The Sierra Nevada range in the US grows about half an inch in elevation every 10 years, according to scientists. Researchers at the University of Nevada's geodetic laboratory in Reno and the University of Glasgow in the UK say they have recorded annual elevation increases between 1mm and 2mm for more than 10 years along the entire 400-mile range between Nevada and California. A combination of GPS data and space-based radar has provided them with unprecedented accuracy. "The exciting thing is we can watch the range growing in real time," said Bill Hammond, lead researcher of the multi-year project at 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 research was funded by the National Science Foundation and Nasa, along with the UK's Natural Environment Research Council.

Hammond said the findings would be published in July in the journal Geology and may help resolve an active debate regarding the age of the modern Sierra in California and Nevada.

The Sierra Nevada stretches from 10,000-foot peaks in the north around Lake Tahoe to the highest peak in the continental US 400 miles south – Mt Whitney at about 14,500 feet.

"Combined with more GPS stations, and more radar data, detecting motions in the Earth is becoming more precise and ubiquitous," he said. "We can see the steady and constant motion of the Sierra in addition to episodic events such as earthquakes."

Hammond said the history of the Sierra's elevation is complex and the uplift process "fairly unique on Earth." It exhibits features of both ancient elevation – as old as 40 million years – and relatively young elevation dating to less than 3 million years ago.

"Our data indicate that uplift is … active and could have generated the entire range in less than 3 million years, which is young compared to estimates based on some other techniques," he said. "It basically means that the latest pulse of uplift is still ongoing."