There are thousands of volcanic features distributed throughout the southwest United States, which are grouped together in volcanic fields. The Yellowstone Volcano Observatory (YVO) monitors these volcanoes using a combination of techniques. While YVO hasn’t seen anything to suggest magma is on the move, the area is stretched and pulled apart to produce numerous tectonic earthquakes. YVO keeps an eye on these volcanoes and the Yellowstone Volcano, as described in this monthly video update by Mik

For this month's video update of the Yellowstone Volcano Observatory, we'd like to introduce you to a friend of ours. This friend has been monitoring changes of the ground surface in Yellowstone for decades and is so good that it can detect movement of just a few millimeters in magnitude (just a fraction of an inch). The friend? A continuous GPS station! There are dozens of continuous GPS stations throughout the Yellowstone region, and they show us that the ground in Yellowstone is always changi