Geophysics

The Geophysics faculty are concerned with the broad range of physical processes affecting the solid Earth, from the core, mantle, and crust to the cryosphere, and carry out related studies of Mercury, Mars, and Earth's moon. We focus on understanding plate-tectonic processes in marine and terrestrial settings, determining the structure of the Earth's interior, and understanding earthquake and volcano dynamics. We study mechanisms for ice, magma, and sediment transport and for the exchange of mass between the solid Earth and its fluid envelope, and we work to understand interactions of large-scale surface deformation with the oceans and atmosphere. We are also concerned with the quantitative study of natural hazards and associated risks, hydrocarbon exploration and extraction, and explosion and earthquake monitoring for the verification of nuclear test-ban treaties. Our research draws on a variety of approaches, including seismology; geodesy; remote sensing; volcanology; physical glaciology; rock mechanics; and geophysical fluid dynamics. We emphasize the integration of data-analysis and modeling approaches, and many faculty maintain active field programs and engage in the development of geophysical instrumentation. The Geophysics faculty contribute expertise to inform decision-making at the local, national and international levels.

Geophysics Courses
 

 

             

 

                 
                 
                 
                 
                 
                 
                 
                 
                 
                 
                 
                 

Timothy Crone
Personal Information
Timothy
Crone
Lamont Associate Research Professor
Lamont-Doherty Earth Observatory
Marine Geology and Geophysics
Contact Information
303D Oceanography
61 Route 9W - PO Box 1000
Palisades
NY
10964-8000
US
(845) 365-8687

Fax: 

(845) 365-8156

I am a marine geophysicist interested in the interplay between relatively large-scale geophysical processes and the microbial biosphere.I am currently studying the tidal modulation of aqueous fluid flow within mid-ocean ridge hydrothermal systems, with the hope of understanding how such flow variations can affect subseafloor primary production. I also study spatial variations in the tidal triggering of microearthquakes within ridge systems, and I study problems in acoustics associated with high-temperature hydrothermal vents and seafloor seismic networks.

Ultimately my work has implications for theories about the origins and evolution of life on this planet, and for theories regarding life elsewhere in the universe. I use numerical models to investigate these processes, and I develop new observational techniques and seafloor instrumentation to verify model predictions.

Education
Ph.D. Oceanography
University of Washington
2007
M.S. Oceanography
University of Washington
2004
B.S. Oceanography
University of Washington
1999
Selected Publications:
Mantle helium reveals Southern Ocean hydrothermal venting, Winckler, G.; Newton, R.; Schlosser, P.;Crone, T Geophysical Research Letters (2010) 10.1029/2009GL042093
Flow rate perturbations in a black smoker hydrothermal vent in response to a mid-ocean ridge earthquake swarm, Crone, T J; Wilcock, W S D; McDuff, R E Geochemistry, Geophysics, Geosystems, Volume: 11 p.: Q03012 (2010)
Broadband calibration of the R/V Marcus G. Langseth four-string seismic sources, Tolstoy, M.; Diebold, J; Doermann, L.; Nooner, S.; Webb, S.C.; Bohnenstiehl,D.R.; Crone, T.J.; Holmes,z t.C. Geochem. Geophys. Geosyst., Volume: 10, Issue: Q08011 (2009) 10.1029/2009GC002451
Systematic along-axis tidal triggering of microearthquakes observed at 9-50'N East Pacific Rise, Stroup, D F; Tolstoy, M; Crone, T J; Malinverno, A; Bohnenstiehl, D R; Waldhauser, F Geophys Res Lett, Volume: 36, Issue: L18302 (2009)
Broadband calibration of the R/V four‐string seismic source, Tolstoy, M; Diebold, J; Doermann, L; Nooner, S; Webb, S C; Bohnenstiehl, D R; Crone, T J; Holmes, R C Geochem Geophys Geosys, Volume: 10, Issue: 8 p.: doi (2009)
Optical plume velocimetry: a new flow measurement technique for use in seafloor hydrothermal systems, Crone, T. J.; McDuff, R. E.; Wilcock, W. S. D. Experiments in Fluids Nov, Volume: 45, Issue: 5 p.: 899-915 (2008) DOI 10.1007/s00348-008-0508-2
Helene Carton
Personal Information
Helene
Carton
Adjunct Associate Research Scientist
Lamont-Doherty Earth Observatory
Marine Geology and Geophysics
Contact Information

Fields of interest: 

Mid-ocean ridges, oceanic crust, subduction zones, transform boundaries, multi-channel and wide-angle seismics

I am a marine geophysicist specialized in active source (reflection and refraction) seismic imaging. My research interests include mid-ocean ridge processes, the structure and evolution of oceanic crust and uppermost mantle, subduction zone processes and submarine strike-slip fault systems. I am also interested in airgun source modeling and underwater sound propagation.

