Stress transfer among en echelon and opposing thrusts and tear faults : triggering caused by the 2003 Mw = 6.9 Zemmouri, Algeria, earthquake
Stein, Ross S.
MetadataShow full item record
The essential features of stress interaction among earthquakes on en echelon thrusts and tear faults were investigated, first through idealized examples and then by study of thrust faulting in Algeria. We calculated coseismic stress changes caused by the 2003 Mw = 6.9 Zemmouri earthquake, finding that a large majority of the Zemmouri afterslip sites were brought several bars closer to Coulomb failure by the coseismic stresses, while the majority of aftershock nodal planes were brought closer to failure by an average of ∼2 bars. Further, we calculated that the shallow portions of the adjacent Thenia tear fault, which sustained ∼0.25 m slip, were brought >2 bars closer to failure. We calculated that the Coulomb stress increased by 1.5 bars on the deeper portions of the adjacent Boumerdes thrust, which lies just 10–20 km from the city of Algiers; both the Boumerdes and Thenia faults were illuminated by aftershocks. Over the next 6 years, the entire south dipping thrust system extending 80 km to the southwest experienced an increased rate of seismicity. The stress also increased by 0.4 bar on the east Sahel thrust fault west of the Zemmouri rupture. Algiers suffered large damaging earthquakes in A.D. 1365 and 1716 and is today home to 3 million people. If these shocks occurred on the east Sahel fault and if it has a ∼2 mm/yr tectonic loading rate, then enough loading has accumulated to produce a Mw = 6.6–6.9 shock today. Thus, these potentially lethal faults need better understanding of their slip rate and earthquake history.
Author Posting. © American Geophysical Union, 2011. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 116 (2011): B03305, doi:10.1029/2010JB007654.
Suggested CitationArticle: Lin, Jian, Stein, Ross S., Meghraoui, Mustapha, Toda, Shinji, Ayadi, Abdelhakim, Dorbath, Catherine, Belabbes, Samir, "Stress transfer among en echelon and opposing thrusts and tear faults : triggering caused by the 2003 Mw = 6.9 Zemmouri, Algeria, earthquake", Journal of Geophysical Research 116 (2011): B03305, DOI:10.1029/2010JB007654, https://hdl.handle.net/1912/4468
Showing items related by title, author, creator and subject.
Stress triggering in thrust and subduction earthquakes and stress interaction between the southern San Andreas and nearby thrust and strike-slip faults Lin, Jian; Stein, Ross S. (American Geophysical Union, 2004-02-03)We argue that key features of thrust earthquake triggering, inhibition, and clustering can be explained by Coulomb stress changes, which we illustrate by a suite of representative models and by detailed examples. Whereas ...
Llenos, Andrea L. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2010-06)Large earthquake rupture and triggering mechanisms that drive seismicity in subduction zones are investigated in this thesis using a combination of earthquake observations, statistical and physical modeling. A comparison ...
Cattania, Camilla; McGuire, Jeffrey J.; Collins, John A. (John Wiley & Sons, 2017-01-18)While dynamic earthquake triggering has been reported in several continental settings, offshore observations are rare. Oceanic transform faults share properties with continental geothermal areas known for dynamic triggering: ...