- Author
-
Mileti, D. S.
|
Fitzpatrick, C.
|
Farhar, B. C.
- Title
- Risk Communication and Public Response to the Parkfield Earthquake Prediction Experiment. Final Report.
- Coporate
- Colorado State Univ., Fort Collins
- Sponsor
- National Science Foundation, Washington, DC
- Report
-
Final Report
December 1990
219 p.
- Contract
- NSF-GRANT-CES-8814690
- Keywords
-
earthquakes
|
experiments
|
public awareness
|
information dissemination
|
statistical analysis
|
human behavior
|
risk analysis
|
human response
- Identifiers
- Parkfield earthquake, San Andreas fault; theory that guided this research; methods used in the research; public information about the earthquake prediction; description of public prediction response; statistical impacts of experience and distance; factors that influenced what people thought and did; causal explanation of public prediction response; conclusions for theory and practice
- Abstract
- The Parkfield earthquake prediction is for a moderate earthquake of magnitude 5 to 6 on the Parkfield segment of the San Andreas fault between 1985 and 1993. It was given more than 90% probability of occurrence when it was issued. Contained in the prediction was the possibility that the next Parkfield earthquake could be magnitude 7. The larger event would offset the fault by 10 feet; the characteristic magnitude 5 to 6 event would only offset the fault by one foot. The director of the U.S. Geological Survey issued a public statement on 5 April 1985. This statement, in essence, forecast an earthquake of magnitude 5.5 to 6.0 in the next several years (1985-1993) with more. than a 90% probability that it would happen. The forecast stated that there was potential for this quake to be larger (magnitude 7), and for the fault rupture to extend southward into the adjacent 25-mile Cholame segment of the San Andreas fault. The release of this prediction was a national media event. The prediction was reported in national weekly news magazines. The national media came to interview the residents of Parkfield. The interviews and editorial comments were broadcast on national network evening news programs. California's Office of Emergency Services (DES) prepared and mailed a brochure describing the prediction and recommended actions to more than 122,000 central California households--every household within the extended area at risk assuming a magnitude 7 earthquake. The brochure was mailed directly to households at risk and it covered information about the earthquake hazard, the prediction, a possible short-term warning of the impending earthquake, and what to do about each. The brochure was entitled "The Parkfield Earthquake Prediction" and looked like a large map that could be folded up. It was printed on both sides in multiple colors and represented graphical and textual information concerning the earthquake risk. Concentric circles depicted the areas of potential impact; pictures and diagrams showed the warning sequence for the short-term warning.