Nunataks are small volumes of rock that emerge above ice sheets and glaciers. They are isolated from mountain ranges and are often easier to access. This makes them particularly useful to geologists as a source of data about bedrock. The photos here shows the view of nunataks in Antarctica taken by Euphro and Chantal, who are both nunatak scientists and photographers.
Photo Friday highlights photo essays and collections from areas with glaciers. If you have photos you’d like to share, let us know in the comments, by Twitter @glacierhub or email us at firstname.lastname@example.org.
In an age when satellite images are often the only source of data you could need about a glacier, few people will still strap on ice cleats and lug a theodolite up to a calving ice front. What’s even more unusual is finding a group of 16 and 17 year olds who do just that.
For over 30 years, students from the high school in Petersburg, a town in southeastern Alaska, have been taking part in the LeConte Survey Program, a two-year training course where they spend their lunch break gaining the skills they need to produce reliable survey data from the LeConte Glacier. In their first year, they focus on the basics of surveying and mathematics, while in the second year, they, and two supervisors, visit the glacier as a group to survey it.
The LeConte Glacier is the southernmost tidewater glacier in the northern hemisphere. Tidewater glaciers are unconfined ice streams that stretch down from mountains, reach the coast and extend into open sea. The bottoms of tidewater glaciers rest on the sea floor, at elevations below sea level. These glaciers lose ice by calving, often creating copious numbers of icebergs.
On the day of the survey the group splits into two, with each hiking to a different ledge. Each group measures as many points on the glacier as possible (usually between 15 and 20) before a helicopter takes each group to the other ledge, where they cross-measure the other group’s points. They end the day with a “math night” of intensive trigonometry and data validation.
The LeConte Survey Program was founded in 1983 by geology teacher Paul Bowen. Trautman has been running the it since in the late 1990s, when Bowen retired. The LeConte Survey Program has given students a new perspective on the environment they grew up in and contributed to the science of glaciology. The student-collected data has used by professional scientists and published in academic papers.
In 1993, the students discovered very significant retreat of the glacier, half a mile in 6 months. Scientists became very interested in the Survey Program’s data. “That was way before we had any of the other, quote, unquote, huge recessions of glaciers,” said Vic Trautman, who runs the program. This discovery prompted researchers to collection additional data, particularly the height of the glacier’s terminus above the water level.
Researchers from the University of Alaska Southeast suggested to the students that the rapid retreat might indicate a thinning trend. Additional years of steady data collection proved this hypothesis to be correct. Their earliest records showed the glacier to be 250 to 260 feet above water level, but currently they are measuring it at 190 feet. “The face falls off continuously, but we have a map and we plot each point, so every year we get a new line,” Trautman said. “We can compare this year’s line to last year’s line, all the way back.”
Through measurement and monitoring of glaciers is often automated, direct field research can still be of value. It is satisfying to know that glaciers are providing young people with research skills, with direct experience of environmental change, and with the sense of participating in a community effort that has lasted for decades. Perhaps the dedicated efforts of two teachers to support this activity will inspire others to such establish such programs as well.