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Graduate
Study in Geoscience at the Department of Earth
and Atmospheric Sciences, Graduate Geoscience Program Brochure (PDF file) Graduate School Application Information SLU Tradition SLU Tradition Our
Faculty David Crossley crossley@eas.slu.edu John Encarnación jpe@eas.slu.edu Robert Herrmann rbh@eas.slu.edu David Kirschner dkirschn@eas.slu.edu Tectonics, structural geology, growth of continental crust Lupei Zhu lupei@eas.slu.ed Global seismology, plate tectonics, digital signal processing, inverse theory, exploration geophysics. Faculty Research Interests Interesting , high quality research is of utmost importance in a graduate student’s education. To help you find out more about our individual research interests, each of us has written a brief summary of some of the details of our current research. Please contact us if you wish to discuss any of our work in more detail. Dr. David J. Crossley (Professor of Geophysics, Ph.D. University of British Columbia) Research: I am interested in all aspects of the Earth’s core and global Earth dynamics. The first topic includes fluid dynamics of the liquid core at all periods from seismology (10s of seconds) to time scales of the magnetic field generation (about 104 years) and the motions of the inner core at all possible periods, including the hard-to-detect Slichter triplet. With respect to the magnetic field I have worked on the problem of the reversal mechanism, but not the dynamo field generation mechanism that currently requires sophisticated numerical modeling on supercomputers. In the area of global dynamics of the Earth, I am interested in the seismic free oscillations of the Earth and in the wobble and nutation modes associated with the Earth’s rotation. At the present time I am heavily involved in the Global Geodynamics Project (GGP), which is a 6-year campaign to record and analyze the Earth’s global gravity field at all period ranges. While my ultimate goal is to use this data to search for core modes, as they affect gravity, there are many interesting problems that arise in modeling the gravity response to environmental effects such as atmospheric pressure and hydrology. I am willing and eager to supervise students in all of the above subjects. Research Collaborators: I work most closely with Jacques Hinderer (Institut de Physique du Globe in Strasbourg) and other international colleagues connected with GGP. I have also collaborated recently with the NOAA group in Boulder on the treatment of the data from their superconducting gravimeter. Su Xu, a post-doctoral fellow, worked with me on some of the above problems from 1996-98. Selected Publications:
Dr. John Encarnación (Associate Professor of Geoscience, Ph.D. University of Michigan) Research: My research is in the area of tectonics, petrology and geochemistry. I use geochronology and the chemistry of rocks to decipher the tectonic and magmatic history of an area. The results of such studies lead not only to a better account of the geologic history of an area, but reveal new insight to processes that have shaped the Earth. In one of my projects we are studying rocks in the Transantarctic Mountains to determine their age as well as their tectonic and geographic setting. This will allow us to evaluate Antarctica’s tectonic setting in the Precambrian and test if it was once connected to the ancient North America. It will also help us understand the timing and kinematics of the assembly of the Gondwana supercontinent. In another study we are establishing the timing and structural setting of flood basalts in Antarctica and South Africa. This will hopefully shed light on the origin of flood basalts, their relationship to supercontinent (Gondwana) breakup, and even their significance for mass extinctions. Most recently, I have developed an interest in the problem of subduction initiation. We are addressing this problem from a field, geochemical, and geochronological perspective on the island of Palawan, Philippines, where a young slab of oceanic crust and mantle has preserved the timing and conditions for the initiation of subduction in that area. Research Collaborators: Michael Watkeys, University of Natal, South Africa; Anne Grunow, Timothy Paulsen, and David Elliot, Byrd Polar Research Center, Ohio State University; James Mattison, U.C. Santa Barbara; Larry Snee, U.S.G.S; Robert Tucker, Washington University. Selected Publications:
Dr. Robert B. Herrmann (Otto W. Nuttli Professor of Geophysics, Ph.D. Saint Louis University, Geosciences Graduate Program Director) Research: My recent research emphasis has been directed toward the application of seismology to seismic hazard reduction but I enjoy all aspects of quantitative seismology. Some specific interests include earthquake history, earthquake processes and seismic wave propagation. You might say that I have focused my research on Earth's outer shell, the lithosphere, for my earthquake and Earth structure studies. I have estimated earthquake source parameters using long-period surface-wave spectra and broad-band seismogram modeling using signals recorded at local and regional distances. Recently my students and I have used regional seismic network recordings to examine the propagation of high frequency S-waves in the 10-500 km distance range. I have supervised the operation of our short-period radio-telemetered seismic network and am now installing a 15-station broadband digital network that relies on the Internet for data transmission. I have a strong interest in numerical computations and I am proud of Computer Programs in Seismology, a collection of tools for seismogram analysis and numerical modeling of wave propagation which are available for MS-DOS and UNIX systems. This compilation has extensive documentation and is the result of software-development and software-modification efforts of many of our graduates. The package provides students and researchers worldwide with the tools for doing modern seismological research. This is especially important be-cause of the advances in data due to modern seismological instrumentation. Research Collaborators: Current students: Young-Soo Jeon, Mohammed Fnais. Recent collaborators: Glenn Rix, Georgia Institute of Technology; Paul Bodin, University of Memphis; Jaime Yamamoto, Universidad Nacional Autónoma de México, Luca Malagnini and Aybige Akinci, ING Rome, Italy. Selected Publications:
