REMOTE 3-D MAPPING OF LASSEN VOLCANIC CENTER, CALIFORNIA

Lassen Peak is one of two Cascade volcanoes to erupt during the twentieth century. Eruptions from 1914 to 1917 produced numerous small phreatic explosions, a pyroclastic flow, and viscous dacite lava near the summit, which mixed with snow and triggered lahars. Earlier episodes of volcanism include the development of silicic domes at Chaos Crags (1,100 to 1,000 yr ago) followed by dome collapse (Chaos Jumbles). Fumarolic activity at several sites continues near Lassen Peak.

We used MODIS/ASTER (MASTER) airborne simulator data to map the distribution of the above volcanic features. False-color RGB images generated using channels 0.58 µm, 1.78 µm, 4.93 µm, respectively, along with results from a minimum noise fraction transformation were used to develop 2-D images of volcanic features. These were subsequently co-registered and “draped” over a 10 m USGS DEM (digital elevation model) data to produce 3-D imagery.

Rotation of the 3-D images provides opportunities for enhanced study of volcanic and dome collapse features. Although volcanic hazards at Lassen do not threaten a large number of people, this research does provide a test case for the use of 3-D imagery to enhance volcanic hazard mapping. The application of this technology provides a tool to assess volcanic hazards at other stratovolcanoes around the world.