Current projects:

  • Study of the structure, evolution and hydration of the Juan de Fuca plate along a ridge-to-trench wide-angle reflection-refraction transect (Endeavour segment to Washington margin) and Cascadia subduction zone structure in Washington
  • 3D multi-channel seismic imaging of the axial magma lens and seismic layer 2A at the East Pacific Rise 9 50'N Ridge 2000 Integrated Study Site
  • Bending-related faulting and subduction of oceanic reliefs at the southern and central Sumatra margin using seismic reflection profiles of the 2009 CGGVeritas survey and multibeam bathymetry
  • Airgun source/ sound propagation modeling for marine mammal mitigation

Cruises since 2007: R/V Langseth 3D seismic shakedown in the Gulf of Mexico (January 2008), 3D MCS cruise MGL0812 at the East Pacific Rise 9 50'N (June-August 2008), CGGVeritas - M/V Wavefield Inseis long-offset survey of the Sumatra subduction zone (May 2009), R/V Langseth JMS inspection (March 2011), Cruise 0C1206A on the Juan de Fuca plate and Cascadia subduction zone (June-July 2012)

Research Blog: http://www.ldeo.columbia.edu/research/blogs/cascadia-in-motion

Education
Ph.D., Geophysics
Institut de Physique du Globe de Paris, France
12/2005
Diploma
Ecole de Physique du Globe de Strasbourg, France
12/2001
DEA (~MSc), Geophysics
Universite Louis Pasteur, Strasbourg, France
06/2001
Selected Publications:
Deep seismic reflection images of the Wharton Basin oceanic crust and uppermost mantle offshore northern Sumatra: Relation with active and past deformation, Carton, H.; Singh, S.C.; Hananto, N.; Martin, J.; Djajadihardja, Y.; Udrekh; Franke, D.; Gaedicke, C. Journal of Geophysical Research (Submitted)
Fine-scale segmentation of the crustal magma reservoir beneath the East Pacific Rise, Carbotte, S.M.; Marjanovic, M.; Carton, H.; Mutter, J.C.; Canales, J.P.; Nedimovic, M.R.; Han, S.; Perfit, M. Nature Geoscience, Volume: 6 p.: 866-870 (2013) doi:10.1038/ngeo1933
Network of off-axis melt bodies at the East Pacific Rise, Canales, J.P.; Carton, H.; Carbotte, S.M.; Mutter, J.; Nedimovic, M.; Xu, M.; Aghaei, O.; Marjanovic, M.; Newman, K. Nature Geoscience, Volume: 5 p.: 279-283 (2012) doi:10.1038/ngeo1377
Aseismic zone and earthquake segmentation associated with a deep subducted seamount, Singh, S.C.; Hananto, N.; Mukti, M.; Robinson, D.; Das, S.; Chauhan, A.; Carton, H.; Gratacos, B.; Midenet, S.; Djajadihardja, Y.; Harjono, H. Nature Geoscience, Volume: 4 p.: 308-311 (2011) doi:10.1038/ngeo1119
Seismic evidence for Neogene and active shortening offshore of Lebanon (Shalimar cruise), Carton, H.; Singh, S. C.; Tapponnier, P.; Elias, A.; Briais, A.; Sursock, A.; Jomaa, R.; King, G. C. P.; Daeron, M.; Jacques, E.; Barrier, L. Journal of Geophysical Research-Solid Earth Jul 24, Volume: 114 p.: - (2009) Doi 10.1029/2007jb005391
Seismic evidence for broken oceanic crust in the 2004 Sumatra earthquake epicentral region, Singh, S. C.; Carton, H.; Tapponnier, P.; Hananto, N. D.; Chauhan, A. P. S.; Hartoyo, D.; Bayly, M.; Moeljopranoto, S.; Bunting, T.; Christie, P.; Lubis, H.; Martin, J. Nature Geoscience Nov, Volume: 1, Issue: 11 p.: 777-781 (2008) Doi 10.1038/Ngeo336
Seismic imaging of the three-dimensional architecture of the Cinarcik Basin along the North Anatolian Fault, Carton, H.; Singh, S. C.; Hirn, A.; Bazin, S.; de Voogd, B.; Vigner, A.; Ricolleau, A.; Cetin, S.; Ocakoglu, N.; Karakoc, F.; Sevilgen, V. Journal of Geophysical Research-Solid Earth Jun 21, Volume: 112, Issue: B6 p.: - (2007) Doi 10.1029/2006jb004548
Thrusting offshore Mt Lebanon: source of the tsunamigenic, 551 AD Beyrut-Tripoli earthquake, Elias, A.; Tapponnier, P.; Singh, S.C.; King, G.; Briais, A.; Daëron, M.; Carton, H.; Sursock, A.; Jacques, E.; Jomaa, R.; Klinger, Y. Geology, Volume: 35, Issue: 8 p.: 755-758 (2007)
Discovery of a magma chamber and faults beneath a Mid-Atlantic Ridge hydrothermal field, Singh, S. C.; Crawford, W. C.; Carton, H.; Seher, T.; Combier, V.; Cannat, M.; Canales, J. P.; Dusunur, D.; Escartin, J.; Miranda, J. M. Nature Aug 31, Volume: 442, Issue: 7106 p.: 1029-1032 (2006) Doi 10.1038/Nature05105
Felix Waldhauser
Personal Information
Felix
Waldhauser
Lamont Research Professor
Lamont-Doherty Earth Observatory
Seismology Geology and Tectonophysics
Adjunct Professor
Earth and Environmental Sciences
Contact Information
221 Seismology
61 Route 9W - PO Box 1000
Palisades
NY
10964-8000
US
(845) 365-8538

