Julia K. Morgan
Professor of Earth Science
My research interests are focused on the mechanics and deformation of the Earth's shallow crust. I am interested in deformational processes at convergent margins, relating to sediment accretion and plate boundary seismogenesis. I also study the unique tectonics of oceanic volcanic islands, where magmatic and gravitational forces cause large scale flank collapse and associated hazards. The formation and evolution of fault gouge influences the frictional behavior and mechanical strength of natural and experimental faults. My field studies are coupled with particle based numerical simulations to explore the mechanics of natural systems in the brittle-frictional regime.
** ACCRETIONARY PRISM DEFORMATION (w/ G. Moore, D. Karig, M. Ask)
Interpretation of 3D seismic reflection data; kinematic and mechanics of prism deformation; in-situ stress state; DEM simulations of accretionary wedge deformation.
** GIANT LANDSLIDES IN HAWAII (w/ G. Moore, D. Clague, and others)
Interpretation of marine seismic reflection data; evolution, structure, and stratigraphy of Kilauea's south flank; offshore structure and stratigraphy of S. Kona landslide, Mauna Loa.
** SEISMIC TOMOGRAPHY OF HAWAII (w/ C. Zelt, P. Okubo, J. Park)
Onshore-offshore 3-D tomographic modeling of the Island of Hawaii; gravity modeling to constrain volcano stress fields.
** ORIGIN AND STRUCTURE OF MARTIAN VOLCANOES (w/ P. McGovern, M. Bulmer, J. Smith)
Structure of Olympus Mons Volcano; interpretation of slope morphology; slope stability, and landslide emplacement.
** MODELING VOLCANIC DEFORMATION (w/ P. McGovern)
Particle dynamics simulations of volcanic growth, deformation, and spreading; applications to terrestrial and Martian volcanoes.
** NUMERICAL SIMULATIONS OF GRAVITY SPREADING (w/ Scott Maxwell and others)
Particle dynamics simulations of extensional and contractional deformation and structural evolution along continental margins and similar settings.
** PARTICLE DYNAMICS MODELS OF GRANULAR SHEAR ZONES (w/ C. Marone & Y. Guo)
Simulations of gouge formation and deformation; granular friction and localization; calibration of numerical simulations with laboratory data; evaluation of micromechanical factors influencing fault strength and frictional behavior.
Park, J., J.K. Morgan, C.A. Zelt, and P.G. Okubo "Volcano-tectonic implications of volcanic structures derived from 3-D active-passive source tomography of the Island of Hawaii." J. Geophys. Res. (2008).(In Revision)
Ask, M.V.S., and Morgan, J.K. "Projection of mechanical properties from shallow to greater depths seaward of the Nankai Accretionary Prism." Tectonophysics (2008).(Submitted)
Guo, Y, and Morgan, J.K. "Fault gouge evolution and its dependence on normal stress and rock strength - Results of discrete element simulations: Gouge zone micromechanics." J. Geophys. Res., 113 (2008): B08417,doi:10.1029/2006JB004525.
McGovern, P.J., and Morgan, J.K. ", Volcanic spreading and lateral variations in the structure of Olympus Mons, Mars." Geology (2008).(In Press)
Morgan, J.K., Clague, D.A., Borchers, D., Davis, A., and Milliken, K.L. "Mauna Loa's submarine western flank: Evidence for deep volcanic spreading and hydrothermal alteration." Geochem. Geophys. Geosyst., 8 (2007): Q05002, doi:10.1029/2006GC001420.
Guo, Y, and Morgan, J.K. "Fault gouge evolution and its dependence on normal stress and rock strength - Results of discrete element simulations: Gouge zone properties." J. Geophys. Res., 112 (2007): B10403, doi:10.1029/2006JB004524.
Morgan, J.K., Sunderland, E.B., and Ask, M.V.S. "Deformation and diagenesis at the Nankai subduction zone: Implications for sediment mechanics, décollement initiation, and propagation." The Seismogenic Zone of Subduction Thrust Faults, MARGINS Theoretical Institute Series (2007): 210-256.
Park, J., Morgan, J.K., Zelt, C., Okubo, P., Peters, L., Benesh, N. "Comparative velocity structure of active Hawaiian volcanoes from 3-D onshore-offshore seismic tomography." Earth Planet. Sci. Lett., 259, 3-4 (2007): 500-516.
