Cristin-resultat-ID: 1779094
Sist endret: 21. januar 2020, 11:49
Resultat
Poster
2019

Wide angle seismic data constraints on crustal structure and erosion of the northernmost Norwegian shelf

Bidragsytere:
  • Asbjørn Johan Breivik
  • Jan Inge Faleide
  • Rolf Mjelde
  • Ernst R. Flueh og
  • Yoshio Murai

Presentasjon

Navn på arrangementet: AGU Fall Meeting
Sted: San Francisco
Dato fra: 9. desember 2019
Dato til: 13. desember 2019

Arrangør:

Arrangørnavn: American Geophysical Union

Om resultatet

Poster
Publiseringsår: 2019

Beskrivelse Beskrivelse

Tittel

Wide angle seismic data constraints on crustal structure and erosion of the northernmost Norwegian shelf

Sammendrag

The Norwegian continental shelf has been through several rift phases since the Caledonian orogeny. Early Cretaceous rifting created the largest sedimentary basins, and Early Cenozoic continental breakup between East Greenland and Europe affected the continental shelf to various degrees. The Lofoten/Vesterålen shelf is located off Northern Norway, bordering the epicontinental Barents Sea to the northeast, and the oceanic Lofoten Basin to the west. An ocean bottom seismometer (OBS) survey was conducted over the area in 2003. This study documents Profile 8-03, located between the outer islands and the shelf edge. The wide-angle seismic data were modeled using raytracing to build a crustal velocity-depth transect. Gravity modeling could resolve an ambiguity in seismic Moho identification in the south. Results show a crustal thickness of 30-31 km, thicker and thus less affected by breakup tectonism than previously believed. The results of the new survey shows that older nearby refraction profiles may be too short to constrain Moho depth in the area. Profile 8-03 and other OBS profiles to the southwest show high sedimentary velocities at or near the seafloor, suggesting greater burial in the past. Velocities from the current profile and from a previously published crossing profile of the same survey were compared to the velocity-depth function derived from an OBS profile at the Barents Sea margin, tied to a coincident well log, where there is little erosion. Results indicate three major erosion episodes; Late Triassic-Early Jurassic, tentatively mid-Cretaceous, Late Cretaceous-early Cenozoic breakup-related, and a minor late glacial erosion episode off Vesterålen.

Bidragsytere

Asbjørn Breivik

Bidragsyterens navn vises på dette resultatet som Asbjørn Johan Breivik
  • Tilknyttet:
    Forfatter
    ved Senter for Jordens utvikling og dynamikk ved Universitetet i Oslo

Jan Inge Faleide

  • Tilknyttet:
    Forfatter
    ved Institutt for geofag ved Universitetet i Oslo

Rolf Mjelde

  • Tilknyttet:
    Forfatter
    ved Universitetet i Bergen

Ernst R. Flueh

  • Tilknyttet:
    Forfatter

Yoshio Murai

  • Tilknyttet:
    Forfatter
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