Measuring beneath the Pine Island Ice Shelf

On the margins of Antarctica, an ice shelve acts as a dam slowing the movement of outlet glaciers flowing toward the sea. However, the ice shelves are exposed to the underlying ocean and may weaken as a result of warm ocean currents. Scientists recently completed an expedition to the ice shelf buffering the Pine Island glacier, a major outlet of the West Antarctic Ice Sheet that has rapidly thinned and accelerated in recent decades. Drilling a shaft through the ice shelf, they submerged instruments beneath the ice to measure ocean velocity, temperature, and salinity. Their observations revealed a 600-m-wide 80-m-deep channel cut into the underside of the ice-shelf that incurs melting beneath the ice shelf of 0.06 m per day. See the paper here for details.

This animation shows the ocean currents colored by their velocity circulating around and under the Pine Island ice shelf. Orange and yellow indicate faster currents while green and blue depict slower. A small red marker indicates the location of the drill site. In this animation, the Pine Island ice shelf is temporarily sliced away to reveal the ocean flows under the ice and subsequently restored up to the location of the drill site. A shaft penetrates through the ice sheet and the instrument is lowered through the shaft into the water that flows beneath the ice shelf.

In this animation, the topography and ice shelf thickness is exaggerated by 15 times.