December 21, 2012
Hawaiian Mountains Could One Day Be Extinct
Lee Rannals for redOrbit.com — Your Universe Online
One day, Hawaiian mountains on the island of Oahu could be reduced to nothing more than a flat, low-lying stretch of land, according to new research.
Scientists wrote in the journal Geochimica et Cosmochimica Acta that Oahu´s Koolau and Waianae mountains are dissolving from within.
“We tried to figure out how fast the island is going away and what the influence of climate is on that rate,” Brigham Young University geologist Steve Nelson said in a statement. “More material is dissolving from those islands than what is being carried off through erosion.”
For the study, the researchers pitted groundwater against stream water to see which removed more mineral material. The team spent about two months sampling both types of sources.
The U.S. Geological Survey (USGS) took part in the study by helping the team to calculate the total quantity of mass that disappeared from the island each year, in addition to ground and surface water estimates.
“All of the Hawaiian Islands are made of just one kind of rock,” Nelson said. “The weathering rates are variable, too, because rainfall is so variable, so it´s a great natural laboratory.”
In order to forecast the island's future, scientists needed to account for plate tectonics as well. The scientists said that Oahu actually rises in elevation at a slow, but steady rate.
While the idea of Oahu going from a place of beautiful diversity, to a flat land seems scary, don't worry it's not going to happen anytime soon.
According to the researchers' estimates, the net effect is that Oahu will continue to climb for as long as 1.5 million years. After this, groundwater will eventually overtake the island, and it will begin its descent to a low-lying topography.
Undergraduate student Brian Selck, who co-authored the study, performed mineralogy analysis of soil samples in the lab back in Provo. The island's volcanic soil contained at least one surprise in weathered rock called saprolite.
“The main thing that surprised me on the way was the appearance of a large amount of quartz in a saprolite taken from a 1-meter depth,” Selck said.