SSA 2016 - Nanometrics Event Schedule - Booth # 6

Join Nanometrics in Reno, Nevada from April 19 to 22 for the Seismological Society of America’s 2016 annual meeting. The event promises to be a stimulating exchange of research on a wide range of topics with colleagues from all over the world, including oral and poster presentations from Nanometrics researchers. 

Wednesday, April 20

Session: Induced Seismicity

11:30 am         Oral presentation
 “A Ground Motion Prediction Equation for Induced Earthquakes in Oklahoma”
 Presenter: Emrah Yenier
 Room: Tuscany A


2:45 pm    Poster presentation
 “Prediction of Earthquake Ground Motions in Western Alberta”
 Presenter: Emrah Yenier
 Poster #49, Tuscany F



Thursday, April 21

Session: Induced Seismicity Monitoring: What is Really Needed?
8:30 am   Oral presentation
 “Challenges and Strategies for Monitoring Induced Seismicity”
 Presenter: Sepideh Karimi
 Room: Tuscany 1 / 2
Session: Advancements in Network Operations and Station Design
8:30 am       Poster presentation
 “Feasibility of Tilt Measurement Using Seismometer Mass Position Data”
 Presenter: Geoff Bainbridge
 Poster #31 / Tuscany F

Friday, April 22

Session: NGA-East: Research Results and Ground-Motion Characterization Products for Central and Eastern North America
11:00 am                         
Oral presentation
 “Prediction Equation for Central and Eastern North America Based on a Regionally Adjustable Generic Ground Motion Model”
 Presenter: Emrah Yenier
 Room: Tuscany 7 / 8
Session: Active Tectonics, Faults and Large Earthquakes
11:00 am               Poster presentation
 “Sources of Latency and Associated Design Trade-Offs in Earthquake Early Warning Systems”
 Presenter: Geoffrey Bainbridge
 Poster #7 / Tuscany F





A Ground Motion Prediction Equation for Induced Earthquakes in Oklahoma

Emrah Yenier (1),  Gail M. Atkinson (1) & Danielle D. F. Sumy Sumy (2)
(1) Western University, London, ON, Canada (2) Incorporated Research Institutions for Seismology, Washington DC, USA
Seismic activity in Oklahoma has substantially increased within the last decade. Deep injection of wastewater from hydrocarbon production is believed to be responsible for the evolving seismicity in the region. The growing seismicity in Oklahoma has raised concerns regarding the hazard associated with induced seismicity. Estimation of ground motions that can be produced by induced earthquakes is key to determining hazard contributions from induced seismicity.
In this study, we aim to develop a ground motion prediction equation (GMPE) for induced earthquakes in Oklahoma. Available ground motion data from induced seismicity are insufficient to develop a robust empirical GMPE for moderate-to-large magnitudes (M > 5). In order to obtain a predictive model applicable for a wide range of magnitudes, we adopt a regionally-adjustable generic GMPE whose parameters have been calibrated to the rich empirical data in California. We investigate the region-specific source and attenuation attributes of induced events, using ground motions obtained from the 2011 Prague, Oklahoma earthquake sequence. We examine the spatial and temporal variation of stress parameters determined from ground motions of induced events, and compare their values to those obtained from naturally occurring earthquakes, to gain insights into the source characteristics of induced events in the region. We adjust the generic GMPE using the regional model parameters and calibration factor calculated from empirical data. The adjusted GMPE provides predictions for average horizontal-component response spectra and peak motions that may be produced by induced earthquakes in Oklahoma.


Prediction of Earthquake Ground Motions in Western Alberta

Emrah Yenier (1), Dario Baturan (1), Andrew Law (1) & Gail M. Atkinson (2)
  1. Nanometrics, Inc., Ottawa, Canada (2) Western University, London, ON, Canada
We develop a ground-motion prediction equation (GMPE) for earthquakes in western Alberta, where hazard contributions from induced seismicity is of particular interest. We investigate the regional source and attenuation attributes using peak ground motions and response spectra from recorded seismic events. We supplement the seismic data with ground motions obtained from mining/quarry blasts in the region, to gain insights into the regional attenuation over a wide distance range. The available empirical data is limited for deriving a robust predictive model in the magnitude range of engineering interest (M>4). We therefore adopt a regionally-adjustable generic GMPE (Yenier and Atkinson, 2015 BSSA), with parameters that have been calibrated to the rich empirical data in California, to ensure seismologically robust predictions for moderate-to-large magnitudes. We modify the model parameters of generic GMPE based on the source and attenuation attributes observed in western Alberta, and determine an empirical calibration factor that accounts for the overall differences between the generic model and the empirical data in the region. This provides a hybrid GMPE that is fully-adjusted for observed motions in western Alberta and is applicable for wide ranges of magnitude and distance.

