3 ms·
Cascadia subduction zone events don't seem to trigger large earthquakes in the faults above the subduction zone: http://onlinelibrary.wiley.com/doi/10.1002/201
by cossatot 10y ago
Cascadia subduction zone events don't seem to trigger large earthquakes in the faults above the subduction zone:
http://onlinelibrary.wiley.com/doi/10.1002/2013JB010635/epdf http://onlinelibrary.wiley.com/doi/10.1002/2013JB010635/epdf
And the 1857 and 1906 M7+ events on the San Andreas did not cause earthquakes in the Pacific Northwest.
However, dynamic triggering of earthquakes does happen:
http://lanl.gov/orgs/ees/ees11/geophysics/nonlinear/2005/Nature2005GJ.pdf http://lanl.gov/orgs/ees/ees11/geophysics/nonlinear/2005/Nat...
Note that this type of triggering (by passing seismic waves) is, in the absolute sense, really unlikely to specifically nucleate a M7+ earthquake; otherwise there would be chains of huge earthquakes every time there's a big earthquake in Tonga (which is all the time). However, the relative likelihood is increased substantially.
There is a lot of research on earthquake triggering (both 'static' and 'dynamic') much of which is publicly available on Google Scholar (or sci-hub...). Static (or 'Coulomb') triggering is the most physically comprehensible; dynamic triggering, where passing seismic waves cause new quakes, is statistically supported but hard to understand mechanistically. The basics of static triggering are that, if you think of the earth's upper crust as a compressed elastic (e.g. rubber, but far more rigid) sheet, when a tear in it happens (an earthquake) it changes the distribution of stress/forces in the elastic sheet. Some regions will be stressed more, particularly around the edges of the tear, and some will be stressed less. The areas that are stressed more by the new tear tend to have more earthquakes following the first one. This is largely a local (i.e. 10s of km) phenomenon.
The big paper on this is here: http://www.ipgp.fr/~king/Geoffrey_King/Publications_files/King1994%20BSSA.pdf http://www.ipgp.fr/~king/Geoffrey_King/Publications_files/Ki...