Back in July, satellite images showed an iceberg bigger than the state of Delaware calving and drifting away from Antarctica’s Larsen C ice shelf. Well, it’s summertime now in Antarctica, which means scientists are finally able to view this behemoth from up close – and the pictures are just as spectacular as we imagined.
The edge of A-68, the iceberg the calved from the Larsen C ice shelf in July 2017. (Image: NASA/Nathan Kurtz)
Known as iceberg A-68, the gigantic slab of ice weighs about a trillion tonnes and features a surface area of 5800km2. The berg is slowly drifting away from the Larsen C ice shelf, possibly heading towards the South Georgia and South Sandwich Islands. As it floats away from the Antarctic Peninsula, A-68 is splintering and forming more icebergs in the process.
This past Sunday, November 12, members of Operation Icebridge – a NASA-led initiative to produce detailed 3D maps of Antarctic and Arctic polar ice – flew a P-3 aircraft armed with a sophisticated array of measuring instruments to take a closer look.
A remarkable shot of A-69, revealing the extent of its size. (Image: NASA/John Sonntag)
“Perhaps you know the feeling: that moment when you see with your eyes something you have previously only seen in pictures,” wrote science writer Kathryn Hansen, who participated in the trip, in an article penned for NASA’s Earth Observatory. “Before today, I knew the Larsen C ice shelf only from the satellite images we have published since August 2016.”
A wide view showing iceberg A-68B (front), iceberg A-68A (middle) and the Larsen C ice shelf (back). (Image: NASA/Nathan Kurtz)
Hansen said she wasn’t prepared for the enormity of the iceberg, as most bergs she’s seen were relatively small and blocky.
“A-68 is so expansive it appears if it were still part of the ice shelf,” she said. “But if you look far into the distance you can see a thin line of water between the iceberg and where the new front of the shelf begins. A small part of the flight today took us down the front of iceberg A-68, its towering edge reflecting in the dark Weddell Sea.”
Who’s up for a swim? Larsen C ice shelf (left) and iceberg A-68A (right). (Image: NASA/Nathan Kurtz)
In addition to taking photos, the Operational Icebridge scientists sought to measure the depth of water below iceberg, which they did using radar and a gravimeter.
IceBridge project scientist Nathan Kurtz and Sebastián Marinsek from Instituto Antártica Argentino observe Larsen C from a window on the P-3 aircraft. (Image: NASA/Kathryn Hansen)
Scientists now have the clearest picture yet of A-68, which will help them track and study its progress moving forward.