The New Madrid Seismic Zone – America’s Most Enigmatic Earthquake Threat
Deep beneath the American Midwest lurks one of the planet’s most puzzling earthquake hazards. The New Madrid Seismic Zone has been called “really one of the most enigmatic seismic zones on the planet” by seismologist Eric Sandvol at the University of Missouri, who notes “We’re not supposed to have earthquakes here.” There is broad agreement in the scientific community that a continuing concern exists for a major destructive earthquake in the New Madrid seismic zone, with many structures in Memphis, Tennessee, St. Louis, Missouri, and other communities in the central Mississippi River Valley region vulnerable and at risk from severe ground shaking.
The USGS estimates that the region has a 25 to 40 percent chance of a magnitude 6.0 or higher earthquake in the next 50 years, and as much as a 10 percent chance of a repeat of the 1811-1812 sequence. Recent studies found that a magnitude 7.6 earthquake in the NMSZ could cause losses exceeding $43 billion (adjusted for 2024 inflation).
Seattle’s Hidden Fault Network – A Sleeping Giant Under Four Million People
The Seattle fault zone is a network of shallow faults slicing through the lowlands of Puget Sound, threatening to create damaging earthquakes for the more than four million people who live there. Most of the evidence of these faults lies hidden beneath the major population centers of Seattle, Bellevue, and Bremerton. The Seattle fault could generate something like a magnitude 7.2 earthquake.
A large Seattle Fault earthquake could trigger a tsunami up to 16 feet high that would strike the Seattle shoreline within seconds of the earthquake and flood it within 5 minutes. Research finds that Seattle could experience thousands of landslides following a strong (M7.0) Seattle Fault earthquake, with estimates ranging from 5,000 in dry conditions to 30,000 in the wettest conditions.
The 500 New Fault Lines Scientists Just Discovered
New tools and technology identified nearly 500 additional faults that could produce a damaging quake, showcasing the evolving landscape of earthquake research. The 2023 NSHM added 350 faults to past models, bringing the total number to 1,000 and providing a more comprehensive view of possible seismic sources. USGS scientists and partners recently revealed the latest National Seismic Hazard Model, showing that nearly 75% of the United States could experience a damaging earthquake…