## Abstract

Finite-fault source inversions reveal the spatial complexity of earthquake slip over the fault plane. We develop a stochastic characterization of earthquake slip complexity, based on published finite-source rupture models, in which we model the distribution of slip as a spatial random field. The model most consistent with the data follows a von Karman autocorrelation function (ACF) for which the correlation lengths a increase with source dimension. For earthquakes with large fault aspect ratios, we observe substantial differences of the correlation length in the along-strike (a_{x}) and downdip (a_{z}) directions. Increasing correlation length with increasing magnitude can be understood using concepts of dynamic rupture propagation. The power spectrum of the slip distribution can also be well described with a power law decay (i.e., a fractal distribution) in which the fractal dimension D remains scale invariant, with a median value D = 2.29 ± 0.23, while the corner wave number k_{c}, which is inversely proportional to source size, decreases with earthquake magnitude, accounting for larger "slip patches" for large-magnitude events. Our stochastic slip model can be used to generate realizations of scenario earthquakes for near-source ground motion simulations.

Original language | English (US) |
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Journal | Journal of Geophysical Research: Solid Earth |

Volume | 107 |

Issue number | 11 |

State | Published - Nov 10 2002 |

## Keywords

- Complexity of earthquake slip
- Correlation length of asperities growing with earthquake magnitude
- Earthquake rupture dynamics
- Earthquake source characterization
- Spatial random fields
- Strong ground motion simulation

## ASJC Scopus subject areas

- Geophysics
- Geochemistry and Petrology
- Earth and Planetary Sciences (miscellaneous)
- Space and Planetary Science