Word: geophysicist
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...floor sediments and Greenland glaciers to study the chemistry of ancient mud and ice, and they are increasingly convinced that climate change is anything but smooth. The transition from warm to frigid can come in a decade or two -- a geological snap of the fingers. Says Gerard Bond, a geophysicist at Columbia University's Lamont-Doherty Observatory: "The data have been coming out of Greenland for maybe two or three decades. But the first results were really so surprising that people weren't ready to believe them...
There is hope, though, that forecasts will improve. In Nature, geophysicist Hazel Rymer and colleagues at England's Open University reported a possible sign of an impending eruption: shifts in gravity. They found that the gravitational field around Italy's Mount Etna increased sharply six months before it spewed forth in December...
...numerous smaller fault lines along the San Andreas, giving the region the look of a smashed windshield. Over the millenniums, the Mojave shear zone to the east may offer a path of less resistance to the giant plates and replace the San Andreas as a new plate boundary, suggests geophysicist Amos Nur of Stanford...
...today more sophisticated systems can alert people as much as a minute before a city starts to shake. "This is possible," explains Massachusetts Institute of Technology geophysicist M. Nafi Toksoz, "because seismic waves propagate through the earth's crust relatively slowly, 5 to 8 km/sec. With an extensive network of sensors, we can locate the epicenter and determine the magnitude of an earthquake. This gives us the opportunity to warn people in outlying areas." How long a warning depends on the distance from the epicenter. Had such a system been in place in Mexico, for example, residents of Mexico City...
...Tilling's colleagues, geophysicist Bernard Chouet, believes he may have found an answer to this dilemma. Prior to many large-scale eruptions, he says, seismometers have picked up tremors that appear to be caused, not by the fracturing of rock, but by low-frequency waves that resonate through the magma itself. While their origin remains a mystery, these vibrations may result from small surges of gas and molten rock. Large numbers of such signals preceded Mount St. Helens' 1980 blast. They also appeared before the unexpected explosion of Mexico's El Chichon in 1982, the blowup of Colombia's Nevado...