Analysis of continuous seismic data from Svalbard to reveal near-surface structural changes and potential links to permafrost variability

Ambient seismic noise is continuously recorded on seismometers and can be used to analyze sub-surface structures and changes therein. The methods being used include cross-correlation of noise between seismic stations which allows us to measure the seismic velocity in propagation medium between the receivers. This processing can be done in a time-lapse manner to measure temporal changes of the velocities which are related to changing material properties (noise interferometry).

The SPITS array at Janssonhaugen in Svalbard is a small network of seismometers and recorded over 25 years of continuous data. It has been shown recently using a short part of the record that temporal changes of seismic velocities below the array can be retrieved from ambient seismic noise. These changes can be explained by the seasonal and long-term variations of permafrost temperatures.

In this thesis, the candidate will extend the analysis time period, analyze daily, seasonal and annual velocity changes, and correlate those with permafrost temperature measurements in a nearby borehole. Potentially, long-term permafrost changes at the study site retrieved from existing permafrost models should be compared with the results of SPITS data analysis and prediction of velocity changes at SPITS expected in future can be assessed.

The candidate may apply for an Arctic Field Grant to do additional measurements and on-site investigation of permafrost at SPITS. 

The potential student is expected to have general skills in geophysics and advanced knowledge in seismology or computational geosciences. General scientific programming skills are also expected (e.g., Python or MATLAB).

Tags: ambient seismic noise, Permafrost
Published Oct. 11, 2021 11:32 AM - Last modified Oct. 11, 2021 11:33 AM