[marc / berkeley]

(11-13-2016, 08:21 PM)Island Chris Wrote: There was a M7.8 earthquake in New Zealand today. Looks like the aftershocks extend over 160 km NE-SW. I can't find a focal mechanism on USGS, but there must be one. It is in an area where there are right-lateral faults with more or less that orientation. But it is also the south end of subduction and there is contraction farther south along the plate boundary Alpine fault.

OK, found the focal mechanism: is right-lateral.

A cnn.com reporter said it was good news that they increased the depth from 10 km to 22 (?). It is not good news for a strike-slip quake: it probably ruptured all the way to the surface or close to it. The deep (for strike-slip) hypocenter just means a larger area ruptured and the shaking may be worse, not better.

There was also a local 1.5 m tsunami:
http://ptwc.weather.gov/ptwc/text.php?id...11.13.1304

Chris

The Moment Tensor solution looked mighty intereesting.

Mostly thrust, but with a volcanic fluid component.  Are we going to see magma?

That combined with the successive triggering along the faulting makes this event far more interesting than a typical strike-slip.

You can bet this will be one of the poster child at next months AGU!