sismica a scala nazionale
Description:
JCR Journal
Description:
open
Keywords:
earthquakes
;
seismic hazard
;
geodesy
;
b-value
;
04. Solid Earth::04.01. Earth Interior::04.01.02. Geological and geophysical evidences of deep processes
;
04. Solid Earth::04.01. Earth Interior::04.01.05. Rheology
;
04. Solid Earth::04.03. Geodesy::04.03.01. Crustal deformations
;
04. Solid Earth::04.03. Geodesy::04.03.06. Measurements and monitoring
;
04. Solid Earth::04.04. Geology::04.04.06. Rheology, friction, and structure of fault zones
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
Permalink