Dr. David L. Kirschner (Associate Professor of Geoscience, Ph.D. University of Minnesota) Research: My research is focused on documenting and understanding the interaction of fluids and rocks during deformation of the Earth’s crust. I am working primarily on seismogenic strike-slip faults and in fold-thrust belts located along the margins of large mountain belts. To date I have worked on the San Andreas strike-slip fault (California) and on the fold-thrust belts of the Alice Springs Orogen (Australia), Alps (Switzerland), Pyrenees (Spain), Apennines (Italy), and Rocky Mountains (Canada and U.S.). The research involves extensive fieldwork, structural analysis, sample collection, and laboratory analyses. These laboratory analyses are needed to document the mineralogy, meso- and microstructures, and geochemistry (stable isotopes, radiogenic isotopes, elemental chemistry) of the deformed rocks. By combining the results of the structural and geochemical analyses, I hope to document the structural pathways fluids (water, oil, natural gas) use to move through the earth’s crust, the relative timing between fluid migration and deformation of the crust, the role fluids play in localizing deformation, and the role fluids play in initiating and facilitating earthquakes. Research Collaborators: Current students: David Cuevas. Recent collaborators: Fred Chester, Texas A & M; Judith Chester, Texas A & M; Lori Kennedy, University of British Columbia, Canada; Francesca Ghisetti, University of Catania, Sicily; Livio Vezzani, University of Torino, Italy. Selected Publications:
Dr. Keith Koper (Assistant Professor of Geophysics, Ph.D., Washington University) Research: My current research activities fall into three broad categories. The first is determination of deep Earth structure from analysis of seismic body waves. Such data provide extremely high resolution constraints on interesting problems such as aspherical inner core structure, topography on the inner core-outer core boundary, topography on the core-mantle boundary, possible asphericity in the liquid outer core, and the nature of lower mantle heterogeneities (chemical, thermal, partial melt?). Second, I work quite a bit on analysis of exotic seismic sources such as truck bomb attacks, pipeline explosion, and submarine accidents. Seismic investigation of such incidents often provides info that is useful to investigative agencies, insurance companies, and the general public. This type of work is known as forensic seismology. Third, I am interested in developing and applying global optimization techniques to geophysical problems. I feel that iterative, matrix methods of inversion will continue to give way to global schemes (such as Monte Carlo methods, genetic algorithms, and simulated annealing) as computational power increases. Most recently I have been applying a niching genetic algorithm to inversion of waveforms and receiver functions for crustal and upper mantle structure. Research collaborators: Rick Aster, Susan Beck, Megan Flanagan, Hans Hartse, Bob Reinke, Steve Taylor, Terrry Wallace, Doug Wiens, Michael Wysession, George Zandt Selected Publications:
Dr. Timothy M. Kusky (Associate Professor of Geoscience, Ph.D. Johns Hopkins University, Reinert Chair in the Natural Sciences) Research: My research is in the areas of tectonics, structural geology, and growth of the continental crust. Two of the main themes of my research are 1) unraveling the evolution of orogenic systems through integrated structural, tectonic, geophysical, petrologic, geochronologic, paleogeographic, and plate kinematic studies, and 2) geodynamic modeling of the role that plate margin processes have played in the growth of continental crust, partly through comparison between the styles of Precambrian and younger orogens and continental margin accretionary processes. I use these data to estimate how plate tectonics, which is the surface expression of planetary heat loss, has evolved from a period of higher heat flow from the early Earth to its present state. This knowledge is essential to our understanding of how the surface and interior of the planet has evolved with time, and how previous interactions of the lithosphere, atmosphere, hydrosphere, and biosphere have been driven by the fundamental heat loss from the interior of the earth. I am currently working on Archean rocks from North China, Zimbabwe, the Slave and Superior Cratons of the Canadian Shield, and Proterozoic rocks of the Arabian/Nubian Shield in Egypt, Saudi Arabia, Madagascar, and Oman. Much of my recent work on young orogens has been concentrated on the southern Alaska accretionary margin, which has experienced episodes of subduction of very young oceanic lithosphere, including ridge subduction, and has a suite of rocks that very much resembles that found in Archean granite-greenstone terranes. I have an active NSF- and USGS- funded research program investigating these processes along the Cordilleran margin of North America. In this area, structurally complex graywacke/argillite turbidites, tectonically mixed with basalts and gabbros, are intruded by several generations of tonalitic - granodioritic plutons, and underwent a high-temperature, low-pressure metamorphic event. This work serves as a modern analog for processes possibly responsible for the present character of many Archean granite - greenstone terranes. Additionally, I have been working in the Appalachians for more than 10 years. Recent Research Collaborators:
Mohamed El-Shafei and Imbarak Hassan, Suez Canal University; Mohamed
Matsah and
Mohamed Qari, Kin AbdulAziz University; Mohamed Yehia, Hasan El-Etr,
and
Mohamed, Ramadan, National Authority for Remote Sensing and Space
Sciences,
Egypt; Ibrihan Himida and Salal Adel-Mogeeth, Desert Research Center,
Cairo; W.C.
