Quantifying turbidity current interactions with topography

This thesis advances our understanding of how transport properties of turbidity currents are mediated by interactions with seafloor topography, specifically channelized surfaces. Turbidity currents are responsible for crafting the morphology of continental margins. Unfortunately, very few direct observations exists defining turbidity current interactions with submarine channels and canyons because infrequent occurrence, great water depths, and high current velocities make measurements difficult to obtain. To overcome this problem, I utilize reduced scale laboratory experiments, remote sensing of the seafloor and subsurface deposits, and numerical analysis of transport processes. I focus on resolving the topography and composition of the evolving water-sediment interface with additional measurements that characterize the sediment transport and flow fields. I begin by quantifying interactions between turbidity currents and channel-bounding levees. Levees are the primary elements of self-formed channels and act to confine flows within channels, thereby increasing transport efficiency. I quantify the morphology and growth of levees in a submarine channel network offshore Borneo. Levee deposit trends are interpreted using laboratory observations and a morphodynamic model describing levee growth. Channel and levee deposits resulting from interactions between turbidity currents and sinuous submarine channels are then studied using reduced-scale laboratory experiments. Measurements of current superelevation in channel bends are used to illustrate the importance of current runup onto the outer banks of channel bends. This runup resulted in focused overbank flow and production of thick, coarse, steep levees at these sites.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Earth, Atmospheric, and Planetary Sciences.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2007

Author dc:creator

• Straub, Kyle M

Advisor dc:contributor.advisor

• David Mohrig.

• Earth, Atmospheric, and Planetary Sciences.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/40864

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/40864