I was living in the U.K. when Mount St. Helens blew its top in 1980, but I remember the spectacular pictures and the mayhem that resulted. The volcano remains active, erupting most recently in 2004. So when I read about the current collaboration between NASA's Jet Propulsion Laboratory, the USGS, and the University of Washington State Vancouver to create and install a network of networked, instrumented 'spiders' into and around the volcano's crater, I was intrigued, to say the least.
Because volcanoes can cause massive destruction so quickly, early warning of any behavior changes is critical for deciding when, where, or if to evacuate and also to better understand volcanic behavior; hence the interest in creating volcano monitoring systems and placing them around active volcanoes. Nobody sane wants to argue with millions of tons of molten rock. Or ash. Or boiling mud. Or all three. And the extreme environments characteristic of active volcanoes—heat, caustic chemicals, extremely rugged terrain, the earth moving—means that acquiring measurements of ground movement, gas emissions, and other characteristic phenomena has never been particularly easy or safe. A project to develop a low-cost sensor network to monitor active volcanoes seeks to change that.
The article "NASA Goes Inside a Volcano, Monitors Activity" explains the project in greater depth, but I'll reiterate the high points here. Essentially, tripod-mounted instrumentation cases are lowered from a helicopter onto various hot spots in and around the crater proper. The cases contain an array of different sensors as well as communications equipment. The spiders or 'pods' communicate with each other, creating a ground-based sensor network, and also with NASA's Earth Observing-1 (EO-1) satellite. The resulting Sensor Web provides both terrestrial and satellite data, the higher-resolution ground measurements supplementing those from the satellite's sensors. As USGS instrumentation engineer Rick LaHusen says in the article, "With these high-tech instruments, we can rapidly respond during periods of volcanic unrest to supplement our permanent monitoring network or quickly replace damaged stations without excessive exposure to personnel."
So, we can build these devices, plonk 'em in harms way, and get useful data out of them without requiring people to dress up in protective gear and go frolic around molten rock. What's not to love?