JOCKEY'S RIDGE STATE PARK, NC, AS A POTENTIAL MARS DUNE ANALOGUE

Jockey’s Ridge State Park, located on the North Carolina Outer Banks, is the largest sand dune complex on the east coast of the U.S. Historical observations of the dunes date back to the early 1900s, and offer a useful record of dune migration over a considerable period of time. Technological advances in the early twenty-first century have provided a means for effectively resolving short-term dune changes. In particular, with unmanned aerial vehicles (UAVs, colloquially termed “drones”) we can create high-resolution orthomosaics and digital elevation models (DEMs), with resolutions of <5 cm/pixel and <10 cm/pixel, respectively. Here, we compare the Jockey’s Ridge dunes to select counterparts on Mars in terms of slope, aspect, scale, and morphology. We carried out several mapping campaigns at Jockey’s Ridge State Park in fall 2016 and early spring 2017 with the DJI Phantom 4 UAV. Image data were processed as stereo photos to create DEMs of the entire park for each visit. The altitude at which we flew the drone, as well as the percentage of image overlap, was varied to explore how image data quality was affected. Our results indicate that the dunes at Jockey’s Ridge are of the same scale and tranverse form of many dunes on Mars, and so this State Park represents a previously unrecognized analogue study site for Martian dunes in the eastern U.S. The major difference between these Terran dunes and those on Mars is the depositional environment: Jockey’s Ridge State Park is situated in an area dominated by aeolian and marine deposition (the latter during storm events). Aeolian activity is dominated by a north–south wind regime, with the largest volume of sand being moved during the winter nor’easters. In contrast, dunes on Mars are controlled only by aeolian activity. Nonetheless, both sets of dunes have the same transverse morphology, indicating that differences in depositional environment do not hinder the use of coastal dunes on Earth as meaningful analogues to dunes on Mars.