Fax: 

(845) 365-8150

Fields of interest: 

earthquake seismology, seismotectonics of active plate boundaries, real-time seismology

Seismic monitoring systems detect and locate tens of thousands of earthquakes globally every year, adding to an ever growing archive of instrumentally recorded seismic data that goes back almost a century. Most of these earthquakes occur along the boundaries of tectonic plates and provide the fundamental data to study the physical processes that drive plate tectonics. My research centers on the development of new high-resolution earthquake location algorithms and their application to vast digital seismic archives to study the nature of active faults, the spatio-temporal evolution of seismicity, and the physical processes underlying seismic failure. I am also developing operational real-time procedures that enable high-resolution monitoring of changes in seismic signals and fault properties over time periods of seconds to decades. This has considerable societal and economic impacts in the immediate evaluation and mitigation of seismic hazards, the potential for forecasting future events, and for effective monitoring of compliance with the Comprehensive Nuclear-Test-Ban Treaty.

Education
Ph.D. Geophysics
ETH Zurich
1996
Diploma Geophysics
ETH Zurich
1992
Selected Publications:
Splay faults imaged by fluid-driven aftershocks of the 2004 Mw 9.2 Sumatra-Andaman earthquake, Waldhauser, F.; Schaff, D. P.; Diehl, T.; Engdahl, E. R. Geology, Volume: 40, Issue: 3 p.: 243-246 (2012) doi:10.1130/G32420.1
Seismogenic structure and processes associated with magma inflation and hydrothermal circulation beneath the East Pacific Rise at 9°50'N, Waldhauser, F; Tolstoy, M. Geochem. Geophys. Geosyst., Volume: 12, Issue: Q08T10 (2011) doi:10.1029/2011GC003568
Seismic identification of along-axis hydrothermal flow on the East Pacific Rise, Tolstoy, M.; Waldhauser, F.; Bohnenstiehl, D. R.; Weekly, R. T.; Kim, W. Y. Nature Jan 10, Volume: 451, Issue: 7175 p.: 181-U7 (2008) Doi 10.1038/Nature06424
Large-scale relocation of two decades of Northern California seismicity using cross-correlation and double-difference methods, Waldhauser, F.; Schaff, D. P. Journal of Geophysical Research-Solid Earth Aug 15, Volume: 113, Issue: B8 p.: - (2008) Doi 10.1029/2007jb005479
Regional and teleseismic double-difference earthquake relocation using waveform cross-correlation and global bulletin data, Waldhauser, F.; Schaff, D. Journal of Geophysical Research-Solid Earth Dec 5, Volume: 112, Issue: B12 p.: - (2007) Doi 10.1029/2007jb004938
A narrowly spaced double-seismic zone in the subducting Nazca plate, Rietbrock, A.; Waldhauser, F. Geophysical Research Letters May 22, Volume: 31, Issue: 10 p.: - (2004) Doi 10.1029/2004gl019610
A Double-Difference Earthquake Location Algorithm: Method and Application to the Northern Hayward Fault, Waldhauser, F.; Ellsworth, W. L. Bull. Seism. Soc. Am., Volume: 90 p.: 1353-1368 (2000)
Slip-Parallel Seismic Lineations on the Northern Hayward Fault, California, Waldhauser, F., Ellsworth, W. L.; Cole, A. Geophys. Res. Lett., Volume: 26 p.: 3525-3528 (1999)
Three-dimensional interface modelling with two-dimensional seismic data: the Alpine crust-mantle boundary, Waldhauser, F.; Kissling, E.; Ansorge, J.; Mueller, S. Geophysical Journal International Oct, Volume: 135, Issue: 1 p.: 264-278 (1998)
Michael S. Steckler
Personal Information
Michael
S.
Steckler
Lamont Research Professor
Lamont-Doherty Earth Observatory
Marine Geology and Geophysics
Contact Information
108E Oceanography
61 Route 9W - PO Box 1000
Palisades
NY
10964-8000
US
(845) 365-8479

