Pahoehoe Lava

Last night, Science on Tap kicked-off its new season. We also used this event as an opportunity to celebrate Joanie’s birthday and watch the Cardinals clinch their latest divisional title. Science on Tap is a collaborative effort between Washington University and in the past Schlafly Bottleworks, but that partnership has become a victim of its own success. We out grew that facility and moved out to the Kirkwood Station Brewery, which boasts a capacity that is four times greater than Schlafly’s. Still, the room was mostly full last night.

The speaker was a geologist, Phil Skewer, an assistant professor. Standing up before the large crowd, he led with a line about being between a rock and a hard place, such is the tenor of his geology jokes. He researches the Earth’s mantle by squishing rocks in his lab. His best line involved a description of the Earth’s density, the average of which is equivalent to that of four Prius stuffed into the volume of a washing machine. Skewer is an experimentalist, who enjoys squishing rocks and then studies how they deform.

After his talk, I asked two questions. First, whether he also uses finite element modeling to study his rock squishing. He was rather dismissive of FEM, “Aw Gawd no!”. I also asked him about studying volcanos, like in Hawaii. I think that this question caught him a little off-guard, because it is so divorced from his own work, professional rock squishing in the lab. I was hoping for something more encouraging, like maybe a post-doc opportunity. 

The accompanying photo shows some pahoehoe lava, from the Hawaiian Kilauea Volcano. The photograph was taken at the Smithsonian’s Natural History Museum. This twisted, ropy surface is typical of pahoehoe (pa-HOY-hoy), a form of basaltic lava. As fluid lava flows downhill, a thin skin on top cools and solidifies. It wrinkles by continued movement of the molten interior.