Computer simulations reveal that the Earth's crust must stay really warm to keep most of North America above water. Karen Hopkin reports.
Global warming is bad. But a warm globe is good—at least if you live in North America. Because researchers from the University of Utah have shown that if the Earth’s crust weren’t so toasty, most of North America would be undersea. Most people think that mountains are made by the movement of tectonic plates…those massive slabs of land that drift across the earth’s surface. Well, that’s partly true. Tectonic forces do build mountains. But those forces, say the Utah scientists, act in part by changing the temperature of the rocks they move. Hot rocks are less dense—and more buoyant. And the more buoyant you are, the higher you float.
The scientists used a computer program to chill the North American crust to about 750 degrees Fahrenheit. That’s the temperature of the coldest crustal rock in the continent, which covers half of Canada. Without the heat, they found, North America sank: New York City dropped a quarter mile into the Atlantic ocean. Dallas, Chicago, Las Vegas…all blub blub blub. Interestingly, cooling the crust caused Seattle to soar to an elevation of nearly 6000 feet. Those of you looking for the high ground might check out real estate in the Puget sound.