THE 23 AUGUST 2011 VIRGINIA MW5.8 EARTHQUAKE: HIGHLIGHTING EARTHQUAKE HAZARDS THROUGHOUT THE SOUTHEASTERN UNITED STATES

On August 23^rd, 2011 an earthquake of magnitude 5.8 occurred near Mineral, VA. According to the USGS, this was the largest earthquake in Virginia since 1897 and the most widely felt earthquake in U.S. history. A comprehensive, spatial database of residential property damage caused by the earthquake is being compiled based on damage reports from the counties of Louisa, Norfolk, Fluvanna, Goochland, Spotsylvania, as well as the independent city of Fredericksburg. The database includes approximately 1800 damage reports. The database fields include property owner comments and recorder notes, monetary damage, and Mercalli intensity values. Reported damage includes but is not limited to surficial damage, damage to interior and exterior walls house shift, foundation and structural cracking.

Earthquake damage is related to ground movement which is a function of the strength of the earthquake and the physical properties of the substrate (Trifunac 1975, Bulletin of the Seismological Society of America, 65(1),p.139-162). The purpose of this study is to examine how the underlying geology of the area impacted the damage caused by the earthquake. Depth of bedrock, soil type, and structure type are expected to influence the amount of damage experienced as a result of the earthquake. If a congruency between geologic conditions and zones of damage intensity is apparent, this information may be used to help reduce residential property damage from future earthquakes.