OK, we’ve had a bunch of odd little ‘quake storms’ often around old volcanic structures. R. de Haan, George, Scarlet Pumpernickel, Jason Calley and others have been pointing them out in ‘tips’, so I guess it’s time to make a ‘quake posting’ and move the discussions to a discussion thread and out of ‘tips’…
First up, the R. de Haan El Hiero Volcano Canary Islands tip
There is a very nice map in the article he linked at:
That article says it reached 700 events as of yesterday. That is rather a lot of ‘events’, even if small. (Most, per the article, are around 2 +/- 1/2 )
So the big question is, what’s happening here?
It is possible that there is magma on the move at depth, perhaps moving into a magma chamber.
Does this mean that there will be an eruption? Maybe, maybe not.
The majority of magma intrusions do not reach the surface, and as has been seen elsewhere, in the past, activity can cease at anytime.
As of yet (to my knowledge) there have been no other signs of moving magma at the surface such as ground deformation or increased gas emission, although GPS antenna have been set up by officials at the Canary Islands.
For now it is too early to tell what (if anything) will happen, so keep watching.
If you would like to follow these earthquakes in more detail or look at the raw data, visit here .
The ‘visit here’ link goes to Spanish site, I think. http://www.02.ign.es/ign/layoutIn/sismoListadoTerremotos.do?zona=1&cantidad_dias=10
The USGS map is not showing anything, but I think this is due to a 2.5 magnitude ‘cut off’. Hmmm…. That tends to make the USGS maps particularly poor for early volcanic quake storm detection where there are a mass of low magnitude quakes…
If this turns into a Real Volcano ™ then we could have some interesting tidal waves on the East Coast… Oh, wait I am on the East Coast now… well, that’s ‘not good’! ;-)
Jason and Scarlet have pointed to the area around Southern California. As I’m not in California any more, that’s of no real concern… Oh, wait my KID is in Southern California now … well, maybe that’s an issue too… ;-)
At any rate, the comments here: https://chiefio.wordpress.com/tips/#comment-20528 and here https://chiefio.wordpress.com/tips/#comment-20637 have videos of what looks like a dust or steam venting event. Personally, if it isn’t red, glowing, and melting Chevys, then it’s just normal ‘volcanic field events’ for the area, IMHO. While I’d love to see a volcanic fissure open up and demonstrate how the subducted spreading zone is still spreading, I think it will take a while for that to happen.
I’m not seeing much on the California map (down below). Mostly just the “usual” on the larger faults. There’s a tiny it of action on the line up past Mammoth toward Nevada (where we had a quake event under some old volcanoes) but nothing major (yet)…
Nice action on the Hayward / Calaveras / Rodgers complex with the slippage clearly moved inland from the N. San Andreas. (Berkeley and Oakland are toast… it’s just a question of “when”… which could be ‘in 400 years’… or could be ‘tomorrow’…) The action around The Geysers is the most intriguing as it is in keeping with the ‘quakes near volcanic stuff’ theme.
The Pisgah crater is between Barstow and Needles (Needles being just about on the Nevada border with Arizona and Barstow being at the start of the Mojave) so it is in the big empty zone with no quake activity on the California map below.
I’ve zoomed in on where it ought to be and I’m not seeing much:
As the caption for this runs down to “1” scale events, even a large dump truck dumping a load ought to show up …
We do see some 1 scale events, but spread out over various clearly marked fault zones or near them.
If you go to the active map, you can use the wedges on each side to scroll around and / or click on a dot to get quake info.
But move up a bit on the spreading zone, and there is an interesting chain of dots (all small ones) on the approach to Mammoth “lakes”…
This is the static capture. Below is a live map.
My “take” on all this is just that: As we’ve had a bunch of major subduction events on the Pacific Plate, that releases some of the ‘back pressure’ on spreading zones as far away as the Atlantic Mid-Ocean Ridge, and we see various magmatic events start to ooze some. Enough for a volcano? Who knows… or when…
But as the subduction events ‘clear the way’, the plates can slide over and then the spreading zones ought to ‘do what they do’ in places like Iceland, Canaries, and even Barstow to Death Valley.
Further down in comments, there was a pointer to a cluster in Mexico (in the Gulf of California).
