Ever wonder what mathematicians do on vacation? In Texas A&M professor Wolfgang Bangerth’s case, he kicked off summer 2015 by hiking through history related to another of his disciplinary specialties: geophysics.
A widely respected expert in computational mathematics and mathematical modeling, Bangerth is the author of the software program ASPECT (Advanced Solver for Problems in Earth’s Convection). His code is helping geodynamics researchers around the world visualize the Earth’s interior and related processes, thanks to funding assistance from a major facility in California at the epicenter of geodynamics research.
Earlier today, Bangerth found himself at the site of one of the worst geological disasters in U.S. history, Mount St. Helens in Washington State. Roughly one month after the 35th anniversary of the historic eruption, Bangerth toured the area, posting these incredible photographs on Facebook and agreeing to share them via the Texas A&M Science blog.
“What a treat,” Bangerth writes, “A seven-hour hike through the devastation area and then halfway up Mount St. Helens. (Additional treat: Total number of people encountered in the first six hours: 1. In fact that equals the total number of mammals encountered during this time.)”
In addition to the photos and captions, Bangerth — ever the educator — offered to expound on the science as follows:
“So here’s the story: Mount St. Helens is one of the chain of Cascade volcanos along the U.S. West Coast that exist because the Pacific (or, more exactly, the Juan De Fuca plate) subducts beneath the North American plate. They take with them millions of years of sediments, entrapped water, etc., and this leads to melting of material when they get to certain depths, and this melt then comes up a couple of 100 miles inland of the subduction zone.
“In 1980, magma rising up bulged out the side of the volcano. After an earthquake, this whole bulge collapsed in a gigantic landslide. Liberated of the pressure of the overlying rock, two enormous explosions then ripped apart most of the mountain within seconds of the landslide. There is a fantastic video of this created from a sequence of 10 or 15 pictures and also another series here.
“What you see in my pictures are the remains of the volcano (1,300 feet shorter than it was before, with its enormous gash on one side) and the valley below the landslide and miles downstream from there — in some places up to 700 feet of debris, ash and the results of several later pyroclastic flows. The deep incisions are streams that have eroded this loose material.
“The landscape is largely barren since it had, of course, not a single living organism left after the 1980 event, and is only slowly re-growing. Along the streams there are man-high trees these days, but elsewhere you only find bare gravel and sand — some covered by hardy mosses and lichens — and in many places lots of miniature bluebonnets and some Indian paintbrushes. There are ants and a few insects, but generally few vertebrates. I did see a small number of birds, including a pair of hummingbirds. By and large, it’s a huge contrast from the densely forested areas around the mountain (and how it looked before the event, as seen in older pictures).”
Texas A&M Science 