Deep tremors in Cascadia subduction zone perplex scientists

[Emily]

http://www.pnsn.org/tremor/ets-event-of-fall-2013

Blog for ETS of Fall, 2013
Deep Tremor News: Sep, 2013 -

We were not expecting the next northern Washington - Southern Vancouver Island ETS until late Oct or Nov. 2013....... BUT, it may have started early. As of Sep 12, 2013 there have been 6 days of tremor activity in the area we have often seen an ETS start in the past; that is south-central Puget Sound. Thus we are again starting a blog here to document how this fall event goes.

Information will be posted on this page (latest at the top) and references to figures from time to time.
NEWS (latest at the top)

Sep. 19, 2013: What a strange ETS; if it really is one yet. After almost dying out to nothing on Sep 17, the tremor picked up slightly and started moving back south to partially fill in the gap left at the end of Sep 13. Then today that section of tremor quit intirely and fairly strong tremor started up back south in the central Olympics. Previous ETS events progress more or less smoothly, mostly in one direction with some minor reversals now and then. But this one seems to jump around quite a bit leaving gaps. Our working model for an ETS is that a slow-slip slip front moves along strike at an average rate of about 10 km/day with streaks up and down dip and short reversals moving maybe ten times faster. The past 12 days have seen very little of this sort of pattern. What next?

Nothing, I hope!