We don't really have to worry about Japan until they start having 7.0+ quakes. Because of the past behavior of that subduction zone area near Honshu, if a 7.2 happens followed by silence for a couple days, then we need to watch out.
The scary part about Cascadia is that it will very likely pop off a 9.0+ likely without warning in the general area, without the prior 7.0+ quakes. It is very similar to the subduction zone off the coast of Sumatra in 2004, that let loose a 9.1 without prior warning. Technically any subduction zone could. But we have a situation where it hasn't popped off a 9.0+ in over 300 years. The general recurrence is every 243 years. We are 315 years into the cycle, which means we are 72 years overdue. Source: [
link to www.newyorker.com]
Instead, the stress building underneath the Juan De Fuca / Cascadian Subduction Zone is affecting all of the other areas of the plate except that general area. So no one is going to see it coming unless those of us astute enough to attribute activity going on on the other sides of these plates to the stress being placed on the Juan De Fuca / Cascadia Subduction Zone (hint: it is enormous).
I think, judging by the plate movements we are experiencing, it's likely going to be similar to Japan's 9.0, without the 7.2 beforehand.
We have the upwelling of volcanic activity along with the sigNIFICANT earthquake activity the likes of which we have not seen for a long long time. We are basically in a WORSE situation than we saw for the Japan 2011 quake. Could there be another Japan 2011 quake? Absolutely. But, signs are pointing more towards Cascadia:
1. Upwelling of volcanic activity along the eastern side of the Ring of Fire (including quakes at the dormant volcanoes in California).
2. Awakening of long-dormant volcanoes like El Misti (having been dormant for over 500 years).
3. Upwelling of earthquake activity ALL ALONG the eastern side of the Ring of Fire into the 7.0s (6.9 Mexico, 7.1 Alaska, 7.2 Russia -- don't forget the 40 meter drop of that end of the plate that HAS NOT COMPENSATED yet on the opposite side - the Juan De Fuca)
4. Now we have 6.0 SWARMS near New Zealand (remember what happened before the 7.1 Alaska quake -- a bunch of 2s & 3s).
It's only a matter of time. And I am getting very concerned for the people of the Pacific Northwest.
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