Four SSA sessions plus two other announcements from the SCEC community

Dear SCEC Community,

Happy New Year from the Southern California Earthquake Center!

Please see the following six announcements, which include four regarding SSA sessions with abstract submission deadlines THIS WEEK (Wednesday, January 11):

• SSA Session: Opportunities and Challenges in Source Modeling for Seismic Hazard Analysis
• SSA Session Announcement: Crustal Imaging of High Seismic Hazard Regions
• SSA 2023 Session: From Earthquakes to Plate Boundaries
• Call for abstract submissions- SSA 2023: Fault Damage & Healing
• Geophysics Instructor needed at Cal Poly Pomona beginning January 23, 2023
• Announcement for Geodetic and Remote Sensing Postdoc (LANL)

 

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On behalf of Chris Rollins, GNS Science

SSA Session: Opportunities and Challenges in Source Modeling for Seismic Hazard Analysis

Abstract submission for the 2023 Seismological Society of America (SSA) Annual Meeting (https://meetings.seismosoc.org/) is open until 17:00 PM, January 11, 2023.

We would like to draw your attention and invite you to submit your abstracts to the session:  Opportunities and Challenges in Source Modeling for Seismic Hazard Analysis.

Evaluating earthquake rates is critical to assess seismic hazards for a variety of applications including national building codes, catastrophe risk modeling, and site-specific studies for critical facilities. To accomplish this, recent national and regional seismic hazard models have used interdisciplinary approaches that combine geological, geodetic and seismological models. Often, fault-based models are complemented with distributed (or smoothed) seismicity models derived from earthquake catalogs, especially in regions where knowledge of the fault network is largely incomplete. Some efforts have begun to incorporate physics-based (dynamic) earthquake models, which produce synthetic catalogs spanning hundreds of thousands of years. In active areas, there are complicated cases where different seismotectonic regimes are present, such as subduction zones (interface and intraslab sources) juxtaposed with crustal sources. Some other frontiers include complex multi-fault ruptures, models for earthquake occurrences (Poissonian versus non-Poissonian rates), and region-specific source scaling properties. 

In this context, there is an impetus for integrated approaches that take advantage of different datasets to deliver a consistent model of earthquake rates, their spatial distribution and potential rupture mechanisms. In this session, we welcome contributions that are focused on the advancements in the development of source models, with new methods, datasets and/or hypotheses. Research topics pertinent to this session include but are not limited to: distributed seismicity models, magnitude-frequency distributions, models for earthquake occurrences, time-dependent seismicity, active fault models, region-specific source scaling properties, inversion of slip-rates, simulated seismicity and synthetic catalogs, and subduction sources. We also look forward to region-specific investigations that provide useful case studies.    

Best wishes,

Kiran Thingbaijam, Chris Rollins,  Andrea Llenos, Andrew Michael, Andy Nicol, Delphine Fitzenz, Marco Pagani, Matt Gerstenberger

 

 

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On behalf of Patricia Persaud, University of Arizona

SSA Session Announcement: Crustal Imaging of High Seismic Hazard Regions

Dear Colleagues,

We want to draw your attention to the following 2023 SSA Annual Meeting session:
Crustal Imaging of High Seismic Hazard Regions
 
In this session, we aim to gather contributions from passive and active-source seismic studies that discuss the characterization of crustal structures. We welcome contributions based on gravity and magnetic data, velocity and attenuation tomography (t* method, direct wave attenuation, coda waves), and other imaging techniques (e.g., using ambient noise and converted waves). Studies that include tomographic models and other multidisciplinary geophysical and geological data in ground motion modeling, seismic hazard assessments and site response analysis are welcomed. We also encourage submissions from early-career researchers and studies using innovative methodologies (e.g., machine learning).
 
The full session description is included below.
Please consider submitting your abstract to our session before the deadline on January 11, 2023.
https://meetings.seismosoc.org
 
Happy New Year and we look forward to seeing you in Puerto Rico!
Chiara Nardoni (Louisiana State University)
Simona Gabrielli (INGV)
Patricia Persaud (University of Arizona)
Eric Sandvol (University of Missouri)
 
Session Description:
In high seismic hazard areas, imaging both the elastic and anelastic properties of the medium is key for evaluating deformation processes and the impact of complex fault systems on ground motion amplification. Characterizing crustal features is especially challenging when wave focusing and conversions, or fluid interactions occur such as in geothermal and volcanic areas. Combining attenuation and velocity models is crucial for predicting site response and seismic wavefield amplitudes. This session aims at providing an overview of techniques and applications related to the imaging and validation of seismic velocity and attenuation across various scales ranging from laboratory samples to basin and plate boundary scales. We welcome onshore and offshore passive and active-source seismic studies and studies based on gravity and magnetic data that discuss the characterization of crustal structures, including faults, volcanic and geothermal areas. We aim to gather contributions from velocity and attenuation tomography (t* method, direct wave attenuation, coda waves) and other imaging techniques (e.g., using ambient noise and converted waves). We welcome studies aimed at including these models and other multidisciplinary geophysical and geological data in ground motion modeling, seismic hazard assessments and site response analysis. We also encourage submissions from early-career researchers and studies using innovative methodologies (e.g., machine learning).

