Volcanic Awakenings


Our planet’s lithosphere is never quiet for very long, and there’s nearly always something going on with earth’s top layer. Today is no exception, and while Alaska’s Cleveland volcano has calmed down some, having been downgraded to yellow alert status by AVO, elsewhere in the world volcanoes are waking up and reminding us they are not extinct by any measure.

In Mexico Popocatepetl has been notifying locals this week that it’s not to be ignored with four loud explosions on Tuesday, rockfalls, ash, and water flowing down it’s flanks. Gosh, this could be bad. Popo, as we volcanogeeks call it, is immediately southwest of Mexico City, which has a rather large population I hear, and so this might just concern them a bit.

Popocatepetl doing it's thing

My Dad lives in Oaxaca, 175 miles southeast of Popo, so he’s not likely to be affected by it unless it erupts massively and ash falls there in Oaxaca. There are likely to be more explosions from Popo over the next few days, which doesn’t really indicate a significant eruption at this point, but I sure would like access to the seismographs there so I could follow this as closely as I would so much like to.

Ya know, webicorders are a joy for me, I just love pouring over seismograms for hours on end, (well gosh, don’t we all?) and having immediate access to seismic data from active volcanoes is just about the best thing in life for me. I will of course be scouring the web today for any data on Popo that I can find, and will update this post with any goodies I come up with. Moving right along…

Any of you who may have followed my blog here (unlikely as that may be) know that Tambora is my very favorite volcano in the whole world, and for very good reasons. Frankly I wish I could start up the Tambora Fan Club and have T-shirts and caps made up. Most people have never heard of it and are far more interested in Dancing with the Stars, Survivor, and American Idol, but Tambora may be getting ready to grab our attention again.

The crater of Tambora, five miles across, as seen from orbit

Over the last five months Tambora has been observed becoming more active seismically and visually. Ground-based observers at an observation post in Tambora village noted dense white plumes rising 50-75 m above the caldera rim during April and June, but no plumes during May or July. This month (August) dense white plumes rose 20 m above the caldera rim. This is not insignificant.

In 1815 this volcano produced the largest eruption in recorded history, a VEI 7, resulting the the global “year without a summer”, blowing off the top 4000 feet of the mountain, and blasting 36 cubic miles of rock and ash into the stratosphere. As eruptions go that’s a pretty tough act to follow. VEI 7 is one notch short of a super-eruption.

There has been quite a bit of seismic activity in the region there of late, with a 6.8 quake in the Banda Sea this week and three others of lesser magnitude along the subduction zone of the Solomon Islands, which may be in some way related to Tambora’s increased activity of late. I’m guessing at this point that the dense white plumes being seen indicate a big increase hydrothermal activity, which of course means that magma has moved closer to surface in the floor of the crater and it’s boiling off the water in there. Things are heating up at Tambora and next we can look for a lava dome to be pushed up in the crater.

Looking out into Tambora's crater

Here we can see water in the crater, and that’s what’s boiling out right now. (By the way, there are no bass in that lake.)

Again at Tambora there are no seismographs available to me on the web, which I find enormously frustrating in this case because it’s my very favorite volcano in the world, okay? Arrrrgggghhh!

Indonesian volcanologists have yet to provide webicorders for any of their volcanoes with the exception of Merapi, which has four of them, but isn’t doing anything at all right now, so biggie wow guys. It’s the same story in the Philippines, where PHIVOLCS has all the most interesting volcanoes there fully instrumented and won’t let me at the data. I wrote them about this outrage, but thus far no response.

Update:

Papandyan becoming active again

The Papandayan volcano in Indonesia has been active over the last week and is starting to worry folks there. Papandayan is a complex andesitic/basaltic stratovolcano best known for it’s last eruption in 1772, when it’s northeast flank collapsed resulting in gigantic avalanche that wiped out 40 villages killing almost 3000 people. Papandayan has calmed down a bit and the alert is downgraded for now, but another Indonesian volcano has started acting up in it’s stead.

Soputan volcano on Sulawesi has begun erupting and alerts have been posted, as Soputan entered the eruptive phase at 11 p.m. on Saturday night and erupted at 6:03 a.m. on Sunday morning.
The eruption sent searing gas up to 6,000 meters into the air, released hot volcanic rocks and spewed heat clouds that were heading west. National Disaster Mitigation Agency (BNPB) spokesman Sutopo Purwo Nugroho said the government warned locals to stay six kilometers away from the center of the crater. This is a young volcano, so far un-vegetated, but one of the most active in Indonesia.

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About Martina Vaslovik

Volcano nerd and seismogeek
This entry was posted in Popocatepetl, Tambora, Volcanology. Bookmark the permalink.

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