McLelland, University of Idaho; Jim M. McLelland, Colgate University;
Ahmed Al-Malki,
Said Al-Hattaly, Alai Al-Marjeby, Said Al Khamisi, Ministry of Water
Resources,
Sultanate of Oman, Katherine Dietrich and Rachael Huson, St. Louis
University. Selected Publications:
Dr. Brian Mitchell (Professor of Geophysics, Ph.D., Southern Methodist University) Retired, June, 2005 Research: My current research utilizes various seismic waves to study the structure and evolution of the Earth’s crust and upper mantle. I have measured the attenuation of both fundamental-mode and higher-mode seismic surface waves in various parts of the world and found that the attenuation rate of both types of waves with distance is proportional to the time that has elapsed since the most recent episode of major tectonic or orogenic activity in any region. I am currently developing methods by which regional variations of seismic wave attenuation can be determined on a much finer scale, so that individual fault zones, segments of plate boundaries, subsurface structure of volcanoes, or other smaller structure can be studied. I have also recently studied the velocity and attenuation structure of the New Madrid seismic zone. My research of two decades ago (with Cheng-chuan Cheng and Fr. William Stauder) showed that seismic wave velocities were considerably reduced beneath the active portion of the New Madrid seismic zone relative to regions at the same depth outside that zone. More recently Haydar Al-Shukri and I obtained a detailed tomographic velocity map of the New Madrid region and found that seismic velocities were lowest in regions of greatest seismic activity. Currently I am trying to map variations of seismic-wave attenuation there using the attenuative dispersion of seismic waves. Research Collaborators: Current students: Alemayehu Jemberie, Behsara Sholy, and Hongyi Li. Recent collaborators: Andrzej Kijko, Council of Geosciences, South Africa; G.-Akis Iselentis, University of Patras, Greece; Antonio Correig, University of Barcelona, Spain; Zoltan Der, ENSCO Inc., Ray Buland, USGS. Selected Publications:
Dr. Lupei Zhu (Assistant Professor of Geophysics, Ph.D., California Institute of Technology) Research: Waveform modeling is the seismological tool of choice for providing detailed descriptions of Earth structure, and my interests and specialties lie in utilizing the waveform information carried in regional broadband recordings to image structural features within the Earth's crust and lithospheric mantle. The information about the Earth which can be gleaned from a modern, broadband seismogram is truly prodigious, and my research provides first order information and constraints on all aspects of solid Earth science, including plate tectonics, geodynamics, and the source processes in seismic nucleation and propagation. My interests have revolved around developing new computational techniques which take advantage of the growing ubiquity of broadband arrays and the ever-increasing computational power of desktop computers. With these tools I generate 1-D and 3-D seismic velocity models, determine source mechanisms, and invert waveforms for the fine scale lithospheric structure which are unresolvable with other techniques, such as travel time tomography.Current research projects include high resolution imaging of deep crustal structure across plate boundary (e.g. the San Andreas Fault), the study of lithospheric structure of the Tibetan Plateau and related tectonics of the India-Eurasia continental collision and determining sedimentary basin structure and estimating strong ground motion produced by big earthquakes. Other projects include rapid earthquake moment tensor determination using regional broadband seismic network, locating earthquake and estimating its magnitude in real-time and generating early warning for damaging earthquake, and nuclear test detection and CTBT verification. Selected Publications:
Contacting Our
Current Graduate
Students Graduate Employment Information Research Facilities Saint Louis University has a long tradition of seismic observation including a seismogram collection dating back to the early part of the century and involvement in a number of seismic networks. Currently, we are involved in two regional seismometer networks: the BILLIKEN network and the Cooperative New Madrid Seismic Network. Together these regional networks contain about 20 seismometers distributed throughout the central conterminous United States. Data are collected and archived in-house, as part of the IRIS (Incorporated Institute for Seismology) global seismic network, or along with the US Geological Survey's National Seismic Network. Financial
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Department of Earth & Atmospheric Sciences Saint Louis University 3507 Laclede Ave St. Louis, MO 63103 VOICE: (314) 977-3116 and FAX: (314) 977-3117 Formal applications materials are available from the Graduate School, Saint Louis University:
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