Seismic loss assessment of sequential rupture of New Madrid Seismic Zone on the Central US

The New Madrid Seismic Zone (NMSZ) is described as a low probability high risk event. In case of a repetition of the 1811-1812 earthquake series, the expected consequences will cause catastrophic impacts to directly affected areas and beyond. An accurate earthquake impact assessment of the NMSZ is essential to generate an efficient response from FEMA and its associates and to educate and prepare the general population. The objective of this project is to provide scientifically defensible earthquake impact assessments with the most improved hazard, inventory, and fragility data to save lives and protect property. The study region encompasses eight states: Alabama, Arkansas, Illinois, Indiana, Kentucky, Mississippi, Missouri, and Tennessee. The implemented scenario aspires to recreate the events of 1811-1812 as accurately as possible within modeling constrains. The resulting scenario is a 7.7 magnitude earthquake event with sequential rupture of all three segments of the NMSZ simultaneously. Hazard improvements include complete liquefaction and shaking maps, while multiple inventory datasets are incorporated and added to the existing default assets. An advanced methodology for fragility derivation is applied and improved fragility functions are included for buildings and bridges, based on inelastic response. Additionally, secondary effects of flooding due to dam failure are analyzed. The analytical analysis is executed in HAZUS-MH MR3 developed by FEMA. Several damage criteria were developed to determine the most critically impacted counties. The results of the impact assessment are staggering, with 140 impacted counties and over 700,000 damaged buildings. Essential facilities such as schools and hospitals incur severe damage. Transportation and utility lifelines experience serious functionality impairments. Catastrophic consequences result in nearly 86,000 casualties and approximately $300 billion in direct economic loses. Finally, essential components of future research work are identified. The employed approaches and lesson learned in this project are applicable for worldwide earthquake impact assessments