Geophysical constraints on the subseafloor environment near mid-ocean ridges

Geophysical Monograph Series

Volumn 144, Issue , 2004, Pages 51-74

  Wilcock, Williams S D ^a   Fisher, Andrew T ^b  

^a UNIVERSITY OF WASHINGTON   (United States)

^b University of California   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 17044432507     PISSN: 00658448     EISSN: 23288779     Source Type: Book Series    
DOI: 10.1029/144GM05     Document Type: Chapter

References (130)

1. Baker, E.T., Y.J. Chen, and J. Phipps Morgan, The relationship between near-axis hydrothermal cooling and the spreading rate of mid-ocean ridges, Earth. Planet. Sci. Lett., 142, 137-145, 1996.
2. Baker, E.T., C.R. German, and H. Elderfield, Hydrothermal plumes over spreading-center axes: Global distributions and geological inferences, in Seafloor Hydrothermal Systems, edited by S.E. Humphris, R.A. Zierenberg, L.S. Mullineaux, and R.E. Thompson, pp. 47-71, American Geophysical Union, Washington DC, 1995.
3. Baker, E.T., G.J. Massoth, and R.A. Feely, Cataclysmic hydrothermal venting on the Juan de Fuca Ridge, Nature, 329, 149-151, 1987.
4. Barclay, A.H., and D.R. Toomey, Shear wave splitting and crustal anisotropy at the Mid-Atlantic Ridge, 35°N, J. Geophys. Res., in press, 2003.
5. Bear, J., Dynamics of fluids in porous media, 764 pp., American Elsevier, New York, 1972.
6. Becker, K., In situ determinations of the permeability of igneous oceanic crust, in Hydrogeology of the Oceanic Lithosphere, edited by E.E. Davis, and H. Elderfield, in press, Cambridge University Press, Cambridge, UK, 2004.
7. Becker, K., and A.T. Fisher, Permeability of upper oceanic basement on the eastern flank of the Juan de Fuca Ridge determined with drill-string packer experiments, J. Geophys. Res., 105, 879-912, 2000.
8. Becker, K., M. Langseth, R.P. Von Herzen, and R. Anderson, Deep crustal geothermal measurements, Hole 504B, Costa Rica Rift, J. Geophys. Res., 88, 3447-3457, 1983.
9. Becker, K., R.P. Von Herzen, J. Kirklin, R. Evans, D. Kadko, M. Kinoshita, O. Matsubayashi, R. Mills, A. Schultz, and P. Rona, Conductive heat flow at the TAG active hydrothermal mound: results from 1993-1995 submersible surveys, Geophys. Res. Lett., 23, 3463-3466, 1996.
10. Bischoff, J.L., and R.J. Rosenbauer, Salinity variations in submarine hydrothermal systems by layered double-diffusive convection, J Geol., 97, 613-623, 1989.
11. Bradley, A.M., D.R. Yoerger, H. Cormier, W.B. Ryan, and B.B. Walden, High resolution mapping of a fast spreading mid-ocean ridge with the autonomous benthic explorer, Eos Trans. AGU, 80, Fall Meeting Suppl., Abstract V11A-01, 1999.
12. Butterfield, D.A., I.R. Jonasson, G.J. Massoth, R.A. Feely, K.K. Roe, R.E. Embley, J.F. Holden, R.E. McDuff, M.D. Lilley, and J.R. Delaney, Seafloor eruptions and evolution of hydrothermal fluid chemistry, Philos. Trans. R. Soc. London, Ser. A, 355, 369-386, 1997.
13. Butterfield, D.A., R.E. McDuff, M.J. Mottl, M.D. Lilley, J.E. Lupton, and G.J. Massoth, Gradients in the composition of hydrothermal fluids from the Endeavour segment vent field: Phase separation and brine loss,J. Geophys. Res., 99, 9561-9583, 1994.
14. Carbotte, S.M., R. Detrick, G. Kent, J.R Canales, J. Diebold, A. Harding, M. Nedimovic, D. Epstein, I. Cochran, E. van Ark, J. Dingier, and A. Jacobs, A multichannel seismic investigation of ridge crest and ridge flank structure along the Juan de Fuca Ridge, Eos Trans. AGU, 83 (47), Fall Meet. Suppl., Abstract T72C-07, 2002.
15. Carlson, R.L., Se ismic velocities in the uppermost oceanic crust: age dependence and the fate of layer 2A, J. Geophys. Res., 103, 7069-7077, 1998.
16. Carson, R.L., and C.N. Herrick, Densities and porosities in the oceanic crust and their variation with depth and age, J. Geophys. Res., 95,9153-9170, 1990.
17. Chave, A.S., S.C. Constable, and R.N. Edwards, Electrical exploration methods for the seafloor, in Electromagnetic Methods in Applied Geophysics, vol. 2, Applications, edited by M. Nabighian, pp. 931-966, Society of Exploration Geophysicists, Tulsa, Oklahoma, 1991.
18. Chen, Y., and W.J. Morgan, A nonlinear rheology model for mid-ocean ridge axis topography, J. Geophys. Res., 95, 17583-17604, 1990.
19. Chen, Y.J., Thermal effects of gabbro accretion from a deeper second melt lens at the fast spreading East Pacific Rise, J. Geophys. Res., 106, 8581-8588, 2001.
20. Cherkaoui, A.S.M., W.S.D. Wilcock, R.A. Dunn, and D.R. Toomey, A numerical model of hydrothermal cooling and crustal accretion at a fast spreading mid-ocean ridge, Geochem. Geophys. Geosyst., 4(9), 8616, doi:10.1029/2001GC000215, 2003.
21. Christeson, G.L., G.M. Purdy, and G.J. Fryer, Seismic constraints on shallow crustal emplacement processes at the fast spreading East Pacific Rise, J. Geophys. Res., 99, 17957-17973, 1994.
