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19-5. Next generation aftershock and earthquake forecasting methods and products

By Mendenhall Research Fellowship Program

 

Closing Date: January 4, 2021

This Research Opportunity will be filled depending on the availability of funds. All application materials must be submitted through USAJobs by 11:59 pm, US Eastern Standard Time, on the closing date.

How to Apply

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Large earthquakes are followed by aftershocks, which can cause additional damage along with ongoing psychological distress (e.g. Dorahy et al., Journal of Loss and Trauma, 2016).  Aftershock forecasts can help a wide range of users including the public, emergency managers, and lifeline engineers prepare for, respond to, cope with, and recover from earthquake disasters. Currently the USGS delivers timely public forecasts of the expected number of aftershocks following domestic earthquakes (Michael et al., SRL, 2019), including recent damaging earthquakes in Alaska, California, Puerto Rico, and Utah.  These forecasts have been used by FEMA, the U.S. Navy, states, and local agencies to inform planning and staging decisions (van der Elst et al., USGS OFR 2020-1009, 2020), such as the resumption of operations at the China Lake Naval Air Weapons Station and the crafting of Federal disaster declarations (Michael, USGS OFR 2018-1195, 2018). 

There are many ways to improve our forecasts. Advancing our understanding of earthquake processes, statistical methods, and crisis and risk communications can improve outcomes for users. Further, we need to expand our abilities to test our methods and communication products during earthquake sequences.  

Recent work (Gulia and Wiemer, Nature, 2019) suggests that our ability to forecast whether or not an aftershock sequence will include an event even larger than the mainshock can be improved through the use of new approaches that focus on changes in the ratio of small to large magnitude aftershocks.  Understanding if this proposed new method is an improvement requires understanding the earthquake physics behind it and rigorous testing using well-recorded aftershock sequences to demonstrate improved performance over current methods. 

The USGS Operational Aftershock Forecasts currently use a model that ties all earthquake triggering to the mainshock (Reasenberg and Jones, Science, 1989; Page et al., BSSA, 2016), but we are evolving toward the ETAS model in which all earthquakes can trigger aftershocks (Ogata, J. Am. Stat. Assoc., 1988).  Using the ETAS model brings new possibilities for producing aftershock hazard maps, a frequent request of many key users, but also poses new challenges for parameter estimation and computational efficiency.  With both models, our initial forecasts after earthquakes are based on pre-determined generic parameters. Outside of California, these generic parameters are based on past sequences in similar tectonic environments around the world.  Thus, developing regionally specific parameters for other areas of the U.S. will improve our initial forecasts. 

People want to access forecasts in different ways, including maps, tables, charts, diagrams, and narratives (Becker et al., IJDRR, 2019) as well as timely two-way discussion from the science agencies about the forecasts (McBride et al., SRL, 2020). Currently the forecasts at the USGS are communicated via a tiered narrative and table template (Michael et al., SRL, 2019) and visual elements should be added to increase usability of the information. Another challenge is the coordination of messaging across science advisory, emergency management, and public health communication roles (Wein et al., SRL, 2016). 

We look forward to proposals that advance USGS aftershock forecasting goals, including any of the following: 

  1. Improved methods for determining ETAS parameters, including uncertainties, and producing computationally efficient spatiotemporal aftershock forecasts, including user-selectable hazard curves. 
  2. Generic ETAS parameter distributions for complex tectonic environments such as spatially complex subduction zones (e.g. Alaska, Cascadia, Puerto Rico), and regions such as Hawaii and areas of induced seismicity, where time-varying processes create changes in earthquake rates that combine with inter-earthquake triggering to produce complex earthquake sequences. 
  3. Development of new forecast methods including constraints from earthquake source physics or determining whether Gutenberg-Richter b-value variations improve our ability to forecast large magnitude aftershocks. 
  4. Development of regional earthquake forecasts that include contributions from both independent events and their aftershocks while accounting for spatial and intersequence variability in aftershock behavior. 
  5. Testing existing earthquake forecasts and new methods, for example with the Collaboratory for the Study of Earthquake Predictability. Carrying out these tests will require the development and implementation of new testing methods that account for correlations between forecast windows. 
  6. Developing and testing new methods to visually communicate spatiotemporal forecasts of earthquake rates, ground motion and other hazards, and risk. 
  7. Exploring how decision-makers in diverse communities in the United States and associated territories access, understand, and take actions based on the forecasts. 
  8. Exploring information needs and forecast use in decision making by emergency managers, first responders, public health officers, critical infrastructure operators, insurers, structural engineers, and Urban Search and Rescue (USAR) Teams. 

