Ratio of the Dead to Wounded (D/W) Indicators and Associated Factors in Major Earthquakes of America from 1960 to 2011

The paper presented deals with the casualties, mortality, and morbidity occurred during the major earthquakes of America during a period of 51 years. The work provides statistical evidence that the deaths/wounded (D/W) ratio used for many agencies in the planning of the preparation and response activities to earthquakes does not fit the relation 1 : 3. In addition, a model is presented in order to evaluate the possible association between different analysis variables such as the subregion of the American continent affected, population density, HDI, and the time and magnitude of the earthquake and the effects of these on the death toll, the number of the wounded, and the D/W indexes. Although the model generated it is not robust enough for decision making, it could be useful and improvable in order to apply it in the planning and management of these kinds of natural disasters. For these reasons, we think that it would be interesting to do further progress in this line of research by making a more comprehensive study of the variables associated with mortality and morbidity, using a more representative sample of earthquakes that sure will confirm the results presented in this work. 1. Introduction Every year there are more than one million earthquakes in the world [1]. In the past decade the earthquakes caused more than 780,000 deaths. Among all natural catastrophes, such as floods, tornados, and avalanches, earthquakes have shown to be associated with higher mortality rates [2]. The impact of these events is increased when their occurrence triggers other events such as Tsunamis. The most conservative statistics have mentioned that, in the last 20 years, earthquakes have led to more than 500,000 deaths and more than 1,400,000 wounded, that is to say, one death for every three wounded [3, 4]. The most recent earthquakes with the higher numbers of deaths have occurred in 2003 in Bam (Iran) [5, 6], in 2005 Kashmir (Pakistan) [7–9], in 2008 Sichuan (China) [10–14], and in 2010 Haiti [15]. Several factors have been described as responsible for the high mortality and morbidity of earthquakes. However, among these factors intrinsic factors like their magnitude, the location (urban-rural), the epicentre, the distance between the population affected to the epicentre, the depth, and the time at which the earthquake occurs (day or night) and extrinsic factors, such as the preparation of the populations for this phenomenon (mitigation measures) [1], the type of house, and the population density, are the most considered influencing and associated variables with the