Quick news updates for a Wednesday...
The island (and volcano) of Gran Canaria in the Atlantic Ocean. It last erupted in ~20 B.C.
- The earthquakes keep coming at Yellowstone - up to a M3.5 in the last 24 hours. Time has already put up an article wondering about whether people need worry about the swarm (there might be other things to worry about before this swarm). YVO's statement on the earthquake swarm seems pretty standard (as it should be): "At this time the Yellowstone Volcano Observatory does not consider the swarm to be unusual and the earthquakes are likely related to tectonic fault sources. Also there is no indication of premonitory volcanic or hydrothermal activity, but ongoing analyses will evaluate these different sources." Eruptions reader Akira Shirakawa has posted another audio transcription of the seismicity on the January 19th, including the M3.5 quake for your listening (and pondering) pleasure.
- Not really much science in this article, but some cool pictures of HVO scientists going right up to the front of an a`a flow. A'a flows tend to move slow in a tractor-tread fashion, so description of the scientists as choosing to "stare death in the face to get a closer look" is a little over the top, but hey, it is the The Mail. The Halema`uma`u Crater activity continues unabated and an aerial video of the crater shows the stream of lava coming from the vent at the bottom.
- Finally, if you're interested in the Canary Islands, a hazard map/assessment has been published for Gran Canaria in the Journal of Quaternary Science. Twenty-four eruptions have occurred in the last 11,000 years on the island, meaning that there is an eruption every ... just kidding! The eruptions are dominantly small monogenetic strombolian cones and, occasionally, phreatomagmatic calderas. It is the north side of the island that faces the most risk in future eruptions, according to the study.
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Perhaps a hazard map for La Palma/Cumbre Viejo (sp?) would have been more interesting, that's the one where there have been warnings made of possible massive slope failure. But what's that about not-very-violent Strombolian eruptions generating pyroclastic flows? And what is a phreatomagmatic caldera when it's at home? A maar?
Some of the 'related stories' are pretty good stuff too (subglacial eruption in Antarctica, regional earthquakes triggering eruptions)
One of the guys in the Kilauea photos is the late Robert Decker, I believe. So, it's highly unlikely he's 'looking back' on anything!
To Mike (comment #1): the fact that the areas subjected to the hazards from future eruptions on Gran Canaria are very densely populated gives the issue some urgency, I would say. Moreover, many of the recent eruptions on Gran Canaria had phreatomagmatic components, and phreatomagmatic eruptions are known to produce base surges, which are a dilute but very violent and destructive/deadly sort of pyroclastic flow. The so-called "calderas" on the Canary Islands are indeed often maars, or large craters on Strombolian scoria cones. The term "caldera" comes from the Canary Islands and was not originally applied the same way it is now in volcanology.
Also at Cumbre Vieja on La Palma, the most likely volcanic events in the future are Strombolian eruptions with some phreatomagmatic activity; there have been thousands of similar eruptions since the last major catastrophic collapse. The apocalyptic scenario of a massive tsunami-generating collapse is certainly an attractive subject for the mass media but in the spectrum of different categories of future events it is the least likely. While it is correct to somehow include this scenario in civil defence planning in coastal areas at risk from such a gigantic tsunami, it is all but certain that none of us will be alive when this happens.
Do the people need to worry about the swarm! Ah, the media....
As for quake swarms, there is one going on about halfway between Lone Pine and China Lake right to the east of Hwy 395. There are over 300 quakes in the area in the last week and nobody talks about that one. Of course, the quakes are not coming as fast as they are at Yellowstone, but I just though I would mention it. No other reason than to poke a little fun at the media.
Boris, thank you for your explainations on Gran Canaria. I found it very interesting and your comment on the one part of it sliding in the ocean and creating a huge tsunami for the eastern coast put that issue in better perspective. The media sure tries to make it sound like we are in dire danger right now. It is something to be aware of, but not overly so.
Is there any news on eruptions, anyone?
You guys are scaring me! (Only half kidding). This is far too technical for me to understand. Is there a for-dummies-who-live-on-gran-canaria version?
I live on the island and nobody here seems to really be worried about things. Is that head-in-the-sand or is it reasonable and you are talking far future things? What worries me is I know this stuff is of course not 100% predictable so maybe there is risk today even if not so high.
I'm thinking of leaving actually (for other reasons) and this is one of the things that is making me think I'd love to live somewhere safe!
