Results!

Today is an exciting day because I finally have some concrete results to share! These revelations have been hiding among large spreadsheets of MATLAB output matrices for the past couple of weeks, but only after plotting up over 100 graphs of various model parameters (channel slope, width/depth ratio, vertical erosion rate, minimum and maximum erodibility, and others) were Dr. Hancock and I able to understand why the graphs of times to equilibrium I posted last time differed so significantly between weathering and non-weathering model runs.

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Finishing Field Work

Ok, so it’s the end of my 8th week of summer research and things seem like they’re finally starting to come together a little bit. Last week, Max Cunningham and I spent our last days in the field exploring variations in rock strength over the longitudinal profile of Renick Run. We spent 14 total days in the field and ended up with thousands of rock strength measurements for 19 cross sections. I am happy because I feel like we’ve accomplished something pretty rare; not many geomorphologists study any one stream as closely as I feel like we’ve studied Renick Run. Also, the initial data look encouraging. Though the results are noisy (and more to the point are Max’s research focus, not mine), there are some initial patterns that appear to show systematic changes in rock strength with cross-sectional channel geometry and distance along the longitudinal profile. But I’ll leave it to Max to discuss those in depth.

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Road Trippin’

So I’ve done a little over three weeks of summer research, and it’s going pretty well so far. The first week mostly consisted of getting oriented and learning how to use the various (and extremely expensive it turns out) pieces of equipment that I would be using in the field. Among these are the Schmidt Hammer (to test rock strength), the Total Station (for surveying sample points), and the GPS. During week two, I set up and began running trials with the channel erosion computer model developed by Dr. Hancock last year. I am currently using the model to explore channel cross-section response to changes in baselevel lowering rate (this is effectively the rate at which the channel is cutting down through the bedrock). I do this by running trials lasting 200,000 years. For the first 100,000 years, the model operates with an annual baselevel lowering rate of .01 m/yr. Then, at year 100,000, the rate is changed by a factor of my choosing. I have run trials changing the erosion rate by factors as varied as .o1 and 100. Once these models have run, I use a MATLAB script I put together to smooth the data with a moving average method and export the data to fixed-width text files so that I can use it for further analysis. Though I am still sorting through the millions of years of erosion data I have produced, I can begin to make some preliminary observations.

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Computer Modeling of Bedrock Channel Erosion

Hello W&M community! I’m Charlie Shobe, a sophomore geology major and ENSP minor here at the College. My academic interests relate to the formation and evolution of rivers and how those rivers drive the evolution of the broader landscape. Many thanks to the W&M Charles Center and Mr. Tim Renick, the grandson of the benefactor behind the Dewey Renick Memorial Award, for their support of my research.

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