(1954- ) American Petrologist (Volcanology)
When a major volcanic eruption occurs, a huge amount of gas is released into the atmosphere, an explosion may occur, ash and other particles may be ejected into the atmosphere, and lava may flow down the volcano slopes. Depending upon the location of the volcano, it may impact human habitations in one way or another. If the volcano exists in a populated area, the intensity and extent of those components of an eruption will determine whether the eruption can be used as a tourist attraction or if it will cause significant death and destruction. A major control on this intensity and extent is the mechanisms, rates, and timing of the release of gas from the magma. Katharine Cash-man has developed intricate observational methods of textures in volcanic rocks to predict and constrain some of these destructive events. She looks at the size and density of holes (vesicles) left by the passage of gas through the magma and lava. If the volcanic gases are released quickly, the eruption will be explosive, just like the carbon dioxide being released quickly from soda. Several papers document this work including “Vesicula-tion of Basalt Magma During Eruption.” She also measures crystal sizes and crystallization rates in the same rocks. If the crystallization rates are quick, the lava flow will not travel as far. She measures crystal density and crystal sizes and the distribution of them to study rates and relative viscosity. She also uses Ar/Ar thermochronology (age dating of the individual minerals) to put absolute timing on these rates. By comparing these natural results with physical and thermodynamic models currently being developed for processes occurring in magma reservoirs a predictive capability may be provided for the hazardous aspects of volcanic eruptions.
Cashman is also studying the formation of pumice in volcanic systems especially with regard to submarine eruptions. She has done extensive work on Mount Saint Helens both regarding the 1980 eruption and the minor eruptions that have occurred since. This research is the most exhaustive of any on this famous eruption and is leading to new insights on the processes of the eruption. This work is establishing new protocols on how to study volcanic eruptions that will be applied to other eruptions worldwide. Some of the other projects that Cashman is involved with include the crystallization, degassing and physical properties of lava from the Mauna Loa volcano, Hawaii, the growth of crystals in lava from Mount Erebus, Antarctica, flow patterns and cooling histories of volcanic feeder pipes in Brazil, and studies of fallout from pyroclastic volcanism from the Shira-hama Formation, Japan.
Katharine Cashman was born on July 19, 1954, in Providence, Rhode Island. She attended Middlebury College, Vermont, where she earned a bachelor of arts degree in geology and biology with honors in 1976. She earned a master of science degree in geology with first-class honors from Victoria University, New Zealand, in 1979. She returned to the United States to accept a position as research scientist at the U.S. Geological Survey at Woods Hole, Massachusetts, from 1979 to 1981. She earned a doctorate in geology from the Johns Hopkins University, Maryland, in 1986. Cashman joined the faculty at Princeton University, New Jersey, in 1986, but moved to the University of Oregon in Eugene, where she remains today. During her tenure, she was a visiting professor at Queen’s University, Kingston, Ontario, Canada, in 1991, at the Woods Hole Oceanographic Institute of the Massachusetts Institute of Technology in 1993, and at GEOMAR in Kiel, Germany, in 1999.
Katharine Cashman is leading a productive career. She has published some 50 articles in international journals and professional volumes. Several of these studies establish new processes in volcanism and the crystallization of volcanic rocks. She has received several professional awards in recognition of her achievements. She is a member of the American Association for the Advancement of Science. She received several honors as a student, including being inducted into Phi Beta Kappa, and receiving the Charles B. Allen Award and a Fulbright scholarship. She received the Group Cash Award in 1982 for her work on Mount Saint Helens.
Cashman’s service to the geologic profession is extensive. She served on numerous panels and committees, both national and international, on volcanic processes and volcanic hazards. She is a section president for the American Geophysical Union, for which she has served on several committees. She has also served for the Geological Society of America and the Geochemical Society. She has held a number of editorial positions for Geology, Earth in Space, and Journal of Geophysical Research.