Huh. Those pics from Hawaii look familiar. I'm not sure that being put on the internet 7 years ago really counts as "recently unearthed," but they are neat photos.
Dianeâ how strong is the swarm in Owens Valley? I was there hiking on Friday and Saturday, but didn't feel anything. Then again, I've slept through several quakes in California only to have one wake me up in Massachusetts.
@Victoria, I don't know of anyplace on Earth that is totally safe. There are places that are safer than others. As for eruptions on Gran, I think mostly they are talking about strombolian eruptions and those are named for the island volcano Stromboli. Ususally an eruption of this type puts on a show, but doesn't necessarily do much else. It can get explosive, but I wouldn't worry too much. Just be aware things happen and have some kind of plan to deal with it.
@Locutus, the largest quake in the area was a 4.4 on the 15th. Also on the 15th two 3.4, 3.6, 3.5 and a 3.0. After that, and before for that matter, most of the quakes are small and below 2. A lot of them are below 1 so it doesn't surprise me you didn't feel anything. The 4.4 occurred at 12:23am and the last 3.4 was at 10:36pm.
Right now there are over 335 quakes listed on the map for the last week. Not all of them are in the area of the swarm.
Massachusetts eh? LOL
i agree on Boris words. As far as we´re living in densely populated areas, this kind of maps are really wellcome. For sure it should be nice to perform this kind of maps at Cumbre Vieja, but even more than that, it should be really fantastic to have some attention from those who are supposed to act in case things get ugly. Everyday i go to Teide to check my stations and i take a look to the Orotava Valley...i just don´t want to think about it...
Anyway, does anyone have more information about the Yellowstone swarm? i have no updates since last Tuesday and the Madison River Station still shakes....
Cheers!
@Diane: I woke up in Somerville, MA about a minute before it started. I thought it was a truck going by at first, but it lasted much too long for that. Sure enough, in the morning I had an email from the quake guys at Harvard with the moment tensor solution for a 2.9Mw (if I remember correctly) in New Hampshire at the same time I was woken up. Only one I've ever felt.
00.23 on the 15th. Missed it by one day. I was in Beatty, NV (the other side of Death Valley). No way I'd have felt it.
@Diane: I woke up in Somerville, MA about a minute before it started. I thought it was a truck going by at first, but it lasted much too long for that. Sure enough, in the morning I had an email from the quake guys at Harvard with the moment tensor solution for a 2.9Mw (if I remember correctly) in New Hampshire at the same time I was woken up. Only one I've ever felt.
00.23 on the 15th. Missed it by one day. I was in Beatty, NV (the other side of Death Valley). No way I'd have felt it. I wonder if the campers at Fossil Falls felt it— looks like it was centred just a little south.
@Locutus,
I have felt many quakes. I was in Yosemite when I felt after shocks from some quakes (6+) that hit the Mammoth area. That was quite a while ago.
I was in the Administration tower on Hayward campus, now called East Bay, when the Colinga quake hit. I was on the 4th floor and was that a ride!
Anyway, I have been in a lot of them. One woke me up at about 5am and it was an up and down motion and it sounded like a freight train. I mean it was loud!
I could go on, but I won't bore everybody. Suffice it to say, I have been though many of them. Fortunately, I have not been were they were really large. I was on I80 when the Loma Prieta hit and I thought they needed to fix the road. It looked rather corrigated. LOL It was years later that I figured out it was due to the quake.
If you are walking, you can see the ground roll if the quake is strong enough. That is a weird feeling!
Boris: thanks for putting me right on Gran Canaria. Consider me suitably chastised :o) I'd forgotten about base surges..they may not always be as hot as other types of PF, but a hurricane-force blast at 100 degrees C is just as fatal as one at 400!
Re Cumbre Vieja: OK, a collapse may not be an immediate hazard, but what worries me is the possibility that such a collapse might be triggered by an earthquake WITHOUT any associated volcanic activity. Although I'm not going to lose sleep over it. Yet.
Yellowstone is still shaking. Interesting. Here is the link to The closest station.
http://quake.utah.edu/helicorder/ymr_webi.htm
Those the guys in the Kilauea photo were released years ago. I have a copy of them that dates pre 2000
If I remember right, a Canary Island eruption could cause a tsunami that would devastate the East Coast.
One other fascinating put up! This is among the few blogs I can return to on a regular basis.
Not sure if anybody mentioned this, I didn't read every one of the comments, but your websites' layout is a litte off in Flock running on Windows7.