Geosciences (GS)

Interested in applying to our MS or PhD programs? View presentations from this year's info sessions.


Information for the Geosciences PhD program and Master's degree programs

Geosciences emphasizes the application of general principles of geology, geochemistry, cosmochemistry, and geophysics to problems in the marine and terrestrial environments of the Earth and to other planetary bodies. Graduate students routinely participate in expeditions at sea and on land and many doctoral theses evolve from these experiences.

Research areas in geological sciences include:

  • The origin and evolution of the ocean-atmosphere system, global climate, and biosphere
  • Geology, geochemistry, and geophysics of oceanic crustal rocks and near-shore environments
  • Tectonic and structural evolution of the oceans, plate margins, and back-arc basins
  • The role of fluids in the crust
  • Chemistry of rare gases and stable and radiogenic isotopes in active volcanoes and magmatism
  • Cosmochemistry
  • The use of natural nuclear processes for understanding physical and chemical processes in the Earth
  • Paleomagnetic applications in geology and geophysics
  • Interaction of humans with their natural environment


Requirements for Admission

In addition to the general requirements for admission to the PhD program listed here, a major in one of the earth sciences including undergraduate coursework in physical chemistry and calculus are required. Preparation beyond the minimum requirements in mathematics, physics, and chemistry is strongly recommended.

GS Applicant evaluation Criteria

Admissions applications are reviewed using a rubric that includes the criteria: (1) Academic preparation, (2) Scholarly potential, (3) Potential relative to opportunities, (4) Diversity, Equity and Inclusion contributions, (5) Alignment with the SIO Program, (6) Self Appraisal, (7) Long term goals. Hence, students are encouraged to address these themes in their research statement or other aspects of their application. The GRE is not required and is not used in the application evaluation. Applications are reviewed by an admission committee, the prospective advisor(s) and a Diversity Admissions Committee. Finalists are invited to the SIO open house, typically held in late January to mid-February.


The following faculty and research scientists are interested in seeking new students for Fall 2024 intake. If you wish to find out more about their research, please email them individually.

Sarah Aarons |

Isotope geochemistry, paleoclimate, Earth surface processes. Projects could include: 1) Exploring stable zirconium isotope variability in the ocean and terrestrial aqueous environments; 2) Developing new records of dust geochemistry in the ice core record and modern time series.

James Day | 

Volcanology, Petrology, Geochemistry and Cosmochemistry. Projects could include 1) times series geochemical and petrological studies of basaltic volcanic eruptions; 2) determining the age and evolution of the mantle lithosphere beneath non-cratonic regions; 3) volatile depletion processes during planet formation. 


Igneous and Metamorphic Petrology, Geochemistry, Tectonics, Geology. Projects could include: 1) interaction of volcanism and plate reorganization in the oceans, 2) geochemistry and rheology of the continental lithosphere, 3) geology and tectonics of Western North America

Margo Odlum |

Tectonics, structural geology, thermochronology. Project focuses on using fault rock and regional thermochronology to date deformation along a strike-slip fault in Alaska and Yukon.


Financial Support

Applicants are strongly encouraged to contact potential advisors prior to admissions, since support of one or more faculty greatly increases the likelihood of being offered admissions. Students are also encouraged to identify faculty in the admissions application that most closely match the interests or likely graduate research area of the students.

Program of Study for PhD

Students admitted to Geosciences of the Earth, Oceans, and Planets (GEO) are assigned an adviser, who is the chair of their three-person guidance committee. Based on the student’s interests and the major affiliation of the adviser, students are assigned to a curricular group upon admission. Although students may change curricular groups in the course of the year, they must choose which departmental exam they will take. Departmental exams have similar structures among the curricular groups within GEO (a written exam at the end of spring quarter of their first year and an oral exam before the beginning of fall quarter of their second year). The material covered is quite different so students must begin preparing for a particular group's exam from the start. Student support for the first year comes from a variety of sources including departmental fellowships and research grants. Students are encouraged to begin a research project from the beginning and typically do not hold teaching assistant positions during their first year. Students may change advisers during their first year, and they must find an adviser by the end of the first year.

The geosciences curriculum consists of a series of core courses and a series of research focus courses.  Students are expected to take at least nine classes in their first year. They are expected to take at least four units of research per quarter during their first year for a total of at least forty-eight units.

All students are responsible for material in Marine Geology (SIOG 240). Additionally students must take at least one geochemistry, one geology, and one geophysics class from the following groups of core classes:

  • Geochemistry core classes include Whole Earth Geochemistry (SIOG 251), and Introduction to Isotope Geochemistry (SIOG 252A).
  • Geology core classes include Field Methods (SIO 100), Stratigraphy and Sedimentology (SIO 105), Petrography and Petrology (SIO 152), Introduction to Volcanology (SIO 170), Geological Record of Climate Change (SIOC 201), Shape and Structure of the Ocean Floor (SIOG 244), and Interactions of Oceanic Plates and the California Margin (SIOG 253). 
  • Geophysics core classes include Introduction to Geophysics (SIO 103), Geodynamics (SIOG 234), and Rock Magnetism and Paleomagnetism (SIOG 247).

Students are also encouraged to take Introduction to Computers at SIO (SIOG 233), Analysis for Physical Oceanographic Data (SIOC 221B), Physical Oceanography (SIOC 210), Marine Chemistry (SIOG 260), and Biological Oceanography (SIOB 280), but these may not be used to substitute for the geology, geophysics and geochemistry core requirements.

Program of Study for MS

The geosciences curriculum consists of a series of core courses and a series of research focus courses.

Required course work:

  • SIOG 240. Marine Geology (4 units)
  • One geochemistry course, from the following:
    • SIOG 251. Whole Earth Geochemistry (4 units)
    • SIOG 252A. Introduction to Isotope Geochemistry (4 units)
  • One geology course, from the following:
    • SIO 105. Stratigraphy and Sedimentology (4 units)
    • SIO 160. Introduction to Tectonics (4 units)
    • SIO 170. Introduction to Volcanology (4 units)
    • SIOC 201. Geological Record of Climate Change (4 units)
    • SIOG 244. Shape and Structure of the Ocean Floor (4 units)
    • SIOG 253. Interactions of Oceanic Plates and the California Margin (4 units)
  • One geophysics course, from the following:
    • SIO 103. Introduction to Geophysics (4 units)
    • SIOG 234. Geodynamics (4 units)
    • SIOG 247. Rock Magnetism and Paleomagnetism (4 units)

Elective course work:

Students may fulfill the remaining units of required course work through elective course offerings selected in consultation with the students’ guidance committee. Recommended course electives are below:

  • SIOG 233. Introduction to Computers at SIO (4 units)
  • SIOC 221B. Analysis for Physical Oceanographic Data (4 units)
  • SIOC 210. Physical Oceanography (4 units)
  • SIOG 260. Marine Chemistry (4 units)
  • SIOB 280. Biological Oceanography (4 units)

Research in Geosciences

Geosciences Faculty and Researchers: