by Shane Byrne 

This semester (Spring 2022), the LPL field trip (PTYS 590) headed off to the Mojave Desert in California armed with various remote sensing datasets. There is a wide variety of test data in the Mojave from Synthetic Aperture Radars to visible wavelength cameras and there is an even wider range of geologic features to examine, from sand dunes to lava flows. We often spend a lot of time looking at data from places we’ll never see in person, so this was a chance for us to do both!

The next destination was a volcanic crater known as Kilbourne Hole, where the LPLers saw a textbook example of stratigraphy On the first evening, we stopped at the giant Kelso sand dunes and tried to figure out how to explain their radar appearance in different bands. A sunset hike to the top allowed us to take in a gorgeous moonrise from the summit. We experienced the Kelso dunes’ rare ability to boom. Booming dunes make low rumbling sounds during sand avalanches thanks to their very specifically shaped and sized sand grains.

The desert southwest has a lot of playas and the Mojave is no exception. We visited two of these dry lake beds with very different radar signatures. Soda Lake (a bone-jarring hour-long drive down dirt roads) is still connected to the subterranean Mojave River and is wet just below the surface, whereas Broadwell Playa is hydrologically isolated and dry.

The Mojave has plenty of volcanos and we were able to visit cinder cones and lava flows at Cima, Pisgah, and Amboy. The different flows at these sites have very different radar behavior that is a proxy for their age. We camped beside the most recent (~11 thousand years old). Although a bit hard to scramble into, caves at Cima and Pisgah added an astrobiological dimension to the trip. Data from airborne spectrometers help us figure out the weathering state of the cinder cones and composition of other geologic units.

Our last night was spent near the town of Amboy on Route 66 (a ghost town that refuses to die). Roy’s motel will always be beloved by the group and the high winds we had that night certainly made the last campsite memorable. The Mojave is always a favorite as it teaches all kinds of things about remote sensing, geology, and four-wheel-drive controls.

You can support LPL field trips with a gift to the Wilkening-Sill Field Trip Fund: https://give.uafoundation.org/science-lpl

Gathering at top of a cinder cone in the Cima Volcanic Field.

Aerial view of the campsite at the edge of a young lava flow. Photo courtesy of student Nathan Hadland and his drone.