A holistic approach to 3-component beamforming on seismic arrays

Seismic arrays are installations where several seismic sensors are typically distributed over an aperture covering up to 10 km or more. Routine array signal processing is applied to the data streams recorded. This generates near-realtime estimates of direction-of-arrival for impinging signals that, for example, are due to earthquakes.

Globally, seismic data from arrays have proven to be of great value, for example, in characterization of earthquakes, in monitoring that the nuclear test-ban-treaties to limit nuclear testing, in vulcanology, in glaciology, in monitoring CO2 storage sites, and beyond.

For so-called 3-component arrays, each array site comprises 3 sensors, where each of them records the earth's displacement in different directions (typically north/south, east/west, and up/down). The 3-component sensors allow for "rotating" the data towards specific directions, while the arrays also allow for spatio-temporal filtering (beamforming) in order to separate waves arriving from different directions. We apply time-delays to the different array sensor traces to achieve the focus of our "beams" towards different directions of arrival.

This MSc project is targeted towards exploiting a holistic approach to process data from such 3-component seismic arrays. This kind of processing might open up, for example, for a better characterization of seismic events, for for a more accurate measurement of earthquake characteristics, or for revealing weak signals which otherwise would be buried in noise. There is even a chance that your MSc work can make a contribution which might enhance the monitoring of the comprehensive nuclear-test-ban treaty.

Picture from the SPITS seismometer array on Svalbard.  (Image: NORSAR)

 

In this project,

  • You will work on enhancing and developing signal processing recipes for time-series of 3-component seismic array recordings.
  • You will be supported by experienced advisors both from the university and from the research institute.
  • You will gain hands-on experience in scientific data processing and programming using state-of-the art Python package ObsPy, which is used by seismology researchers and centers worldwide. You will write your own code that takes advantage of the ObsPy framework.
  • You will get the opportunity to work on real-world data that is contributing to a safer society.
  • You will be able to make comparisons to big datasets of earthquake catalogues.
  • An interest and background in Python programming and in one or several of the following fields will be an advantage:
    • Signal processing
    • Array signal processing
    • Geosciences
    • Data science and visualization

This project is a collaboration with the independent research institute NORSAR, which is a research center for earthquakes in Norway, based in Lillestrøm/Kjeller, close to Oslo. The MSc project will be integrated with ongoing research projects.

Emneord: Array signal processing, signal processing, wave propagation, seismology, geophysics, data science
Publisert 14. sep. 2023 09:00 - Sist endret 29. sep. 2023 13:00

Veileder(e)

Omfang (studiepoeng)

60