Louis Sass, III

Zan Frederick (USGS) installing a camera on the Mt. Foraker weather station, located on the southeast ridge at 7,826'. This site is a collaboration between USGS, Denali National Park, and the National Park Service Inventory and Monitoring program. The camera transmits low-latency images once daily in winter and hourly during the busy summer season.

Zan Frederick (USGS) installing a camera on the Mt. Foraker weather station, located on the southeast ridge at 7,826'. Mt. McKinley (20,320 ft) and Mt. Hunter (14,573 ft) are in the background. This site is a collaboration between USGS, Denali National Park, and the National Park Service Inventory and Monitoring program.

The wind was too strong for a helicopter to land, therefore, glaciologist skied down Wolverine Glacier to Paradise Lake.

By 4:42 pm on December 13, the sun has set and it is time leave Wolverine Glacier.

At site S on Wolverine Glacier. Zan digs down to the previous summer surface to see where the ablation stake intersects the melt surface. This will allow scientists to calculate the ablation (melt) from the previous summer.

Taking notes at site EC on Wolverine Glacier.

Extending a mass balance stake at site EC on upper wolverine glacier. These stakes are used to measure snow accumulation and ablation (melt). 

Wind driven snow transport across the glacier surface near site Y on upper Wolverine Glacier.

A core section from Kahiltna Glacier at 3,055 m (10,023 feet) on September 30, 2024, showing ice layers in finegrained snow. These "internal accumulation" layers form when water from surface melt percolates into the snowpack and refreezes.

Emily Baker (USGS) sampling a snow-pit on Kahiltna Glacier at 3,055 m (10,023 feet).

These are large glaciers, and even with a helicopter they make you feel very small. Here the scale of the crevasses is illustrated by the small helicopter shadow. This is typical of the complicated topography and significant relief that is common on larger glaciers in Alaska.

This is a 16 m (52.5-foot) core from Kahiltna Glacier at 3,055 m (10,023 feet), May 26, 2023. Kakiko Ramos-Leon (NPS, on the left) is standing where the core intersected the surface. Eric Ridington (pilot, in the middle) is pointing to the melt layers from summer 2022. The melt layers barely visible as grey stripes in the foreground are from summer 2021.

Remote weather stations, like this one at Wolverine Glacier, collect data near each glacier so scientists can understand regional climate influence on the glaciers.

Scientist uses radio-echo-sounding to study firn compaction on Wolverine Glacier, Alaska. Radio-echo sounding (RES) is a technique used by glaciologists to measure the internal structure, ice thickness and sub-ice morphology of glaciers. This tool is equivalent to X-rays for the medical profession and the physicists. 

The Wolverine Glacier weather station was installed in 1968, and at 3250 ft is the highest elevation long-term weather record on the Kenai Peninsula. On October 19, 2020, USGS scientists upgraded the power system to a Lithium battery bank and installed a radar-based precipitation sensor (Lufft WS-100) to compare with the weighing based precipitation gage.

The Wolverine Glacier weather station was installed in 1968, and at 3250 ft is the highest elevation long-term weather record on the Kenai Peninsula.

The Wolverine Glacier weather station was installed in 1968, and at 3250 ft is the highest elevation long-term weather record on the Kenai Peninsula. In Ocotober 2020, USGS scientists upgraded the power system to a Lithium battery bank and installed a radar-based precipitation sensor (Lufft WS-100) to compare with the weighing based precipitation gage. The

The Wolverine Glacier weather station was installed in 1968, and at 3250 ft is the highest elevation long-term weather record on the Kenai Peninsula. Close up of the new radar precipitation sensor on the top of the pole. The crazy looking thing in the middle of the picture is an aspirated temperature sensor.

Ablation stakes on Gulkana Glacier, Alaska. Late summer fieldwork on Gulkana Glacier reveals ablation stakes emerging from the ice. Measurements of the change in the height of the snow and ice at these stakes is one aspect of determining glacier mass balance.

A scientist checks data collection on multiple sensors at the Gulkana Glacier weather station where snow blankets the glacier surface. 

A scientist prepares to extract a snow core from one of the Benchmark Glaciers. Cores are used to determine the density of the snow and ice on the surface of the glacier in order to determine the mass balance.