Racetrack Playa Trivia Quiz

Answer: A dried lake bed with rocks

Playa means "beach" in Spanish, but has changed to mean a dried up lake bed in English. In this case, the lake bed contains not only dried up and cracked mud, but some special rocks that have a mystery associated with them.

Answer: Death Valley National Park

Death Valley National Park has portions in both Nevada and California. The Racetrack (as it is often called) is in California.

Answer: A high clearance, fourwheel drive vehicle

While the Racetrack is located near other Death Valley features that are visited often and are fairly easily accessed, this is as the crow flies. The road to the Racetrack is long and extremely rough and difficult drive with a 1/2 mile hike at the end (don't go alone). The best way to access the feature is using a high clearance, four wheel drive vehicle. While the park does not specifically prohibit dirt bikes and ATVs on the road, it does prohibit off-road driving, so ATVs are not a good choice. It would be a difficult hike, so using your two feet is not recommended.

Answer: Sliding rocks that appear to move by themselves leaving long tracks

The stones on the lake bed move, leaving long tracks. This mystery wasn't explained for a long time. You'd think that someone would see the rocks moving, but this wasn't even caught on camera until recently. One of the tasks I was given in my GIS course was to map the trails of the sliding rocks.

Answer: Miners, while travelling and prospecting in the area

Miners were the first to have reported the sliding rocks, approximately one century ago.

Answer: They are all sizes, up to hundreds of pounds!

One of the reasons it was so difficult to explain the movement of the rocks was the variation in size. Some explanations would have solved the movement of small rocks, but not those of large rocks. The rocks not only vary in size, but also vary in their profiles, making it difficult to come up with an explanation that covers the movement of all the rocks, while excluding debris that is material other than rock (such as wood).

Answer: 2013

A team of led by a paleobiologist from the Scripps Institute of Oceanography partially solved the mystery in 2013. Other researchers on the team were from Johns Hopkins University, Boise State University and Interwoof.

Answer: They are pushed by wind moving thin sheets of ice on the inundated lake bed

Movement required specific conditions. The lake bed needs to be inundated (which only seems to happen in the winter). The nights need to be cool enough to freeze the lake surface. Then, as the ice melts, wind pushes the ice and the ice pushes the rocks. Apparently only light winds are needed to do this.

This is considered only a partial solution, as some of the largest moving rocks have not been observed to move under these conditions.

Answer: Direct observation and videos

This was an exciting discovery because the team was actually on site when the conditions were perfect for movement. They were able to directly observe the stones' movement and also catch the movement on video. They also had GPS data, as well as data on temperature and wind speed to confirm the direct observations and videos.

Answer: Increasing vandalism by tourists

While climate change might be reducing the conditions necessary for the stones to move, the biggest threat to the area is from people. Many tourists are now visiting the area and are walking on the fragile playa surface when it is wet, or even driving on the surface. In addition, many tourists are moving or stealing stones in order to get pictures or to keep others from taking pictures. There is consideration that maybe this should be a permit-only site.

If you wish to visit this unique site, please do not drive off-road, move the stones or walk on the playa when it is wet. This will preserve the area for everyone to enjoy this mysterious place!