Remotely Triggered Earthquakes: Observations, Interpretations

Remotely triggered earthquakes have now been observed commonly in geothermal and volcanic regions. Analysis of historic earthquake sequences reveals that remotely triggered earthquakes occur commonly in intraplate crust as well. Because neither abundant geothermal/volcanic fluids nor weak faults are expected to exist in intraplate crust, this provides evidence that at least some faults in intraplate regions are critically stressed. The locations of observed remotely triggered earthquakes suggest that intraplate crust is not critically stressed everywhere, but rather in certain regions where long-lived stress concentrations persist. (See Hough et al., BSSA, 10/03 for more details; links below for figures)

Remotely Triggered Earthquakes

Remotely Triggered Earthquakes

Intraplate Triggered Earthquakes: Observations and Interpretion (BSSA, v. 93, 2212-2221, 10/03)

Locations of remotely triggered earthquakes in 1812, 1886 (Hough, 2001; Hough and Martin, 2002; Hough et al., 2003)

A New View of the 1811-1812 (New Madrid or Central U.S.?!) Sequence

ShakeMap for a triggered earthquake at 10:40 pm, 2/7/1812 (see BSSA 12/2001)

Broadband recordings of triggered earthquakes in 1999 (Hector Mine, CA; see BSSA 4/2002)