USGS geologist Don Ritchter stands near the base of a stratified, 4.8-meter-thick (15.8 feet) section of primary tephra (mainly pumice) fall deposit (White River Ash) located 20 km (12.5 miles) north of the Churchill vent along the Klutlan Glacier.
Image courtesy of AVO/USGS.
Please cite the photographer and the Alaska Volcano Observatory / U.S. Geological Survey when using this image. Full Resolution.