EGU2020-12092
https://doi.org/10.5194/egusphere-egu2020-12092
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Near-field directionality of earthquake strong ground motions measured by displaced geological objects

Tamarah King1, Mark Quigley1, and Dan Clark2
Tamarah King et al.
  • 1University of Melbourne, School of Earth Sciences, Australia
  • 2Geoscience Australia, Canberra, Australia

Coseismically displaced rock fragments (chips) in the near-field (less than 5 km) of the 2016 moment magnitude (MW) 6.1 Petermann earthquake (Australia) preserve directionality of strong ground motions. Displacement data from 1437 chips collected over an area of 100 km2 along and across the Petermann surface rupture is interpreted to record combinations of co-seismic directed permanent ground displacements associated with elastic rebound (fling) and transient  ground shaking, with intensities of motion increasing with proximity to the surface rupture. The observations provide a proxy test for available models for directionality of near-field reverse fault strong ground motions in the absence of instrumental data. This study provides a dense proxy record of strong ground motions at less than 5 km distance from a surface rupturing reverse earthquake, and may help test models of near-field dynamic and static pulse-like strong ground motion for dip-slip earthquakes.

How to cite: King, T., Quigley, M., and Clark, D.: Near-field directionality of earthquake strong ground motions measured by displaced geological objects, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-12092, https://doi.org/10.5194/egusphere-egu2020-12092, 2020

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