Oakley, A.J., Taylor, B., Fryer, P., Moore, G.F., Goodliffe, A.M., and Morgan, J.K. ", Emplacement, growth, and gravitational deformation of serpentinite seamounts on the Mariana forearc." Geophys. J. Int., 170 (2) (2007): 615-634.
Huhn, K., Morgan, J.K., Kukowski, N. "Deformation and mass transfer processes in accretionary wedges using distinct element simulations: Implications for the structure of the Makran forearc." J. Geophys. Res. (2006).(Submitted)
Morgan, J.K., Resig, J.M.,and Siesser, W.G. "Microfossil assemblages on Tuscaloosa Seamount and their constraints on the age of Nuuanu Landslide, north of Oahu, HI." J. Volc. Geotherm. Res., 151 (2006): 269-278.
Guo, Y., and Morgan, J.K. "The frictional and micromechanical effects of grain comminution in fault gouge from distinct element simulations." J. Geophys. Res., 111 (2006): B12406, doi:10.1029/2005JB004049.
Morgan, J.K. "Volcanotectonic interactions between Mauna Loa and Kilauea volcanoes, Insights from 2-D discrete element simulations." J. Volc. Geotherm. Res., 151 (2006): 109-131.
Cardozo, N., Allmendinger, R.W., and Morgan, J.K. "Influence of mechanical stratigraphy and initial stress state on the formation of two fault propagation folds." J. Struct. Geology, 27, (2005): 1954-1972.
Morgan, J.K., and McGovern, P.J. "Discrete element simulations of gravitational volcanic deformation: 2. Mechanical analysis." J. Geophys. Res., 110, (2005): B05403, doi: 10.1029/2004JB003253.
Morgan, J.K., and McGovern. P.J. "Discrete element simulations of gravitational volcanic deformation: 1. Deformation structures and geometries." J. Geophys. Res., 110, (2005): B05402, doi: 10.1029/2004JB003252.
Morgan, J.K. "Particle dynamics simulations of rate and state dependent frictional sliding of granular fault gouge." Pure Appl. Geophys., 161 (2004): 1877-1891.
McGovern, P.J., J.R. Smith, J.K. Morgan, M. Bulmer "Olympus Mons aureole deposits: New evidence for a flank-failure origin." J. Geophys. Res., 109, E8 (2004): E08008, doi: 10.1029/2004JE002258.
Sunderland, E.B., and J.K. Morgan "Microstructural variations in sediments from the toe of the Nankai accretionary prism: Results of scanning electron microscope analysis." Proc. ODP, Sci. Results, 190/196 (2004).
Leslie, S.C., G.F. Moore, J.K. Morgan, and D.J. Hills "Internal structure of the Puna Ridge: Evolution of the submarine east rift zone of Kilauea volcano, Hawaii." J. Volc. Geotherm. Res., 129 (2004): 237-259.
Guo, Y., and Morgan, J.K. "Influence of normal stress and grain shape on granular friction: Results of discrete element simulations." J. Geophys. Res., 109 (2004): doi:10.1029/2004JP003044.
Morgan, J.K. and M. Ask "Consolidation state and strength of underthrust sediments and evolution of the decollement at the Nankai accretionary margin: Results of uniaxial reconsolidation experiments." J. Geophys. Res., 109 (2004): B03102, doi: 10.1029/2002JB002335.
Morgan, Julia K., and David A. Clague "Volcanic Spreading on Mauna Loa Volcano, HI: Evidence from Accretion, Alteration, and Exhumation of Volcaniclastic Sediments." Geology, 30 (2003): 411-414.
Cowan, Darrel S., Cladouhos, Trenton T., and Morgan, J. K. "Structural geology and kinematic history of rocks formed along low-angle normal faults, Death Valley, California." GSA Bulletin, 115 (2003): 1230-1248.
Morgan, J.K., G.F. Moore, D.A. Clague "Slope failure and volcanic spreading along the submarine south flank of Kilauea volcano, HI." Journal of Geophysical Research, 108 (2003): 2415.
Underwood, M., A. Taira, G.F. Moore, M. Wilson, S. Hirano, C. Fergusson, J. Steurer, Morgan, J. K. and Leg 190 Scientific Party "Sedimentary and tectonic evolution of a trench slope basin in the Nankai subduction zone of southwest Japan." Journal of Sedimentary Research, 73 (2003): 589-602.
