Skip to Main Content
Skip Nav Destination
GEOREF RECORD

Two-dimensional numerical modeling suggests preferred geometry of intersecting seismogenic faults

Abhijit Gangopadhyay and Pradeep Talwani
Two-dimensional numerical modeling suggests preferred geometry of intersecting seismogenic faults (in Continental intraplate earthquakes; science, hazard, and policy issues, Seth Stein (editor) and Stephane Mazzotti (editor))
Special Paper - Geological Society of America (2007) 425: 87-99

Abstract

We undertook a parametric study, using a two-dimensional distinct element method, to investigate if there is a preferred geometry of intersecting faults that may favor the occurrence of intraplate earthquakes. This model subjects two and three vertical, intersecting faults within a block to a horizontal force across them, representing the maximum horizontal compression (S (sub Hmax) ). The main fault is oriented at an angle alpha with respect to S (sub Hmax) , and beta is the interior angle between the main fault and the intersecting fault. The third fault is oriented parallel to the main fault and is half its length. The distribution of shear stresses is examined along the faults for different values of alpha and beta , and varying lengths of the main and intersecting faults. In all cases, maximum shear stresses are generated at the fault intersections. The modeling results reveal that the magnitudes of the shear stresses depend on the values of alpha and beta , with an optimum range for alpha between 30 degrees and 60 degrees . In the case where the sign of the shear stress on the intersecting fault is opposite that on the main fault, the largest stresses at the fault intersections are obtained when beta is between 65 degrees and 125 degrees . When the stresses on these two faults are of the same sign, the largest stress values at the intersections are obtained when 145 degrees < or =beta < or =170 degrees . The results of the modeling are consistent with the observed geometry of faults in the New Madrid and Middleton Place Summerville seismic zones.


ISSN: 0072-1077
EISSN: 2331-219X
Coden: GSAPAZ
Serial Title: Special Paper - Geological Society of America
Serial Volume: 425
Title: Two-dimensional numerical modeling suggests preferred geometry of intersecting seismogenic faults
Title: Continental intraplate earthquakes; science, hazard, and policy issues
Author(s): Gangopadhyay, AbhijitTalwani, Pradeep
Author(s): Stein, Setheditor
Author(s): Mazzotti, Stephaneeditor
Affiliation: University of South Carolina, Department of Geological Sciences, Columbia, SC, United States
Affiliation: Northwestern University, Department of Earth and Planetary Sciences, Evanston, IL, United States
Pages: 87-99
Published: 2007
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
ISBN: 978-0-5137-2425-6
References: 40
Accession Number: 2008-040019
Categories: Seismology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 2 tables, sketch maps
N32°47'60" - N32°47'60", W79°58'00" - W79°58'00"
Secondary Affiliation: Geological Survey of Canada, CAN, Canada
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute.
Update Code: 200812
Close Modal

or Create an Account

Close Modal
Close Modal