Fax: 

(845) 365-8156

Fields of interest: 

Tectonics of Sedimentary Basins, Isostasy, Stratigraphic Modeling, Marine Geophysics

Some of projects include:

  • PIRE: Life On A Tectonically-Active Delta: Convergence Of Earth Science And Geohazard Research In Bangladesh With Education And Capacity ( details )
  • Collaborative Research: Uplift and faulting at the transition from subduction to collision - A field and modeling study of the Calabrian Arc ( details )
  • Collaborative Research: Basin Evolution along Continental Transforms: Nested Hi-Resolution Multichannel Survey in the Marmara Sea, Turkey (details)
  • Collision of the Burma Arc accretionary prism with the Ganges-Brahmaputra Delta in Bangladesh
  • Modeling gravity filed and earth deformation from monsoonal flooding in Bangladesh using hydrographic, GRACE and GPS data
  • RAPID: Collaborative Research: Off-Shore Coseismic Effects Of The Port Au Prince Earthquake, Haiti (details)
Education
Ph.D. Thesis: The Thermal and Mechanical Evolution of Atlantic-type Continental Margins.
Columbia University
1981
B.S.
Massachusetts Institute of Technology
1976
Luc Lavier (UTIG)
Dave Reynolds (Exxon)
Selected Publications:
Continental transform basins: Why are they asymmetric?, Seeber, L; Sorlien, C; Steckler, M; Cormier, M-H EOS, Volume: 91, Issue: 4 p.: 29-30 (2010)
Modeling Earth Deformation from Monsoonal Flooding in Bangladesh using Hydrographic, GPS and GRACE Data, Steckler, MS; Nooner, SL; Akhter, SH; Chowdhury, SK; Bettadpur, S; Seeber, L; Kogan, MG J Geophys Res (2010)
Spectroscopy of Sediments in the Ganges-Brahmaputra Delta: Spectral Effects of Moisture, Grain Size and Lithology, Small, C; Steckler, M; Seeber, N; Akhter, H; Goodbred, S; Mia, B; Imam, B Remote Sensing of Environment, Volume: 113 p.: 342-361 (2009)
Imaging the subducted slab beneath the Calabrian Arc, Italy, from receiver function analysis, Piana Agostinetti, N; Steckler, M S; Lucente, F P Lithosphere - GSA Journal , Volume: 1 p.: 131-138 (2009)
Collision of the Ganges-Brahmaputra Delta with the Burma Arc: Implications for earthquake hazard, Steckler, M. S.; Akhter, S. H.; Seeber, L. Earth and Planetary Science Letters Sep 15, Volume: 273, Issue: 3-4 p.: 367-378 (2008) DOI 10.1016/j.epsl.2008.07.009
Modeling of sequence geometry north of Gargano Peninsula by changing sediment pathways in the Adriatic Sea, Steckler, M. S.; Ridente, D.; Trincardi, F. Continental Shelf Research Feb 1, Volume: 27, Issue: 3-4 p.: 526-541 (2007) DOI 10.1016/j.csr.2006.11.007
Seismic anisotropy reveals focused mantle flow around the Calabrian slab (Southern Italy), Baccheschi, P.; Margheriti, L.; Steckler, M. S. Geophysical Research Letters Mar 3, Volume: 34, Issue: 5 p.: - (2007) Doi 10.1029/2006gl028899
Chapter IX: Prediction of margin stratigraphy, Syvitski, J. P. M.; Pratson, L.; Wiberg, P.; Steckler, M.; Garcia, M.; Geyer, R.; Harris, C.; Hutton, E.; Imran, J.; Lee, H.; Morehead; M.; Parker, G. Continental-Margin Sedimentation: Transport to Sequence, Volume: 37 p.: 459-530 (2007)
Won-Young Kim
Personal Information
Won-Young
Kim
Lamont Research Professor
Lamont-Doherty Earth Observatory
Seismology Geology and Tectonophysics
Contact Information
205 Seismology
61 Route 9W - PO Box 1000
Palisades
NY
10964-8000
US
(845) 365-8387

Fax: 

(845) 365-8150

Fields of interest: 

Earthquakes in stable continental regions, regional seismic wave propagation, monitoring underground nuclear explosions, observational seismology

My research interests, to date, have focused on regional seismology -- a broad field where one typically analyzes seismic signals recorded at a few tens of kilometers to a couple thousand kilometers to infer geologic structure of the Earth's upper layers, including the crust, to quantify the seismic sources and their implications on regional tectonics, and to characterize the nature of the seismic sources. The results of the analyses have diverse applications in earth science and they offer important contributions to our society and environment. For example, I analyzed regional seismic signals from earthquakes in Scandinavia to determine regional intraplate stress fields to evaluate earthquake hazard for nuclear power plants and for high-level nuclear waste depository. I analyzed regional signals in Eastern North America and in former Soviet Union to characterize various types of seismic source, which is an important issue in seismic monitoring for compliance of the comprehensive test ban treaty (CTBT).
            I am the director of the Lamont-Doherty Cooperative Seismographic Network (LCSN) project which monitors earthquakes in the northeastern United States for evaluating earthquake hazards in the region and to understand better the occurrence of earthquakes in the stable continetal region. Since the summer of 1994, I have been working with my colleagues at the National Nuclear Center (NNC) of Kazakhstan in installation and operation of eight-station broadband seismographic network and a 21-element seismic array in Kazakhstan. These broadband stations and the array at very quiet sites provide some of the best observational seismic data in the world.    

           In recent years, I studied mechanism of earthquakes in Korea with my colleagues in Korea. 

Education
Ph.D.
Uppsala University, Sweden
04/1986
Diploma di Perfezionamento in Fisica
University of Trieste, Italy
12/1980
Master of Science
Yonsei University, Korea
02/1977
Bachelor of Science
Yonsei University, Korea
02/1973
Selected Publications:
Induced seismicity associated with fluid injection into a deep well in Youngstown, Ohio, Kim, W. Y. Journal of Geophysical Research: Solid Earth, Volume: 118 p.: 1-13 (2013)
Seismic signature, Richards, P. G.; Kim, W. Y. Nature Physics Jan, Volume: 3, Issue: 1 p.: 4-6 (2007) Doi 10.1038/Nphys495
The 9 December 2003 central Virginia earthquake sequence: A compound earthquake in the central Virginia seismic zone, Kim, W. Y.; Chapman, M. Bulletin of the Seismological Society of America Dec, Volume: 95, Issue: 6 p.: 2428-2445 (2005) Doi 10.1785/0120040207
The 18 June 2002 Caborn, Indiana, earthquake: Reactivation of ancient rift in the Wabash Valley seismic zone?, Kim, W. Y. Bulletin of the Seismological Society of America Oct, Volume: 93, Issue: 5 p.: 2201-2211 (2003)
Determination of seismic energy from Lg waves, Shi, J. H.; Richards, P. G.; Kim, W. Y. Bulletin of the Seismological Society of America Apr, Volume: 90, Issue: 2 p.: 483-493 (2000)
The M-L scale in eastern North America, Kim, W. Y. Bulletin of the Seismological Society of America Aug, Volume: 88, Issue: 4 p.: 935-951 (1998)
James Davis
Personal Information
James
Davis
Lamont Research Professor
Lamont-Doherty Earth Observatory
Seismology Geology and Tectonophysics
Contact Information
213 Seismology
61 Route 9W - PO Box 1000
Palisades
NY
10964-8000
US
(845) 365-8425

Fax: 

(845) 365-8150

Positional and physical geodesy using space-based and satellite techniques.  Applications of space geodesy to studies of geophysics, climate, ice sheets, glacier dynamics and kinematics, and the atmosphere. Development and geophysical applications of permanent GPS networks.  Research and development of technology aimed at the improvement of the accuracy of satellite geodetic systems

