Woods Hole Oceanographic Institution

Jeffrey J Mcguire

»Gofar Transform Earthquakes

The Network Strain Filter - A New Tool for Monitoring and Detecting Transient Deformation Signals in GPS Arrays


Scaling Relations for Seismic Cycles on Mid-Ocean Ridge Transform Faults

»Earthquake Swarms on Transform Faults
»Modeling Seismic Swarms Triggered by Aseismic Transients
»Analysis of Seafloor Seismograms of the 2003 Tokachi­Oki
  Earthquake Sequence for Earthquake Early Warning

»Seismic Cycles
»Fore-arc structure and subduction zone earthquakes
»Salton Trough Swarms
»Earthquake Predictability
»SEAJADE Experiment

Boettcher and McGuire,

Scaling Relations for Seismic Cycles on Mid-Ocean Ridge Transform Faults


Mid-ocean ridge transform faults (RTFs) have thermal structures that vary systematically

with tectonic parameters, resulting in predictable seismic characteristics and clear seismic

cycles. We develop a scaling relation for repeat time, tR, of the largest expected

earthquake, MC: tR−1Δσ2/3CMc1/3AT1/4V-1, where μ is the shear modulus, Δσ is the stress

drop, CMc is a constant, AT is the area above 600°C, and V is the slip rate. We identify

repeating MC earthquakes by measuring differential arrival times of first orbit Rayleigh

waves to determine centroid offsets between pairs of events. Comparing our

observations of tR (5-14 years for earthquakes on Gofar and Blanco RTFs) with

predictions from our scaling relation, we can constrain RTF stress drops. Specific tests of

this scaling relation are proposed for earthquakes on Blanco, Gofar, Discovery, and

Clipperton RTFs, which are all expected to have large ruptures in the next few years.

FILE » Boettcher_McGuire_2009_57791.pdf

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