One of the strongest earthquakes of intraplate origin known in North America in historical times is?
1. the 1964 Anchorage, Alaska, earth-
quake.
2. the 1984 Mount St. Helens, Washington,
earthquake.
3. the 1906 San Francisco earthquake.
4. the 1811 New Madrid, Missouri, earthquake
4. New Madrid. The earthquake was so strong it changed the course of the Mississippi River.
Downtown Anchorage, Alaska