Why put a GPS tracker on a rock?

An enduring mystery in Geology is why and how rocks move of their own accord over a nearly flat, mud-cracked lake bed in Death Valley National Park–the Racetrack Playa. We set up the “Slithering Stones Research Initiative” in 2011 to find out.  With NPS permits in hand, we set up a weather station, and outfitted 15 rocks with GPS loggers to record when they moved, how fast they went and where they went. This past December, Jim Norris and I saw them go, and our GPS trackers recorded what they did. Now we have a paper in PLOS ONE  that tells the curious tale of the wayward rocks of Death Valley!  This is a free download thanks to my paying for open access: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0105948

We also have a couple videos that show what we saw….See: