People

My work brings me into various research projects needing precise isotope composition determinations, allowing me to work closely with faculty as well as undergraduate and graduate students. The approach I use is to involve students as much as possible with hands-on training for sampling, isotope measurement, and data processing. My own research consists of paleo-rainfall reconstructions using the chemistry of speleothems from caves in Alabama (Desoto Caverns and Cathedral Caverns). The most recent focus of this work is understanding how seasonal changes in carbon dioxide in the cave atmosphere affects these paleo-rainfall records.

My research focuses on reconstructing paleoenvironmental conditions in deep time, particularly with regard to the end Cretaceous (or K-Pg) mass extinction. I am also working to better understand the paleoecology of extinct organisms, most specifically ammonites, as they are an important victim of the K-Pg extinction. Primarily I address these questions through analysis of carbon and oxygen isotopic values in carbonate, as well as sedimentary organic carbon material.

My research primarily focuses on reconstructing past human-environment interaction, such as how climate changed in key times and places in prehistory, how people adapted to their changing world, and how we may have altered our environment, such as through pollution or ecosystem alteration. I also reconstruct Quaternary paleoclimate and ecology based on fossil remains independent of humans. In nearly all cases I utilize sclerochronological approaches to creating isotope time-series data, using bivalve, gastropod, algal, and other skeletal remains.

My recent projects have focused on samples from the Southeastern US Gulf of Mexico and Atlantic coasts, the Pacific coasts of North America from Southern California to the Aleutian Islands, coastal Peru, the Caribbean and central America and Greenland. Most of my work has involved measuring stable oxygen and carbon isotopes and radiocarbon in bio-carbonates, stable nitrogen isotopes in the organic fraction of bio-carbonates, along with some growth structure and elemental analyses.”

Dr. Paul Aharon is the former Ray. E. Loper Endowed Chair in Geology since 2001, and Professor Emeritus since 2016. His expertise lay in the acquisition of light stable isotopes (Carbon, Hydrogen, Nitrogen, Oxygen and Sulfur) by Isotope Ratio Mass Spectrometry (IRMS), Secondary Ion Mass Spectrometry (SIMS) and heavy radioactive isotopes (Uranium-Thorium Series) by Multiple-Collector Inductive Plasma Mass Spectrometry (MC-ICPMS). Applications include isotopes as tracers of source, reconstruction of regional and global water, ice and carbon cycles during the Quaternary, chronology of layered geological materials such as corals, giant clams and speleothems and marine-based gas hydrates. Present investigations are focused on speleothems in the Southeast US and on the island of Niue in the tropical Pacific that serve as time capsules of past hydroclimate variability and El-Niño-Southern Oscillation (ENSO) frequency and intensity changes.

I am funded by the NSF Graduate Research Fellowship to work on my PhD with Dr. Becky Totten. We are a part of the Thwaites Offshore Research (THOR) Team as part of the International Thwaites Glacier Collaboration (ITGC) funded by NSF & NERC. I use foraminifera microfossil assemblages to reconstruct past changes in the ocean seaward of Thwaites Glacier, Antarctica.

I also study the impacts of sea-level rise and climate change in low-latitude coastal systems as a part of the UA Collarborative Research on Paleoenvironments and Societies (CoRPS) team. My other study area is Mobile Bay, AL, where I study elemental composition, foraminifera, grain size, and stable isotopes of Holocene sediment cores to reconstruct past floods, nutrients, and ecological responses.

I am a co-organizer of the Polar Impact Network to establish a networking community for ethnic and racial minorities in polar science. Check it out! PolarImpactNetwork.org

My primary research interests involve reconstructing the paleoenvironment and paleobiology of charismatic extinct cephalopods, particularly ammonites. I work predominantly in the Late Cretaceous Western Interior Seaway of North America, using oxygen and carbon isotopes of ammonite shell material to gain insight into their watery world! Past research has utilized light stable isotopes and trace element ratios in numerical models to reconstruct intra-annual growth rate of Pacific corals and how the timing of their growth relates to different aspects of their environment. I enjoy all work using stable isotopes as a tool to understand past life of marine calcifying organisms.

My research interests include Holocene conservation paleoecology and the use sclerochronology of marine organisms. My thesis research involves establishing the growth rate of unattached nodules of coralline red algae from the Gulf of Mexico using radiocarbon dating and sclerochronology.