Dr. Alan M. Shiller

Professor

Complete resume and additional course information can be found: http://ocean.otr.usm.edu/~w305860

Trace elements in natural waters; marine and estuarine chemistry; chemistry of rivers and weathering; oil spill effects on ocean chemistry; global carbon system; sedimentary fluxes.

At present, most of the work in my lab involves trace element studies, though we are also involved in some oil spill and sediment studies as well as examinations of methane and carbon dioxide. Over the years I have worked in many different areas of geochemistry ranging from sediment studies to radionuclide studies to studies of the oceanic carbon dioxide system. Thus, I am prepared to help students interested in most any sort of geochemically-oriented project.

My lab has a wide variety of research tools including a clean lab, a high resolution inductively coupled plasma mass spectrometer (HR-ICP-MS), methane analyzer, water isotope analyzer, field flow fractionator, ion chromatograph, and flow injection analysis equipment. We're particularly proud of the HR-ICP-MS (Finnigan Element 2) which is far more sensitive than optical ICP and conventional quadrupole ICP-MS instrumentation.

Current Research

Trace elements in rivers and streams, including mechanisms of seasonal concentration variations in the Mississippi River, effect of landscape differences on trace elements in the Yukon River Basin, and the global variability of concentrations.

Trace element and nutrient behavior in the outflow region of the Mississippi River along the Louisiana Shelf. We are also working in Mississippi coastal waters on the east side of the birdfoot delta. New aspects of this work include using Rn and methane as indicators of submarine groundwater discharge and using water isotopes as mixing tracers.

Reactive trace elements in the Atlantic Ocean. We've been examining the distributions of certain trace elements which have air-borne sources, including manganese, lead, aluminum, and gallium. The work should shed light on input of dust, pollutants, and trace nutrients to the ocean. This work is part of an international program called Geotraces.

Composition of colloids. Colloids are sub-micron particles and macromolecules and they are an important factor regulating trace element transport and bioavailability/toxicity. In some of our work we utilize small pore size (20 nm) filters to process samples in remote field sites. In other work we use a technique called field flow fractionation that allows colloidal particles to be size fractioned for further analysis.

Chemical effects of the Deepwater Horizon oil spill. We have examined distributions of trace elements, nutrients, polycyclic aromatic hydrocarbons (PAH’s), and methane in submerged plumes in the spill area. The work is funded by the National Science Foundation and the NGI/BP Gulf Research Initiative.

 

Courses

  • Marine Chemistry (MAR 541) Sea water chemistry and cycles and their impact on the marine environment.
  • Estuaries (MAR 655) An introduction to estuary processes and ecology with discussion of the impact of human activities.
  • Aquatic Chemistry (MAR 683) Principles of inorganic and physical chemistry applied to quantitative description of processes in natural waters.
  • Global Carbon System (MAR 641) An examination of the biogeochemical cycling of carbon through global systems with an emphasis on the problem of climate change.
  • Seminar in Marine Science (MAR 689) A course examining the fundamentals of and providing experience in presenting the results of scientific research in scientific meetings.

 

Selected Publications

(a complete publication list can be found at http://ocean.otr.usm.edu/~w305860)

Stolpe, B., L. Guo, A.M. Shiller and G.R. Aiken, 2013. Abundance, size distributions and trace-element binding of organic and iron-rich nanocolloids in Alaskan rivers, as revealed by field-flow fractionation and ICP-MS. Geochimica et Cosmochimica Acta 105, 221-239. doi:10.1016/j.gca.2012.11.018.

Shiller, A.M. and DJ. Joung, 2012. Nutrient depletion as a proxy for microbial growth in Deepwater Horizon subsurface oil/gas plumes. Environmental Research Letters 7: 045301, doi:10.1088/1748-9326/7/4/045301.

Shim, M.-J., P.S. Swarzenski, and A.M. Shiller, 2012. Dissolved and Colloidal Trace Elements in the Mississippi River Delta Outflow after Hurricanes Katrina and Rita. Continental Shelf Research 42: 1-9, doi:10.1016/j.csr.2012.03.007.

Shiller, A.M., 2010 Dissolved Rare Earth Elements in a Seasonally Snow-covered, Alpine/Subalpine Watershed, Loch Vale, Colorado. Geochimica et Cosmochimica Acta 74: 2040-2052.  DOI:10.1016/j.gca.2010.01.019.

Shiller, A.M and G.R. Bairamadgi., 2006. Dissolved Gallium in the Northwest Pacific and the South and Central Atlantic Oceans: Implications for Aeolian Fe Input and a Reconsideration of Profiles. Geochemistry, Geophysics, Geosystems 7, Q08M09, doi:10.1029/2005GC001118.

Yuan, J. and A.M. Shiller., 2005. The distribution of hydrogen peroxide in the Northwest Pacific Ocean.  Geochemistry, Geophysics, Geosystems 6: doi:10.1029/2004GC000908.