The Big Obsidian Flow covers 2.6 km² of the floor of Newberry caldera and was emplaced about 1,300 years ago. The eruption began from a vent at the base of the southern caldera wall with a large pumice fall deposit followed by a pyroclastic flow that entered Paulina Lake, and finally with emplacement of the obsidian flow. East Lake lies in the background in this view from the southern caldera rim.

Photo by Lee Siebert, 2002 (Smithsonian Institution).

This image is made available under the Public Domain Dedication CC0 license, but proper attribution is appreciated.

Keywords: lava flow | obsidian | caldera

Newberry