Just before graduating, four department undergraduates shared their thoughts on their time with the department and the topics of their senior theses.

Stephen Cox

Thesis:  The Low-temperature Thermochronology of the Lambert Graben-Prydz Bay Basin

Advisor: Prof. Sidney Hemming.

"I came to DEES as an unsure freshman weighing such diverse options as political science, history, math, and physics. However, I quickly discovered that the geosciences are the perfect place for someone with a wide range of interests. As an Earth Science major, I have been able to explore climatology, atmospheric science, geochemistry, and geology. While I will soon leave Columbia to pursue a PhD, I, like most people who have worked at Lamont, hope to return eventually."

My research has grown out of a larger survey of Antarctic geology, sedimentation, and ocean currents by Sidney Hemming's group at Lamont. We looked at detrital sediments from ocean cores in Prydz Bay to try to figure out why the Gamburtsev Subglacial Mountains exist as large peaks in the middle of the old East Antarctic craton. Using (U-Th)/He, fission-track, ⁴⁰Ar/³⁹Ar, and U-Pb dating, we discovered that the bedrock in the Prydz Bay catchment area is very old and that East Antarctic erosion rates are extremely low. Our results imply that common assumptions about erosion rates in high mountain ranges might not always be correct.

Stephen has deferred admission to the Ph.D. program at Caltech for one year in order to continue his work with Sidney Hemming.

Yasemin Erboy

Thesis:  Detective Work Using an Environmental Tracer

Advisor: Dr. William M. Smethie.

"I have the distinct pleasure of being the only international senior in DEES, and I chose to come to New York from Izmir, Turkey and major in environmental science because I wanted an interdisciplinary education. I love being part of this department because everyone is so approachable, and there's always someone to turn to when things don't make sense (like your classes), or go very wrong (like your thesis)! My other interests include playing the piano, writing, and learning Chinese, but the gneiss outcrop in Central Park remains dearest to my heart."

My thesis research is on the most potent greenhouse gas to date, SF5CF3, whose full name is nearly unpronounceable (it took me a month to memorize it). It was recently discovered, so nobody knows exactly where it comes from or where it’s going; which has the potential to make all activists, and some scientists who want to use it as an environmental tracer, rather uncomfortable. I’m documenting its trend in the atmosphere, comparing it to other tracers and trying to find what atmospheric variables it correlates with. So far it seems to be well mixed and just hangs out uniformly, which is great news for whoever wants to use it as a tracer, but bad news for my thesis, since it doesn’t leave me with much to talk about!

Yasemin achieved early Phi Beta Kappa status (top 2% of the Columbia College graduating class) and earned Departmental Honors for performance in her environmental science major. She will enter the graduate program in environmental management at Yale in September 2009.

Ilana Somasunderam

Thesis:  Early Miocene Sedimentation and Strontium Isotope Geochronology in the Gulf of Suez, Egypt

Advisor: Prof. Nicholas Christie-Blick and Prof. Steven L. Goldstein.

"I came to DEES with the hope of getting a well-rounded education in the geosciences and directly engaging with faculty members who are doing cutting edge research. I got that, but more importantly, I will leave Columbia with a stockpile of amazingly bad geology puns."

My project concerned strontium isotope geochronology, which is one way to date shells of marine origin. Our ultimate goal is to compare sedimentary cyclicity in a region associated with active deformation, the Gulf of Suez, with another region in which cyclicity is both well known and closely tied to global sea-level change, the New Jersey continental margin. Dating is essential to making such a comparison. In order to evaluate whether the strontium isotope method would work, I analyzed macrofossil samples from a single outcrop section at Wadi Nukhul on the eastern side of the Gulf of Suez. All of the samples prove to be of earliest Miocene age, as expected. They are also very close in age, and not necessarily in the right order based on their stratigraphic position. I suspect that geology rather than chemisty is the culprit: for example, the reworking of older shells into younger layers. Analyzing additional samples is likely to resolve such details. My overall conclusion is that strontium dating is a viable approach for a much more comprehensive study that is now being planned.

Ilana will spend the next two years in northern California teaching for Teach For America.

Alexandrina Tzanova

Thesis:  Cadmium and Molybdenum as Proxies: Soledad Basin, Baja California

Advisor: Dr. Lex vanGeen and Dr. Jacob Mey.

"It may seem strange that a girl who grew up in New York City would end up choosing to study environmental science, but that is precisely what I did - and I've never regretted it. Lamont has been a great resource through my four years at Columbia and has been one of the deciding factors in my choice of pursing graduate study in environmental science. As I graduate this year I don't know where I’ll be 10 years from now but I know that I will be doing environmental science and it will be thanks to my time at DEES.""

My senior thesis project examined the Cadmium and Molybdenum measurements obtained through sediment digestions of sediment cores and HR ICP-MS analysis. The variability of the measurements is used to draw paleoclimate inferences at a high resolution.

Alexandrina will enter the Ph.D. program in the department of Geological Sciences at Brown University in September 2009.