 new responsibilities. People must use it wisely to gain its benefits. And geoscientists need to open their thought to new perspectives, including nonscientists' viewpoints. What probably is the greatest geophysical discovery of this century - discovery of the underlying mechanism that shapes Earth's surface - makes the point.
From 1912 to his death in 1930, German meteorologist Alfred Wegener was a geologist's hair shirt. He promoted the heretical notion that continents whose outlines fit together once were together. Geologists thought they knew better. They believed Earth's surface is shaped by wrinkling as the planet slowly cools down and shrinks. Continents could move up or down, but not sideways. Wegener integrated knowledge from several fields, including paleobiology, at a time when those fields were segregated. Their practitioners rarely interacted. Meteorologist Wegener was treading on forbidden turf. Feelings ran so strong that, 50 years ago, the professor of my geomorphology class described Wegenerism as "a great evil." But a decade later, Roger Revelle - then director of the Scripps Institution of Oceanography in La Jolla, Calif. - remarked that "we no longer have to talk about [continental drift] in the washroom."
A flood of new evidence revolutionized geoscientists' concept of Earth. It revealed Earth's crust to be a collection of plates that bump together, rub together, or overlap. New crust wells up along plate boundaries at ocean ridges and moves away carrying continents with it. Old ocean crust plunges back down beneath other plate boundaries along continental edges. There the crustal material is often recycled and returned to the surface and the atmosphere through volcanoes. This incessant action causes most earthquakes and many volcanoes.
What scientists call plate tectonics now provides an overarching perspective for Earth science. It guides research into earthquake and volcano mechanisms. It provides a framework for fields as diverse as global climate change and the ecology of a mountain range. Seismologists can't predict when an earthquake will hit. But knowing where plates interact and form fault lines, they can warn of vulnerability. Climatologists know that recycling of ocean crust and sediments - including carbon sequestered from atmospheric carbon dioxide - influences the composition of the atmosphere. Ecologists can better understand habitats in the Canadian Rockies when they know how these mountains crumpled up as two plates crunched together.
However, knowledge is only as beneficial as people make it. It did little good for seismologists to warn of Turkey's earthquake risk when building codes weren't enforced and people refused to leave high-risk areas. As Donald Swanson at the US Geological Survey's Hawaii Volcano Observatory has observed, "When you mesh natural hazards with politics, economics, development, etc., it's a recipe from which it's hard to make an edible dish."
Volcanologist Michael Sheridan with the State University of New York at Buffalo says the way to make it palatable is to combine public education with local monitoring. He says, for example, people "should know their volcano ... and identify safe areas." When Mt. Pinatubo erupted in the Philippines in 1992, such preparation was what Dr. Sheridan calls "the key to mitigation."
A decade of such cooperative planning also worked for Papua, New Guinea, when Mt. Rabaul erupted in 1994. Twelve people died, as opposed to 500 in the 1937 eruptions.
Such successes are relatively rare, though. Fouad Bendimerod at RMS Inc. in Menlo Park, Calif., and several colleagues writing in Science International warn that "the rate of urban risk caused by explosive population growth far exceeds the progress made in preparedness," especially in developing countries. The authors are part of an international scientific organization called the Earthquakes and Megacities Initiative, which is trying to speed up the needed preparedness.
Citing United Nations statistics, Dr. Bendimerod and colleagues note that 80 percent of our planet's human population 