SECTION 4: RISK ASSESSMENT
MMI
Shaking
Description/Damage
VII
Severe
Damage slight in specially designed structures; considerable damage in ordinary substantial buildings with partial collapse. Damage great in poorly built structures. Fall of chimneys, factory stacks, columns, monuments, walls. Heavy furniture overturned. Damage considerable in specially designed structures; well-designed frame structures thrown out of plumb. Damage great in substantial buildings, with partial collapse. Buildings shifted off foundations. Some well-built wooden structures destroyed; most masonry and frame structures destroyed with foundations. Rails bent.
IX
Violent
X
Extreme
Source: USGS Earthquake Hazards Program
The most severe earthquake to impact the Wake County area was the Charleston earthquake of 1886. It is estimated to have been felt as a 7 or 8 on the MMI Scale. Since then, six earthquakes have been felt in Wake County, and all were at an MMI Scale of 4 or lower.
Impact: 1 – Minor
Spatial Extent: 4 – Large HISTORICAL OCCURRENCES
The USGS Earthquake Hazards Program maintains a database of all historical earthquakes of a magnitude 2.5 and greater. These events are illustrated in the following pages. Figure 4.13 shows historical earthquakes by magnitude in relation to North Carolina and the Quaternary Faults identified by USGS. This includes events from 1973 to 2023. Figure 4.14 provides a more detailed view of earthquakes that have occurred within 50 and 100 miles of Wake County.
Wake County, NC Multi-Jurisdictional Hazard Mitigation Plan
WSP June 2024 Page 108
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