Science for All | What is the Petermann Glacier?

The Hindu’s weekly Science for All newsletter explains all things Science, without the jargon.

Updated - May 18, 2023 11:47 am IST

Published - May 17, 2023 03:36 pm IST

A calving front of Petermann Glacier.

A calving front of Petermann Glacier.

The Petermann Glacier connects the Greenland ice sheet to the Arctic Ocean and is named for German cartographer, August Heinrich Petermann. It consists of a 70km long and 15km wide ‘ice tongue’ whose thickness varies from 600 m to 60 m.

Recent research discovered an unknown mechanism, in how the glacier’s ice interacted with the ocean and suggests that climate scientists may be vastly underestimating the magnitude of future sea-level rise from polar ice deterioration. It emerges that the Petermann Glacier’s grounding line — where ice detaches from the land bed and begins floating in the ocean — shifts substantially during tidal cycles, allowing warm seawater to intrude and melt ice at an accelerated rate. The grounding line retreated nearly four kilo-meters — 2½ miles -- between 2016 and 2022, warm water carved a 670-foot-tall cavity in the underside of the glacier, and that abscess remained there for all of 2022.

The traditional view of grounding lines beneath ocean-reaching glaciers was that they did not migrate during tidal cycles, nor did they experience ice melt. But the new study over turns that idea and suggests that warm ocean water intrudes beneath the ice through pre-existing subglacial channels, with the highest melt rates occurring at the grounding zone.

Factoring in this, would mean that sea level rise from global warming would be thrice what is now expected of glaciers ending in the ocean, which includes most of northern Greenland and all of Antarctica.

From the Science pages

The first time climate change ‘went viral’ – 70 years ago

Baby’s got three parents: explaining Mitochondrial Donation Treatment

Can you spot the quantum physics around your house?

Question Corner

Has the future sea level rise been correctly estimated? Find out here.

Flora and Fauna

A break in the Western Ghats

The marine organism with a surprising wiring of neurons

Groundwater exploitation is silently sinking the ground beneath India’s feet

Explained | How are nutrients in millets affected by processing and polishing?

Mizoram records new parachute gecko

0 / 0
Sign in to unlock member-only benefits!
  • Access 10 free stories every month
  • Save stories to read later
  • Access to comment on every story
  • Sign-up/manage your newsletter subscriptions with a single click
  • Get notified by email for early access to discounts & offers on our products
Sign in


Comments have to be in English, and in full sentences. They cannot be abusive or personal. Please abide by our community guidelines for posting your comments.

We have migrated to a new commenting platform. If you are already a registered user of The Hindu and logged in, you may continue to engage with our articles. If you do not have an account please register and login to post comments. Users can access their older comments by logging into their accounts on Vuukle.