Massive Ice Hole Opens in Antarctic Sea Ice
A rare 34,400-square-mile polynya formed off Breid Bay, Antarctica, in August 2024.
Updated on Oct. 26, 2026 in Severe Weather
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A massive hole in the sea ice, known as a polynya, appeared off the coast of Breid Bay, Antarctica, between August 4 and August 10, 2024. This 34,400-square-mile opening is the first of its kind recorded in this area since at least 1979.
Why it matters
The event was triggered by a series of six atmospheric rivers that delivered warm air and wind to the region, causing ice to melt from above and below. This suggests that previously stable regions of East Antarctica may be increasingly vulnerable to similar thinning as atmospheric rivers strengthen.
A marine heat wave raised upper ocean temperatures by up to 1.1°F, while air temperatures reached 31°F warmer than usual during peak events. The polynya covered 34,400 square miles, significantly impacting the area that had maintained 93.1% ice coverage since 1979.
The details
Six atmospheric rivers swept over Breid Bay between July 6 and August 6, 2024, creating conditions where warm deep water welled up to the surface. As the surface layer thinned, the combination of downward radiation and rising warmer ocean water caused the ice cover to collapse.
Timeline
Six atmospheric rivers reached the bay from July 6 to August 6, 2024.
The polynya first appeared on August 4, 2024.
The ice hole reached its peak size on August 8, 2024.
The bay closed as the ice reformed on August 10, 2024.
Seasonal Patterns
While polynyas have been historically documented in the Weddell Sea, this event represents a rare emergence in the Breid Bay region after 45 years of stability. It highlights a shift in coastal Antarctica where extreme meteorological events now mirror patterns previously seen in more volatile sectors.
There are no immediate safety protocols for the general public regarding this localized Antarctic event. Researchers continue to monitor the region for signs of further instability and ice thinning.
The takeaway
The formation of this hole demonstrates how atmospheric rivers can overcome historical sea-ice stability in Antarctica. As these events become more frequent, scientists anticipate that previously frozen bays may face similar unpredictable melting cycles.
Further reading
Learn more about recent climate phenomena on our Severe Weather page.
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