Jeff Valenza has been awarded an NSF Postdoctoral Fellowship. These postdocs allow the recipient to carry out their own work with a mentor of their choice, and can be split between US and international labs. Jeff will do exactly that to continue his work on fluvial processes including river avulsion events. He will work with Vamsi Ganti at UC Santa Barbara and Alex Whittaker at Imperial College.
Jeff is working with Doug Edmonds.
"I will be studying pre-vegetation river dynamics and stratigraphy. Vegetation-free rivers have been shown to migrate at rates up to 10x faster than vegetated counterparts, which could create fluvial stratigraphy resembling braided, or multi-thread, river deposits. Using a two-pronged approach, I aim to identify the defining characteristics of rapidly-migrating single thread channels using bar and channel body stratigraphy. First, I will conduct flume experiments at UC Santa Barbara to establish a scaled-down, actively meandering stream to observe channel and bar migration rates and resulting stratigraphy. We will apply observations from flume-generated stratigraphy to the Precambrian (and pre-vegetation) Torridonian Sandstone in the Scottish Highlands to determine if the amalgamated bar forms in outcrop represent an ancient meandering or braided stream. Confirming meandering conditions in pre-vegetation rivers would explain the appearance of single-thread meander channels on Mars, and shed light on Earth's early sedimentological history. Furthermore, constraining migration rates of vegetation-free channels may soon become relevant for human management of rivers in warming and drying arid and semi-arid environments in the midst of global climate change.
I'll be working under Dr. Vamsi Ganti and UCSB and Dr. Alex Whittaker at Imperial College London. I'll be at UCSB for the majority of time, travelling to the UK for field work and also to be a visiting scholar at Imperial College during the summer of 2022."