 

 

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On behalf of Nadine Reitman, USGS

SSA 2023 Session: From Earthquakes to Plate Boundaries

Please consider submitting an abstract for the 2023 SSA meeting to our session:

From Earthquakes to Plate Boundaries: Insights into fault behavior spanning seconds to millennia

Presenters are expected to attend SSA in person, and abstract submissions are due on January 11: https://meetings.seismosoc.org/submit/

Full description:

The processes of strain accumulation and release and related topographic evolution happen over disparate timescales – from seconds to millennia and longer. Quantifying and understanding the earthquake cycle in the continental crust and how tectonic strain is expressed at the surface in the landscape thus requires integrating methods that measure deformation at a range of timescales. While geodetic methods record regional infinitesimal strain accumulation over decadal timescales and finite coseismic deformation from individual large events, paleoseismology and tectonic geomorphology measure site-specific or regional-scale strain release over thousands to millions of years. Numerical modeling and analog experiments attempt to replicate processes that can span multiple temporal scales, but they must be validated with observations to ensure they are physically meaningful. In this session, we invite abstracts that integrate observations and methods from different temporal and/or spatial scales to address topics such as: surface rupture and slip distribution patterns in space and time; variations in earthquake timing and recurrence; fault growth, linkage, and scaling; (dis)agreement of geologic and geodetic rates; and tectonic landscape evolution. We welcome contributions from geodesy, earthquake geology, tectonic geomorphology, numerical modeling, analog experiments, and especially contributions with novel approaches to integrating multiple data sources that help further our understanding of strain accumulation and release spanning coseismic to geologic timescales.

We look forward to seeing you in Puerto Rico.

Cheers,
Nadine Reitman, U.S. Geological Survey (nreitman@usgs.gov)
Solène Antoine, California Institute of Technology (solene.antoine@jpl.nasa.gov)
Austin Elliott, U.S. Geological Survey (ajelliott@usgs.gov)
Chris Milliner, California Institute of Technology (milliner@caltech.edu)
Marion Thomas, Earth Sciences Institute of Paris, Sorbonne Univeristé (marion.thomas@sorbonne-universite.fr)

 

 

 

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On behalf of Travis Alongi, UC Santa Cruz

Call for abstract submissions- SSA 2023: Fault Damage & Healing

We invite you to submit abstracts to our SSA session (title & abstract below). Reminder that abstracts are due Wednesday, January 11 at 5:00 pm Pacific. We welcome submissions from observations, laboratory experiments, numerical modeling and theoretical studies.

https://meetings.seismosoc.org/

Above the Seismogenic Zone: Fault Damage and Healing in the Shallow Crust 
Fault damage zones provide a window into the inelastic processes and products that result from coseismic stress changes. The spatial extent of fault damage during earthquakes is greatest in the upper-most kilometers of the crust, above the seismogenic zone. Inelastic processes within this volume modify the bulk long-term properties of the shallow crust, increasing local seismic hazard through enhanced shaking. Fault damage zones have attracted the interest of a broad range of geoscientists because of their relevance to fundamental earthquake physics problems, i.e., the earthquake energy balance, strong ground motions and near fault fluid flow. Higher resolution datasets, a growing number of observations and increased computational power have advanced our understanding of the spatial extent, physical properties and time-integrated evolution of the shallow portion of damage zones. Our understanding of fault damage zones, the processes that form them and their feedbacks with various phases of the earthquake cycle is improving; however, there remain many unanswered questions such as the mechanism and rate of fault healing above the seismogenic zone, the role of subsidiary faults on earthquake nucleation and a complete model that extends damage observed at the surface to seismogenic depth. In this session, we welcome contributions and recent advances in the quantitative understanding of the shallow properties of fault damage 4 zones. We are particularly interested in contributions that explore and combine observations, laboratory experiments, numerical modeling and theoretical studies.

 

 

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On behalf of Jon Nourse, Cal Poly Pomona

Geophysics Instructor needed at Cal Poly Pomona beginning January 23, 2023

We have a sudden need for Geophysics Instructor(s) to teach undergraduate-level Global Geophysics and graduate-level Shallow Subsurface Geophysics (details below).  Please send inquiries to:

Dr. Jon Nourse, Professor and Chair
Geology Department
Cal Poly Pomona
janourse@cpp.edu
(909) 869-3460

Global Geophysics
Lecture meets Thurs 10-11:50AM, with Lab Thurs 1:00-3:50PM
TA is available to assist with lab
Lecture Topics:

