On the Kenai Fjords National Park Visitor Center plaza, a triangular-shaped kiosk shaded by a roof displays three signs.
The sign's title appears over a photograph taken in August, 2005, of the Harding Icefield and Northwestern Glacier. Three inset photographs accompany text and illustrations.
Sign Text:
"Visit Kenai Fjords National Park by land, sea, or air, and one thing is sure: You will see lots of ice. The Harding Icefield and its outflowing glaciers are quite easy to access—making them ideal to study. Scientists have measured and monitored changes in these glaciers for decades.
Studies intensify with today's growing concern about climate change. Earlier scientific work sought to learn the glaciers' history and how glaciers shape our world. Studies now focus on how glaciers respond to climate change and what this means for Kenai Fjords and our planet's overall health."
In the background photograph, the Northwestern Glacier slopes from the mountain peaks and Harding Icefield down to the water.
Three insets discuss scientific studies.
Measuring Glacier Mass Balance
A photo shows scientists standing in an excavated hole in a glacier as they work. A red line on a graph rises during winter accumulation, then falls during the summer melt. The difference between the starting point at the beginning of winter and the end of summer is labeled "mass balance."
Caption:
"Year after year, scientists measure the amount of winter snow accumulation vs. summer melting at different elevations on the glacier. This data, called mass balance, along with other glacial traits —such as elevation and area — help us understand how each glacier is responding to climate change. Overall, Kenai Fjords' glaciers are losing mass."
Radar Reveals Ice Thickness
A photo shows a scientist using a laptop and radar equipment on a glacier. An illustration shows how radio waves go through the ice of the glacier, bounce off the rock at the bottom of a glacier, and come back up to the surface.
Caption:
"Glacial ice forms over time, as the steady weight of accumulated snow compresses lower layers of snow. Ground-penetrating radar is a tool that allows scientists to determine ice depth. Repeat measurements can show the rate of glacier thinning."
Mapping the Terminus
A photo shows a ranger with a GPS backpack walking along the edge of a glacier. A simple map shows shrinking outlines of Exit Glacier in 1950, 1973, 2007, and 2014.
Caption:
"Changes to a glacier's leading edge, its terminus, are easy to observe. Long-term data confirms that both land-based and tidewater glaciers at Kenai Fjords have retreated dramatically over the past century — sometimes losing miles in length. Researchers use both repeat photography and GPS technology to monitor changes at a glacier's terminus."