Hiawatha Glacier
Glacier in northwestern Greenland From Wikipedia, the free encyclopedia
Hiawatha Glacier is a glacier in northwest Greenland, with its terminus in Inglefield Land.[1][2] It was mapped in 1922 by Lauge Koch, who noted that the glacier tongue extended into Lake Alida (near Foulk Fjord).[3] Hiawatha Glacier attracted attention in 2018 because of the discovery of a crater beneath the surface of the ice sheet in the area.[4] A publication noted in 1952 that Hiawatha Glacier had been retreating since 1920.[5]
| Hiawatha Glacier | |
|---|---|
 Land-terminating Hiawatha Glacier (left-center) emerging from its semicircular parent ice lobe, in NW Greenland | |
| Coordinates | 78°49′N 67°01′W |
Probable impact structure
The proposed impact structure was identified using airborne radar surveys that showed the presence of a 31 km wide crater-like depression in the bedrock beneath the ice.[6] Shocked quartz grains and melt rock clasts have been found in fluvio-glacial sediments deposited by a river that drains the area of the structure. The timing of the impact has been dated using argon-argon dating and uranium-lead dating of zircon crystals within the melt rock to 57.99 ± 0.54 million years ago, during the late Paleocene.[7]
From an interpretation of the crystalline nature of the underlying rock, together with chemical analysis of sediment washed from the crater, the impactor was argued to be a type of iron asteroid with a diameter in the order of 1.5 kilometres (0.9 mi). If an impact origin for the crater is confirmed, it would be one of the twenty-five largest known impact craters on Earth.[6]
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