The polar vortex hit its peak across much of America on Wednesday, with an icy grip that made Arctic Greenland seem like a toasty vacation spot in comparison.
These juddering 'ice quakes' were found by dropping a fiber-optic cable into a mile-deep borehole dug into Greenland ice.
The Greenland Climate Network (GC-NET), established in spring 1994, currently consists of 18 stations with a distributed coverage over the Greenland ice sheet. The GC-Net emphasis is to monitor ...