Acquisition, processing and interpretation of snow-streamer seismic profiles in Masi and Sennalandet, Finnmark, northern Norway

NGU-RAPPORT
|
2021.004
|
Forfattere
Ruud, Bent Ole
Olesen, Odleiv
Gellein, Jomar Gellein
Johansen, Tor Arne
|
Utgivelsesår
2021
Publikasjonstype
Utgivelsesår
2021
ISSN
0800-3416
Prosjektnr
347100
Summary
Two snow-streamer profiles were acquired by the University of Bergen in March and April 2012
within the programme ‘Mineral Resources in Northern Norway - MINN’. The two profiles are
located in the Masi and Sennlandet areas in the Kautokeino and Hammerfest municipalities. The
data were acquired using a combination of snow-streamer and autonomous nodes. The obtained
reflectors can be traced to a depth of 4-5 km. P-wave velocities are obtained from travel-time
tomography of manually picked first breaks. The velocities can be resolved down to a few
hundred meters depth.
We have included two interpretation examples of the Masi profile in the current acquisition and
processing report. The regional c. 4-5 km wide Mierojávri-Sværholt shear zone is represented by
several reflectors dipping at an angle of c. 40-50° to the southeast below the northwestern margin
of the Jergul Gneiss Complex. The migrated seismic profile shows that the dip of the western and
eastern segments of the Masi fault system (within the Stuoragurra fault complex) is 52° and 65°,
respectively. The two postglacial fault segments seem to merge at a depth of c. 500 m.
The present study proves that snow-streamer technology is an efficient way to carry out seismic
profiling in snow-covered and relatively flat terrain. Using detonating cord as a seismic source
has left no permanent footprint on the sparse vegetation in the Arctic, which is an advantage. We
conclude that the reflection seismic data are of high quality and that the obtained reflectors can
be interpreted in terms of regional geological structures continuing to a depth of 3-4 km. We
suggest that the western part of the reprocessed Masi profile, and the Sennalandet profile,
should be interpreted in a similar integrated way as the examples shown in the present report.
Kommune
KAUTOKEINO
HAMMERFEST
Fylke
TROMS OG FINNMARK
Tilgjengelig
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