Julia M. Moriarty

Ph.D. Candidate

Email: moriarty@vims.edu
Phone: (804) 684-7574
Office: AH 215
Department: Physical Science: Physical & Geological oceanography

Click here to see my CV (pdf)

Research Interests
  • Transport of sediment, nutrients, and contaminants
  • Estuarine and coastal hydrodynamics
  • Numerical modeling
Advisors & Labs

           Dr. Courtney Harris (Sediment Transport Modeling Lab)

           Dr. Marjy Friedrichs (BIOCOM Lab)

                          (Biogeochemical Circulation Ocean Modeling)

Ph.D. Research

The Role of Resuspension and Advection on Particulate Fluxes and Oxygen Levels in Coastal Systems

I'm developing a coupled hydrodynamic-sediment transport-biogeochemical numerical model to evaluate how resuspension and redistribution of sediment, particulate organic matter, and porewater affect biogeochemical dynamics in the coastal ocean.  Research questions include: 1) How does seabed resuspension affect water column oxygen and nitrogen levels?  Seabed oxygen consumption and seabed-water column fluxes of nitrogen? The distribution of particulate organic matter?  The location and timing of hypoxia?  Click here to see preliminary results (pdf).  

This research is part of a broader effort within the research community to improve predictions of oxygen levels in coastal areas.  Specifically, I will focus on the Gulf of Mexico and Chesapeake Bay, USA, and the Gulf of Lions, France.  In addition to researchers at VIMS, I am collaborating with scientists at Dalhousie University, Canada (Katja Fennel and Robin Williams), CNRS & University of Versailles, France (Christophe Rabouille and Flora Toussaint), Texas A&M (Rob Hetland), and Louisiana State University (Kevin Kehui Xu), among others.  This work is funded by NOAA's NGOMEX Gulf of Mexico Ecosystems & Hypoxia Assessment Program, NASA's Interdisciplinary Science Program, and by the VIMS & College of William & Mary's graduate program. 

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M.S. Research Project

Formation and Reworking of Flood Deposits on the Waipaoa River Shelf, New Zealand: Variability in Sediment Transport and Deposition

I used a coupled hydrodynamic-wave-sediment transport numerical model (ROMS-SWAN-CSTMS) to study flood deposits.  Under what conditions may a flood deposit form?  To what extent do waves and currents subsequently rework and redistribute riverine sediment?  What is the role of buoyant vs. gravity-driven transport of sediment?  The role of seabed consolidation? 

This research was part of a larger study analyzing the formation, reworking and accumulation of sedimentary deposits on the Waipaoa Shelf, New Zealand.  We collaborated with researchers at the National Institute of Water and Atmosphere, New Zealand (Mark Hadfield, Alan Orpin), East Carolina University (JP Walsh, Reide Corbett, Joey Kiker), University of Washington (Andrea Ogston, Rip Hale), and VIMS (Tara Kniskern) to investigate changes to the seabed over the course of a year using seabed and water column observations and a numerical model.  This work was funded under NSF's MARGINS Source-to-Sink Initiative.

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Other Research Projects

Along-river variations in sediment fluxes during typhoons: Jhuoshuei River, Taiwan 

Taiwan offers a unique opportunity to study variations in sediment fluxes because of the exceptional historical and ongoing records of river discharge and because the island's sediment yields (sediment discharge divided by watershed area) are among the world's highest.  My research focused on variations in the magnitude, timing, and characteristics of sediment fluxes along the Jhuoshuei River, especially during typhoons.  

This work was in collaboration with scientists at Academia Sinica, Taiwan (Dr. Shuh-Ji Kao) and National Taiwan University, Taiwan (Dr. Tsung-Yu Lee).  It was funded under NSF's EAPSI (East Asia and Pacific Summer Institute) program with Taiwan's National Science Council.  

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