For Students: What do I do?
I study geological, geophysical, and geodynamical processes responsible for the creation of the ocean floor. I go to sea regularly on month-long cruises, collecting information on ocean floor bathymetry, gravity, magnetics, and sediment cover. Back at the lab, I combine these data sets with two- and three-dimensional numerical models to understand why the geology of the ocean basins looks like it does.
I am interested in studying a number of specific settings in the ocean. First, I investigate oceanic hotspots, such as Iceland, Azores, Hawaii, Bouvet, and Marion, to see how they affect the geology and geochemistry of oceanic crust. I also study how these hotspots interact with nearby mid-ocean ridges, such as the Mid-Atlantic Ridge and the Southwest Indian Ridge. I am also interested in oceanic plate boundary triple junctions, such as the Azores, Galapagos, and Rodrigues triple junctions, because these are locations where mantle upwelling patterns are more complex than along "normal" mid-ocean ridges. Additionally, I study large igneous provinces and oceanic plateaus such as Ontong Java in the western Pacific Ocean, to see how these plateaus were created by voluminous, anomalous outpouring of magma from unusual mantle regions. Finally, I combine geological and geophysical studies of the seafloor with some geochemical investigations, such as studying helium isotopes in basalts dredged from the Southwest Indian Ridge.
I also study the geophysics of the Florida continental shelf and nearshore environment, using data like shallow seismics, bathymetry, and sidescan sonar. The goal of these studies is to understand the physical processes that control things like sediment transport and channel formation.
If you are an undergraduate or graduate student (or are applying to be one), and are interested in marine geology and geophysics, geodynamics, or numerical modeling of solid Earth processes, my door is always open. Drop me an e-mail to let me know of your interest.
Current Research Projects
- Triple junction geodynamics and geochemistry (numerical modeling).
- Plume/triple junction interactions and the creation of large igneous provinces (numerical modeling).
- Geological processes around the Azores Triple Junction (analysis of shipboard data; with graduate student Ravi Sankar).
- Microplate geodynamics (analysis of seafloor data).
- Plume/transform fault interactions (numerical modeling and analysis of seafloor data).
- Sediment transport processes off northeastern Florida (analysis of seismic and core data; with graduate student Corrie Neighbors).
- Development of Florida offshore wind farm: Geological considerations (collection and analysis of seafloor data).
What's It Like To Go To Sea?
Vitae
Education
- Massachusetts Institute of Technology/ Woods Hole Oceanographic Institution: Joint Program in Oceanography and Applied Ocean Science and Engineering (Marine Geophysics) Ph.D. 2001.
- University of Virginia: B.A. with honors, Environmental Sciences, 1995.
Employment History
- 2001-2003: Postdoctoral researcher, University of Rhode Island, Graduate School of Oceanography
- 2004-2008: Assistant Professor, Florida State University, Department of Geological Sciences
- 2008-present: Assistant Professor, Old Dominion University, Department of Ocean, Earth, and Atmospheric Sciences
Research Interests
- Marine geophysics and geodynamics of hotspots and ocean ridges.
- Numerical modeling of geophysical fluid flow processes.
- Geophysics of coastal Florida.
- Rare gas geochemistry.
Professional Memberships and Activities
- Editorial Board, Geology, 2008-2010.
- American Geophysical Union, member.
- Geological Society of America, member.
- RIDGE and Interridge, member.
- Sigma Xi, member.
- MIT/WHOI Joint Program student representative/WHOI Educational Assembly member, 1997-1998.
- Co-convener, AGU special sessions, fall 1998 and fall 2004.
- Judge, AGU Outstanding Student Papers.
- Panelist, NSF OCE proposal review panel.
- Proposal reviewer for NSF and Florida Geological Survey.
- Reviewer for Geophys. J. Int., G-cubed, Geology, AGU Geophysical Monographs, J. Geophys. Res., Geophys. Res. Lett.
Sea Experience
- Shipboard scientist. Geophysical and geological survey of the northern Mid-Atlantic Ridge (25-27N) flank: gravity, magnetics, Hydrosweep, HMR1; Tucholke, Lin, and Kleinrock, Chief Scientists; R/V Maurice Ewing, July-August 1996.
