what is the largest recorded earthquake in north america
1964 Alaska earthquake Lasting four minutes and thirty-eight seconds, the magnitude 9.2 megathrust earthquake was the most powerful earthquake recorded in North American history, and the second most powerful earthquake recorded in world history. 600 miles of fault ruptured at once and moved up to 60 feet (about 500 years of stress buildup). Soil liquefaction, fissures, landslides, and other ground failures caused major structural damage in several communities and much damage to property. Anchorage sustained great destruction or damage to many inadequately earthquake-engineered houses, buildings, and infrastructure (paved streets, sidewalks, water and sewer mains, electrical systems, and other man-made equipment), particularly in the several landslide zones along Knik Arm. Two hundred miles southwest, some areas near Kodiak were permanently raised by 30 feet (9.1 m). Southeast of Anchorage, areas around the head of Turnagain Arm near Girdwood and Portage dropped as much as 8 feet (2.4 m), requiring reconstruction and fill to raise the Seward Highway above the new high tide mark.