• History of the development of the theory of plate tectonics 
• Earth’s magnetic field and its reversals
• Reconstructions of plate motions from magnetic anomalies
• Construction of velocity space diagrams of plate motions 
• Geomagnetism
• Different types of seismic waves 
• Determination of earthquake location, magnitude and mechanisms
• Gravity and geoid anomalies
• Isostasy and isostatic rebound
• General theory of radioactive decay 
• Geochronology
• Internal structure of the Earth: density, seismic velocity and elastic constants
• Tomography of the Earth
• Convection in the mantle
• Convection in the outer core and the Earth’s magnetic field
• Apparent Polar Wander Paths in paleomagnetism
• Lithospheric structure near ridges, subduction zones, transform boundaries and collision zones
• Presentations and group discussion of current topics and scientific literature

Laboratory Topics:

• Construction of velocity space diagrams for various types of plate boundaries and triple junctions
• Interpretation of maps or sections of seafloor magnetic anomalies and use of age scale
• Interpretation of gravity anomalies in terms of different types of isostasy
• Plotting measurements of the decay of radioactive isotopes on appropriate types of diagrams to determine ages
• Application of Snell’s law for flat as well as spherical velocity models and the construction of seismic ray paths 
• Reconstruction of plate motions using Apparent Polar Wander Paths and the inherent assumptions/unknowns 
• Field trip to site of geophysical interest
• On or off campus field experiment using geophysical equipment
• Presentations and group discussion of current topics and scientific literature

Shallow Subsurface Geophysics
Lecture meets Monday 9-10:50AM, with Lab Monday noon-2:50PM
TA is available to assist with lab
Available equipment includes ground-penetrating radar, seismic refraction, electrical resistivity, LaCoste- Romberg gravimeter, magnetometer, and drone-mounted LiDAR
Lecture Topics:

• Seismic wave propagation and ray paths in layered material
• Predicted arrival times in refraction experiments for various subsurface models 
• Different geophysical approaches to determine site response factors
• Principles of resistivity
• Experiment design in resistivity
• Interpretation of resistivity measurements for typical subsurface structures
• Gravity corrections needed for typical surveys
• Analysis and interpretation of gravity surveys: forward models
• Principles of electromagnetic surveying and Ground Penetrating Radar
• Physical meaning of different types of magnetic measurements
• Analysis, correction and interpretation of magnetic measurements
• Forward modeling of simplified subsurface magnetic structures
• Advantages and disadvantages of the use of specific geophysical techniques for specific types of problems
• Discussion of case studies and scientific publications
• Discussion of new developments in shallow subsurface geophysics methods, procedures, analysis and modeling

Lab Topics:

• Field procedures and experiment design for various types of geophysical experiments
• Tutorial for geophysical inversion software such as Res2DInv
• Use and installation of various types of geophysical instrumentation
• Processing and correcting of data resulting from various types of geophysical surveys
• Interpretation of results of various types of geophysical surveys
• Advantages and disadvantages of the use of specific geophysical techniques for specific types of problems
• Discussion of case studies 
• Discussion of new developments in shallow subsurface geophysics methods, procedures, analysis and modeling
• On and off-campus field trips to carry out geophysical experiments
• Field trips to sites of geophysical interest or to observe geophysical experiments

 

 

 

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On behalf of Christopher Johnson, LANL

Announcement for Geodetic and Remote Sensing Postdoc

Geodetic and Remote Sensing Postdoc (Job # IRC115919)

View complete post and apply through jobs.lanl.gov

In addition to applying online, applicants should also email their CV and cover letter to Dr. Elena Reinisch (ecreinisch@lanl.gov) and Dr. Christopher Johnson (cwj@lanl.gov).

What You Will Do

The Intelligence and Space Research (ISR) and Earth and Environmental Sciences (EES) Divisions at Los Alamos National Laboratory (LANL) have an immediate opening for a postdoctoral research associate in applied geodetic and remote sensing. The position will include developing InSAR time series for source characterization of ground motions using advanced modeling techniques. The work will involve a combination of developing new signal analysis capabilities and applying newly developed and existing machine learning tools. The successful candidate will collaborate with scientists at LANL and with external industry and academic partners. The term of the appointment is two (2) years, with the option to extend to a third year depending on performance and funding availability.

What You Need

Minimum Job Requirements

• InSAR time series development with open-source software (e.g., ISCE, GMTSAR, MintPy)
• Research experience in code development, and applications in InSAR
• Proficiency in programing languages such as Python, Julia, C/C++
• Experience using supercomputing and HPC resources
• Communication skills as evidenced by publications and oral presentations at conferences
• Experience working on interdisciplinary teams

 
Education/Experience

A Ph.D. degree in a STEM field related to geodesy, seismology, geophysics, applied mathematics, computer science, physics, or other related fields. For a postdoctoral appointment the candidate must have completed all Ph.D. requirements by commencement of the appointment or must be within five years of completion of the Ph.D.

Desired Qualifications

• Experience with big-data processing and analysis methods
• Experience with development or support of research projects and proposals
• Ability to plan and organize assignments to meet project deliverable
• Ability to bring creative solutions to complex problems
• Ability to obtain Q level clearance, which usually requires U.S. citizenship

 

 

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