Focal Depth 2 : Natural Disaster. "Vertical distance from the earth's surface to the place of origin (hypocenter, focus) of an earthquake". (UNDHA, Disaster Management Glossary, 1992, p. 41)
B. Wayne Blanchard, Guide To Emergency Management and Related Terms, Definitions, Concepts, Acronyms, Organizations, Programs, Guidance, Executive Orders & Legislation, A Tutorial on Emergency Management, Broadly Defined, Past and Present, B. Wayne Blanchard, USA 2007 (Last Modified 2008). http://training.fema.gov/EMIWeb/edu/docs/terms%20a nd%20definitions/Terms%20and%20Definitions.pdf, (Emr Mgt/ ND and Other Dzstr - Amer) {11}
United Nations, Department of Humanitarian Affairs (DHA/93/36), Internationally agreed glossary of basic terms related to Disaster Management (Spanish and French also included alongside English text.), UN, DHA-Geneva 1992. http://reliefweb.int/sites/reliefweb.int/files/res ources/004DFD3E15B69A67C1256C4C006225C2-dha-glossa ry-1992.pdf, (Emr Mgt - Brit) {798}