Modeling the Contribution of Poroelastic Deformation to Postseismic Geodetic Signals

Authors

Kimberly McCormack, University of Texas at Austin
Marc A. Hesse, University of Texas at Austin
Timothy H. Dixon, University of South FloridaFollow
Rocco Malservisi, University of South FloridaFollow

Document Type

Article

Publication Date

4-2020

Keywords

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

Digital Object Identifier (DOI)

https://doi.org/10.1029/2020GL086945

Abstract

To constrain the poroelastic component of postseismic deformation, we model the subsurface hydrologic response to the Mw 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‐perpendicular component. By modeling the time‐dependent 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 10–20% overall and up to 50% locally. Poroelastic effects can both mute and amplify the inferred afterslip.

Rights Information

Terms of use for work posted in Scholar Commons.

Was this content written or created while at USF?

Yes

Citation / Publisher Attribution

Geophysical Research Letters, v. 47, issue 8, art. e2020GL086945

©2020. American Geophysical Union. All Rights Reserved.

Scholar Commons Citation

McCormack, Kimberly; Hesse, Marc A.; Dixon, Timothy H.; and Malservisi, Rocco, "Modeling the Contribution of Poroelastic Deformation to Postseismic Geodetic Signals" (2020). School of Geosciences Faculty and Staff Publications. 2265.
https://digitalcommons.usf.edu/geo_facpub/2265