While attempting to rescue two of his colleagues, a UCSB researcher died last week after falling into a volcanic gas vent on Mammoth Mountain.

Charles Walter Rosenthal, a 58-year-old assistant specialist with UCSB’s Institute for Computational Earth System Science, was working for the Mammoth Mountain Ski Patrol on Thursday, April 6, when two of his fellow patrollers fell into a gas vent, called a fumarole, as they tried to rope off the unsafe area, a university press release said. All three perished. Seven other ski patrollers were hospitalized for injuries they received while assisting in the rescue efforts, according to a press release issued by Mammoth Mountain Ski Area.

Rosenthal, who worked as a researcher for the ICESS since 1991, was based at the Sierra Nevada Aquatic Research Laboratory on Mammoth, which is a part of the UC Natural Reserve System. Rosenthal also worked as a teaching assistant in the Geography Dept., where he earned a master’s degree.

Rosenthal was conducting research on snow hydrology and remote sensing.

Jeff Dozier, the founding dean and a professor at UCSB’s Bren School of Environmental Science and Management, worked closely with Rosenthal.

“As our friend, colleague, guide and teacher, Walter had an insightful intellect and an engaging enthusiasm for the study of snow,” Dozier said in the press release. “He had worked in the ski area since the early 1980s, but had always maintained an interest in research and had returned to the university in his 40s to complete his master’s degree in geography in 1994.”

Rosenthal and Dozier, who were recently awarded a grant from the National Science Foundation, were studying sintering in snow, the process by which snow grains bond with each other and increase the stability of the snow pack. In the press release, Dozier said Rosenthal was planning to enroll in the Bren School’s Ph.D. program next fall to work on creating an accurate sintering theory.

“His work would have changed the way the world thinks about processes within the mountain snow pack,” Dozier said.

Daniel Dawson, director of the Valentine Eastern Sierra Reserve of the UC Natural Reserve System, said Rosenthal was “a gifted mathematician who did novel work in image processing.” Dawson said Rosenthal was not planning to work for the ski patrol the day he died.

“Supposedly, April 1 was his last day at the mountain and he just went back on [April 6] to help out, knowing they would be shorthanded after the big storm,” Dawson said in the press release.

Rosenthal is survived by his wife, Lori, and their 14-year-old daughter, Lily. The date for Rosenthal’s memorial ceremony on campus has not yet been announced.