It’s been in the works for a while now. This week the active phase begins. With some 3,500 seismic sensors installed around Mount St. Helens, the plan is to detonate twenty-four 500-1000 kg shots of HE in 12-inch bore holes, each about 80 feet deep. The detonations will occur Tuesday evening, July 22, 2014.
If all goes well, the seismic waves generated should “paint” a 3D picture of the magma chamber under the volcano. If it doesn’t go well, saronara, folks!
Hope they have a large platoon of virgins ready to toss in, just in case things start going really badly. Pele, or whoever is the volcano god in the Pacific Northwest jurisdiction, may need some major placating after this.
ETA: BTW, quite by happenstance, I had the opportunity to fly almost directly over Mt. St. H. shortly after the 1980 blow-out. I was traveling to Seattle for a week-long conference on killer whales, and the plane flew right past it – from my side of the plane, we could see out the window right into the crater.
The pilot announced it, and dipped that wing for our better viewing pleasure. The crater was still smoking. All the trees for about a mile all around were all laying on the ground like piles of Pick-Up Stix. And everything was covered in gray ash all around.
Sounds pretty cool to me. I’ll read the articles and maybe come back with some questions but initially what I’m most interested in is the geometry of the charges and receivers and not just how deep but also how widespread of a data field they’re trying to aquire.
300 to 600 lb charges… can you image the Moho with that?
This seismic mapping of magma chambers seems to have some promise in eventually helping to predict eruptions, but on the other hand, it seems to be generating some nervousness, without, as yet, the ability to make definitive predictions. In the past couple of weeks data from similar studies at Mount Fuji and Mount Rainier apparently have indicated that both volcanoes are perhaps much closer to tipping over into an eruptive state than their appearance would suggest. Both have long been considered extremely dangerous due to the relatively large populations surrounding them, and due to a potential for explosive eruptions that could be consderably larger than the 1980 Mount St. Helens blast. It’s not yet clear how this data will be used practically to mitigate the risk.
Also, not directly related, but I’ve been keeping an eye on Long Valley, in California, in recent months. Since late last year, seismic activity there has been on a decided upswing, much of it concentrated in a couple of small areas; one about four miles west of the town of Mammoth Lakes, the other directly under the town itself. With that said, the USGS has not issued any alerts and the activity does not (yet) fall outside of historical norms.
This puts me in mind of an old bubble - gum card I had as a kid. The caption read, “Think before you louse things up!” …
The picture showed a fool with a brace and bit, boring a hole in a beehive!
