HR: 1340h
AN: OS23B-1304    [Abstracts]
TI: The Holocene (7.250 14C yrs BP) Storegga Slide, Mid-Norwegian Margin: The Modern Analogue To Paleo High-Latitude Mega Slides
AU: * Haflidason, H
EM: Haflidi.Haflidason@geo.uib.no
AF: University of Bergen, Dept. of Earth Science, Allegt. 41, Bergen, 5007 Norway
AU: Sejrup, H P
AF: University of Bergen, Dept. of Earth Science, Allegt. 41, Bergen, 5007 Norway
AU: Nygaard, A
AF: University of Bergen, Dept. of Earth Science, Allegt. 41, Bergen, 5007 Norway
AU: Gram, I H
AF: University of Bergen, Dept. of Earth Science, Allegt. 41, Bergen, 5007 Norway
AU: Bryn, P
EM: Petter.Bryn@hydro.com
AF: Norsk Hydro, Sandvika, Oslo, 0246 Norway
AB: The frequency and timing of mega scale (> 2000 km3) submarine slides identified on the Mid-Norwegian margin clearly indicate that this downslope process seems to be associated with the frequency and timing of shelf-edge glaciations, inititated at c. 1.1 Ma and repeted shelf edge glaciations from 0.5 Ma. Most of these paleo-slides have been released within the present Storegga Slide depression or in the nearby North Sea Fan area. The Storegga Slide is found to have affected an area of ca. 90.000 km2 and a sediment volume of 2500-3200 km3 have been displaced. The large volume of sediments displaced, or mobilised, created a pattern of morphological and topographical features, reflecting the erosional, compressional and depositional slide processes within the Storegga area. From the seafloor texture it has furthermore been shown that a considerable difference in type of source material, length of transportation and degree of disintegration have taken place. The morphological characteristics and the available chronological data show that the Storegga Slide represent one main retrogressive slide event dated to 7.250+/-250 14C yrs BP (8.100+/-250 cal. yrs BP). Based on the detailed morphological mapping a slide generation map for the Storegga Slide event has been generated. The morphological analysis give furthermore an important contribution to the bulk material properties (rheology) characterising the area. Statistical analyses, which will give a good approach to the rheological parameters of the failed sediments and provide a basis for a more complete failure and flow model of the Storegga Slide, show a regression coefficient as high as 0.9 by correlating the run-out distance and the slide area. As an analogue to the recent Storegga Slide event, two paleo mega slides and their associated escarpment, representing the two most extreme slide escarpment settings found within the Storegga Slide, have been studied in some detail. The stratigraphical setting and the slide development of these escarpment features will be presented and discussed.
DE: 9335 Europe
DE: 9604 Cenozoic
DE: 3022 Marine sediments--processes and transport
DE: 3045 Seafloor morphology and bottom photography
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting