PBS Terra and SciShow examine the volcanoes under Antarctica's ice

PBS Terra examined ancient climate change in 'Earth's Worst Mass Extinction Is Actually a Warning' for Flashback Friday on Endangered Species Day and modern volcanic threats in Local news remembers Mount St. Helens eruption 45 years later. I combine the two today, beginning with PBS Terra asking What's Really Under Antarctica's Ice?

If all of Antarctica’s ice melted, our coastlines would be drastically altered. Fortunately, that’s not going to happen anytime soon, but new evidence suggests that West Antarctica - which holds around 5 METERS of sea level rise - is melting a lot faster than scientists once thought. And, a new study warns of a sinister threat buried deep beneath the melting ice - one that may cause a feedback loop that speeds up the melt of the already precarious West Antarctic ice sheet. Stay tuned to find out what new maps reveal about the under-ice world of Antarctica, and how a tiny octopus can help us understand the South Pole’s ice-free past.

SciShow also examined this topic in Antarctica’s Hidden Volcanoes are About to be a Problem.

Antarctica probably isn't the first place you think of when you hear about volcanoes. But there's a lot happening under the icy tundra, and not all of it's a good thing. Here's how rising temperatures could lead to an even more explosive future for the frozen continent.

I've been worried about the West Antarctic ice sheet collapsing since 2014, but my worries were about directly human-caused climate change. It turns out there is an additional source of heat, the volcanoes below the ice. The effect is more indirect, as glacial ice melts, reducing pressure on the volcanoes and the magma chambers beneath them, causing them to erupt more and melting the ice above them. That's a positive feedback loop, which can run away. And I thought methane released by thawing permafrost was bad. Yikes!

Enough scary science. Stay tuned for Wayback Wednesday.