Education
Ph.D.
Massachusetts Institute of Technology
04/1986
B.S.
Michigan State University
05/1981
Selected Publications:
Spatial and temporal melt variability at Helheim Glacier, East Greenland, and its effect on ice dynamics, Andersen, M. L.; Larsen, T.B; Nettles, M.; Elósegui, P.; van As, D.; Hamilton, G. S.; Stearns, L. A.; Davis, J. L.; Ahlstrøm, A. P.; de Juan, J.; Ekström, G.; Stenseng, L.; Khan, S. A.; Forsberg, R.; Dahl-Jensen, D. J. Geophys. Res., Volume: 115 (2010) 10.1029/2010JF001760
Combination of geodetic observations and models for glacial isostatic adjustment fields in Fennoscandia, Hill, E. M.; Davis, J. L.; Tamisiea, M. E.; Lidberg, M J. Geophys. Res., Volume: 115 (2010) 10.1029/2009JB006967
Geodetic observations and global reference frame contributions to understanding sea-level rise and variability, Blewitt, G.; Altamimi, Z.; Davis, J. L.; Gross, R.; Kuo, C.-Y. ; Lemoine, F. G.; Moore, A. W.; Neilan, R. E.; Plag, H.-P.; Rothacher, M.; Shum, C. K.; Sideris, M. G.; Schöne, T.; Tregoning, P.; Zerbini, S. Understanding Sea-Level Rise and Variability p.: 428 (2010)
Detecting large-scale intracontinental slow-slip events (SSEs) using geodograms, Wernicke, B. P.; Davis, J. L. Seismol. Res. Lett., Volume: 81 p.: 694-698 (2010) 10.1785/gssrl.81.5.694
Sudden increase in tidal response linked to calving and acceleration at a large Greenland outlet glacier, de Juan, J.; Elosegui, P.; Nettles, M.; Larsen, T. B.; Davis, J. L.; Hamilton, G. S.; Stearns, L. A.; Andersen, M. L.; Ekström, G.; Ahlstrøm, A. P.; Stenseng, L.; Khan, S. A.; Forsberg, R. Geophys. Res. Lett., Volume: 37 (2010) 10.1029/2010GL043289
Precise Geodetic Infrastructure: National Requirements for a Shared Resource, Minster, J. B.; Altamimi, Z.; Blewitt, G.; Carter, W. E.; Cazenave, A.; Dragert, H.; Herring, T. A.; Larson, K. M.; Ries, J. C.; Sandwell, D. T.; Wahr, J. M.; Davis, J. L. , Washington, D.C. p.: 156 (2010)
Mikhail G. Kogan
Personal Information
Mikhail
G.
Kogan
Lamont Associate Research Professor
Lamont-Doherty Earth Observatory
Seismology Geology and Tectonophysics
Contact Information
230A Seismology
61 Route 9W - PO Box 1000
Palisades
NY
10964-8000
US
(845) 704-2520

Fax: 

(845) 365-8150

Fields of interest: 

Using space geodesy, specifically GPS, to study plate tectonics and earthquakes at plate boundaries.
Suzanne M. Carbotte
Personal Information
Suzanne
M.
Carbotte
Bruce C. Heezen/Lamont Research Professor
Lamont-Doherty Earth Observatory
Marine Geology and Geophysics
Contact Information
305D Oceanography
61 Route 9W - PO Box 1000
Palisades
NY
10964-8000
US
(845) 365-8895

Fax: 

(845) 365-8156

Fields of interest: 

Marine Geophysics, Mid-Ocean Ridges, Multi-channel seismics, Hudson Estuary

My primary research interests concern the formation of oceanic crust at the global mid-ocean ridge. I make use of a variety of marine geophysical techniques, including reflection seismic studies to image the interior of oceanic crust and acoustic methods to image the seafloor surface of the crust. One focus of my ridge studies is the extensional failure of newly formed crust. Faulting at mid-ocean ridges is one of the primary relief forming processes that shapes the seafloor. Tectonism plays an important role in determining the subsurface architecture of ridge crest hydrothermal systems and is also one of the key drivers of change in these hydrothermal systems. As crust ages and moves away from the ridge by sea-floor spreading, the faults formed near the axis provide conduits for ongoing low-temperature seawater circulation by which chemical exchange between the oceans and the earth's crust continues for millions of years after crustal creation. My current work involves the application of seismic methods to study the alteration of the crust that occurs as a result of these fluid-rock interactions on the Juan de Fuca plate. I have also used comparative studies of fault parameters and brittle strain at ridges spreading at different rates to better understand the processes governing extensional failure on the ridge crest.

