Multiple SSA Session Announcements/Calls for Abstracts

Dear SCEC Community,

Please see below for the following SSA session announcements. The deadline to submit abstracts is Wednesday, January 11th, 2017.

1. Understanding and Modeling Ground Motions and Seismic Hazard from Induced Earthquakes
2. PSHA Source Modeling: Approaches, Uncertainty, and Performance

Regards,

SCEC Information

1. Understanding and Modeling Ground Motions and Seismic Hazard from Induced Earthquakes
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Are you interested in any aspect of hazard from induced earthquakes, including modeling ground motion, understanding the physical controls (such as stress drop) on ground motion, seismic source characterization or testing of hazard maps?

Well, then, we encourage you to submit a presentation to our session on "Understanding and Modeling Ground Motions and Seismic Hazard from Induced Earthquakes" at the SSA Annual Meeting in Denver, CO from April 18 to 20, 2017.

Abstract submission is now open on the meeting website: http://meetings.seismosoc.org/ and the deadline is 5:00 PM U.S. Pacific Standard Time (UTC −0800) on Wednesday 11 January, 2017.

We hope to see you in Denver!

Sincerely,
Annemarie Baltay, Dan McNamara, Eric Thompson and Mark Petersen
USGS

Understanding and Modeling Ground Motions and Seismic Hazard from Induced Earthquakes

Performing a probabilistic seismic hazard analysis (PSHA) for induced seismicity is very difficult because we have neither a complete understanding of the genesis and recurrence of induced earthquakes nor a comprehensive model for the ground motion excited by them. Whether there is a fundamental physical difference between natural and induced events is still an open question, and how any potential difference manifest themselves in the ground motion is of great interest. Furthermore, the level of seismic activity may be dependent on human activity, complicating any hazard analysis. We seek contributions that will help establish the modeling input parameters that are critical for the analysis, including controls on both seismic activity and ground motion, the building blocks of a PSHA. For earthquake activity, this may include including declustering earthquake catalogs or determining rates, hypocenters, or maximum magnitudes. By combining information on the state of stress, hydrologic properties of injection formations and the basement, and the locations and orientations of faults with injection data, we have the possibility of building predictive models that anticipate the seismic potential of an area based on its past history. On the ground motion side, we encourage contributions related to understanding if ground motion from induced events is similar or different to existing models, or how ground motion scales at very close distances to these shallow events. This could include testing of existing GMPEs, development of new empirical or simulation based GMPEs, or understanding of the source, path, or site controls on observed ground motion. We encourage submissions regarding the phsysical parameters controling ground motion genesis (such as stress drop or depth) or propagation (attenuation or other path effects). In particular, resolving if these stress drop of these events is similar or very different from that of other tectonic environments is of great interest. Addressing the trade offs in stress drop and hypocentral depth is also of great interest. We especially encourage novel, creative and ground-breaking presentations on concepts that contribute to advancing next-generation induced earthquake PSHA models.

Session Chairs
Annemarie Baltay <abaltay@usgs.gov>
Daniel McNamara <mcnamara@usgs.gov>
Eric Thompson <emthompson@usgs.gov>
Mark Petersen <mpetersen@usgs.gov>

2. PSHA Source Modeling: Approaches, Uncertainty, and Performance
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Dear Colleagues

We would like to draw your attention to a Special Session at the 2017 Annual Meeting of the Seismological Society of America, taking place 18–20 April, in Denver, Colorado.

Abstract Deadline is January 11, 2017

PSHA Source Modeling: Approaches, Uncertainty, and Performance

Source modeling in probabilistic seismic hazard analysis (PSHA) is evolving rapidly in response to increasingly complex source models, increasingly parameterized ground motion models (GMMs), and a desire in most applications to better understand the epistemic uncertainties associated with each. The recently completed Pacific Earthquake Engineering Research (PEER) Center's PSHA code verification project provided an opportunity to compare results from a variety of public and private codes. While there was good agreement between the codes for relatively simple source models, the project spawned rich discussion and exposed a broad variety of modeling approaches with regard to more complex models where, for example, hanging-wall terms were considered, the depth distribution of ruptures were a focus, and approximations of the finiteness of point sources were applied, among others. A common theme that emerged was that convergence between codes could often be attained by increasing the discretization of different model components, for example, the distribution density of point sources or the number of magnitude bins in magnitude-frequency distributions, with commensurate increases in processing time.

Whereas general engineering applications of PSHA have long focused on mean hazard, increasing attention is being paid to understanding the associated uncertainties that are usually considered in site-specific analyses. Such uncertainties are often quite large, and this raises the questions: How does one balance modeling choices in light of uncertainty and performance considerations? At what point do increases in model complexity cease to add value to a PSHA? We invite submissions that focus on all aspects of PSHA source models and the uncertainties associated with the parameterization thereof. We are particularly interested in generating discussion on and sharing results that exhibit the sensitivity of hazard values to alternate modeling choices. Presentations should frame those choices in the context of both source and GMM uncertainty with a focus on what is most important for the particular PSHA application at hand.

Session Chairs

Peter M.Powers <pmpowers@usgs.gov>
Christie D. Hale <christie.d.hale@berkeley.edu>