A General Note about Earthquake Casualty Totals

Why Are the Numbers Different in Every List I See?

Whenever a major natural disaster occurs, it is very rare that an exact count can be obtained of the number of people killed and injured. Some bodies are never found, others are counted twice or multiple times by the various agencies who rush in to try to provide assistance. Transients or visitors in the area might be overlooked because their names are not in the local town records. People with minor injuries might not seek any medical assistance; other people with severe injuries might be moved from one assistance center to another and counted twice. All of this is compounded when an entire town - and all its records - are buried in debris or washed away in a flood. For these reasons, at some point after most disasters, the official agency stops giving actual body counts and begins making estimates. Based on more than 40 years of operating the Earthquake Early Alerting Service, it is our observation that initial body counts are usually very low, followed by early estimates that are often much too high, then finally a later estimate that is - hopefully - a more accurate figure. On top of this must be added the political reality that governments occasionally consider casualty tolls to be a matter of national security and therefore understate the true number. In return, opponents of those governments, or others seeking to obtain greater assistance, may intentionally overestimate the actual number. Therefore, articles written just after an event tend to have low casualty figures, later ones often have the high estimates, and the latest ones either have the most correct number or else the one that has been most influenced by the political considerations.

Because it is virtually impossible for any compiler of a global list to go back to all original sources, they usually select numbers given by secondary sources, then later listmakers use the lists compiled by their predecessors. Each time a list is prepared, there is the chance of typographical errors or mis-translations of something written in a different language. There is even the chance that a single disaster is duplicated one or more times in catalogs, because of incorrect conversions or misunderstandings of the various calendars used throughout the Earth's history. Sometimes a totally fictitious event is repeated in enough catalogs that it becomes a "known fact" - to the point that a list that excludes the event is considered incomplete.

Our lists are no more immune to these problems than anyone else's. We have tried, however, to select the figures from sources which we believe to be the most reliable for that area of the world and that time period in history. We are also making an increasing effort to identify the sources of the numbers we use in our lists and publications, hopefully without turning these summaries into unreadable scientific journals. To that end, we encourage anyone who has well- substantiated evidence of corrections to these lists to tell us so we can make the information as correct as possible.