The other focus of my ridge research concerns the origin of the segmentation of mid-ocean ridges. Segmentation is linked to both the pattern of melt delivery from the mantle and the thermal structure of the axial lithosphere, and plays an important role in crustal accretion and subsequent disruption by brittle deformation. My research interests include using reflection seismics to image magma chambers beneath ridges and to characterize the relationship between the magmatic segmentation of the crust defined by these magma bodies and morphological segmentation. In recent work characterizing morphological changes along the ridge, I have found that ridge segmentation may be directly related to plate kinematics, resulting from the migration of the plates over the mantle. From analysis of changes in ridge morphology across large discontinuities of the fast and intermediate spreading ridges we find that the shallow and broad ridge segments are consistently leading in the hotspot reference frame. We attribute these relationships to asymmetric mantle upwelling and melt production beneath migrating ridges, with entrainment of melts generated in the upwelling zone of adjacent segments across discontinuities.

In addition to these mid-ocean ridge studies I am also involved in the application of similar marine geophysical techniques to study sedimentary processes and characterize benthic habitats in the near shore setting. Beginning in 1998 I have been involved in a major collaborative effort with researchers at Lamont, SUNY, CUNY and IES to map the Hudson River estuary. With funding from the New York State DEC, we completed mapping the entire length of the Hudson from the New York Harbor to the Troy Dam in 2004. Our maps of the river bottom reveal a fascinating record of human activities within the Hudson Valley over the past several hundred years. My particular interests in this project are the evolution of the river during the Holocene and the linkages between rising sea-level and climate fluctuations with the changing faunal populations documented in the river sediments.

Some of projects include:

  • Marine Geoscience Data Management System ( details )
  • Hudson River Benthic Mapping Project ( details )


Education
Ph.D.
University of California
1992
MSc
Queen's University, Kingston, Canada
1986
HBSc
University of Toronto, Canada
1982
Janet Baran
Delwayne Bohnenstiehl
Gustavo Correa
Angela Slagle
Selected Publications:
Seismic reflection images of a near-axis melt sill within the lower crust at the Juan de Fuca Ridge, Canales J P; Nedimovi, M R; Kent G; Carbotte, SM; Detrick, R S Nature, Volume: 460 p.: 89-93 (2009)
Variable crustal structure along the Juan de Fuca Ridge: Influence of on-axis hot spots and absolute plate motions, Carbotte, S. M.; Nedimovic, M. R.; Canales, J. P.; Kent, G. M.; Harding, A. J.; Marjanovic, M. Geochemistry Geophysics Geosystems Aug 2, Volume: 9 p.: - (2008) Doi 10.1029/2007gc001922
Rift topography linked to magmatism at the intermediate spreading Juan de Fuca Ridge, Carbotte, S. M.; Detrick, R. S.; Harding, A.; Canales, J. P.; Babcock, J.; Kent, G.; Van Ark, E.; Nedimovic, M.; Diebold, J. Geology Mar, Volume: 34, Issue: 3 p.: 209-212 (2006)
Frozen magma lenses below the oceanic crust, Nedimovic, M. R.; Carbotte, S. M.; Harding, A. J.; Detrick, R. S.; Canales, J. P.; Diebold, J. B.; Kent, G. M.; Tischer, M.; Babcock, J. M. Nature Aug 25, Volume: 436, Issue: 7054 p.: 1149-1152 (2005) Doi 10.1038/Nature03944
Environmental change and oyster colonization within the Hudson River estuary linked to Holocene climate, Carbotte, S. M.; Bell, R. E.; Ryan, W. B. F.; McHugh, C.; Slagle, A.; Nitsche, F.; Rubenstone, J. Geo-Marine Letters Nov, Volume: 24, Issue: 4 p.: 212-224 (2004) DOI 10.1007/s00367-004-0179-9
The influence of ridge migration on the magmatic segmentation of mid-ocean ridges, Carbotte, S. M.; Small, C.; Donnelly, K. Nature Jun 17, Volume: 429, Issue: 6993 p.: 743-746 (2004) Doi 10.1038/Nature02652
Variability of Ocean Crustal Structure Created Along the Global Midocean Ridge, Carbotte, S.;Scheirer, D. S. Hydrogeology of the Oceanic Lithosphere (2004)
James Gaherty
Personal Information
James
Gaherty
Lamont Research Professor
Lamont-Doherty Earth Observatory
Seismology Geology and Tectonophysics
Lecturer
Earth and Environmental Sciences
Associate Director - Seismology, Geology and Tectonophysics
Lamont-Doherty Earth Observatory
Contact Information
108G Seismology
61 Route 9W - PO Box 1000
Palisades
NY
10964-8000
US
(845) 365-8450

