Thread: IRIS WEBINARS: Accurate Seismic Event Location: A Question of Context, and Lessons 24 and 25 of Geology and Geophysics in the Petroleum Industry

Started: 2017-09-19 16:22:43
Last activity: 2017-09-19 16:22:43
Topics: Webinars
Please register for Accurate Seismic Event Location: A Question of Context on September 20, 2017 2:00 PM EDT at:

Presented by: Steven J. Gibbons, Senior Research Geophysicist, NORSAR

Abstract: A great amount of global seismicity occurs in regions with very limited station coverage and significant error in estimates for seismic traveltimes can lead to considerable event mislocation and a very blurred image of seismicity. We present case studies in which modern probabilistic event location algorithms provide dramatically improved images of the distribution of seismic events. So-called precision seismology has vastly improved relative event location estimates over short distances for which waveform similarity is observed. For example, the declared nuclear tests in North Korea can be located relative to each other to within an accuracy of less than hundreds of meters. However, we can demonstrate that the outgoing wavefield is more complicated than is assumed in most double-difference type location estimates. Precision seismology will improve greatly if it can encompass the progress made in the context-based multiple event location algorithms and account for deviations from the applied models resulting from features on smaller length scales than we are currently able to model.

Bio: Gibbons works as a research geophysicist within the programme for Array Seismology and Test-Ban-Treaty Verification at NORSAR. His primary research interests are array processing for seismic signals and full waveform methods for improving the detection capability in the seismic monitoring of nuclear explosions. He is also interested in improving location estimates for seismic events on scales from microseismic, local, regional, and global.

After registering, you will receive a confirmation email containing information about joining the webinar. PLEASE NOTE: Registration does not confirm or guarantee you will have a spot during the webinar, as we are limited to 500 participants. Please hop on the webinar early for your best chances to see the webinar live. Remember that all IRIS webinars are archived for later viewing at


Please register for this week’s webinars on Geology and Geophysics in the Petroleum Industry, presented by Dr. Fred Schroeder, retired from Exxon and ExxonMobil.

Please register for Lesson 24 - Seismic Attributes on September 19, 2017 at 2:00 PM EDT at:
Please register for Lesson 25 - Reservoir Quality on September 21, 2017 at 2:00 PM EDT at:

More information regarding the course can be found at:

Danielle Sumy, PhD

Project Associate
Instrumentation Services
Education and Public Outreach
The IRIS Consortium

1200 New York Ave. NW
Washington, DC 20005
Phone: 202-407-7015
Fax: 202-682-0633
Email: danielle.sumy<at>

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