A Contemporary Review of 1975-1976 Elevated Activity Levels at the Mount Baker Complex, Washington, and Current Community Awareness of Volcanic Hazards

Field: Earth and Planetary Sciences (Physical Sciences)

This investigation seeks to understand the changes in the associated volcanic and human systems during and after the 1975-1976 sudden thermal events at Mount Baker volcano. Included are reviews of some of the conclusions made by scientists from the U.S. Geological Survey and universities around the U.S. during that event. A questionnaire was also presented to people in communities around the volcano to outline current understanding of volcanic activity and hazards associated with Mount Baker.\nThe source of the Mount Baker thermal activity in 1975-1976 was never conclusively identified at the time. There appears to have been a small decrease in the amount of thermal activity since 1975, but thermal activity levels have never returned to their pre-1975 levels. Little has changed in the structure of the volcano: weaknesses identified in 1975-1976 in the hydrothermally altered material that comprises the bulk of the summit of Mount Baker still exist today.\nFour hypotheses about the source of thermal activity at Mount Baker in 1975- 1976 were presented to scientists that worked on, or are working on, Mount Baker. This method was intended to gain perspective about what has changed in our understanding of volcanic activity in general and about Mount Baker. The results helped focus my research on pertinent data that helped identify probable sources of the thermal activity. Most importantly, gas analyses have identified the presence of carbon dioxide and hydrogen sulfide in a plume above the volcano indicative of magma present in the volcanic system. Thus, activity in 1975-1976 might have been magmatic in nature and not strictly hydrothermal in nature as has been previously accepted.\nThis investigation also describes community awareness of volcanic understanding including hazards associated with Mount Baker to better illuminate the connection between a volcano and its surrounding communities. A questionnaire asked individuals around Mount Baker about; 1975-1976 events, Mount Baker volcanics, and volcanology in general. Although construction of the questionnaire proved problematic, some facts are clear. Some individuals have misconceptions about the hazards associated with Mount Baker, including concerns of lava flows disrupting their towns. Individuals are willing to comply with officials in most situations, but not all of them would be willing to leave their homes. Also, most individuals interviewed were unaware of a hazard assessment issued for the public by the U.S. Geological Survey, and individuals have spent little to no time exploring the educational resources already available. These findings indicate that a more active outreach program is necessary to educate the people in surrounding communities about hazards at Mount Baker.\nThe 1975-1976 events at Mount Baker can be better explained today in light of our new understandings and the technology available to volcanologists. Also, the educational needs of the surrounding communities can be outlined with the use of a community survey, thus facilitating future educational outreach opportunities.