Mountains reach new heights
9 Oct 2006 by Evoluted New Media
The mountains in Europe are growing taller and melting glaciers are partly responsible, scientists say.
The mountains in Europe are growing taller and melting glaciers are partly responsible, scientists say.
Heavy glaciers cause the Earth's crust to flex inward slightly. When glaciers disappear, the crust springs back and the overlaying mountains are thrust skyward, albeit slowly.
The conclusion by the University of Milan based team is based on a new computer model which assumes that over timescales of a few years to thousands of years, the surface of the Earth behaves like a very thick fluid.
“Imagine honey or molasses, only a billion, billion times more viscous,” said study leader Valentino Barletta. “When you remove the weight [of the glacier], the viscous fluid takes some time to refill the depression that's left behind.”
The European Alps have been growing since 1850 when glaciers began shrinking as temperatures warmed, but the rate of uplift has accelerated in recent decades because global warming has sped up the rate of glacier melt, the researchers say.
The region where the most uplift is occurring is in the French Alps near Mount Blanc, the tallest mountain in Western Europe. The mountains in this region are growing at a rate of about .035 inches per year. In 50 years, they will be about 1.8 inches taller than today. The average maximum growth for the rest of the Alps is a more modest .013 inches per year.
Glacier shrinkage accounts for half of the observed increase, while other geological factors, such as active shifting of the Earth’s tectonic plates, drainage and erosion, are responsible for the rest, the researchers say.
