United States Permafrost Association

John Zarling
President Elect
Cathy Wilson
Past President
Dmitry Streletskiy
Susan Wilson
Peppi Croft
Board Members
Mark Bennett
Torsten Mayrberger
PYRN Representative:
Matthew Whitley
IPA Executive Committee
Frederick "Fritz" Nelson
IPA Representative
Frederick "Fritz" Nelson
Thomas Krzewinski

US Permafrost Association
PO Box 750141
Fairbanks, AK

Frozen Ground
Frozen Ground 2019

Educational Permafrost Gallery (EPPG): Skip Walker

Please attribute photo credit and copyright to Skip Walker, unless otherwise indicated.

Camp at Isachsen
Camp at Arctic Field Course
Camp at Isachsen. Evening lectures were conducted in the large yurt on the right and the smaller yurt was lab space. The electric fence around the camp and two native hunters from Sachs Harbor protected the camp from polar bears.
Camp for the Arctic Field Ecology course.
Students studying permafrost
Permafrost ground formations
Students working along a microtopographic transect, studying the relationship between patterned ground features, vegetation, and invertebrate populations. Photo by Fred Daniels.
Typical landscape in vicinity of Isachsen with small non-sorted polygons in the foreground. Slopes leading down to the creek have turf hummocks, and creek margin has wetland vegetation with weakly developed string hummocks. The hill in background is composed of diabase volcanic rocks, and most of the more gently rolling terrain is composed of colluvium derived from Christopher Shale.
Small nonsorted polygons
Larger nonsorted polygons
Small nonsorted polygons, 10-20 cm diameter, with strong cracking pattern developed on salty clayey soils derived from Christoper Shale.
Larger nonsorted polygons, 30-50 cm diameter, with well-developed vegetation in the cracks between polygons.
Soil pit, ice wedges
Expedition Truck
Soil pit in zonal vegetation. The active layer is about 35 cm. Massive ice at 55 cm is part of a very large ice wedge. Such wedges were commonly encountered in the soil pits on zonal sites.
Expedition truck on return trip from Inuvik along the Dempster Highway.
DC-3 Stuck in Mud
DC-3 Stuck in Mud
DC-3 stuck in the mud on the Isachsen runway. Five Twin Otter flights were required to bring the equipment and people into Isachsen. The DC-3 was planned to reduce the number of Twin Otter flights required on the return trip, but this proved to be a mistake. During the days prior to this picture, the previously dry runway had developed wet patches due to water wicking up from the permafrost table. This condition went unnoticed until the DC-3 tried to turn on a soft spot. Once the plane was stuck, vibration from the engines caused the wheels to sink deeper until they contacted the permafrost table.
The final solution required digging down to permafrost and building a solid low-angle ramp consisting of planks overlaid with concrete blocks (one block is being handled by one of the pilots). These blocks were previously supports for runway markers along both sides of the runway. Photo by Chien-Lu Ping.