Interpretation
The damage and casualty data presented here is intended to inform and support these studies and applications. Users are encouraged to explore the data, take copies of it, interpret it, and derive their own interpretation of vulnerability relationships. The damage and casualty survey information here is presented as purely as possible, in its raw format, minimizing the amount of interpretation or modelling of the data. For each survey, a set of counts of observed damage states are presented for defined building types.

Societal focus
The building surveys cover the common building types affected by significant damage – mainly residential and standard types of commercial property. These are the buildings that constitute the predominant risk to the population, and are the primary concern for societal economic and human impacts.

Ground motion severity metrics
The relationship between damage and ground motion is one of the key elements of vulnerability analysis. In most earthquake-damaged locations, there is no record of the severity or characteristics of the actual ground motion that caused it. Where ground motion records exist, these are identified in the surveys. There are many different techniques for inferring ground motion at a location, and users are encouraged to apply various modelled seismic near-field hazard parameters to observed data – hence the importance we place on preserving the spatial geography of survey locations, and providing a standard measure of epicentral distance for each survey location.

A standard methodology for intensity assessment is also provided in the form of the USGS PAGER Shakemap spatial interpretation of intensity. A Shakemap is available for each of the events for which damage and casualty data is available.

Models of vulnerability
The Cambridge Earthquake Impact data has been used to create various models of building and human vulnerability (such as presented in Coburn & Spence 2002). However by providing this data in a more accessible format we hope to encourage more uses, reinterpretation, and improved statistical models of how populations of buildings will perform under earthquake loads, and the human casualty consequences. We encourage users to make use of this information freely and creatively. We ask that any resulting models or applications of the CEQID data be credited in publications and references. We trust that this data will add to the overall understanding of seismic vulnerability and lead to the reduction of earthquake losses over time.

Prof. Robin Spence
Dr. Andrew Coburn
Dr Emily So