Fax: 

(845) 365-8150

Fields of interest: 

Earthquake Seismology, Geodynamics

The surface of the Earth is constantly deforming, over time scales ranging from seconds to eons, and spatial scales ranging from centimeters to thousands of kilometers. This deformation fundamentally impacts human life by generating natural hazards such as earthquakes and volcanoes, as well as by modulating our natural environment and climate. The underlying cause of this deformation is convection in the Earths mantle, the large-scale circulation pattern where hot material is constantly cycled to the surface, where it cools and then sinks. In my research, I utilize seismic images of the Earths deep interior to gain a better understanding of mantle convection and its effect on Earths surface. This effort often requires collecting new seismic data in field locations ranging from the mountain peaks of far northwestern Canada, to the newly formed seafloor in the Gulf of California.

Education
Ph.D. Geophysics
Massachusetts Institute of Technology
1995
M.S. Geology
University of Michigan
1990
B.S. Geophysics
Brown University
1986
Selected Publications:
Seismic velocity structure and depth-dependence of anisotropy in the Red Sea and Arabian shield from surface wave analysis, Hansen, S. E.; Gaherty, J. B.; Schwartz, S. Y.; Rodgers, A. J.; Al-Amri, A. M. S. Journal of Geophysical Research-Solid Earth Oct 14, Volume: 113, Issue: B10 p.: - (2008) Doi 10.1029/2007jb005335
The teleseismic signature of fossil subduction: Northwestern Canada, Mercier, J. P.; Bostock, M. G.; Audet, P.; Gaherty, J. B.; Garnero, E. J.; Revenaugh, J. Journal of Geophysical Research-Solid Earth Apr 29, Volume: 113, Issue: B4 p.: - (2008) Doi 10.1029/2007jb005127
Evaluating hot spot-ridge interaction in the Atlantic from regional-scale seismic observations, Gaherty, J. B.; Dunn, R. A. Geochemistry Geophysics Geosystems May 11, Volume: 8 p.: - (2007) Doi 10.1029/2006gc001533
Surface wave tomography of the upper mantle beneath the Reykjanes Ridge with implications for ridge-hot spot interaction, Delorey, A. A.; Dunn, R. A.; Gaherty, J. B. Journal of Geophysical Research-Solid Earth Aug 24, Volume: 112, Issue: B8 p.: - (2007) Doi 10.1029/2006jb004785
Upper mantle structure beneath the eastern Pacific Ocean ridges, Gu, Y. J.; Webb, S. C.; Lerner-Lam, A.; Gaherty, J. B. Journal of Geophysical Research-Solid Earth Jun 11, Volume: 110, Issue: B6 p.: - (2005) Doi 10.1029/2004jb003381
Mantle defomation during slow seafloor spreading constrained bv observations of seismic anisotropy in the western Atlantic, Gaherty, J. B.; Lizarralde, D.; Collins, J. A.; Hirth, G.; Kim, S. Earth and Planetary Science Letters Dec 15, Volume: 228, Issue: 3-4 p.: 255-265 (2004) DOI 10.1016/j.epsl.2004.10.026
Spreading-rate dependence of melt extraction at mid-ocean ridges from mantle seismic refraction data, Lizarralde, D.; Gaherty, J. B.; Collins, J. A.; Hirth, G.; Kim, S. D. Nature Dec 9, Volume: 432, Issue: 7018 p.: 744-747 (2004) Doi 10.1038/Nature03140
A surface wave analysis of seismic anisotropy beneath eastern North America, Gaherty, J. B. Geophysical Journal International Sep, Volume: 158, Issue: 3 p.: 1053-1066 (2004) DOI 10.1111/j.1365-246X.2004.02371.x
Structure of the Kaapvaal craton from surface waves, Freybourger, M.; Gaherty, J. B.; Jordan, T. H.; Grp, Kaapvaal Seismic Geophysical Research Letters Jul 1, Volume: 28, Issue: 13 p.: 2489-2492 (2001)
Seismic evidence for hotspot-induced buoyant flow beneath the Reykjanes Ridge, Gaherty, J. B. Science Aug 31, Volume: 293, Issue: 5535 p.: 1645-1647 (2001)
Bruce E. Shaw
Personal Information
Bruce
E.
Shaw
Lamont Research Professor
Lamont-Doherty Earth Observatory
Seismology Geology and Tectonophysics
Contact Information
111 Seismology
61 Route 9W - PO Box 1000
Palisades
NY
10964-8000
US
(845) 365-8380

Fax: 

(845) 365-8150

Pages