The variations of characteristic scale length of friction evolution affect earthquake dynamics

Main Article Content

Andrea Bizzarri
http://orcid.org/0000-0001-8313-4124

Abstract

Within a fault governing model the characteristic scale length is one of the most relevant physical parameters because it accounts for the so–called fracture energy (density) of the system, its dynamics, the time during which the accumulated stress is released and the seismic waves are excited, the amount of slip developed during an instability event. Friction laboratory experiments reveal that it is not a material property, but that it changes with the sliding velocity. We propose two rather different analytical models to fit laboratory evidence and we incorporate them into a fault model able to simulate repeated earthquakes in the framework of various formulations of rate and state friction. We demonstrate that temporal variations of the scale length do not prevent the system to reach its limit cycle, but they systematically reduce the magnitude of the expected event (both in term of developed slip, and thus seismic moment, and released stress) and also reduce the inter–event time (recurrence interval). Depending on the friction model, the system can penetrate into the stable regime and can either continue the accelerating phase toward to failure or decelerate and abort instability.

Article Details

How to Cite
1.
Bizzarri A. The variations of characteristic scale length of friction evolution affect earthquake dynamics. Ann. Geophys. [Internet]. 2021May26 [cited 2021Sep.27];64(2):SE217. Available from: https://www.annalsofgeophysics.eu/index.php/annals/article/view/8595
Section
Seismology
Author Biography

Andrea Bizzarri, Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Bologna

Andrea Bizzarri (AB) is a physicist (with magna cum laude honor from the Università degli Studi di Bologna, Bologna, Italy, 1998).

AB received a Ph.D. degree in geophysics from the Università degli Studi di Bologna, Bologna, Italy, in 2003.

AB' s expertises spread over many different aspects of earthquake source dynamics, including the study of fault triggering phenomena, the modeling of the physical processes occurring during faulting, the inference of fault governing equations from laboratory experiments. Fundamental problems in theoretical seismology are of great importance in his research. As a part of his research, AB has been actively involved in the development of massively parallel numerical algorithms to be used in the numerical models.

AB is a Full Researcher at the Istituto Nazionale di Geofisica e Vulcanologia - Sezione di Bologna.

 

Additional information at: http://www.bo.ingv.it/~bizzarri