Ujiie, K., Hisamitsu, T., Maltman, A.J., Tobin, H.J., Morgan, J.K., Sanchez-Gomez, M., Moore, G.F., Taira, A., and Klaus, A. "Deformation structures and magnetic fabrics at Site 1178: implication for deformation history recorded in accreted sediments at an evolved portion of the Nankai accretionary prism." Proceedings ODP, Scientific Results, 190/196 (2003): 190196SR/202.
Morgan, J. "Capturing physical phenomena in particle dynamics simulations of granular fault gouge." 3rd ACES Workshop Proceedings (2003).
Smith, J.R., K. Satake, Morgan, J.K. and P. Lipman "Collapse features revealed by recent multibeam sonar surveys on the Hawaiian Ridge." Hawaiian Volcanoes: Deep Underwater Perspectives, Geophys. Monograph 128 (2002): 11-28.
Naka, J., T. Kanamatsu, P. Lipman, T. Sisson, N. Tsuboyama, Morgan, J. K., J.R. Smith, and T. Ui "Deep-Sea Volcaniclastic Sedimentation around the Southern Flank of Hawaii Island." Hawaiian Volcanoes: Deep Underwater Perspectives, Geophysical Monograph 128 (2002): 29-50.
Screaton, E., D. Saffer, P. Henry, S. Hunze, and Leg 190 Scientific Party "Porosity loss within underthrust sediments of the Nankai accretionary complex: Implications for overpressures." Geology, 30 (2002): 19-22.
Stephen C. Leslie, Gregory F. Moore, Morgan, J. K., and Denise J. Hills "Seismic Stratigraphy of the Frontal Hawaiian Moat: Implications for Sedimentary Processes at the Leading Edge of an Oceanic Hotspot Trace." Marine Geology, 184 (2002): 143-162.
Hills, D.J., Morgan, J. K., G.F. Moore, and S.C. Leslie "Structural variability along the submarine south flank of Kilauea volcano, Hawaii, from a multichannel seismic reflection survey." Hawaiian Volcanoes: Deep Underwater Perspectives; Geophys. Monograph 128 (2002): 105-124.
Moore, G.F., A. Taira, A. Klaus, L. Becker, B. Boeckel, B.A. Cragg, A. Dean, C.L. Fergusson, P. Henry, S. Hirano, T. Hisamitsu, S. Hunze, M. Kastner, A.J. Maltman, J.K. Morgan, Y. Murakami, D.M. Saffer, M. Sánchez-Gómez, E.J. Screaton, D.C. Smith, A.J. Spivack, J. Steurer, H.J. Tobin, K. Ujiie, M.B. Underwood, and M. Wilson, "New insights into deformation and fluid flow processes in the Nankai Trough accretionary prism: Results of Ocean Drilling Program Leg190." Geochem. Geophys. Geosyst., 2 (2001): 10.129/2001GC000166.
Morgan, J.K. "Distinct element simulations of granular shear zones: Micromechanics of localization and frictional behavior." in 2nd ACES Workshop Proceedings (2001): p. 83-90.
Naka, J., E. Takahashi, et al. "Tectono-magmatic processes investigated at deep-water flanks of Hawaiian volcanoes." EOS Trans. AGU, 82 (2000): 221, 226-227.
Morgan, J.K., Moore. G.F., Hills, D.J., and Leslie, S., "Overthrusting and sediment accretion along Kilauea's mobile south flank, Hawaii: Evidence for volcanic spreading from marine seismic reflection data." Geology, 28 (2000): 667-670.
Morgan, J.K. "Numerical simulations of granular shear zones using the distinct element method: II. The effect of particle size distribution and interparticle friction on mechanical behavior." J. Geophys. Res. B., 104 (1999): 2721-2732.
Morgan, J.K. and M.S. Boettcher "Numerical simulations of granular shear zones using the distinct element method: I. Shear zone kinematics and micromechanics of localization." J. Geophys. Res. B., 104 (1999): 2703-2719.
Rice University, Earth Science, Associate Professor. (2006 - present). (Houston, TX)
Rice University, Earth Science, Assistant Professor. (1999 - 2006). (Houston, TX)
University of Hawaii, Geology and Geophysics, Assistant Researcher. (1996 - 1999). (Honolulu, HI)
University of Washington, Geological Sciences, Postdoctoral Research Associate. (1994 - 1996). (Seattle, WA)
Cornell University, Geological Sciences, Postdoctoral Associate. (1993 - 1994). (Ithaca, NY)
Harvard University, Earth, Atmospheric, and Planetary Sciences, Visiting Associate Scholar. (2008 - 2008). (Cambridge, MA)