The Arctic Kobuk Dunes: Significant Harbors of Water and Implications for Solar System Dunes

Session: Geomorphology and Surface Processes Across the Solar System

Presenting Author:

Jani Radebaugh

Authors:

Radebaugh, Jani¹, Dinwiddie, Cynthia², Stillman, David³, Phillips-Lander, Charity⁴, Baginski, Emma⁵, Flores, Mauricio⁶, Parmenter, Dylan⁷, Wendt, David⁸, Atekwana, Estella⁹, Oladeji, Emmanuel Oluwatimilehin¹⁰

(1) Brigham Young University, Department of Geosciences, Provo, UT, USA, (2) Southwest Research Institute, San Antonio, TX, USA, (3) Southwest Research Institute, San Antonio, TX, USA, (4) Southwest Research Institute, San Antonio, TX, USA, (5) Brigham Young University, Provo, UT, USA, (6) Southwest Research Institute, San Antonio, TX, USA, (7) Southwest Research Institute, San Antonio, TX, USA, (8) Southwest Research Institute, San Antonio, TX, USA, (9) University of California Davis, Davis, CA, USA, (10) University of California Davis, Davis, CA, USA,

Abstract:

The Kobuk Dunes of northern Alaska span a region of 75 km2 and alternate between being covered in up to several meters of snow in winter and being dry at the surface and mobile in summer. The ARRAKIS project (Assessing Regional Reflectors of Astrobiology in Kobuk Dunes for Interplanetary Science), part of the NASA PSTAR (Planetary Science and Technology for Analog Research) program, seeks to understand the surface and subsurface properties, in particular the wetness and astrobiological potential of such a system. Our findings have applicability to solar system dunes, especially to the seasonally frost-covered dunes of Mars.

The first project field season in March 2025 saw deployment of field-portable, planetary mission-style biological, geophysical and geomorphological instruments onto dune and interdune surfaces frozen and covered in >1 m of snow. Drones revealed broad, tall (up to 15 m) transverse dunes with snow-covered surfaces. We obtained hand-drilled cores in our study interdune at 3 m below the sand surface and on the dune stoss slope at 4.5 m, both of which saw wet (unfrozen) sand from ~2 m depth downwards, with some intermittent dry zones. These samples will be evaluated for their Optically Stimulated Luminescence (OSL) age, a proxy for dune overturn rate. We deployed ground-penetrating radar at frequencies of 100, 200, and 250 MHz behind a snowmobile and collected capacitively coupled resistivity data with an OhmMapper instrument, all of which saw significant wetness several meters below the sand surface. A Spectral Induced Polarization (SIP) instrument, which measures the frequency-dependent impedance, related to the resistance, showed potential wetness. The second field season is occurring in summer 2025. Similar measurements will reveal the impact of meteoric infiltration from snowmelt and seasonal rain on observations.

Our studies of the Kobuk dunes reveal they are a slowly overturning system compared to lower latitude dunes. Water is retained high up in the dune through slow infiltration from melted snow and rainfall. The wet layers of the dunes and interdunes may persist over long time periods, making them ideal sites for life to thrive. Similar conditions may exist on the giant (470,000 km2) Olympia Undae polar dune field of Mars, where slow throughput of liquid could lead to conditions favorable for life.