- Shipboard scientist. Heat flow survery of the Hawaiian archipelagic apron; heat flow measurements, SeaBeam, gravity, magnetics, three-channel seismics, gravity coring; McNutt, Von Herzen, and Garven, Chief Scientists; R/V Roger Revelle, August-September 1997.
- Shipboard scientist. Geophysical and geological survey of the southern Azores platform; gravity, Simrad bathymetry, seismics, magnetics and dredge sampling; Cannat, Chief Scientist; N/O L'Atalante, July-August 1998.
- Brief (one day duration) coastal geophysical surveying, Gulf of Mexico, 2006.
Courses Taught at Florida State University
- GLY 4905/5931/6982: Tools of Geophysics Seminar (spring 2004)
- GLY 4905: Physics and Calculus Shadow Course (spring 2004)
- GLY 1000H: Dynamic Earth (honors) (fall 2004)
- GLY 1000: Dynamic Earth (~200 students) (fall 2005, fall 2006, fall 2007)
- GLY 4905/5906: Geodynamics (fall 2004)
- GLY 4451/5455: Introduction to Geophysics (spring 2005, spring 2006, spring 2008)
- GLY 4730/5726: Marine Geology/Geological Oceanography (with P. Froelich) (spring 2006)
- GLY 5906: Coastal and Marine Geophysics (spring 2007)
- GLY 5906: Matlab in Marine Geophysics (fall 2007)
- GLY 5906: Geological Oceanography Research (spring 2008)
Selected Publications and Abstracts
Publications
- Georgen, J., J. Lin, and H.J.B. Dick, Evidence from gravity anomalies for interactions of the Marion and Bouvet hotspots with the Southwest Indian Ridge: Effects of transform offsets, Earth Planet. Sci. Lett.,187, 283-300, 2001.
- Georgen, J. and J. Lin, Three-dimensional passive flow and temperature structure beneath oceanic ridge-ridge-ridge triple junctions, Earth Planet. Sci. Lett., 204, 115-132, 2002.
- Georgen, J., M. Kurz, H.J.B. Dick, and J. Lin, Low 3He/4He ratios in basalt glasses from the western Southwest Indian Ridge (10-24oE), Earth Planet. Sci. Lett., 206, 509-528, 2003.
- Georgen, J. and J. Lin, Plume-transform interactions at ultra-slow spreading ridges: Implications for the Southwest Indian Ridge, Geochem. Geophys. Geosys., 4(9), 9106, doi: 10.1029/2003GC000542, 2003.
- Georgen, J., Mantle flow and melting beneath oceanic ridge-ridge-ridge triple junctions, Earth Planet. Sci. Lett., 231-240, doi:10.1016/j.epsl.2008.03.040, 2008.
- Georgen, J., North-south asymmetry in Iceland plume-ridge interactions: Effects of the Tjornes FZ, revised for Geology, 2007.
- Harris, R.N., Garven, G., Georgen, J., McNutt, M., Christiansen, L., and Von Herzen, R., Submarine hydrogeology of the Hawaiian archipelagic apron, Part 2: Numerical simulation of coupled heat transport and fluid flow, J. Geophys. Res., 105, 21371-21386, 2000.
- Cannat, M., Briais, A., Deplus, C., Escartin, J., Georgen, J., Lin, J., Mercouriev, S., Meyzen, C., Muller, M., Pouliquen, G., Rabain, A., and da Silva, P., Mid-Atlatic Ridge-Azores hotspot interactions: along-axis migration of a hotspot-derived event of enhanced magmatism 10 to 4 Ma ago, Earth Planet. Sci. Lett., 173, 257-269, 1999.
Abstracts
- Georgen, J. and J. Lin, Constraints from bathymetric and gravity anomalies of the effects of the Marion and Bouvet hotspots on the Southwest Indian Ridge, EOS, Trans. AGU, 77, F671, 1996.
- Lin, J., G. Ito, and J. Georgen, Plume-ridge interaction and its effects on ridge magma supply: Examples from the Atlantic, Galapagos, and SW Indian Ridge, EOS, Trans. AGU, 78, F671, 1997.
- Georgen, J., G. Garven, and M. McNutt, Hydrogeological models of the Hawaiian moat near Oahu, EOS, Trans. AGU, 79, S346, 1998.
