Alaska Volcano Observatory

The Lost jim vent, when active, erupted lava into a perched lava lake, which emptied into a large lava tube, its entrance shown here, that carried lava downslope to the front of the flow. The Lost Jim lava flow, the youngest lava flow in the Imuruk Lake Lava Field, is thought to have erupted roughly 1,000–2,000 years ago. Erika Rader (University of Idaho) for scale.