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Magnitude-recurrence relation for central Mississippi Valley earthquakes


 Earthquake magnitudes are estimated for all known felt earthquakes in the central Mississippi River valley seismic region for the interval 1833 through 1972. The resulting data-set is examined for completeness, and used to determine a magnitude-recurrence relation. The value of the slope b in the recurrence equation is found to be 0.87 ± 0.11 for 95 per cent confidence limits using the maximum likelihood method, and 0.92 ± 0.08 using weighted least squares.