On our journey across the Southern Ocean, we flew directly over the Drygalski Ice Tongue!
An ice tongue forms when a glacier that is confined by a valley moves very rapidly out into a lake or (in this case) ocean, relative to other ice along the coastline. The ice tongue is actually a part of a glacier that is floating on the ocean.
When an ice tongue surges past adjacent coastal ice, the boundary experiences physical forces described as “shearing”. Look for the sheared, zig-zag edge of the Drygalski ice tongue in the timelapse video below.
Here are some amazing facts about the Drygalski Ice Tongue:
- It is the largest ice tongue in the world!
- It reaches 70 kilometers (43 miles) out to sea from the David Glacier
- It ranges from 14 to 24 kilometers (9 to 15 miles) wide
- It is thought to be at least 4,000 years old
- The David Glacier grounding line, where the ice leaves the shore and begins to float, is in a depth of ~1,900 m (6,200 ft)
- In 2016 a 30 km (19 mi) long section of the ice shelf calved to form two large icebergs