Subplinian fall deposits of Inyo Craters, CA

The Inyo volcanic chain in east central California last erupted explosively around 1350A.D., ejecting 0.13km³ of tephra during four successive eruptions from the South Deadman, Obsidian Flow, and Glass Creek vents. The first two eruptions, from South Deadman, produced bent, pulsating subplinian columns separated by a period of column collapse. The Obsidian Flow eruption began with a phreatomagmatic vent-clearing blast, then continued with a sustained weak plume. The last and largest eruption, from the Glass Creek vent, produced a sustained subplinian eruption marked by a mid-eruption period of phreatomagmatism. These eruptions dispersed more than 0.27km³ tephra over an area greater than 9000km². Inversion of the deposits produced column heights ranging between 6 and 20km, with wind speeds in excess of 30m/s, the highest windspeed included in the nomograms. Inversion results suggest limitations of the nomograms for weak plumes due to their simplifying assumptions regarding the influence of the eruption column on ambient flow.