A regional earthquake catalogue spanning is complete above

PHYSICS · Multi-part · Fermi University Physics · Earth, Climate & Energy Physics · Seismology, tectonics and geodynamics · Seismology, tectonics and geodynamics

The Solid Earth, Ch Faults, the earthquake cycle and seismic hazard

Problem

A regional earthquake catalogue spanning T=25 yrT = 25\,\mathrm{yr} is complete above Mw=4.0M_w = 4.0. Cumulative counts read from the catalogue's magnitude-frequency plot (number of events at or above each magnitude, over the full 25 years) are. Data: Mw≥4.0M_w\ge4.0 has 2500 events, Mw≥5.0M_w\ge5.0 has 250 events and Mw≥6.0M_w\ge6.0 has 25 events. ((a)) Convert the counts to annual rates and fit the Gutenberg-Richter law log⁡10N(≥M)=aGR−bM\log_{10}N(\ge M) = a_{\rm GR} - bM to find bb and aGRa_{\rm GR}. ((b)) Use the fit to predict the annual rate of Mw≥7M_w \ge 7 events and the corresponding mean time between them. ((c)) State one reason this extrapolation to Mw≥7M_w \ge 7 should be treated with caution.

Browse the problem library