My research focuses on the stratigraphy and dynamics of depositional sedimentary systems. Scales of interest range from detailed flow structures and sedimentation in rivers to whole system behavior of coastal systems and river belts. I use a combination of mathematical modeling, field observation, and occasionally experimentation to understand these systems. My research is generally directed toward understanding the coupled surficial and sedimentological evolution of these systems. Following is a list of research interests and a brief description of each.
Numerical Modeling of Deltas
Research in this area focuses on using numerical models to understand how deltas evolve through time and the processes that create their channel networks. Understanding delta formation has implications for predicting their stratigraphy, hydrocarbon exploration, and protecting these valuable environments from natural and anthropogenic perturbations. The animation below is a model output from Delft3D showing a delta forming into a standing body of water. In the example below the delta on the left is composed of a sand and mud mixture, while the delta on the right is composed of pure sand. Note the drastic differences in morphology.
Unraveling aqueous sedimentation on Mars
Images from the surface of Mars show spectacular landforms that are often interpreted as the result of flowing liquid. Often the patterns observed are 'matched' to a similar pattern on Earth and the formative conditions are assumed to be similar. This assumption, while possibly valid, has never been thoroughly tested with state of the art models. This reserach seeks to answer the basic question, what should fluvial features look like on Mars under conditions of reduced gravity? For instance, it is not clear that if the same hydraulic parameter that produce a delta on Earth, would produce the same kind of delta on Mars. The image below is an example of a Martian delta from the Aeolis/Zephyria Plana region, taken from Burr et al. (2006).
Predicting stratigraphy from physics-based models
The history of surface conditions on earth are primarily recorded when sediments are deposited and stratigraphy is created. Interpreting stratigraphy relies on inferring past conditions from incomplete information. This research seeks to supplement field observations with stratigraphy created using physics-based morphodynamic models. The advantage of using models is that all stratigraphy is readily observable and the nature of surfaces can be easily understood.
Understanding river avulsion
River avulsion is the process by which a channel, sometimes catastrophically, changes course on its floodplain. This can have devastating effects on densely populated areas. It is also recongized as one of the primary processes that builds fluvial stratgraphy. This research focuses on understanding how that process occurs, predicting its occurence, and understanding the associated deposits.
Modeling the growth of fluvial levees
Fluvial levees are ubiquitous sedimentary deposits in terrestrial and deep-sea channelized systems. However, there exists no general theory to predict and understand their growth and sedimentary architecture. Currently, two end member models exist: levees growth can be dominated by advection, or diffusion of sediment. This work seeks understand the controls on formation of each end-member type of levee.
Flow and sedimentary processes in bifurcations
The process of bifurcation is the fundamental mechanism that creates braided stream and river deltas. This research focuses on that process by conducting detailed field observation of these fluvial features coupled with numerical modeling. If we can understand and predict the behavior of these interesting features then we can likely begin to predict the behavior of the entire system. On the left is a perspective view of the bathymetry of a fluvial bifurcation.