(Updated: Early start for 2011 ETS) ETS event officially starts in N. Cascadia subduction zone

[Emily]

***This is a non-volcanic deep tremor that occurs roughly every 14 months. It has been observed for about 10 years without an earthquake being triggered, but researchers are hoping to gain knowledge about the fault from observations of the tremor below. They have been set up with lots of monitoring equipment since March.

From what I understand reading about the ETS events, they are sensitive to lunar tides and the event did kick off under a new moon at perigee which, (I think) exerts a stronger than usual tidal effect.

Deep Tremor Array Studies, On going observations

Seismology: The secret chatter of giant faults : Nature News

AGU: Future Cascadia megathrust rupture delineated by episodic tremor and slip

YouTube - ‪Pacific Northwest Megaquake Imminent‬‎

Non-volcanic Tremor: A Window into the Roots of Fault Zones

 

[Emily]

Re: ETS event officially starts in N. Cascadia subduction zone

Re: ETS event officially starts in N. Cascadia subduction zone

They've been updating the ETS log most days. It's done some unexpected things like bifurcating and now there is even a third patch. (And the main tremor has moved into Canada.)
http://www.pnsn.org/WEBICORDER/DEEPTREM/summer2010.html

Aug 22,2010 - Yikes! Lots of Cascadia is lighting up with tremor today. The main ETS patch is now straddling the Straits (Honn's TAMS system using only Canadian data has been reporting tremor being seen on southern Vancouver Island stations for a few days). The patch of tremor just south of Olympia continues. There is a new patch just south of Portland and a burble in southern Oregon. What the heck is going on? Time will tell.

 

[Emily]

Re: ETS event officially starts in N. Cascadia subduction zone

Re: ETS event officially starts in N. Cascadia subduction zone

This year's tremor started off-schedule for the first time since it has been observed.

http://www.pnsn.org/WEBICORDER/DEEPTREM/summer2011.html
Blog for ETS of Summer, 2011 (Three Months Early ????)
Deep Tremor News: Aug, 2011 - .... (why so early))

Interactive tremor map:
http://www.pnsn.org/tremor/

 

[Emily]

Re: (Updated: Early start for 2011 ETS) ETS event officially starts in N. Cascadia subduction zone

http://www.pnsn.org/WEBICORDER/DEEPTREM/summer2011.html

Sep 6, 2011 - This ETS is over. The last burst of tremor seen at the north end of this ETS in BC occurred on Sep 3. It was followed on Sep 4 by a burst back in the south end of Puget Sound but nothing has been seen since then. Thus we declare the ETS over. It lasted from Jul. 23 until Sep. 4, longer than any previous ETS well recorded and processed by us. Besides starting much earlier than expected it started farther south than most previous ones and didn't proceed quite as far north.