SSA 2017 has ended
SSA could not be possible without the generous support of Drs. Herbert A. and Betty Lou Lubs and the Science, Society, and the Arts Research Conference Endowment. We are deeply grateful!
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Friday, March 17 • 3:00pm - 4:15pm
Easel 70: Sensing fluid pressure during plucking events in a natural bedrock channel

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Plucking, the wholesale removal of bedrock blocks from channel beds, is thought to be a dominant mechanism of river incision over geologic time, yet it remains a poorly understudied phenomenon. Observations from our flume studies indicate that plucking is most likely to occur in the presence of free surface undulations such as hydraulic jumps and standing waves produced by resistant bedrock steps or flow constrictions. We hypothesize that these free surface undulations also create sub-block pressure differences that are transmitted through the crack network and that may contribute to the plucking process. To investigate the relationship between fluid pressure and block movement, this study uses motion- and pressure-sensors embedded within a bedrock block to detect variations in fluid pressure above and below the block as well as record associated movement. Film footage and early experimental data support the presence of dynamic water exchange between the sub-bed network and river above.

Friday March 17, 2017 3:00pm - 4:15pm
Leyburn Library