- Georgen, J., J. Lin, and H.J.B. Dick, Interaction of the Southwest Indian Ridge with the Marion and Bouvet hotspots, Gordon Research Conference on Interior of the Earth, June 28-July 3, 1998.
- Georgen, J., J. Lin, and H.J.B. Dick, Constraints from gravity, bathymetric, and geochemical anomalies on the interaction of the SW Indian Ridge with the Marion and Bouvet hotspots, Geol. Soc. America Penrose Conference, Sept. 13-17, 1998.
- Georgen, J., J. Lin, and H.J.B. Dick, Models of mantle upwelling beneath the Southwest Indian Ridge: The effects of ridge-transform geometry on magma supply at an ultra-slow spreading ridge, EOS, Trans. AGU, 79, F854, 1998.
- Lin, J., M. Cannat, J. Georgen, and C. Rommevaux-Jestin, Changes in ridge morphology and gravity anomalies along the SW Indian Ridge and comparisons with the northern Mid-Atlantic Ridge: Assessing the effects of hotspots and fracture zones, EOS, Trans. AGU, 80, F957, 1999.
- Georgen, J. and J. Lin, Mantle dynamics and melting in the vicinity of oceanic triple junctions in seafloor spreading systems, EOS, Trans. AGU, 81, S410, 2000.
- Georgen, J. and J. Lin, Ridge-hotspot interactions: The effects of ridge geometry, RIDGE Plume-Ridge Interaction Workshop, June 26-28, 2000.
- Georgen, J. and J. Lin, The effects of transform offsets on reducing along-ridge plume flux: Implications for ridge-hotspot interactions, EOS, Trans. AGU, 81, F1129, 2000.
- Georgen, J. and J. Lin, The effects of transform offsets on along-axis flow of plume material: Implications for Iceland and the Tjornes FZ, RIDGE Iceland Symposium, September 2001.
- Georgen, J., M.D. Kurz, H.J.B. Dick, and J. Lin, Helium isotope systematics of the western Southwest Indian Ridge: Effects of plume influence, spreading rate, and source heterogeneity, EOS, Trans. AGU, 82, F1169, 2001.
- Georgen, J., M.D. Kurz, H.J.B. Dick, and J. Lin, Helium isotope systematics and gravity anomalies along the western Southwest Indian Ridge: Effects of the Bouvet hotspot, InterRidge Southwest Indian Ridge Workshop abstract volume, 2002.
- Georgen, J. and J. Lin, Mantle dynamics of oceanic triple junctions: the Southwest Indian Ridge near the Rodrigues Triple Junction, EOS, Trans. AGU, 83, F1359, 2002.
- Georgen, J. and Y. Shen, Mantle flow around the Iceland plume: Preliminary results from geodynamic and seismic anisotropy models, EOS, Trans. AGU, 83, F1039, 2002.
- Georgen, J. and J. Lin, Plume-transform interactions at ultra-slow spreading ridges: Implications for the Southwest Indian Ridge, InterRidge Ridge-Hotspot Interactions Workshop, September 2003.
- Stroup, D. (student) and J. Georgen, Inferred variations in crustal accretion processes along the Southwest Indian Ridge near the Marion hotspot, EOS, Trans. AGU, 85(47), Fall Meet. Suppl., 2004.
- Georgen, J., Effects of plate boundary migration on mantle dynamics of oceanic triple junctions, EOS, Trans. AGU, 85(52), Fall Meet. Suppl., 2005.
- Georgen, J., Modeling mantle dynamics of oceanic triple junctions: Effects of variable viscosity, EOS, Trans. AGU, 87(36), West. Pac. Geophys. Meet. Suppl., 2006.
- Georgen, J., Modeling mantle melting at an oceanic triple junction: Effects of variable viscosity, asthenospheric flow, and plate divergence, EOS, Trans. AGU, 87(52), Fall Meet. Suppl., 2006.
- Georgen J., Effects of triple junction plate boundary geometry on mantle thermal structure and crustal production, EOS, Trans. AGU, 88(52), Fall Meet. Suppl., Abstract V21B-0603, 2007.
- Neighbors, C. (student) and J. Georgen, Predictive modeling of modern sediment transport dynamics on the northeastern Florida continental shelf, GSA Abstracts with Programs, 40(4), 2008.
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