Remote Sensing
The acquisition of information or measurement of some property of an object by a recording device that is not in physical or intimate contact with the objects under study.
Return Period
The time period (years) in which there is a good statistical probability that an earthquake of a certain magnitude or a hurricane will recur.
Richter Magnitude Scales
A measure of earthquake size that describes the amount of energy released. The measure is determined by taking the common logarithm (base 10) of the largest ground motion observed during the arrival of a P-wave or seismic surface wave and applying a standard correction for distance to the epicenter.
Risk
The relative degree of probability that a hazardous event will occur. An active fault zone, for example, would be an area of high risk.
Risk Mapping
The process of identifying high-risk areas. This is done by correlating a hazard, such as an earthquake, to the terrain and to the probability that such an event will occur. The results of these analyses are usually presented in the form of risk maps, which show the type and degree of hazard represented by a particular natural phenomenon at a given geographic location. Risk mapping is usually the first step in vulnerability reduction.
