Technicians visiting autonomous instruments on Greenland’s northwest coast last week found more evidence that polar bears have a taste for science. An American and a Danish scientist conducting maintenance on GNET stations south of the Thule Air Base found one had been “aggressively damaged” by a bear, wrote Finn Bo Madsen of Technical University of Denmark (DTU). The Danish institute is collaborating with U.S. National Science Foundation-funded researchers led by Mike Bevis (The Ohio State University) to maintain a network of more than 45 Global Positioning System (GPS) and seismic monitoring stations that ring the perimeter of the world’s largest island.
GNET is part of the larger Polar Earth Observing Network, or POLENET, which has also instrumented Antarctica’s ice sheet with autonomous monitoring devices. Scientists study the data collected by these instruments to monitor the mass balance of the world’s great ice sheets. Seismic information, combined with very precise GPS measurements, tell scientists about regional changes in melting or accumulation on the ice sheets, information that helps them to explain how the ice sheets are responding to changing climate. The GNET system also records earthquake activity believed to be caused by post-glacial rebound—the land bouncing back under the lessening weight of Greenland’s shrinking ice cap.
Though GNET planners avoided areas known to be frequented by bears when they selected project sites, this is not the first time a polar bear has left its mark on a GNET monument. In 2009, a maintenance team visiting a site north of Thule Air Base found suspected polar bear damage on instruments and solar panels used to power the site during the summer. They repaired the damage, but the installation stopped sending data to scientists back in their labs shortly thereafter. A repeat inspection in 2010 revealed that bears “may have rubbed their backs on the monument, been chewing on cables or have given the equipment a thorough pounding with their paws,” reported Bo Madsen at the time.
This time, Madsen speculates that the bear was “perhaps scratching its back on the solar panels,” as a panel, antenna and cable were damaged. Technicians armed with repair kits spent more than five hours repairing the site, improvising additional ways to make the site less interesting to bears. Madsen mentioned that the team would later assess how much data the site had collected in the interim.
Meanwhile, a polar bear spotted on the edge of town was the talk of Kangerlussuaq, where CPS personnel staff the NSF’s logistics hub in Greenland. Polar bears are known along Greenland’s northern coasts, but are rare to the south, where Kangerlussuaq is located. Locals recalled that this was the first bear spotted near Kangerlussuaq since 1998; prior to that, the last bear was seen in 1957.—Kip Rithner