Modeling the Contribution of Poroelastic Deformation to Postseismic Geodetic Signals

Kimberly McCormack, Marc A. Hesse, Timothy H. Dixon, Rocco Malservisi

Research output: Contribution to journalArticlepeer-review

Abstract

<p> To constrain the poroelastic component of postseismic deformation, we model the subsurface hydrologic response to the <em> M </em> <em> w </em> 7.6 subduction zone earthquake that occurred on the plate interface beneath the Nicoya peninsula in Costa Rica on 5 September 2012. The model shows that poroelastic relaxation occurs on multiple time scales and the associated deformation can be up to 2 cm for the trench&hyphen;perpendicular component. By modeling the <em> time&hyphen;dependent </em> deformation associated with poroelastic relaxation, we can begin to remove its contribution from the observed geodetic signal. Inversions for after slip that ignore poroelastic deformation have errors of 10&ndash;20% overall and up to 50% locally. Poroelastic effects can both mute and amplify the inferred afterslip.</p>
Original languageAmerican English
JournalGeophysical Research Letters
Volume47
DOIs
StatePublished - Apr 1 2020

Keywords

  • postseismic deformation
  • poroelastic deformation
  • Costa Rica earthquake
  • groundwater
  • Nicoya penninsula

Disciplines

  • Earth Sciences

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