The Glacier Ablation Sensor System (GASS) is a ice-melt measuring device developed by Michigan Tech Research Institute (MTRI) in partnership with the U.S. Geographic Survey (USGS) and the Department of Interior Bureau of Land Management (BLM). It measures glacier melt rates along with other meteorological parameters. Once every hour, a GASS unit "wakes up" from low power mode and records the distance between itself and the ice, the ambient air temperature, wind speed, latitude, longitude and solar albedo. Beginning in 2004, a minimum of 6 GASS units have been placed at different locations throughout the Bering Glacier. For the 2008 field season, one of the GASS sensors was engineered to transmit data to a database using the ARGOS satellite service. The ARGOS satellite service uses a network of satellites to allow scientific data transmission from anywhere in the world. This website was created to display the ARGOS transmitted data from a single GASS unit in real-time.
Below are graphs reporting the most recent melt rate and termperature values recorded by the GASS sensor. In addition, the overall progress of the glacier melt is reported in a time-series chart, along with air temperature and wind speed and albedo.
Site B01-2008, the GASS site with the satellite data transmitter.
How to use these graphs:
These are dynamic time series graphs of GASS data. Move your mouse over the point you are interested in and it will display the value at that time (rounded up to the nearest integer). The types of data being displayed, as well as units, are listed below each graph. They are updated as the satellite transmissions arrive.
The following data is provisional and subject to revision
Total Ice Melt starting 06-04-2008 (cm).
(+/- 2 cm of sensor noise is expected)
Ambient Air Temperature (degrees C)
Wind Speed (m/s)
*This measurement comes from an uncalibrated light-level sensor. The values are proportional to incoming radiance from the sun.
Bering Glacier is rapidly retreating and thinning since it surged in 1993-95. From 2002 to 2007 we have mapped the terminus position and measured the surface ablation from the terminus region up glacier to the snow line in the Bagley Ice Field. Since the last surge the terminus has retreated, primarily by calving, approximately 0.4-0.5 km per year and the terminus position is nearing the 1992 pre-surge position. The glacier surface in the terminus region is presently downwasting by melting at approximately 8-10 m per year and 3.5-6.0 m per year at the approximate altitude of the equilibrium line, 1,200 m. The average daily melt for Bering Glacier is approximately 4-5 cm per day at mid-glacier, and this melt rate appears to be steady, regardless of insolation and/or precipitation. The melt from the Bering Lobe of the glacier system generates between 8-15 cubic km of fresh water yearly, which flows directly into the Gulf of Alaska, via the Seal River, potentially affecting its circulation and ecosystem. Elevation measurements from 1957 compared with our measurements made in 2004, combined with bed topography from ice penetrating radar, show that the Bering Lobe has lost approximately 13 percent of its total mass.
Since the new 2008 GASS unit was installed on June 4th, 2008 at site B01:
- There has been 262 cm (103 in) of total melt.
- The average temperature has been 6.02 C (42.83 F).
- The average wind speed has been 2.69 m/s (5.22 knots)
GASS Installation at the Bering Glacier
The helicopter leaves camp and heads for site B01-2008.
A steam drill is used to drill a small hole 10 m (about 30 ft) into the ice.
|A view of the Bering Terminus, in the direction of B01, taken from the helicopter while it was still near Bering camp.||An internal view of a GASS sensor.|
A set of poles are attached to create a single 12 meter long pole. The pole is 2 meters longer than the hole is deep so that the GASS device can be attached to it above the ice surface.
The pole is placed in the steam-drilled hole. The GASS device is fitted to the part of the pole that remains above the ice. The GASS device is then turned south to receive the maximum amount of sunlight for battery charging.
For more information about the Bering glacier, please visit beringglacier.org
The data found on this website is provisional and subject to revision.