MOUNT VESUVIUS, the volcano that buried Pompeii, threatens Naples.
Image: Courtesy of Pastorius/Wikimedia Commons
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The volcano that buried Pompeii in A.D. 79 still rumbles deep down. Last erupting in 1944, Mount Vesuvius poses an ever-present threat to the Italian populations around Naples. Whether the volcano will erupt in Pompeiian proportions again is a question that preoccupies scientists monitoring it, as they hope to predict when Vesuvius will blow and provide adequate warning time.
One way to gauge the magnitude of an impending volcanic eruption is to determine the size of its "throat"—the internal tube through which magma travels upward to the surface. The larger the tube, the bigger the eruption is likely to be.
Hiroyuki Tanaka of the University of Tokyo reasoned that the throat could be "x-rayed" with energetic muons produced in cosmic-ray showers. The number of muons passing through the volcano would depend on the density of intervening rock, so measuring the number of muons passing through various parts of the volcano could yield a crude, 3-D view of the interior.
This clip from "Deadliest Volcanoes," by PBS's NOVA, provides a look at muon imaging. The entire NOVA program explores the threats from volcanoes around the world, including the supervolcano below Yellowstone National Park and the eruption threat in the U.S. Pacific Northwest. It airs on Wednesday, January 4, at 9 P.M. on PBS.
Watch Sneak Peak: Deadliest Volcanoes on PBS. See more from NOVA.
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7 Comments
Add CommentI don't know why PBS/Nova doesn't give permission to view their clips on the net from Canada. They are the only ones doing this.
Reply | Report Abuse | Link to thisIt's probably one of those digital rights management things; remember PBS is partly government-funded and must adhere to strict import-export regulations. No doubt they'll soon figure out that Canada isn't trying to steal U. S. secrets and open their videos to you.
Reply | Report Abuse | Link to thisAnyway, (spoiler alert) the technique works and is very very cool despite not being real-time, at least not yet. It's an outstanding example of pure research having practical application with real-world benefits.
While the narrator seemed to indicate that this method measured the amount of lava that would be ejected by an eruption, it seems to me that only the size of the magma tube is measured. This would indicate only the potential amount lava that could be ejected at a specific pressure and flow rate...
Reply | Report Abuse | Link to thisSeems like this method would only work well for the portion of the volcano that is above the surrounding ground level. It is difficult to see how the volcano throat could make a large enough difference when compared to the sum of differences if the muons must transit hundreds or thousands of miles through the earth.
Reply | Report Abuse | Link to thisCanada has some rules requiring that a certain portion of content show in Canada be produced in Canada. Perhaps that is the reason.
Reply | Report Abuse | Link to this"Canada has some rules requiring that a certain portion of content show in Canada be produced in Canada. Perhaps that is the reason."
Reply | Report Abuse | Link to thisThat applies to Television I believe and is extremely unlikely to apply to internet video.
For the record I can't view it from the UK either.
Anyone know how long it takes muons to travel through the volcano?
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