“Doomsday Glacier” melting fast 

A new study providing a close-up view of Antarctica’s vast Thwaites Glacier shows warm water is seeping into its weak spots, worsening melting caused by rising temperatures


THWAITES GLACIER
192,000km2

If melted completely, Thwaites could raise global sea levels by half a metre

Icefin: Underwater robot fed through borehole drilled through glacier. It carries cameras, sonar, and instruments for monitoring water flow, salinity, oxygen and temperature


ANTARCTICA
South Pole

Europe for size comparison


3.5 metres


HOW THWAITES IS MELTING
Changing winds and currents allow warmer water to well up under ice, reaching grounding line – point where ice sheet begins to float

Grounding line has retreated 14km since late 1990s

ICE SHELF
Grounding line
Ice flow
THWAITES GLACIER 
Retreat
AMUNDSEN SEA
CONTINENTAL SHELF

In parts of underside of glacier that are flat and uniform, melt rate is slow – 5m per year – because layer of fresh water insulates ice from warmer water below

But where there are fissures or sharp steps, warm water is eroding glacier at much higher rate – 30m per year – contributing to nearly one third of ice loss


Sources: thwaitesglacier.org, International Thwaites Glacier Collaboration, British Antarctic Survey
© GRAPHIC NEWS