Robert J. Hollis, M.S.


Areas of Expertise

  • Holocene geology and subsidence

  • Analysis of regional wetland change

  • Coastal and nearshore processes

  • Coastal GIS analyses


2018 M.S., Marine Science, University of Southern Mississippi
2014 B.S., Geology and Geological Oceanography, University of Rhode Island

Project Experience

Evaluation of Natural and Anthropogenic Processes Impacting Wetland Change on the Mississippi River Delta

  • Quantified wetland changes using historical imagery, maps, and Lidar;

  • Evaluated natural processes and engineering factors associated with wetland change in the Louisiana coastal zone, including storm impacts, sea level rise, subsidence, surface geologic controls, regional water level and drought events, flood and hurricane protection features, and changes in sediment supply

Late Quaternary Evolution and Stratigraphic Framework Influence on Coastal Systems along the North-Central Gulf of Mexico

  • Investigated how the underlying geology influenced the Holocene evolution of the Mississippi-Alabama barrier chain in response to relative sea-level rise, storm impacts, and changes in sediment supply;

  • Identified relict inner shelf sand deposits that supplied sand to the modern barriers through wave and tidal scour during rising sea level; and

  • Recognized critical thresholds of sea-level rise rates and sediment supply that forced barrier geomorphic change (island formation, transgression, progradation, degradation) in the geologic record to help predict future barrier response to climate change

Rhode Island Beach Management Plan, Rhode Island Geological Survey

  • Collaborated as part of an interdisciplinary Beach Special Area Management Plan group to promote coastal erosion and sea level adaptation, outreach, flood risk vulnerability awareness, and coastal policy in local RI communities;

  • Conducted coastal mapping of the upper shoreface and subaerial berm sand volumes using side scan sonar, CHIRP, Ponar grab samples, underwater video, and 350 extracted Lidar profiles to assess nearshore sediment budgets;

  • Updated shoreline change maps using recent orthoimagery, using ArcMap/DSAS, that were adopted for local coastal regulation policies and the Coastal Environmental Risk Index (CERI);

  • Produced a series of technical reports documenting field results and risk assessment to local communities experiencing significant historical erosion, storm surge inundation, and/or future sea level rise for hazard mitigation purposes;

  • Aided monitoring of beach replenishment at Misquamicut State beach using RTK-GPS surveys; and

  • Collected drone aerial photography for wetland inundation mapping

Selected Publications

Hollis, R.J., Wallace, D.J., Miner M.D., Gal, N.S., Dike, C.H., Flocks, J.G., (in review), Late Quaternary Evolution and Stratigraphic Framework Influence on Coastal Systems along the North-Central Gulf of Mexico, USA. Quaternary Science Reviews

Gal, N.S., Wallace, D.J., Miner M.D., Hollis, R.J., Dike, C.H., Flocks, J.G., (in review), Holocene Formation of Horn Island, Mississippi, USA . Marine Geology

Oakley, B. A., Murphy, C., Varney, M., Hollis, R.J., 2019. Spatial Extent and Volume of the Shoreface Depositional Platform on the Upper Shoreface of the Glaciated Rhode Island South Shore. Estuaries and Coasts Special Issue: Shallow water mapping 1-20p.