Collaborative Research: TESPRESSO: Tectonic Encoding, Shredding, and PRopagation of Environmental Signals as Surface Observables

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Sediments and sedimentary rocks record how mountains are built, when climate changes, how sea level fluctuates, and the processes that erode, move, and deposit sediment. This information can inform our understanding of modern Earth surface processes, natural hazards, and environmental systems crucial to sustainable food and water resources. A key location to study these processes is in the Peloritani Mountains, northeastern Sicily, where the mountains are going up rapidly as a result of large and frequent earthquakes. Hillslopes are prone to landslides during both earthquakes and violent storms, sending large amounts of sediment into the rivers. This sediment is transported downstream to a narrow, densely-populated coastal strip, where it spreads out forming a delta at sea level. This project documents episodes of sediment deposition in the deltas and uses computer models to decipher the causative processes. This research will better constrain how the Peloritani Mountain landscape responds to earthquakes, climate, landslides, flash floods, and sea level variability. Results from this work will help inform the local populace on geologic hazards in the region. The project provides support for graduate students, early career post-doctoral researchers, and educational outreach to underrepresented groups at the K-12 level.This project focuses on the construction of a source to sink landscape evolution model (LEM) informed by sediment yield and rock-magnetic cyclostratigraphic data to explore how quasi-periodic and stochastic tectonic forcings are encoded, shredded, propagated, and preserved in sedimentary archives. With a relatively small drainage area ( 500 km2), uniform bedrock, and a known history of climate and base level variation, the study area offers an unparalleled natural experiment that scales well to a LEM exploring the geomorphic and sedimentologic responses to tectonic forcings in a system with low source storage. The project tests hypotheses that changes in rates of rock uplift on short earthquake cycles to long secular uplift time scales (1) impact the response time and the autogenic periods of the system, lengthening both, (2) impact the grain size and sediment yield of the source independent of, and unique to, responses driven by periodic climate change, and (3) impart unique stratal onlap and offlap geometries, bed thickness, textural, and rock-magnetic variations in the sink, distinct from those imparted by periodic climatic forcing and quasi-periodic autogenic processes. The project incorporates a modeling strategy that merges Landlab in the source to Sedflux in the sink in order to predict unsteadiness in the source sediment flux and the resulting basin depositional architecture for a tightly linked source-to-sink system. LEM predictions are evaluated against lithostratigraphy, rock-magnetic cyclostratigraphy, terrestrial cosmogenic nuclide (TCN)-determined modern and paleo-erosion rates, and sediment accumulation rates in fan deltas determined by optical luminescence.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.