Reykjanes ambient noise reflection interferometry

Reykjanes ambient noise reflection interferometry

Verdel, Arie
Wedemeijer, Harry
Paap, B
Vandeweijer, Vincent
Weemstra, C. (TU Delft Applied Geophysics and Petrophysics)
Jousset, Philippe
Franke, Steven
Blanck, Hanna
Águstsson, K.
Hersir, Gylfi Páll

2016

We present results from the application of ambient noise seismic interferometry (ANSI) to data that were recorded continuously in 2014 and 2015 at Iceland’s peninsula Reykjanes. The objective of this study is the retrieval of reflected body waves (P-waves) that provide high-resolution velocity-versus-depth as well as subsurface structural information. We show, for a subset of the onshore seismometers, that reflection information is present in the frequency bandwidth 3-8 Hz. We have observed both time-lapse variations where we expect them and time-invariant results where we do not expect to see changes. As we lacked availability of active seismic reflection and well-sonic data that could serve as reference, we discovered, in our search to find a truly independent means for checking the reflection information quality of our ANSI results, that the coda of a global seismic P-wave, that is created by scattering in the crust, contains very high frequent (3-8 Hz) reflectivity information as it shows quite good correspondence with the 40-days ANSI results, whereas random noise correlation results, using the same amount of data as the coda response, shows less resemblance. We conclude that these results justify a more detailed investigation of the merits of the ANSI method for this data set. But then, the ANSI-derived reflectivity estimates in turn clearly suggest that indeed P-wave crustal scattering information from global seismic waves is present in the frequency-range of 3–8 Hz, which is extremely high for global seismic waves. The latter aspect may open up a large range of opportunities for detailed crustal research at any location on the globe where broadband, and even shortperiod, seismometers are installed.

ambient noise
interferometry
reflection

http://resolver.tudelft.nl/uuid:1d5c2b91-6e69-4ee2-8ada-4f7b45bdc308

978-2-9601946-0-9

European Geothermal Congress 2016: Strasbourg, France

European Geothermal Congress 2016, 2016-09-19 → 2016-09-24, Strasbourg Convention and Exhibition Centre, Strasbourg, France

Institutional Repository

conference paper

© 2016 Arie Verdel, Harry Wedemeijer, B Paap, Vincent Vandeweijer, C. Weemstra, Philippe Jousset, Steven Franke, Hanna Blanck, K. Águstsson, Gylfi Páll Hersir