Discovering Your Planet: A Complete Guide to Earning A Ph.D. in Earth Sciences

Aqueous Geochemistry

Students considering problems in aqueous geochemistry typically combine laboratory and fieldwork with a theoretical analysis. Some of the topics considered in the department include the nature of fluids during paleoclimate reconstructions, the water cycle, urban surface water compositions and characterization of reactions at the mineral/solution interface. Students can make use of equipment in the wet geochemical lab to measure the concentration of elements in solution and the electron microprobe lab to look at elemental concentrations and zoning patterns in minerals.

Geology

Geology is the study of our earth and its history — it provides a new understanding of our physical environment, resources and our place in its evolution. This research focus is of particular interest to those that would like to apply principles from other sciences, mathematics, and engineering to understand the world we live in. Outdoor studies of rocks in the field are an integral part of geological studies.

Geothermal Energy and Heat Flow

Geothermal energy is a renewable energy source generated by the Earth's internal heat. Most of the world's geothermal energy is concentrated along plate boundaries and hot spots. Supplying reusable energy for the increased worldwide energy demand, the use of geothermal energy does not require fossil fuel burning; therefore, present research of heat flow and future developments of geothermal energy will largely impact the many generations to come.

Paleoclimates

Research involves both biogenic and abiogenic materials to estimate climates of the past. Geochemical analyses assess chemical, mineralogical, and energy properties in order to relate them to environments throughout geological time. Paleobotanical remains, which may also be characterized through isotope geochemistry, are analyzed for their taxonomy and (in the case of leaves) their shape to infer past climate. The laboratories rely upon intensive fieldwork for sample acquisition and then undertake detailed characterization of those samples to understand their contents and history. Frequently used geochemical analytical methods include petrography to understand depositional textures; X-ray diffraction to understand the occurrence, abundance, and distribution of minerals; X-ray fluorescence to evaluate the distribution of chemical compositions among samples; and stable isotope measurements of carbon, oxygen, and hydrogen isotopes to infer environmental conditions at the time of formation.

Sedimentology

Sedimentology considers the production, transport, deposition and lithification of chemical elements, ions, and compounds through Earth’s near-surface environments. Through an analysis of landscape position and different transport media such as gravity, wind, water and ice, different scenarios that include erosion, transport, deposition, compaction and cementation are used to relate sedimentary systems to the energy that is applied to near-surface environments. This is concept is reinforced through study of modern marine, riverine, lacustrine (lakes), glacial and eolian (wind-dominated) modern environments, and then applied to interpretation and reconstruction of ancient environments from analysis of sedimentary deposits through lecture, laboratory, and field trip exercises.

Stable Isotope Geochemistry

The stable isotope ratios of light (H, C, O,) elements vary greatly in nature and can be used to understand geological and biological processes. In particular, stable isotopes are potent tools for understanding, fluid-rock interactions, tracing the hydrologic cycle, paleoclimatology, and ecosystem ecology as well as paleothermometry. The research program at SMU stresses the evolution of the Earth's fluid envelope and lithosphere. Current projects address diverse topics ranging from the origin of quartz veins in the continental crust to the climate history of the Earth. Interaction of seawater with the cooling oceanic crust at mid-ocean ridges are being investigated as well as anthropogenic inputs of CO2 into the atmosphere. The isotopic concentrations in goethite (a-FeOOH) and hematite (a-Fe2O3) are being measured to understand levels of O2 and CO2 in paleo-atmospheres.

Environmental Science

SMU students who choose to focus their research on environmental geology develop the tools necessary to address urgent problems facing humankind today: contamination of our underground water supply, river flooding and earthquakes, holes in the ozone layer, acid rain, smog, burial of toxic wastes, landslides, hurricanes, coastal hazards, global warming, and preservation of ecosystem diversity. We need a growing number of people with the training and background to understand the biological, toxicological, physical, and chemical aspects of environmental processes, as well as the relevant political, social, and legal considerations.

Geophysics

Geophysical techniques are used to understand the physical behavior of planet Earth, including plate-tectonic processes, earthquake mechanisms, and nuclear test-ban verification. Those who chose to pursue research in the area of Geophysics will have a strong quantitative background in seismology, geothermics, tectonics, and digital signal processing.

Remote Sensing

Satellite radar provides an all-weather, day-and-night imaging capability for imaging landscapes and monitoring their changes. Through interferometric synthetic aperture radar (InSAR) techniques, satellite radar imagery can be used to measure ground surface deformation and map land surface characteristics at high spatial resolution. The unprecedented spatial resolution of surface deformation measurements from InSAR allows the exploration of various geophysical models and the associated source parameters to understand the causal mechanisms. Applications of InSAR include the study of volcano, landslide, and human-induced geohazard processes (mining, CO2 and wastewater injection, hydrocarbon extraction, sinkhole, ground fissure, etc.).

Paleontology

The objective of paleontological studies at SMU is to apply fossils to understanding significant issues in Earth and life history, including the evolution of communities and ecosystems, and assessment of past climates. Students are encouraged to take a global perspective. Interdisciplinary and international studies are encouraged and have included field areas in both East and western Africa, Texas, and the U.S. Southwest. Particular strengths lie in, systematics, taphonomy, and paleoecology of terrestrial ecosystems, with particular focus on the intersection of geological and biological processes in tropical Africa during the past 66 million years. Students utilize innovative approaches and benefit from departmental strengths in paleoclimatology and stable isotope geochemistry. Current geographic areas of study include Alaska, Texas, Angola, Antarctica, China, Democratic Republic of Congo, Ethiopia, Kenya, Tanzania, Mongolia, Mozambique, Cameroon, Pakistan, and Portugal.

Seismology & Infrasound

Seismology and infrasound studies at SMU span the land, sea and atmosphere. Faculty expertise includes earthquake seismology, explosion source studies, infrasound and exploration seismology methodologies. SMU faculty have globally recognized expertise in data collection and archiving. SMU operates over 200 channels of real-time seismic and acoustic data and leads large land-and-water based acquisitions. Current projects include monitoring human-induced earthquakes in north Texas, exploring methane hydrate stability in the North Sea, and using marine seismology techniques in high-elevation Patagonia to constrain uplift rates. Unique to SMU, instrumentation developmental work consists of seismic and acoustic array design and deployment including the TXAR (Texas), NVAR (Nevada), and South Korea seismo-acoustic arrays relevant to seismic verification of nuclear arms-control treaties and monitoring.

Tectonics and Structural Geology

Tectonics is the study of the deformation of rocks, of Earth’s materials and the forces that produce such deformation. Structural Geology studies the structures formed by those forces (e.g., folds and faults), and together these two fields explore the processes that build mountains, create oceans and basins, and rule the igneous and metamorphic processes of our planet. At SMU current projects in Tectonics and Structural Geology focus on the evolution of the Eastern North American Margin (ENAM), on the isostatic adjustment of the Patagonian Andes, and on using the Mississippi River channel response to detect intraplate active fault deformation.

Discovering Your Planet:

A Complete Guide to Earning a Ph.D. in Earth Sciences

Why Earn a Ph.D. in an Earth Sciences Discipline?