Earlier this month, something exceedingly rare appeared in the crater of Hawaii’s Kilauea volcano: water. What once was a bubbling lake of lava now holds a pond of sorts. And that’s got scientists all worked up—in a good way.
The big question is: where did the water come from, the sky or down below? Scientists reckon the latter at this point, because the pond has been steadily growing without rainfall. But they won’t know for sure until they sample it, which could entail a helicopter and a bucket on a rope (ain’t science grand).
If it is indeed coming from a rising water table, the implications for future eruptions could be big. If magma hits that underground water, it could flash-boil the stuff, leading to steam that powers an explosive eruption. But don’t cancel your Hawaiian getaway just yet—Kilauea is a fundamentally different kind of volcano than a Mount St. Helens.
WIRED sat down with Don Swanson, a geologist with the USGS, to learn more about why Kilauea’s been transforming of late, why it’s not going to blow Hawaii to pieces, and why it’s good news that the volcano’s lava is a bit runny.
Check out the video above for more.