Fault lines in North America sit along the Pacific coastline, in southeastern Missouri and nearby states, in New Jersey and nearby states, and in Alaska. Specific faults include the New Madrid Seismic Zone, Cascadia Subduction Zone, Ramapo Seismic Zone, Hayward Fault and Denali Fault System.
The Cascadia Subduction Zone consists of 680 miles of fault line going up the Pacific coastline, and includes Portland, Seattle and Vancouver within its earthquake zone. The fault line is able to produce a magnitude 10.0 earthquake, capable of far more damage than San Francisco’s notorious 1906 earthquake.
The New Madrid Seismic Zone covers portions of southeastern Missouri, northeastern Arkansas, western Tennessee, western Kentucky and southern Illinois. People as far away as New York reportedly felt the shaking from major quakes that happened along this fault in 1811 and 1812.
The Ramapo Seismic Zone covers parts of Pennsylvania, New Jersey and New York. As of 2015, the risk of earthquakes associated with this fault line is not so much one of magnitude as it is the potential for damage in Manhattan and other highly urbanized areas.
The Denali Fault System comprises parts of Alaska and, as of 2015, was the site of the largest recorded earthquake in North America in terms of magnitude, the Alaskan earthquake of Nov. 3, 2002.