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Introduction
This web site is based on the NASA/Goddard Space Flight Center (GSFC) video,"Glacier Bay, Alaska, from the Ground, Air and Space," which brings glaciers to life with spectacular "fly-bys" of scenic rides over 3-dimensional glaciers, live video footage of ice fronts calving into the sea, dramatic picture sequences of historic and satellite data, and more. The Scientific Visualization Studio (SVS) of GSFC's Earth and Space Data Computing Division produced the video under the direction and guidance of Dr. Dorothy K. Hall/Code 974, Laboratory for Hydrospheric Processes at GSFC's Hydrological Sciences Branch.
This award-winning web site presents many of the stunning images and dramatic movie sequences from the Glacier Bay video, as well as additional footage, animations, and reference material, including:
- what a NASA glaciologist has learned about glaciers and how their formation could be related to climate change;
- how glaciologists and visualization specialists at NASA worked together to produce visualizations that help scientists explain their research;
- how satellite data can be used to measure glacier changes from space; and
- how remote sensing can extend
the records of historical ground-based measurements to the present.
The following images are samples from this web site:
Hand-drawn maps
Dr. Hall has studied the movement of some of the glaciers in Glacier Bay, Alaska, as well as glaciers in other parts of the world. For her studies of Glacier Bay, Dr. Hall obtained material from colleagues and from historical collections including explorers' hand-drawn maps of these glaciers from as far back as 1794.
Satellite image of Glacier Bay, Alaska
Dr. Hall has also studied satellite imagery from NASA's Landsat series of satellites, which has acquired images since 1972. Landsat enables study of the movement of glaciers from the MultiSpectral Scanner, with a spatial resolution of 79 m, and the more advanced Thematic Mapper, with a spatial resolution of 28.5 m.
Recent and historical
slides and photographs.
(119K) An animated glacier diagram.
Using their combined artistic and scientific expertise, NASA's science visualizers and scientists wove historical records of the early 20th century with more recent images, live-action video, and computer animations of satellite imagery. The result: A lively historical perspective of glacier changes at Glacier Bay.
Scientists use special computer techniques to study glaciers. Here, a satellite image is registered to a map drawn by early explorers.
Pushing forward scientific analysis of these glaciers, GSFC's Laboratory for Hydrospheric Processes used special computer techniques to combine historical records of Glacier Bay with satellite data "... providing a wealth of information about the deglaciation at Glacier Bay" according to Dr. Hall. Scientists are able to measure changes in glacier terminus position for periods over the past two centuries by registering satellite images to maps drawn by early explorers.
Scientists can relate the movement of glaciers to regional climate change, where applicable. Because tidewater glaciers (Java Applet) follow their own cycles of advance and retreat, their movement cannot be directly tied to short-term climate. Thus the tidewater glaciers in Glacier Bay are not good indicators of short-term regional climate change. However, the non-tidewater glaciers (Java Applet) of Glacier Bay, which have shown some evidence of retreat over the last 40 years or so, most likely can be tied to regional climate change. Non-tidewater retreat is probably a result of amelioration of regional climate as evidenced by a tendency toward increasing air temperatures measured at nearby meteorological stations.
(1MB) Quicktime animation showing computer techniques used to create glacier
fly-bys.
Cindy Starr/GST produced special effects using images created by Janet Chien/GSFC's Laboratory for Hydrospheric Processes. Starr created nine spectacular "fly-bys" of scenic rides over the glaciers using the SVS' leading edge visualization tools.
(952K) Quicktime animation of live video footage of ice calving from the
Johns Hopkins Glacier.
Dramatic, live footage of ice fronts calving into the sea, as well as other video footage shot on location by David Affens/Code 480 are available on this web site.