State of High-Altitude Permafrost on Tropical Maunakea Volcano, Hawaii

One of the most unusual occurrences of sporadic permafrost is on the summit plateau of Maunakea volcano on Hawaii Island, where permafrost was documented in two cinder-cone craters in the 1970s. To investigate the state of this permafrost, we acquired multi-year ground temperature data and conducted electrical resistivity and ground penetrating radar surveys. The two ice bodies still exist, but one has shrunk in volume by an order of magnitude and is expected to disappear soon. The other is still more than 50 m wide. We also prospected the summit region for additional permafrost bodies, based on insolation modelling, temperature probing and geomorphological indicators, but none was found. Permafrost occurs preferentially in the interiors of craters with a closed basin, even though there are exterior slopes that receive less solar radiation annually.