Brian Franklin Atwater (born September 18, 1951) is a geologist who works for the United States Geological Survey and is also a research professor at the University of Washington.
Atwater has spent much of his career studying the likelihood of large earthquakes and tsunamis in the Pacific Northwest region of North America.
Its occurrence and size are confirmed by evidence of a dramatic drop in the elevation of Northwest coastal land, recorded by buried marsh and forest soils that underlie tidal sediment, the deposition of a layer of tsunami sand on the subsided landscape, the death or injury of affected trees (see dendrochronology), and descriptions of the earthquake and tsunami in regional Amerindian legends.
Atwater has also authored various supporting papers about earthquakes around the Pacific Rim and about other geological topics including great glacial floods in Washington state, and the natural history of San Francisco Bay.
In 2006 he began reconnaissance geologic mapping in coastal Indonesia, part of the ground-truth sleuthing needed to develop a "Smart System" for protecting Indian Ocean communities from future tsunamis.