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April 18, 2024 - Iceberg A23a Continues Northward Drift
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On April 11, 2024, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured a true-color image of a decades-old and immensely large iceberg drifting slowly northwards into warmer waters.
Iceberg A23a broke from the Filcher shelf in Antarctica in 1986 and quickly grounded on the seafloor of the southern Weddell Sea, only about 120 miles (200 km) from its calving location. The berg became unstuck from the seafloor in the early 2020s, likely due to melting from below the waterline.
Since beginning to drift freely, it has made slow progress northward. First, it took its time exploring the Weddel Sea, riding the currents of the Weddel Sea Gyre for most of the summer of 2023. Then, from November 2023 to February 2024 it took a lengthy spin on the currents off the tip of the Antarctic Peninsula, performing a full pirouette before capturing a more northerly current to ride.
On April 12, the U.S. Ice Center reported that A23a was located at 059° 05' 57.01" S latitude and 045° 07' 44.76" W longitude, which is roughly half-way between the tip of the Antarctic Peninsula and South Georgia Island. Icebergs in this region usually drift eastward around South Georgia where they begin to find warmer waters and ultimately melt.
Image Facts
Satellite:
Terra
Date Acquired: 4/11/2024
Resolutions:
1km (1.8 MB), 500m (5.1 MB), 250m (4.3 MB)
Bands Used: 1,4,3
Image Credit:
MODIS Land Rapid Response Team, NASA GSFC
On April 11, 2024, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured a true-color image of a decades-old and immensely large iceberg drifting slowly northwards into warmer waters.
Iceberg A23a broke from the Filcher shelf in Antarctica in 1986 and quickly grounded on the seafloor of the southern Weddell Sea, only about 120 miles (200 km) from its calving location. The berg became unstuck from the seafloor in the early 2020s, likely due to melting from below the waterline.
Since beginning to drift freely, it has made slow progress northward. First, it took its time exploring the Weddel Sea, riding the currents of the Weddel Sea Gyre for most of the summer of 2023. Then, from November 2023 to February 2024 it took a lengthy spin on the currents off the tip of the Antarctic Peninsula, performing a full pirouette before capturing a more northerly current to ride.
On April 12, the U.S. Ice Center reported that A23a was located at 059° 05' 57.01" S latitude and 045° 07' 44.76" W longitude, which is roughly half-way between the tip of the Antarctic Peninsula and South Georgia Island. Icebergs in this region usually drift eastward around South Georgia where they begin to find warmer waters and ultimately melt.
Image Facts
Satellite:
Terra
Date Acquired: 4/11/2024
Resolutions:
1km (1.8 MB), 500m (5.1 MB), 250m (4.3 MB)
Bands Used: 1,4,3
Image Credit:
MODIS Land Rapid Response Team, NASA GSFC