Challenges and Strategies for Monitoring Induced Seismicity

Dario Baturan, Sepideh Karimi & Emrah Yenier
Nanometrics Inc, Kanata, ON, Canada,
Between 2013 and 2015, a number of seismic events characterized as induced with magnitudes above M3.0 were recorded in British Columbia, Alberta, Ohio and Oklahoma. Following increased public awareness and media scrutiny, many jurisdictions have put in place protocols to mitigate risks associated with induced seismicity. Most of the regulations introduced to date mandate the deployment of real-time seismic monitoring networks as drivers of operational traffic light systems. Using some of the regulatory protocols now in place, we address the best practice strategies associated with monitoring for induced seismicity. How many stations are needed to meet the monitoring mandate and what should be their geographical distribution? How many stations could be inoperative before the network does not meet its monitoring mandate? With a number of sensing technologies to choose from, including seismometers, accelerometers and geophones, which one provides the best combination of self-noise, clip level and frequency response to cover the seismic event magnitude and epicentral distance range? As most current “traffic light” protocol thresholds are based on magnitudes, which magnitude scale should be used? The networks initially deployed to manage risk associated with induced seismicity can provide additional benefits. Generated data sets can be used to assist operators in optimizing completion operations, identify or refine knowledge of geological structures, estimate the direction of in-situ stress regimes, monitor critical infrastructures and develop regional attenuation relationships for more accurate ground motion and magnitude estimates.

Feasibility of Tilt Measurement Using Seismometer Mass Position Data

Geoffrey Bainbridge, Sepideh Karimi, Emrah Yenier & Andrew Moores
Nanometrics Inc., Ottawa, ON, Canada
Force feedback seismometers provide mass position outputs which represent the time-averaged feedback force applied to each inertial mass, in order to cancel external forces and keep it balanced at its center point. These external forces are primarily due to tilt and temperature. In a symmetric triaxial seismometer, tilt and temperature effects can be distinguished because temperature affects all 3 axes equally whereas tilt causes a different force on each axis. This study analyzes the resolution of tilt and temperature signals that can be obtained from a force-feedback seismometer, and the potential applicability of this data to applications such as volcano monitoring and cap rock integrity monitoring. Also the synergy of a combined seismic, tilt, and temperature instrument is considered.


Prediction Equation for Central and Eastern North America Based on a Regionally Adjustable Generic Ground Motion Model

E. Yenier & Gail M. Atkinson
Western University, London, ON, Canada
Limited ground-motion observations in central and eastern North America (CENA) create challenges in terms of developing a regional ground motion prediction equation (GMPE) for a wide range of magnitudes and distances using conventional empirical methods. We tackle this problem by adjusting a generic GMPE model based on the observed source and attenuation attributes in CENA.
The basis of the generic GMPE is an equivalent point-source simulation model whose parameters have been calibrated to empirical data in California. We use simulated motions to determine the decoupled effects of basic source and attenuation parameters on ground motion amplitudes. The generic GMPE is defined as a function of magnitude, distance, stress parameter, geometrical spreading rate and anelastic attenuation, for a reference NEHRP B/C boundary site condition. We also include an empirical calibration factor to account for residual effects that are different or missing in simulations compared to observed motions in the target region. This provides a “plug-and-play” GMPE that can be adjusted for use in any region by modifying a few key model parameters based on the observed ground motions.
We calibrate the generic GMPE for CENA using the regional source and attenuation parameters as well as the empirical calibration factor determined from NGA-East ground-motion database. We infer a magnitude- and depth-dependent stress parameter model based on the values obtained from study events. The developed GMPE provides median predictions of ground motions in CENA for average horizontal-component peak ground motions and 5%-damped pseudo spectral acceleration (T ≤ 10 s), for wide ranges of magnitude (M3-M8) and distance (< 600 km).

Sources of Latency and Associated Design Trade-Offs in Earthquake Early Warning Systems

Chris Cordahi, David Easton, Tim Hayman & Ross MacCharles
Nanometrics, Ottawa, ON, Canada
Low latency is a key contributor to the success of an Earthquake Early Warning (EEW) system. There are several points where latency is introduced between the instant in time that a digitizer produces a set of samples across its analog sensor channel inputs and the point at which the corresponding data reaches its destination for EEW analysis outside the instrumentation and networking domains. Typically long distances separate data sources from the location at which analysis is performed. These points of latency arise out of software, mathematical, and networking as well as physical constraints imposed upon the digitizer and associated communication systems. System designs must account for tradeoffs between latency and resource (CPU) utilization, which has an effect on power consumption, and communication network bandwidth. Designers of seismological instrumentation used for EEW deployments must keep these trade-offs in mind and make clever implementation choices to minimize delay. System integrators and network operators must be fully aware of latency and its contributors in order to make the right configuration choices when commissioning EEW systems to ensure the lowest possible latency without compromising the accuracy of the early warning data product. We illustrate the tradeoffs being made at the identified latency points using an analysis of a typical deployment of a digitizer streaming live seismic data to a central site utilizing a Very Small Aperture Terminal (VSAT) communication system.
Download the Schedule

Apr 18, 2016