How Do People Respond During an Earthquake? Using ‘Did you feel it?’ Data to Assess Human Behavioral Response to Earthquakes

Abstract:

The studies described in this abstract provide an assessment of human behavioral response to several large domestic and global earthquakes that occurred between 2005 and 2019; addressing the types of actions taken by those who experienced these events during the actual shaking. The study results add to a small literature on how people respond to earthquake ground motion as well as an assessment of the current recommended response of “drop, cover and hold on” (DCHO). The USGS ‘Did you feel it?’ (DYFI) system, in addition to assigning intensity, asks about the respondent’s mental state and response to the earthquake. Data from DYFI were analyzed using quantitative methods to assess the impact of emotional state, seismic intensity and the observation of damage to evaluate response strategies. For large global earthquakes outside the US, the World Risk Index and Human Development Index were also examined to assess whether risk/vulnerability and levels of development were associated with response behavior. We found statistically significant relationships between emotion, seismic intensity and the observation of damage and response behavior. For global earthquakes, risk/vulnerability and human development also appeared to impact response behavior. As levels of expressed fear and seismic intensity increased to potentially damaging motion, human behavior became active rather than passive. Response at lower intensities elicited very few active responses, but stronger motion accompanied by fear prompted flight from buildings, sheltering in an interior doorway or DCHO. In less developed nations, escape from buildings was highly salient. In developed nations, response was more varied, but despite considerable education and outreach to promote DCHO, this response strategy was among the least likely to be implemented. We suggested that culturally DCHO, a relative newcomer as a response strategy, may have failed to displace older understandings of appropriate response behavior. Appropriate response can make a difference in whether one safely survives an earthquake, so response is important, but current preferred strategies will require continuing education and training before they displace older response actions in earthquakes.