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Metadata Files

Data Publication

Co-seismic Surface Dilatation and Shear Strain Fields Derived from SPOT-5 Displacements

Cheng, Guo | Barnhart, William

4TU.ResearchData

(2021)

Descriptions

Repeated earthquake cycles produce topography, fault damage zones, and other geologic structures along faults. These geomorphic and structural features indicate the presence of co-seismic permanent (inelastic) surface deformation, yet a long-standing question in earthquake research is how much of the co-seismic deformation field is elastic versus inelastic. These questions arise in part because it is unclear what measurable co-seismic characteristics, such as off-fault or distributed surface deformation and cracking, represent true unrecoverable deformation. One emerging descriptor of permanent co-seismic deformation is surface strain magnitudes inferred from imaging geodesy observations. In this study, we present the surface strain field of the 2013 Mw7.7 Baluchistan strike-slip earthquake in southern Pakistan. We invert co-seismic displacement fields generated from pixel-tracking of SPOT-5 and WorldView optical imagery for co-seismic surface horizontal strain tensors. We observe that co-seismic strain field is dominated by negative dilatation strains, indicating that the co-seismic faultspan> zone contracted during the earthquake. We show that co-seismic inelastic failure exhibits a relatively consistent width along the rupture that is localized to a zone 100-200 m wide on the hanging wall side. The width of co-seismic permanent deformation does not correlate with variations in off-fault deformation or surface geology. Based on comparisons to other recent earthquakes, we posit that the permanent surface strains reflect inelastic deformation of the faults inner damage zone, and that the width of this zone reflects fault maturity.

Keywords

Originally assigned keywords

Physical Geography and Environmental Geoscience

FOS: Earth and related environmental sciences

Geophysics

Earthquake deformation

Geodesy

surface strain

MSL enriched keywords

Measured property

strain

Measured property

strain

strain partitioning

Inferred deformation behavior

deformation behaviour

inelastic deformation

microphysical deformation mechanism

intragranular cracking

tectonic deformation structure

tectonic fault

MSL enriched sub domains i

rock and melt physics

analogue modelling of geologic processes

Source

https://data.4tu.nl/articles/_/14066504/1

Source publisher

4TU.ResearchData

DOI

10.4121/14066504.v1

Creators

Cheng, Guo

https://orcid.org/:

0000-0002-4144-8448

Barnhart, William

https://orcid.org/:

0000-0003-0498-1697

Contributors

University Of Iowa, Department Of Earth And Environmental Sciences, USA

Other

References

10.1029/2020jb020622

Citation

Cheng, G., & Barnhart, W. (2021). Co-seismic Surface Dilatation and Shear Strain Fields Derived from SPOT-5 Displacements (Version 1) [Data set]. 4TU.ResearchData. https://doi.org/10.4121/14066504.V1

Dates

Issued:

2021-02-23

Funding References

Funder name: National Aeronautics and Space Administration

Award number: NNX16AK81G

Award title: DISTRIBUTED STRAIN IN SOUTHERN PAKISTAN HOW AND WHY DO SINGLE FAULTS SLIP IN MULTIPLE DIRECTIONS?\NFAULTS ARE FUNDAMENTAL INDICATORS OF STRAIN ORIENTATION AND ACCOMMODATION IN ZONES OF ACTIVE DEFORMATION, AND FAULT SLIP ANALYSIS ILLUMINATES LONG TERM PLA

Funder name: Directorate for Geosciences

Award number: 1917500

Award title: Probing the transient rheology of accretionary prisms and megathrust earthquake hazard in the Indian Ocean basin