California as “volcano country” is USGS evening lecture on April 23, commemorating centennial of 1914-17 eruptions

Everyone knows that California is “earthquake country,” but it is also “volcano country.” The most recent large volcanic eruption in California was 100 years ago at Lassen Peak, in what is now Lassen Volcanic National Park.

California is much different today than it was 100 years ago; in 1915 there were no deaths, no injuries, and minimal economic losses due to the eruption. If we have a similar eruption today at Lassen, what would the impact be?

The U.S. Geological Survey and Lassen Volcanic National Park will jointly commemorate the May 2015 centennial of the climax of the 1914–1917 eruption of Lassen Peak, the only historical volcanic eruption in the conterminous United States until Mount St. Helens in 1981. Steam explosions at the summit of Lassen Peak from May 1914 to May 1915 led to formation of a lava dome and flow on May 19–20, 1915 and to a major explosive eruption on May 22nd. Accompanying avalanches, debris flows, and pyroclastic flows created the Devastated Area on the northeast side of Lassen Peak. Activity then waned, with steam explosions at Lassen continuing until 1917.

The explosive 1915 Lassen Peak eruption forever altered an already dynamic landscape and led to the creation of a national park, which serves as a place of discovery for curious visitors and a living laboratory for a variety of scientists.

USGS geologist Michael Clynne will speak on “A Sight ‘Fearfully Grand” Eruptions of Lassen Peak, California, 1914 to 1917″ at a free USGS public lecture on April 23, 2015 at 7:00 pm.