SECTION 4: RISK ASSESSMENT
4.5.3 Earthquake
Hazard Background An earthquake is a movement or shaking of the ground. Most earthquakes are caused by the release of stresses accumulated as a result of the rupture of rocks along opposing fault planes in the Earth’s outer crust. These fault planes are typically found along borders of the Earth's 10 tectonic plates. The areas of greatest tectonic instability occur at the perimeters of the slowly moving plates, as these locations are subjected to the greatest strains from plates traveling in opposite directions and at different speeds. Deformation along plate boundaries causes strain in the rock and the consequent buildup of stored energy. When the built-up stress exceeds the rocks' strength a rupture occurs. The rock on both sides of the fracture is snapped, releasing the stored energy and producing seismic waves, generating an earthquake. Warning Time: 4 – Less than 6 hours Duration: 1 – Less than 6 hours Location Figure 4.5 reflects the Quaternary faults that present an earthquake hazard for the Wake County planning area based on data from the USGS Earthquake Hazards Program.
Wake County Multi-Jurisdictional Hazard Mitigation Plan 2019
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