Potential for a large earthquake near Los Angeles inferred from the 2014 La Habra earthquake

Earth and Space Science

Andrea Donnellan⁵  Lisa Grant Ludwig⁴  Jay W. Parker⁵  John B. Rundle²  Jun Wang³  Marlon Pierce³  Geoffrey Blewitt¹ 

[1] Nevada Geodetic Laboratory, Nevada Bureau of Mines and Geology, University of Nevada, Reno, Nevada;Departments of Physics and Geology, University of California, Davis, California, USA;University Information Technology Services, Indiana University, Bloomington, Indiana, USA;Program in Public Health, University of California, Irvine, California, USA;Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA

关键词: UAVSAR;    GPS;    La Habra;    earthquake;    geodesy;    modeling;   

DOI  :  10.1002/2015EA000113

来源: Wiley

【 摘 要 】

Abstract

Tectonic motion across the Los Angeles region is distributed across an intricate network of strike-slip and thrust faults that will be released in destructive earthquakes similar to or larger than the 1933 M6.4 Long Beach and 1994 M6.7 Northridge events. Here we show that Los Angeles regional thrust, strike-slip, and oblique faults are connected and move concurrently with measurable surface deformation, even in moderate magnitude earthquakes, as part of a fault system that accommodates north-south shortening and westerly tectonic escape of northern Los Angeles. The 28 March 2014 M5.1 La Habra earthquake occurred on a northeast striking, northwest dipping left-lateral oblique thrust fault northeast of Los Angeles. We present crustal deformation observation spanning the earthquake showing that concurrent deformation occurred on several structures in the shallow crust. The seismic moment of the earthquake is 82% of the total geodetic moment released. Slip within the unconsolidated upper sedimentary layer may reflect shallow release of accumulated strain on still-locked deeper structures. A future M6.1–6.3 earthquake would account for the accumulated strain. Such an event could occur on any one or several of these faults, which may not have been identified by geologic surface mapping.

【 授权许可】

CC BY-NC-ND   
©2015. The Authors.

Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.