Alaska Volcano Observatory

Bear Lake long cores before they were cut for shipping; one is 5.5 m and the other is 5.8 m containing organic lake mud and volcanic ash (tephra) layers deposited over the last 10,000-14,000 years. Lake coring in collaboration with Mt. Holyoke College and Northern Arizona University

Credit: Image courtesy of AVO / U.S. Geological Survey.
Use Restriction: Please cite the photographer and the Alaska Volcano Observatory/U.S. Geological Survey when using this image.
Full Resolution.