Satellite Imagery of D-30A.
NASAs Aqua satellite captured this image of D-30A at the edge of Clarence Island on September 6, 2023 using its MODIS (Moderate Resolution Imaging Spectroradiometer) sensing unit. Other MODIS imagery reveals the berg approaching the island in late August, running into its southeast coast, and then turning around the island in the very first two weeks of September. By late September, the berg had actually moved away from the island and wandered north.
” It didnt stick quite most likely because the eastern side of Clarence Island has a quite sheer drop-off with deep enough water to permit the berg to sail right through,” said Christopher Shuman, a University of Maryland, Baltimore County, glaciologist based at NASAs Goddard Space Flight.
Effect On Local Ecosystem
Still, the arrival of a big iceberg on the coasts of a small island like this can set off a cascade of impacts– some favorable, some unfavorable– for regional wildlife and ecosystems. Iron-rich meltwater from icebergs can help fertilize ocean water and encourage helpful phytoplankton blooms.
On the other hand, a big iceberg parked offshore a small island can disrupt penguins from foraging, and Clarence Island is home to more than 100,000 breeding pairs of chinstrap penguins. “But in this case, the timing was fortunate because the chinstraps that breed there had not returned to the colony yet,” stated Heather Lynch, a Stony Brook University ecologist. “If this had occurred in December when they were reproducing and the adults were compromising incubation daily, it may have been quite severe because even a few days of obstructed access to the colony may indicate a failed breeding year.”
Considering that the berg gone by Clarence Island relatively rapidly without ending up being grounded, the bigger impacts in this case may have included a process called iceberg searching, explained Roseanne Smith, a researcher with the British Antarctic Survey. “Scouring can have significant impact on the benthic plants and animals, with single scouring events causing as much as 98 percent mortality of the local macrofauna and megafauna in shallow areas,” she stated. “Luckily, due to the fact that the seafloor slopes steeply on the east of the island, the scouring damage from the D-30A impact will have been localized.” There can likewise be an upside to searching. Benthic biodiversity in fact peaks when there is some, but not too much, iceberg scour since scour can open space for types that are less competitively dominant but are more tolerant of iceberg scour, she included.
Previous Path and Future Directions
Before reaching Clarence Island, D-30A had drifted west along the Antarctic Coast with the Antarctic Coastal Current for numerous months in 2021, before Weddell Gyre ocean currents pushed the berg northwestward into the open waters of the East Weddell Sea. In November 2022, the berg made a sharp turn north, moving along the Antarctic Peninsula in an area called “Iceberg Alley” on its technique to Clarence Island.
Precisely where D30-A heads next will depend on weather and ocean currents, however icebergs in this location are typically pressed east by the effective Antarctic Circumpolar Current funneling through the Drake Passage, the body of water in between South Americas Cape Horn and the South Shetland Islands of Antarctica. From that point, icebergs often move north across the Southern Ocean towards the South Atlantic and quickly melt in the areas warmer waters.
NASA Earth Observatory image by Wanmei Liang, using MODIS information from NASA EOSDIS LANCE and GIBS/Worldview.
NASAs Aqua satellite caught this image of D-30A at the edge of Clarence Island on September 6, 2023 utilizing its MODIS (Moderate Resolution Imaging Spectroradiometer) sensor. Other MODIS imagery reveals the berg approaching the island in late August, bumping into its southeast coast, and then rotating around the island in the very first 2 weeks of September. By late September, the berg had actually moved away from the island and wandered north.
On the other hand, a large iceberg parked offshore a small island can interrupt penguins from foraging, and Clarence Island is home to more than 100,000 breeding pairs of chinstrap penguins. Given that the berg passed by Clarence Island fairly rapidly without ending up being grounded, the bigger effects in this case may have involved a process called iceberg searching, explained Roseanne Smith, a scientist with the British Antarctic Survey.
Picture of iceberg D-30A at the edge of Clarence Island captured on September 6, 2023, by the MODIS (Moderate Resolution Imaging Spectroradiometer) sensor on NASAs Aqua satellite.
After passing the Antarctic Peninsula, Iceberg D-30A grazed the much smaller Clarence Island, spun around, and drifted north.
In June 2021, the U.S. National Ice Center reported that a collision in between iceberg D-28 and the Borchgrevink Ice Shelf in the Queen Maud Land region of East Antarctica had formed a brand-new tabular berg called D-30. Following the collision, the young berg immediately divided again, forming D-30A
After wandering for more than 2 years, this 39 nautical-mile-long and 11 nautical-mile-wide (72 kilometer-long and 20 kilometer-wide) berg– nearly the location of Rhode Island– grazed the much smaller Clarence Island in September 2023.