HR: 1330h
AN: S42B-0169    [PDF]
TI: Five Years of Citizen Science: Macroseismic Data Collection with the USGS Community Internet Intensity Maps (``Did You Feel It?'')
AU: Quitoriano, V
EM: vinceq@usgs.gov
AF: U.S. Geological Survey, P.O. Box 25046 MS-966, Denver, CO 80225 United States
AU: * Wald, D J
EM: wald@usgs.gov
AF: U.S. Geological Survey, P.O. Box 25046 MS-966, Denver, CO 80225 United States
AU: Dewey, J W
EM: dewey@usgs.gov
AF: U.S. Geological Survey, P.O. Box 25046 MS-966, Denver, CO 80225 United States
AU: Hopper, M
EM: hopper@usgs.gov
AF: U.S. Geological Survey, P.O. Box 25046 MS-966, Denver, CO 80225 United States
AU: Tarr, A
EM: atarr@usgs.gov
AF: U.S. Geological Survey, P.O. Box 25046 MS-966, Denver, CO 80225 United States
AB: The U.S. Geological Survey Community Internet Intensity Map (CIIM) is an automatic Web-based system for rapidly generating seismic intensity maps based on shaking and damage reports collected from Internet users immediately following felt earthquakes in the United States. The data collection procedure is fundamentally Citizen Science. The vast majority of data are contributed by non-specialists, describing their own experiences of earthquakes. Internet data contributed by the public have profoundly changed the approach, coverage and usefulness of intensity observation in the U.S. We now typically receive thousands of individual questionnaire responses for widely felt earthquakes. After five years, these total over 350,000 individual entries nationwide, including entries from all 50 States, the District of Columbia, as well as territories of Guam, the Virgin Islands and Puerto Rico. The widespread access and use of online felt reports have added unanticipated but welcome capacities to USGS earthquake reporting. We can more easily validate earthquake occurrence in poorly instrumented regions, identify and locate sonic booms, and readily gauge societal importance of earthquakes by the nature of the response. In some parts of the U.S., CIIM provides constraints on earthquake magnitudes and focal depths beyond those provided by instrumental data, and the data are robust enough to test regionalized models of ground-motion attenuation. CIIM invokes an enthusiastic response from members of the public who contribute to it; it clearly provides an important opportunity for public education and outreach. In this paper we provide background on advantages and limitations of on-line data collection and explore recent developments and improvements to the CIIM system, including improved quality assurance using a relational database and greater data availability for scientific and sociological studies. We also describe a number of post-processing tools and applications that make use of the extensive intensity data sets now gathered. These new applications include automatic location and magnitude determination, estimating ground motions from the intensity observations thereby augmenting ShakeMap, automatic geocoding to allow for more refined intensity localization, and recovering higher precision decimal intensities rather than limiting intensities to integer values. Because of differences in the data and procedure, CIIM intensities are not strictly comparable to intensities assigned with the Modified Mercalli scale. Hence, continued collection of traditional macroseismic data will be essential to calibrate our understanding of CIIM intensities, and, conversely, CIIM data will improve our understanding of conventional macroseismic intensities. CIIM can be found online at http://earthquake.usgs.gov under ``Did You Feel It?''.
UR: http://earthquake.usgs.gov/
DE: 7212 Earthquake ground motions and engineering
DE: 7223 Seismic hazard assessment and prediction
SC: Seismology [S]
MN: 2003 Fall Meeting