Thread: PostDoc opportunity (2 years): Exploring physics-based earthquake rupture approaches in fault networks for seismic hazard assessment

Started: 2020-05-27 16:15:44
Last activity: 2020-05-27 16:15:44
Dear colleagues,

I would be grateful if you could pass this PostDoc opportunity on to anyone
who might be interested in connecting seismic hazard, supercomputing and
earthquake geology.

Please contact Oona Scotti (oona.scotti<at>irsn.fr) and see
http://fault2sha.net/job-offers/ for more details.

------------------------

*PostDoc opportunity: Exploring physics-based earthquake rupture approaches
in fault networks for seismic hazard assessment (French ANR project EQTIME
in collaboration with LMU Munich)*
Supervisors: A.-A. Gabriel (LMU Munich), S. Hok and O. Scotti (IRSN)

*Contact: oona.scotti<at>irsn.fr <oona.scotti<at>irsn.fr>*

Duration: 2 years

Starting date: Flexible, between Sept 2020 and Sept 2021

Location: Paris, France and Munich, Germany

Pre-requisites: PhD; experience in dynamic earthquake rupture (laboratory
or numerical)

Our offer: Opportunity to develop a new approach in seismic hazard
modeling; collaborate with a well-established European network of fault
modelers internationally renowned and top-level scientists in a
multidisciplinary team (geologists, seismologists, geodesists and hazard
modelers); learn to solve complex problems using high performance computing
facilities.

Objectives:Probabilistic Seismic hazard modeling aims to forecast
earthquake occurrence and its resultant ground shaking. One of the main
challenges relies in an adequate quantification of uncertainty involved in
seismic-source and ground-motion models. Seismic source models are today
evolving towards considering multi-segment ruptures in complex fault
systems as observed in recent events (i.e. the 2016 Mw7.8 Kaikoura, New
Zealand earthquake with more than 20 individual faults involved). However,
evaluating the possibility of future complex earthquake ruptures in any
given fault system remains a major challenge. Physics-based computer models
allow to simulate how fault interact with each other during their rupture
and cause shaking at the surface of the earth. As such they provide a
framework for the exploration of the space of viable rupture scenarios.
The candidate PostDoc will develop 3D dynamic earthquake rupture scenarios
across complex fault systems combining nonlinear frictional failure and
seismic wave propagation by exploring a range of viable physical
parameters. Empowered by supercomputing, such models will produce
physics-based forecasts of ground motions and fault interaction as well as
providing insight into fundamental processes of earthquake physics.

Challenge: The main challenge and task of the candidate PostDoc will be to
first construct the fault model(s) based on the integration of the rich
amount of data available in the Central Appenines, Italy. For this part,
the PostDoc will interact with the ANR-EQTIME partners. In a second phase,
the candidate will focus on the exploration of the physical parameters of
the fault model (3D fault geometry, regional stress orientation and
amplitude, fluid pore pressure, anelastic behavior parameters, faults’
frictional parameters). For setting these parameters and their variability
in such a blind prediction exercise, a puzzling challenge consists in
bridging the apparent gaps between the large range of variations implied by
Bayesian inversions on simple faults (e.g. Gallovic et al. 2019) and the
tighter variability allowed for the reproduction of multi-fault rupture
scenarios of past earthquakes (e.g. Wollherr et al., 2019, Ulrich et al.,
2019).

Expected Results: The final purpose of the PostDoc is to devise an
efficient strategy to compute viable rupture scenarios in a probabilistic
framework. The physically viable earthquake rupture scenarios and their
associated probabilities will be used to compute fault-based seismic hazard
in the region.
Depending on progress the candidate PostDoc may also tackle the delicate
issue of computing physics-based GMPE’s accounting for source/site and path
effects, as a first step towards a comprehensive physics-based approach for
seismic hazard estimates.

Tools: The candidate will use mainly three open-source, user-friendly
codes: SeisSol, a code used to study complex earthquakes such as Landers or
Kaikoura to model multi-fault rupture propagation; SHERIFS to explore
epistemic uncertainties in multi-rupture scenarios and OPENQUAKE to
compute seismic hazard at selected sites.

References:
Wollherr, Stephanie, Alice-Agnes Gabriel, and Paul Martin Mai (2019),
Landers 1992 ”reloaded”: an integrative dynamic earthquake rupture model,
Journal of Geophysical Research – Solid Earth, 124,
doi:10.1029/2018JB016355, open-access available at
https://eartharxiv.org/kh6j9/
Ulrich, Thomas, Alice-Agnes Gabriel, Jean-Paul Ampuero, and Wenbin Xu
(2019), Dynamic viability of the 2016 Mw 7.8 Kaikōura earthquake cascade on
weak crustal faults, Nature Communications, 10(1213),
doi:10.1038/s41467-019-09125-w


--
Dr. Alice-Agnes Gabriel
Geophysics, LMU Munich
bit.ly/AAG8LMU

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