Something A Bit Strange Is Happening
Just north of Mammoth “Lakes” (a supervolcanic site in California) and located about where the subducted spreading zone from the East Pacific Rise is slowly pulling California apart (making Death Valley and the Salton Sea basin in the process) we have this odd set of quakes. I’d brush it off as just a grabben settling, except it’s come back for a ‘double dip’. About a week ago we had a 4.x scale quake and a bunch of aftershocks, now this:
That is a static image, as is this following close-up:
UPDATE 16 APRIL 2011:
Notice that in this image, the total quake count is 233 while yesterday it was 163. We are racking up new quakes (even if very small ones) at a prodigious rate…
OK, it most likely IS just some minor block settling. But why?. IMHO, because we’re getting a bit more “spreading” in that Basin and Range type of geology from that spreading zone. There has been more activity all along that spreading zone (especially near Mexico and on up into Southern California) and it is, IMHO, just wandering on up the line.
And after some more spreading, we get more quaking. The stresses accumulate at the margin where the “jello wedge” of central California is stuck onto the side of the continental North American Plate, but hanging out over the subducted Pacific Plate, and that resolves into “slippage” on the fault system that runs… Right Past Me.
You can see that as all the activity along the San Andreas starting down near L.A. and heading up to Hollister. Then it takes a turn inland a bit and heads up the line of the Hayward / Calaveras system (eventually it gets the name Rodgers Fault on the other size of San Pablo bay) and on up past The Geysers and Calistoga (mineral waters and hot volcanic baths…) You can see a nice image of how they connect and a simulation of what happens if they both “go” at the same time here:
IMHO, something like that is the most likely scenario (or taking it in two pieces, each fault one at a time) in the next couple of decades in the San Francisco Bay Area. “Any time now” in geologic terms.
Here is a live chart of California for keeping up with “What’s happening now”:
Action Closer to Me
As I live in California, it makes it easier for me if I keep them in the list where I can see what’s shaking near me.
Original Image, with captions and description. The original is interactive with clickable regions for ‘close ups’.
While we had a spot count over 300 on this one chart during the “supermoon” it’s now over 574 as I type.
Here is an alternative view of things with the fault lines highlighted:
OK, so is this an indication that we’ve got an increase in the volcanic part of things? Action near spreading centers where we get big volcanos? Well, just as a reminder, Iceland is continuing to build up a “cumulative seismic moment”:
And remember, I have a dedicated CSZ page with closeups
Asia and Russia
h/t Chuckes in comments: Not seeing anything in the area, but as we’ve had a big volcanic “blow” in Kamchatcka, here is the Asia chart:
While we don’t want to forget about Japan, it has very much quieted down. So just one panel. If you want more detail, see:
Australia / New Zealand
This is a map of the Australia / Indonesia / New Zealand area:
Facinating line of “small ones” along the Indonesian arch and out toward Fiji / Tonga…
Here is a “live view” of South America so you can watch anything “new” that develops there:
After some bouncing up and down as they screwed around with the graphs, the Grimsvoten graph is back to normal. But now it’s showing the total energy line almost matching the 2004 point of eruption. It’s time to start watching closely to see if this seismic metric has any predictive power. IMHO, it could be off by up to 50% as a guess, so I’m not holding my breath. Then again, I’d not plan a camping trip to the volcano right now either…
The line of total seismic energy at Grimsvoten in Iceland is continuing it’s very vertical climb… I think Iceland will be “sooner rather than later”… IMHO, we hit “equal to last time” in about a month. The question of what happens then is still an open one, but it is a ‘watch here’ flag…
Take a look again at the Iceland Volcano Watch Metric posting. The total seismic energy line continues to go ever more vertical.
Some Volcano Stuff
http://pangea.stanford.edu/~dsinnett/Pages/Links.html has a nice collection of links to volcano monitor pages. Just click the pictures for the different volcano observatories.
The Smithsonian page: