May 4, 2012 |
From the highest peak in the continental United States, Mt. Whitney at 14,000 feet in elevation, to the 10,000-foot-peaks near Lake Tahoe, scientific evidence from the University of Nevada, Reno shows the entire Sierra Nevada mountain range is rising at the relatively fast rate of 1 to 2 millimeters every year.
“The exciting thing is we can watch the range growing in real time,” University of Nevada, Reno’s Bill Hammond, lead researcher on the multi-year project to track the rising range, said. “Using data back to before 2000 we can see it with accuracy better than 1 millimeter per year. Perhaps even more amazing is that these miniscule changes are measured using satellites in space.”
Miniscule as they may be, the data indicate that long-term trends in crustal uplift suggest the modern Sierra could be formed in less than 3 million years, which is relatively quick when compared to estimates using some geological techniques.
Hammond and his colleagues in the University’s Nevada Geodetic Laboratory and University of Glasgow use satellite-based GPS data and InSAR (space-based radar) data to calculate the movements to this unprecedented accuracy. The calculations show that the crust moves upward compared to Earth’s center of mass and compared to relatively stable eastern Nevada.
The data may help resolve an active debate regarding the age of the modern Sierra Nevada of California and Nevada in the western United States. The history of elevation is complex, exhibiting features of both ancient (40