Cnudde, Veerle

De Batist, Marc

Haeussler, Peter J

Praet, Nore

Van Daele, Maarten

Vandekerkhove, Elke

Vanderniepen, Pieter

English

Ghent University Academic Bibliography

2nd UGCT seminar 10 September 2015   X-ray µCT analysis of sediment cores from Eklutna Lake Elke Vandekerkhove1, Maarten Van Daele1, Veerle Cnudde2, Nore Praet1, Pieter Vanderniepen3, Peter J. Haeussler4 and Marc De Batist1 1Renard Centre for Marine Geology, Department of Geology and Soil Science, Krijgslaan 281/S8, B9000 Gent, Belgium 2Centre for X-Ray-tomography (UGCT) / Dept. of Geology & Soil Science, Ghent University, Belgium 3Centre for X-Ray-tomography (UGCT) / Dept. of Physics & Astronomy, Ghent University, Belgium 4USGS-Alaska Science Center, 4210 University Dr., Anchorage, Alaska, United States   ABSTRACT Lake Eklutna is a glacial lake located close to the Alaskan-Aleutian subduction zone which generated the second largest earthquake ever recorded (1964 AD, Mw = 9.2). Such earthquake events are able to trigger turbidity currents and cause major slope collapses to develop along the sides of the lake basin. Previous studies on sediment cores from Eklutna Lake revealed the presence of many turbidite deposits. However, these are not only linked to earthquake events but can also be caused by delta collapses due to slope instability or flood events. Therefore, we analyzed sediment cores from Eklutna Lake on the potential to differentiate between turbidites originating from floods and earthquake-triggered turbidites. This way, an accurate interval rate of earthquakes can be established. The sediment cores were scanned with the X-Ray CT scanner in order to analyze the turbidite deposits and 3D structures. Using the X-Ray micro-CT scanner HECTOR at UGCT, individual particles could be visualized in the turbidite deposits. Preliminary results indicate the presence of ripple structures and alignment of organic matter at the bottom of the turbidites, which contribute in determining relative flow directions. Our study also revealed the possibility to distinguish cryptotephra using X-Ray μCT-scanning. This would have important implications for tracking cryptotephra and sampling methods in core sediments. Finally, bioturbation was observed throughout all cores while varve formation requires, in addition to seasonal variation, the absence of bioturbation and usually form under anoxic conditions.    REFERENCES Masschaele, B., Dierick, M., Van Loo, D., Boone, M.N., Brabant, L., Pauwels, E., Cnudde, V., Van Hoorebeke, L., 2013: HECTOR: a 240kV micro-CT setup optimized for research. Journal of Physics: Conference Series. 463 (1), p. 012012. 

X-ray µCT analysis of sediment cores from Eklutna Lake

https://biblio.ugent.be/publication/6929767/file/6929777.pdf

X-ray µCT analysis of sediment cores from Eklutna Lake

Abstract

Similar works

Full text

Available Versions

Ghent University Academic Bibliography