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of a volcano, it is possible to identify those hazard areas most likely to be affected in the <br /> future by volcano hazards. <br /> Historic Volcanic Eruptions in the United States <br /> Records of volcanic eruptions within the United States are centered in the states of Alaska, <br /> Washington, Oregon, California, and Hawaii. Since there are no recorded instances of <br /> volcanic eruptions in North Carolina, this natural hazard was not analyzed for potential <br /> impact. <br /> Landslides <br /> According to the United States Geological Survey(USGS), landslides are a major geologic <br /> hazard that occur in a1150 states, cause$3,Sbillion in damages per year and cause between <br /> 25 and 50 fatalities each year(USGS, 2005). Landslides often occur with other natural <br /> hazards such as earthquakes and floods. <br /> Clay-rich soil landslides are common throughout the mountainous Appalachian region of <br /> the United States. The USGS classifies landslide incidence/susceptibility for the eastern <br /> United States as low, medium, or high based on geographic features and geologic <br /> formations. <br /> USGS further defines susceptibility to landslides as the probable degree of response of <br /> geologic formations to natural or artificial cutting,loading of slopes,or unusually high <br /> precipitation. Generally, unusually high precipitation or changes in existing conditions can <br /> initiate landslide movement in areas where rocks and soils have experienced landslides in <br /> the past. <br /> . <br /> Historic recards suggest that destructive landslides and debris flows in the Appalachian <br /> Mountains occur when unusuall heav rain from <br /> hurricanes and intense rain storm <br /> Y Y s soak <br /> the ground,reducing the ability of steep slopes to resist the downward pull of gravity. <br /> Scientists have documented fifty-one debris-flow events in North Carolina between 1844 <br /> and 1985. All of these occurred in the Appalachian Mountains and most were in the Blue <br /> Ridge area. (Gori and Burton, 1996) <br /> USGS Landslide Susceptibility/Incidence <br /> Cate or Incidence Susce tibilit <br /> 1 Low Low <br /> 2 Low Moderate <br /> _ 3 Low Hi h <br /> 4 Moderate Moderate <br /> S Moderate Hi h <br /> 6 Hi h Hi h <br /> Source:Local Hazard Mitigation Planning Manual,Nonh Carolina Division of Emergency Management, 1998. <br /> ' 26 <br />