[Skywise]

USGS Summary Page

Likely to have some casualties and damage.

Brian

[Island Chris]

I missed that one when I looked at the map this morning. There was also a M7.1 quake by the North Solomon Islands, part of Papua New Guinea. It is a reverse slip quake near a subduction zone. The north Chile M8.2 quake has been followed by some quakes deeper on the South American subduction zone that could be related.


http://earthquake.usgs.gov/earthquakes/e...t9#summary

Chris

[Island Chris]

Another, larger quake. The first one was shallow and strike-slip. This one is M6.6 and is thrust.

http://earthquake.usgs.gov/earthquakes/e...si#summary

They are far enough apart and the magnitudes are small enough that the first is not a direct foreshock of the second. But logic says that they are related. But I doubt this is well-understood at all. It will be interesting to see how static stress changes on a shallow quake can weaken a deep part of the subducting slab. Is liable to be another process; for example, the seismic waves from the first initiated some sort of cascade.

I'm not an earthquake seismologist.

Chris

[Skywise]

(04-11-2014, 09:26 PM)Island Chris Wrote: Another, larger quake. The first one was shallow and strike-slip. This one is M6.6 and is thrust.

http://earthquake.usgs.gov/earthquakes/e...si#summary

They are far enough apart and the magnitudes are small enough that the first is not a direct foreshock of the second. But logic says that they are related. But I doubt this is well-understood at all.

My very first thought is the 6.6 subduction was getting close to going anyway. The static stress change from the 6.1 was the proverbial straw.

The problem is we simply have little to no data about what goes on beneath our feet. There's the infamous saying about mankind knowing more about the backside of the Moon than the deep oceans. Well, we know even less about the deep crust.

Brian