Surveys of Maunakea permafrost sponsored by Office of Maunakea Management, findings published

The last permafrost in Hawai‘i: After extensive temperature measurements and targeted geophysical surveys sponsored by the Office of Maunakea Management, the permafrost has been re-documented.

Aerial view of researched area showing permafrost boundaries.
Three people stand inside Pu’uwēkiu Crater, marking the bottom and top end of a buried ice body documented in 1974. The shaded areas illustrate the extent then and now. Courtesy photo, click to enlarge.

In the coldest climate, on the tallest summits of Hawai‘i, temperatures fall below freezing during winter nights. In 1969 Alfred Woodcock discovered areas inside cinder cones on Maunakea that are permanently frozen. At one place the ice was about 32 feet thick and 27 yard long, buried beneath about one foot of boulders, the only permanent ice known in all of the Hawaiian Islands.

Recently, a group of scientists, and their students investigated the state and health of this unique permafrost, in a way that involves minimal disturbance to the environment. Because these ice-rich bodies lie buried beneath the surface, they are not easy to locate. After extensive temperature measurements and targeted geophysical surveys sponsored by the Office of Maunakea Management, the permafrost has been re-documented.

Some of the ice found by Woodcock inside Puʻuwēkiu Crater is still there, but most of it has disappeared. Its north-south extent, once 27 yards, is now 12 yards; its thickness, once 32 feet, is now 12 feet. The ice has retreated all around. If the trend between 1973 and 2015 is extrapolated, the remainder may disappear within a few years.

The results of the permafrost survey were published in the journal Permafrost and Periglacial Processes.

Read more about the permafrost survey: The Last Permafrost in Hawai‘i.

-Via UH System News.