Interested applicants are strongly encouraged to contact the Research Advisor(s) early in the application process to discuss project ideas. 

References: 

Becker, J. S., Potter, S. H., McBride, S. K., Wein, A., Doyle, E. E. H., & Paton, D. (2019) When the earth doesn’t stop shaking: How experiences over time influenced information needs, communication, and interpretation of aftershock information during the Canterbury Earthquake Sequence, New Zealand, International Journal of Disaster Risk Reduction, 34, 397-411. doi:https://doi.org/10.1016/j.ijdrr.2018.12.009 

Dorahy, M. J., Renouf, C., Rowlands, A., Hanna, D., Britt, E., & Carter, J. D. (2016) Earthquake aftershock anxiety: An examination of psychosocial contributing factors and symptomatic outcomes, Journal of Loss and Trauma, 21(3), 246-258. https://doi.org/10.1080/15325024.2015.1075804 

Gulia, L., Wiemer, S (2019) Real-time discrimination of earthquake foreshocks and aftershocks, Nature 574, 193–199. 

McBride, S. K., Llenos, A. L., Page, M. T., & van der Elst, N. (2019). #EarthquakeAdvisory: Exploring Discourse between Government Officials, News Media, and Social Media during the 2016 Bombay Beach Swarm. Seismological Research Letters. doi:10.1785/0220190082 

Michael, A. J. (2018) On the potential duration of the aftershock sequence of the 2018 Anchorage earthquake, U.S.G.S. Open File Report. Reston, VA, U.S.G.S. 2018–1195: 18. 

Michael, A. J., S. K. McBride, J. L. Hardebeck, M. Barall, E. Martinez, M. T. Page, N. van der Elst, E. H. Field, K. R. Milner and A. M. Wein (2019) Statistical Seismology and Communication of the USGS Operational Aftershock Forecasts for the 30 November 2018 Mw 7.1 Anchorage, Alaska, Earthquake, Seismological Research Letters 91(1): 153-173. 

Ogata, Y. (1988). Statistical models of point occurrences and residual analysis for point processes, J. Am. Stat. Assoc. 83: 9-27. 

Page, M. T., N. van der Elst, J. Hardebeck, K. Felzer and A. J. Michael (2016) Three Ingredients for Improved Global Aftershock Forecasts: Tectonic Region, Time‐Dependent Catalog Incompleteness, and Intersequence Variability, Bulletin of the Seismological Society of America 106(5): 2290-2301. 

Reasenberg, P. A. and L. M. Jones (1989) Earthquake hazard after a mainshock in California, Science 243(4895): 1173-1176. 

van der Elst, N. J., J. L. Hardebeck and A. J. Michael (2020). Potential Duration of Aftershocks of the 2020 Southwestern Puerto Rico Earthquake. U.S.G.S. Open File Report. Reston, VA, U.S.G.S. 2020-1009: 16. 

Wein, A., Becker, J., Potter, S., Johal, S. Doyle, E., 2016. Communications during an Earthquake Sequence: Coordinating the Science Message with other Communication Roles, Seismological Research Letters vol. 87, no. 1. 

Proposed Duty Station: Moffett Field, CA; Pasadena, CA; or Golden, CO. 

Areas of PhD: Geophysics, seismology, statistics, social science, sociology, economics, anthropology, communication or media studies, visual design, cartography, UX design, geology, geodesy, engineering, mathematics, or computer science. (candidates holding a Ph.D. in other disciplines, but with extensive knowledge and skills relevant to the Research Opportunity may be considered). 

Qualifications: Applicants must meet one of the following qualifications: Research Geophysicist, Research Geologist, Research Geodesist, Research Computer Scientist, Research Economist, Research Engineer, Research Mathematician, Research Physicist, Research Statistician, Research Social Scientist, Research Sociologist, Operations Research Analyst.  

(This type of research is performed by those who have backgrounds for the occupations stated above.  However, other titles may be applicable depending on the applicant's background, education, and research proposal. The final classification of the position will be made by the Human Resources specialist.) 

Human Resources Office Contact: Beverly Ledbetter, 916-278-9396, bledbetter@usgs.gov 

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