Uneven heat gives regions a lift
Not only is North America floating on a sea of magma, it's riding high, scientists from the University of Utah say. And it's all because of unusual heat.
Currents of molten rock deep in the Earth heat some areas of the surface more than others. These areas expand and thus become more buoyant. They rise and "float" higher. Much of North America would lie far below sea level were it not buoyed by a greater-than-average share of warmth.
Traditional plate tectonics says that colliding plates pushed up the Rockies, the Himalayas, and the Alps. The new study argues that collisions alone aren't keeping Denver a mile high.
"If you subtracted the heat that keeps North American elevations high, most of the continent would be below sea level," says study coauthor Derrick Hasterok, a University of Utah doctoral student in geology and geophysics, in a press release. "Differences within the Earth's crust and upper mantle explain about half of the elevation of any given place in North America." Take that extra heat away, and Denver sinks 727 feet below sea level. New York City would be 1,427 feet down, and Los Angeles a whopping 3,756 feet under the Pacific.
Book your Mars vacation in 2107
Will shirt-sleeve vacations on Mars be a reality by the turn of the century? Noted physicist Lowell Wood, now a visiting fellow at the Hoover Institution in Stanford, Calif. thinks that humanity could be well on its way to making the red planet livable by 2050. The job could be completed in 100 years, he said recently at the Aspen Institute.
Mars is stuck in what Dr. Wood calls a "thermal depression." In a Martian day, temperatures near the equator can swing from 70 degrees F. during daylight to minus 110 degrees F. at night – too extreme for Earth's terraforming vegetation. The first step is to narrow the gap between these highs and lows. A potential solution: Create an artificial greenhouse-gas effect. After decades of warming, when Martian temperatures reach the "biospheric optimum" – temperatures resembling Earth's – Mars will experience a "Great Spring."
"I believe it's roughly a 50/50 chance that young children now alive will walk on Martian meadows … will swim in Martian lakes," said Wood. It's not a matter of technology or money – it's a matter of will, he said.
• Some material, particularly quotes, came from the Associated Press and Space.com.