Description:
This thesis examines different methods of communicating volcanic hazards to the
population of Flagstaff, Arizona using the results of a recent lava flow hazard assessment of the
nearby San Francisco Volcanic Field (SFVF). Harburger (2014) determined that given a lava
flow originating in the SFVF, there is a statistical probability that it will inundate the city of
Flagstaff or even originate from a vent within the city limits. Based on the recurrence rates for
the most recent eruptions (3 x 10-4/year), the probability of lava flow inundation in Flagstaff is
1.1 x 10-5
per year.
This study considers the effects of three different communication methods on
participants’ perceived risk. The methods were administered through a questionnaire and
included a statement of probability of lava flow inundation per year, a statement of probability
over a 100 year period, and an interactive lava flow map derived from the results of the lava flow
hazard assessment. Each method was followed by questions gauging level of concern.
Questionnaires were administered to 213 Flagstaff residents over a two week period in February
2015.