ISSN:
1420-9136
Keywords:
Key Words: Earthquake nucleation, inhomogeneous fault, high rupture growth resistance, a slip-dependent constitutive law.
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
,
Physics
Notes:
Abstract —A specific model of the earthquake nucleation that proceeds on a non-uniform fault is put forward to explain seismological data on the nucleation in terms of the underlying physics. The model is compatible with Gutenberg-Richter's similarity law for earthquake frequency-magnitude relation. A theoretical approach in the framework of fracture mechanics, based on a laboratory-based slip-dependent constitutive law, leads to the conclusion that the earthquake moment M o scales with the third power of the critical slip displacement D c and the critical size 2L c (L c , half-length) of the nucleation zone. This scaling relation quantitatively explains seismological data published, and it predicts that 2L c is of the order of 10 km for earthquakes with M o = 1021 Nm, 1 km for earthquakes with M o = 1018 Nm, and 100 m for earthquakes with M o = 1015 Nm, under the assumption that the breakdown stress drop $\Delta \tau_b$ = 10 MPa. However, L c depends on not only D c but also $\Delta \tau_b$ , so that the scaling relation between L c and D c may be violated by $\Delta \tau_b$ , because $\Delta \tau_b$ potentially takes any value in a wide range from 1 to 102 MPa, depending on the seismogenic environment. The good agreement between the theoretical relation and observed results suggests that a large earthquake may result from the failure of a large patch of high rupture growth resistance, whereas a small earthquake may result from the breakdown of a small patch of high rupture growth resistance. The present result encourages one to pursue the prediction capability for large earthquakes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/PL00001084
Permalink
