This week’s image comes to you from Hawai’i Volcanoes National Park on the “big island” of Hawaii:
Lava is odd and somewhat counterintuitive stuff. Fairly slight changes in its temperature and chemical composition can cause it to behave dramatically differently — and to look different, too!
Pahoehoe lava is basaltic (i.e., relatively rich in magnesium and calcium, and relatively poor in silicon) lava that maintained low viscosity until it finally solidified. The name comes into English from Hawaiian, and means just what you see — lava with a smooth surface. Because of its pre-solid flow characteristics, pahoehoe lava can take on a variety of surface forms (sheets, ropes, folds, etc.) that are often called lava sculpture.