William H. Greenberg Fellowship Awards

Nicole Abdul

Greenberg Fellow
Ph.D. in Geology

Dissertation Research: Abrupt climate change from a sea-level, sea surface temperature, and tropical seasonality perspective - understanding the role of the tropics on our warming planet.

Ms. Nicole Abdul received her Ph.D. in Geology from the Department of Earth and Planetary Sciences in January 2017.  In her research, Nicole used fossil corals offshore of Barbados to investigate sea-level variability during periods of abrupt climate change. She used advanced dating techniques to determine the age of fossilized corals retrieved from Caribbean reefs and used this information to calculate sea-level at the time the corals grew. Sea level is a direct measure of the volume of ice stored on land. As a continental ice sheet is built, the amount of water stored on land increases and sea level drops accordingly. Nicole's research confirms that the transition from the frigid Last Glacial Maximum (LGM) 20,000 years ago to today's more moderate climate was not smooth but punctuated by periods of rapid continental ice sheet disintegration and accelerated rates of sea-level rise approaching 40+ mm per year (16 inches per decade). Nicole's coral data also suggest that sea level did not drop during the Younger Dryas (YD) cooling event, a short-lived reversal of the post-glacial warming trend that took place about 13,000 years ago.

Nicole's work is relevant to understanding the effects of human-induced climate change, which is simultaneously accelerating the rates at which Earth's ice sheets are melting and thermally expanding its oceans. These factors are forcing a sustained sea-level rise of about 3.2 mm/ year (> 1 inch per decade). With more than 50% of America's population living within 50 miles of the coast, and tropical islands in the Pacific just barely keeping their heads above rising sea-levels, a clear understanding of the dynamics of a warming planet's ocean, atmosphere, and ice sheets is critical. Nicole uses information about oxygen isotopes in fossilized corals to reconstruct past sea surface temperatures, a fundamental determinant of ocean circulation patterns. Her preliminary results suggest that the tropics may play a bigger role in triggering abrupt climate change in the high latitudes than previously thought, which has direct implications for understanding the role of the tropics on a warming planet. Nicole's research will provide vital constraints on continental ice volume, rates of sea-level rise, and sea surface temperature, all important boundary conditions essential for climate models that in turn inform climate research and policy. Demystifying the natural climate dynamics of our planet will better prepare us for anticipating the effects of future climate change.

"This fellowship was established to honor Mr. William Greenberg, but I am the one that is truly honored and humbled by this award," said Nicole upon learning of her award. "The Greenberg Fellowship could not have come at a more opportune time. It will allow me to truly immerse myself in and greatly broaden the scope of my research and will also allow me to really focus on my dissertation writing — for that I am eternally grateful." Nicole was able to meet Mrs. Greenberg in February 2013 and personally thank her for her generosity in sponsoring the William H. Greenberg Fellowship.


Greenberg Fellow Nicole Abdul holds 2 key samples of fossil coral used to reconstruct past sea-level and sea surface temperature. In the background is the Magnetic Sector Mass Spectrometer used to determine coral sample ages.