It looks to me like a 5, 4, and smaller cluster and no followthrough, right on the spreading zone. I’d expect more action to happen further north as a consequence “in a few weeks”. If the ‘more spreading’ thesis and the ‘displacement propagates north” thesis are correct, it could get interesting in Southern California ;-)
At any rate, I’m left wondering if anyone has ever done a very long term study of percent quakes on spreading zones vs percent on compression faults to see if there is a pattern of “subduction then spreading quakes” followed by a long “compression zone quakes and no big subduction events”, then back to “more subsections followed by spreading zone events”. Seems like a reasonable “oscillator” thesis to explore to me…
I note in passing that we’ve picked up a more recent 5.3 even in Central Alaska, about where volcanoes are located…
Magnitude 5.3 - CENTRAL ALASKA 2011 July 28 14:00:00 UTC This event has been reviewed by a seismologist. Magnitude 5.3 Date-Time Thursday, July 28, 2011 at 14:00:00 UTC Thursday, July 28, 2011 at 06:00:00 AM at epicenter Time of Earthquake in other Time Zones Location 62.050°N, 151.290°W Depth 81.6 km (50.7 miles) set by location program Region CENTRAL ALASKA Distances 19 km (12 miles) N (356°) from Skwentna, AK 46 km (29 miles) SW (218°) from Petersville, AK 57 km (35 miles) WSW (240°) from Trapper Creek, AK 125 km (78 miles) NW (320°) from Anchorage, AK Location Uncertainty horizontal +/- 0.3 km (0.2 miles); depth fixed by location program Parameters NST= 78, Nph= 84, Dmin=14.7 km, Rmss=0.58 sec, Gp= 47°, M-type=local magnitude (ML), Version=2 Source Alaska Earthquake Information Center Geophysical Institute, University of Alaska Fairbanks Event ID ak10281084
Here are the Mexican 5.0 data for comparison:
Magnitude 5.0 - GULF OF CALIFORNIA 2011 July 26 19:40:28 UTC This event has been reviewed by a seismologist. Magnitude 5.0 Date-Time Tuesday, July 26, 2011 at 19:40:28 UTC Tuesday, July 26, 2011 at 01:40:28 PM at epicenter Time of Earthquake in other Time Zones Location 25.051°N, 109.582°W Depth 12.5 km (7.8 miles) Region GULF OF CALIFORNIA Distances 100 km (62 miles) SW of Los Mochis, Sinaloa, Mexico 124 km (77 miles) NE of La Paz, Baja California Sur, Mexico 149 km (92 miles) WSW of Guamuchil, Sinaloa, Mexico 961 km (597 miles) SSE of PHOENIX, Arizona Location Uncertainty horizontal +/- 15.4 km (9.6 miles); depth +/- 6.9 km (4.3 miles) Parameters NST=308, Nph=308, Dmin=155.8 km, Rmss=1.24 sec, Gp=119°, M-type=body wave magnitude (Mb), Version=5 Source Magnitude: USGS NEIC (WDCS-D) Location: USGS NEIC (WDCS-D) Event ID usc00054hv
And there was this tasty 6.7 “South of the Fiji Islands” that could also be the start of something interesting. There has been a lot of persistent activity in the area of that Island region… h/t to George in this comment: https://chiefio.wordpress.com/tips/#comment-20676 (and I think that covers all the ‘tips’ on quakes… If I missed someone, well, let me know…)
Magnitude 6.7 - SOUTH OF THE FIJI ISLANDS 2011 July 29 07:42:23 UTC Versión en Español Details Maps Scientific & Technical Tsunami Earthquake Details This event has been reviewed by a seismologist. Magnitude 6.7 Date-Time Friday, July 29, 2011 at 07:42:23 UTC Friday, July 29, 2011 at 07:42:23 PM at epicenter Time of Earthquake in other Time Zones Location 23.651°S, 179.822°E Depth 521.7 km (324.2 miles) Region SOUTH OF THE FIJI ISLANDS Distances 631 km (392 miles) SSE (167°) from SUVA, Fiji 1547 km (961 miles) NNE (20°) from Auckland, New Zealand Location Uncertainty horizontal +/- 14.1 km (8.8 miles); depth +/- 6.3 km (3.9 miles) Parameters NST=619, Nph=660, Dmin=659 km, Rmss=1.01 sec, Gp= 14°, M-type="moment" magnitude from initial P wave (tsuboi method) (Mi/Mwp), Version=A Source Magnitude: USGS NEIC (WDCS-D) Location: USGS NEIC (WDCS-D) Event ID usc00055wy
(It has just popped another red one as I’m typing…)
Just to the right of that view, more on the fault:
And, of course, Japan and Chile continue to jiggle and dance. But is it ‘new stuff’ or just long duration aftershocks of their 9 class events…
Asia and Russia
Australia / New Zealand
This is a map of the Australia / Indonesia / New Zealand area:
And remember, I have a dedicated CSZ page with closeups
Here is an alternative view of things with the fault lines highlighted:
Map of Plates
You can see it is where plates collide here:
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: