Geosciences
Overview
The Department of Geosciences, together with its affiliated interdepartmental programs and institutes, serves as Princeton’s central focus for the earth, atmospheric, oceanographic and environmental sciences. As such, the department encompasses a rich diversity of scientific expertise and initiatives that strive to understand Earth’s deep structure, climate, biosphere, atmosphere and oceans, landscapes, and how these systems interact and evolve over all timescales.
Academics and Research
The Department of Geosciences covers a wide range of fields and actively promotes interdisciplinary study and research. Students with interest in tectonics and geophysics, seismology, Earth history, geochemistry, geochronology, petrology, mineral physics, biological oceanography, biogeochemistry, paleontology, paleoceanography and paleoclimate and environmental geology will find most of their research and educational needs accommodated within the laboratories of Guyot Hall.
Atmospheric and oceanic sciences are an integral part of the department, with students typically pursuing a degree through the AOS program (a joint program with the Geophysical Fluid Dynamics Laboratory, GFDL). In addition, Geosciences and AOS have close ties with the programs in water resources in the Department of Civil and Environmental Engineering, as well as with the Princeton Environmental Institute (PEI) and the Princeton Institute for the Science and Technology of Materials (PRISM). We also provide computational geosciences as an interdisciplinary graduate training program.
Graduate education within the department, in general, is strongly focused on research, as well as on developing a keen sense for the interdisciplinary nature of the geosciences. As a consequence, Princeton has been extraordinarily successful in mentoring students to move on to tenure-track positions in academia as well as leading research positions in industry or government laboratories. The department offers only a Doctor of Philosophy (Ph.D.) program, for which students with and without master's degrees may apply. The target time to graduation is five years.
Equipment and Facilities
Modern earth science has a continuum of approaches, ranging from field studies to laboratory and theoretical work using sophisticated instrumentation and large computers. In addition to petrographic, mineralogic, sedimentologic, and paleontologic facilities for routine geoscientific inquiry, the department has specialized equipment for laboratory and field studies rooted in a wide array of disciplines.
Geochemistry: Specific instruments include three inductively-coupled plasma mass spectrometers for high-precision trace element (Thermo Element 2 ICPMS and Thermo iCap) and isotope ratio (Thermo Neptune MC ICPMS) analyses; microwave for rapid silicate dissolution; modern micro-XRF setup; gas chromatographs, HPLC, and ion analyzers; infrared, ultraviolet and fluorescent spectrometers; gamma and scintillation counters; ultracentrifuges; dissolved- and solid-carbon analyzers; and modern wet-chemical laboratory facilities. There is also a hydrothermal laboratory, including large-capacity rocking autoclaves, kinetic flow systems, optical high-pressure and high-temperature cells, and an internally heated high-pressure system.
Geochronology and Petrology: In addition to modern mineral separation and characterization facilities, Guyot hosts new clean lab facilities suitable for ultra-low blank trace metal geochemistry used for ion chromatography for Ca, Mg, Sr, U, Pb, Sm, and Nd elemental separation. The lab also has two IsotopX PhoeniX62 Thermal Ionization Mass Spectrometers used for high-precision U-Pb geochronology and Sr and Nd isotope measurements. Mineral and rock geochemistry that accompanies geochronology is carried out in other facilities on campus and within Guyot, such as in the ICPMS facilities.
The Ocean Tracer Laboratory: Includes alpha detectors and scintillation detectors for measuring low levels of radon and radium radioisotopes and a high-resolution intrinsic germanium well detector for gamma ray measurement.
The Stable Isotope Laboratory: Contains a new V. G. Optima gas source mass spectrometer, with peripheral devices for automated analysis of carbonate minerals and for automated loading and cleaning of CO2, H2O, and N2 gas mixtures. Off-line preparation facilities are available for water samples, organic materials, and minerals.
Biological Oceanography Research: Focuses on carbon and nitrogen cycle processes and trace metals in the oceans. Instruments include controlled temperature rooms for phytoplankton and bacterial culture, epifluorescence microscopes, centrifuges, scintillation counter, gamma counter, autoclave, atomic absorption spectrometer, laminar flow hoods, trace metal clean room, Europa 20/20 mass spectrometer, gel documentation system, and fully equipped molecular biological laboratories for protein and nucleic acid research.
Geophysics: The High-Pressure Mineral Physics Laboratory contains diamond anvil cells for high-pressure/temperature studies. Included in the facility are stereomicroscopes, microdrill, gas loading system, photoluminescence, and Raman and Brillouin spectroscopy. Access is also available to a wide range of national user facilities for conducting experiments including synchrotrons, free electron lasers, and high-powered laser facilities. Mineral characterization is supported by shared facilities on campus featuring multiple scanning electron microscopes equipped with elemental analysis capabilities in addition to backscattered-electron and cathodoluminescence imaging, TEM, and FIB (see the imaging and analysis center on Princeton’s website).
The department owns several 6-channel digital portable seismometers along with support equipment for small-scale field experiments. For larger experiments abroad, we use portable seismographs from the IRIS Passcal Instrument Center.
