LEILA FADEL, HOST:
The world's biggest iceberg is on a collision course with a tiny island in the South Atlantic. The massive ice chunk goes by the unassuming name of A23a.
NICK HOLSCHUH: A23a is huge, 1,400 square miles. It's about the size of Rhode Island.
A MARTÍNEZ, HOST:
Nick Holschuh teaches geology at Amherst College and studies the Antarctic ice sheet.
HOLSCHUH: A23a broke away from the Antarctic ice sheet in 1986. It was fully floating, but it ran aground in the Southern Ocean, where the waters are extremely cold. And it was stuck on the ground, where it sat for 34 years.
MARTÍNEZ: In December, A23a began moving. It got caught in a powerful ocean current local sailors and fishermen call Iceberg Alley.
HOLSCHUH: Where they get transported up near the Antarctic Peninsula, out into the Antarctic circumpolar current, where it is now being sent towards South Georgia.
FADEL: South Georgia is a small British territory in the Atlantic over 1,100 miles from Argentina's mainland. Only a handful of people live there, but the island is home to millions of seals and nearly half the world's population of king penguins.
MARTÍNEZ: Scientists worry that if A23a runs aground and breaks apart, large chunks of ice could clog important wildlife feeding areas. But Holschuh says it's too early to tell if that's going to happen.
HOLSCHUH: If it ends up on a different path, it may end out in the deep ocean, where it will slowly melt and break down by warm surface waters.
FADEL: Holschuh says climate change has little to do with A23a's history because it broke off the Antarctic shelf so many years ago.
HOLSCHUH: There are other places around the Antarctic ice sheet where warming ocean waters melt away some of these floating ice shelves. It's like uncorking the bottle.
MARTÍNEZ: Scientists think it's possible climate change is leading to a growing number of icebergs. What they know for sure is that climate change is affecting Antarctic ice, and...
HOLSCHUH: We know with high confidence that the primary driver of climate change is fossil fuels. So when I think about my role in addressing future climate change, I do feel some personal responsibility. But I also want to motivate my communities, my state, my country to move towards alternative energy, which is important for kind of our net contribution.
FADEL: A23a is now about 170 miles away from the little island named South Georgia. It's hard to predict when or if it will hit.
MARTÍNEZ: Holschuh says he'll be watching to see how the journey ends.
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