Impact of Earthquakes on the Central USA

I just reviewed the following research paper on the potential impact of earthquakes in the Central United States. When we think of earthquakes, we think about the West Coast and California in particular. The fact is that all of the West Coast is susceptible as well as the New Madrid Region of the Central United States where a series of catastrophic quakes occurred in the early 1800's. There are other areas of the U.S.A. that could suffer moderate earthquake damage as well.

The follow abstract of a research study was recently published by the Mid-America Earthquake Center at the University of Illinois. The report is the outcome of one of the largest and most comprehensive earthquake consequence assessment projects fundedby the Federal Emergency Management Agency (FEMA). The report contains earthquake impact assessments for the 8 central US (CUSEC) states, and lists damage and other consequences to the built environment as well as social and economic impacts. The earthquake scenarios used represent the New Madrid, the Wabash Valley and the East Tennesseeseismic zones. The analysis employs new and more reliable hazard and inventory data that has not been used before.The project is managed by the US Army Corps of Engineers' Construction Engineering Research Laboratory, and the work was undertaken in partnership with the Institute for Crisis, Disaster and RiskManagement at the George Washington University, with contributions forthe 8 State Geological Surveys, IEM, FEMA, US Geological Survey and CUSEC.

"The region of potential impact due to earthquake activity in the New Madrid Seismic Zone (NMSZ) is comprised of eight states: Alabama, Arkansas, Illinois, Indiana, Kentucky, Mississippi, Missouri and Tennessee. Moreover, the Wabash Valley Seismic Zone (WVSZ) in southern Illinois and southeast Indiana and the East Tennessee Seismic Zone in eastern Tennessee and northeastern Alabama constitute significant risk of moderate-to-severe earthquakes throughout the central region of the USA.

The hazard employed in this investigation includes ground shaking for three seismic zones and various events within those zones. The NMSZ consists of three fault segments: the northeast segment, the reelfoot thrust or central segment, and the southwest segment. Each segment comprises a deterministic, magnitude 7.7 (Mw7.7) earthquake caused by a rupture over the entire length of the segment. The employed magnitude was provided by US Geological Survey (USGS). The NMSZ represents the first of three hazard events utilized in this report. Two deterministic events are also included, namely a magnitude Mw7.1 in the Wabash Valley Seismic Zone (WVSZ) and a magnitude Mw5.9 in the East Tennessee Seismic Zone (ETSZ) earthquakes.

• The results indicate that the State of Tennessee incurs the highest level of damage and social impacts. Over 250,000 buildings are moderately or more severely damaged, over 260,000 people are displaced and well over 60,000 casualties (injuries and fatalities) are expected. Total direct economic losses surpass $56 billion.
• The State of Missouri also incurs substantial damage and loss, though estimates are less than those in Tennessee. Well over 80,000 buildings are damaged leaving more than 120,000 people displaced and causing over 15,000 casualties. Total direct economic losses in Missouri reach nearly $40 billion.
• Kentucky and Illinois also incur significant losses with total direct economic losses reaching approximately $45 and $35 billion, respectively.
• The State of Arkansas incurs nearly $19 billion in direct economic loss while the State of Mississippi incurs $9.5 billion in direct economic losses.
• States such as Indiana and Alabama experience limited damage and loss from NMSZ events with approximately $1.5 and $1.0 billion, respectively.

Noting that experience confirms that the indirect economic loss due to business interpretation and loss of market share, amongst other features, is at least as high if not much higher than the direct economic losses, the total economic impact of a series of NMSZ earthquakes is likely to constitute by far the highest economic loss due to a natural disaster in the USA.

The results are designed to provide emergency managers and agencies with information required to establish response plans based on likely impacts of plausible earthquakes in the central USA."

As you conduct your risk assessment to build your risk mitigation, emergency management, and business continuity program, you might want to take a look at this important research report. Take a look at some of the resource links on the Preparedness, LLC website to help you assess earthquake risk and build your program to respond to and recover from and earthquake event.