Dawn at the Face of the Bishop Tuff

November 23, 2014


Photographer: Nel Graham 
Summary Authors:
Nel Graham; Jackie Phillips

Bishop Tuff is a massive deposit of ash and pumice left behind by the eruption of the Long Valley Caldera some 740,000 years ago. The Long Valley Caldera eruption spread measurable ash as far east as Kansas and Nebraska and rivaled the eruption of the Yellowstone Caldera. Erosion from the Owens River carved a gorge through the tuff forming the cliff face. The river runs along the base of the cliff before contributing most of its water to the city of Los Angeles, about 300 miles (480 km) to the southwest. On the south edge of the caldera is the very popular Mammoth Mountain ski area. Mammoth Mountain is a dacite volcano formed after the main eruption. Photo taken on Oct. 21, 2014. 

Photo Details: Camera: Panasonic DMC-TZ4; Focal Length: 4.7mm (35mm equivalent: 28mm); Aperture: f/3.3; Exposure Time: 0.0050 s (1/200); ISO equiv: 160.