One of the most dangerous jobs in science has to be a volcanologist. When you watch the video above you can see why (although trying to get that close to a bubbling cauldron of lava is not just dangerous; it’s stupid enough that even your fellow volcanologists will yell at you). But collecting and analyzing samples of lava and deadly gases are just a couple tools in the volcanologist’s box; here are some of the other—safer—ways they study volcanoes:
Measure seismic activity: Earthquakes are an early warning sign that something is going on underground with a volcano. The rumblings can be difficult to interpret, but an increase in activity often presages an eruption.
Measure ground movements: Scientists often set up sensitive tiltmeters that can detect the tiniest changes in the shape of a volcano’s surface. Before an eruption, the volcano may start to bulge as magma accumulates closer to the surface. Before Mount St. Helens erupted in 1980, the north side of the volcano visible bulged, but more often this deformation is detectable only with sophisticated equipment.
Take the volcano’s temperature: If a volcanologist wants to see how hot a volcano has become and which lava flows are newer (and hotter), there’s no need to get up close. A thermal imaging camera on an airplane or satellite can take a picture and identify the hot spots.
Check on its geophysical properties: Minute changes in the electrical conductivity, magnetic field and even gravity around a volcano can indicate that something is brewing beneath the surface.
Map it in three dimensions: A 3-D map of all the nooks and crannies on the surface of a volcano can help scientists make predictions about where the lava will flow and who is most in danger in the event of an eruption.
Study the volcano’s past: Scientists examine geologic deposits to learn about past eruptions, which can give important clues to what a volcano may do in the future.
(HT: Bad Astronomy)