From the outside, glaciers appear to be solid masses of unmoving ice. But meltwater flowing from the surface down to the glacier bed carves canyons, gorges and even caves into the dense sheets of ice. Over time, the fissures form labyrinthine tunnels that open into vast ice caverns few people have ever seen.

University of Oregon glaciologist Kiya Riverman is one of a handful of researchers who ventures into this frozen world of glacier ice caves. What started as a hobby exploring limestone caves in Pennsylvania has become an area of scientific exploration for Kiya, who makes hand-drawn maps of these cave systems and tracks how they change over time. In this episode, listen to Kiya describe what it’s like to rappel down a frozen waterfall, crawl through tiny ice passages and do science 1840s-style.

Read more about Kiya’s work on Eos.org and watch a video of her exploring an ice cave in Svalbard on AGU’s YouTube channel.