We routinely obtain data from digital archives around the world, as well as from our own field experiments. For numerical simulations of seismic wave propagation and tomographic imaging and inversion, we have access to powerful computers provided by the Princeton Institute for Computational Sciences and Engineering (PICSciE), and to even more powerful machines provided by national supercomputing centers.
Applying
Ph.D.
Course work requirements are flexible and depend on the track chosen under advisement from a student’s advisory committee. Students are expected to have completed eight coursesby the end of the semester in which they take the general exam. The eight courses must include GEO 505 and 506 – Fundamentals of the Geosciences, and at least two graduate-level or appropriate-level undergraduate courses outside their field of expertise, chosen with approval of the advisory committee. Students must also take GEO/AOS 503 – Responsible Conduct of Research in Geosciences, which does not count towards the eight courses.
Courses must be taken for a grade when the graded option is offered, and the average of the graded courses is expected to be B or higher.
Research paper and thesis proposal
There are several benchmark research requirements in the first two years of the Ph.D. program. These include a research proposal in the fall of the first year, a progress report in the spring of the first year, and a public presentation in the fall of the second year.
A high-quality research paper summarizing the first two years of research is required at least a week prior to taking the general exam. The research paper does not need to be ready for publication, but the paper should have a scholarly level close to that of a paper submitted to a peer-reviewed journal. The research accomplishments should indicate a reasonable level of productivity, and the interpretation should indicate knowledge of the literature and excellent critical thinking.
In addition to the research paper, a short thesis proposal is required that should clearly express the justification for and direction of the future thesis work (which may or may not be the same as the research conducted before the general exam).
The general examination for advancement to Ph.D. candidacy is normally taken before the end of the second year of graduate work. The examination is designed to establish the student’s depth and breadth of knowledge in the chosen fields of specialization, advancement in scholarly methods of research, and the ability to organize and present research material. The examination is based in part on the written report described above, and also contains an oral component to be carried out in front of a committee of 3-5 faculty members.
During the general examination a student is expected to demonstrate competence and professional expertise in the geosciences and related fields as relevant to the student's research interests and courses taken. Accordingly, the examination is designed to explore: (1) the student's ability to organize and conduct an original research program and to present research results and material, (2) the student's depth of knowledge in the chosen fields of specialization, and (3) breadth in the geological and related sciences.
A typical examination consists of two parts: the research paper and thesis proposal, and two topics of expertise selected by the student. The exam does not normally last longer than 3 hours. The first half of the exam covers the research paper and the thesis proposal, beginning with a student presentation of 20 minutes length. Each committee member will question the student on the student's research area. Then, after a short break, the second part of the exam covers the two topics selected by the student. Each committee member will ask questions testing the student's general knowledge of the basic science underlying the areas of specialization and fundamental concepts in earth sciences and related disciplines.
The Master of Arts (M.A.) degree is normally an incidental degree on the way to full Ph.D. candidacy and is earned after a student successfully passes all course work and the general examination. It may also be awarded to students who, for various reasons, leave the Ph.D. program, with approval from their advisory committee.
Under some circumstances, students may decide prior to the general exam that they do not wish to continue in the Ph.D. program but does wish to qualify for a master's degree (M.A.) from the department. In this case, the student should discuss this option with the adviser and advisory committee well in advance. The general exam for an M.A. degree is similar to that for Ph.D. candidacy but will not include defense of a research plan.
All graduate students are required to participate in the instruction of undergraduates for at least one term (one term as a full assistant in instruction, or two terms as half-time assistant in instruction) as a significant part of their education.
The dissertation shows that the candidate has technical mastery in the chosen field and is capable of independent research. It is expected to be a positive contribution to knowledge, which may consist of a new scientific generalization, a new body of integrated facts that carries scientific implications that extend beyond itself, or a substantial improvement in technique or procedure.
The final public oral examination includes a 45 minute presentation by the candidate that summarizes the dissertation. Candidates are then expected to respond to questions relating to their research and to wide-ranging questions about related subjects.
The Ph.D. will be awarded once the dissertation has been approved and the final public oral has been completed.
Faculty
Chair
Bess B. Ward
Associate Chair
Thomas S. Duffy
Director of Graduate Studies
Blair Schoene
Professor
Thomas S. Duffy
Gerta Keller
Adam C. Maloof
Satish Myneni
Tullis C. Onstott
Michael Oppenheimer
Allan M. Rubin
Daniel M. Sigman
Frederik J. Simons
Jeroen Tromp
Gabriel A. Vecchi
Bess Ward
Associate Professor
Stephan A. Fueglistaler
John A. Higgins
Blair Schoene
Assistant Professor
Jessica C. E. Irving
Laure Resplandy
Xinning Zhang
Courses
Permanent Courses
Courses listed below are graduate-level courses that have been approved by the program’s faculty as well as the Curriculum Subcommittee of the Faculty Committee on the Graduate School as permanent course offerings. Permanent courses may be offered by the department or program on an ongoing basis, depending on curricular needs, scheduling requirements, and student interest. Not listed below are undergraduate courses and one-time-only graduate courses, which may be found for a specific term through the Registrar’s website. Also not listed are graduate-level independent reading and research courses, which may be approved by the Graduate School for individual students.