One of the most amazing functions of GPS technology, is the ability to accurately measure the slightest movements on Earth with instruments orbiting in space. Tracking devices have been used to monitor the movements of wildlife, merchandise, transportation, and even loved ones. Researchers have also been using GPS technology to track the movement of mountain ranges. Incredibly, scientists have found that the Sierra Nevada mountain range is currently growing at a rate of 1 to 2 millimeters annually, which is relatively fast for a mountain.
“The exciting thing is we can watch the range growing in real time,” said lead researcher Bill Hammond, from the University of Nevada. “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 minuscule changes are measured using satellites in space.” The Sierra Nevada mountains are growing quite a bit faster than other ranges, such as the Alps, likely because the ranges are formed from two very different processes. The Alps and Andees mountain ranges are formed as a result of colliding tectonic pates, where the Sierras are thought to be made from mantle flow.
“The Sierra Nevada uplift process is fairly unique on Earth and not well understood,” explained Hammond. “Our data indicate that uplift is distributed along the entire length of the 400-mile-long range, between 35 and 40 degrees north latitude, that it is active, and could have generated the entire range is less than 3 million years, which is young compared to estimates based on some other techniques. It basically means that the latest pulse of uplift is still ongoing.”
“We’ve integrated GPS and InSAR (a type of space radar) measurement techniques, drawing from experience we developed in the past five years in our work with tectonic deformation, to see how the Sierra is gradually being pushed upwards,” said Hammond. “Combined with more GPS stations, and more radar data, detecting motions in the Earth is becoming more precise and ubiquitous. We can see the steady and constant motion of the Sierra in addition to episodic events such as earthquakes.”