Question

Using paleoseismic data, how often do very large earthquakes (Mw>7) occur in the New Madrid Seismic Zone?

Option 1: About every 500 years
Option 2: Approximately every 50 years
Option 3: Roughly every 1,000 years
Option 4: Nearly every 10 years

Answer 1

1. In the New Madrid Seismic Zone, very large earthquakes (Mw>7) occur approximately every 500 years, based on paleoseismic data.

Step-by-step explanation:

Using paleoseismic data, researchers can estimate the recurrence interval of large earthquakes in a given seismic zone. In the New Madrid Seismic Zone, which spans parts of several U.S. states including Missouri, Arkansas, Tennessee, and Kentucky, very large earthquakes with a magnitude of >7 (Mw>7) are estimated to occur roughly every 500 years.

Therefore, Option 1: About every 500 years is the correct answer. Conceivable comparison points include the regular slippage along certain parts of the San Andreas Fault, which have different recurrence intervals; for example, central California near Parkfield has seen movements roughly every 25 years, whereas the Los Angeles region averages major seismic events about every 150 years with more significant motion.