Scientists are listening to the hum of America's great rock arches to keep a check on their integrity. These geological wonders adorn the Colorado Plateau in the southwestern US - not to mention the desktop wallpapers of countless computers worldwide. By attaching seismometers to the sandstone structures, researchers can measure their modes of resonance. Tracking changes through time could highlight any new weaknesses in the rock that might herald a collapse. There is nothing anyone can do about this - the arches are created and destroyed by erosion. It's the natural order. But an alert to potential danger might be useful to the National Park Service as it manages the many visitors who come to marvel at these imposing forms. "They're very impressive - global icons that are super-rare, delicate and of course very beautiful," says Dr Jeff Moore. Jump media playerMedia player helpOut of media player. Press enter to return or tab to continue. Dr Jeff Moore: "A tool to sense the arches' internal mechanical properties" The University of Utah researcher is presenting his team's work at the American Geophysical Union's Fall Meeting in San Francisco this week. The group has been attaching a clutch of sensors - not just seismometers, but tiltmeters and temperature probes - to some of the state's most spectacular arches. These include the Landscape, Double-O and Mesa structures. Dr Moore and colleagues are "listening" to them ring. The arches are excited by the wind and by natural Earth noise, such as distant ocean waves. More pics via BBC News.
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