22. Clauser, C., Permeability of crystalline rocks, Eos Trans. AGU, 73, 233, 237-238, 1992.
23. Cochran, J.R., and W.R. Buck, Near-axis subsidence rates, hydrothermal circulation and the thermal structure of mid-ocean ridge crests,J. Geophys. Res., 106, 19233-19258, 2001.
24. Crawford, W.C., and S.C. Webb, Variations in the distribution of magma in the lower crust and at the Moho beneath the East Pacific Rise at 9°-10°N, Earth Planet Sci. Lett., 203, 117-130, 2002.
25. Davis, E., and K. Becker, Borehole observations record driving forces for hydrothermal circulation in young oceanic crust, Eos Trans. AGU, 79 (31), 369, 377-378, 1998.
26. Davis, E., and K. Becker, Tidal pumping of fluids within and from the oceanic crust: new observations and opportunities from sampling the crustal hydrosphere, Earth Planet. Sci. Lett., 172, 141-149, 1999.
27. Davis, E.E., and K. Becker, Observations of temperature and pressure: Constraints on oceanic crustal hydrologic state, properties and flow, in Hydrogeology of the Oceanic Lithosphere, edited by E.E. Davis, and H. Elderfield, in press, Cambridge University Press, Cambridge, UK, 2004.
28. Davis, E.E., D.S. Chapman, K. Wang, H. Villinger, A.T. Fisher, S.W. Robinson, J. Grigel, D. Pribnow, J. Stein, and K. Becker, Regional heat-flow variations across the sedimented Juan de Fuca Ridge eastern flank: Constraints on lithospheric cooling and lateral hydrothermal heat transport, J. Geophys. Res., 104, 17675-17688, 1999.
29. Davis, E.E., W. Wang, K. Becker, and R.E. Thompson, Formation-scale hydraulic and mechanical properties of oceanic crust inferred from pore pressure response to periodic seafloor loading, J. Geophys. Res., 105, 13423-13435, 2000.
30. Davis, E.E., W. Wang, R.E. Thomson, K. Becker, and J.F. Cassidy, An episode of seafloor spreading and associated plate deformation inferred from crustal fluid pressure transients, J. Geophys. Res., 106, 21953-21963, 2001.
31. Delaney, J.R., D.S. Kelley, M.D. Lilley, D.A. Butterfield, J.A. Baross, W.S.D. Wilcock, R.W. Embley, and M. Summit, The quantum event of oceanic crustal accretion: Impacts of diking at mid-ocean ridges, Science, 281, 222-230, 1998.
32. Delaney, J.R., V. Robigou, R.E. McDuff, and M.K. Tivey, Geology of a vigorous hydrothermal system on the Endeavour segment, Juan de Fuca Ridge, J. Geophys. Res., 97, 19663-19682, 1992.
33. Detrick, R.S., P. Buhl, E. Vera, J. Mutter, J. Orcutt, J. Madsen, and T. Brocher, Multichannel seismic imaging of a crustal magma chamber along the East sPacific Rise, Nature, 326, 35-41, 1987.
34. Detrick, R.S., S. Carbotte, E.V. Ark, J.P. Canales, G. Kent, A. Harding, J. Diebold, and M. Nedimovic, New multichannel seismic constraints on the crustal structure of the Endeavour segment, Juan de Fuca Ridge: Evidence for a crustal magma chamber, Eos Trans. AGU, 83 (47), Fall Meet. Suppl., Abstract T12B-1316, 2002.
35. Dickson, P., A. Schultz, and A. Woods, Preliminary modeling of hydrothermal circulation within mid-ocean ridge sulfide structures, Geol. Soc. Lond. Spec. Pub., 87, 145-157, 1995.
36. Dunn, R.A., and D.R. Toomey, Crack-induced seismic anisotropy in the oceanic crust across the East Pacific Rise (9°30'N), Earth Planet Sci. Lett., 189, 9-17, 2001.
37. Dunn, R.A., D.R. Toomey, and S.C. Solomon, Three-dimensional seismic structure and physical properties of the crust and shallow mantle beneath the East Pacific Rise at 9°30'N, J. Geophys. Res., 105, 23537-23555, 2000.
38. Dziak, R.P., and H.P. Johnson, Stirring the oceanic incubator, Science, 296, 1406-1407, 2002.
39. Elderfield, H., C.G. Wheat, M.J. Mottl, C. Monnin, and B. Spiro, Fluid and geochemical transport through oceanic crust: a transect across the eastern flank of the Juan de Fuca Ridge, Earth Planet Sci. Lett., 172, 151-165, 1999.
40. Evans, R.L., Constraints on the large-scale porosity and permeability structure of young oceanic crust from velocity and resistivity data., Geophys. J. Int., 119, 869-79, 1994.
41. Evans, R.L., A seafloor gravity profile across the TAG hydrothermal mound, Geophys. Res. Lett, 23, 3447-3450, 1996.
42. Evans, R.L., S.C. Webb, M. Jegen, and K. Sananikone, Hydrothermal circulation at the Cleft-Vance overlapping spreading center: Results of a magnetometric resistivity survey, J. Geophys. Res., 103, 12321-12338, 1998.
43. Evans, R.L., S.C. Webb, and RIFT-UMC Team, Crustal resistivity structure at 9°50'N on the East Pacific Rise: Results of an electromagnetic survey, Geophys. Res. Lett, 29, 1082, doi; 10.1029/2001GL014106, 2002.
44. Fisher, A.T., Permeability within basaltic oceanic crust, Rev. Geophys., 36, 143-182, 1998.
45. Fisher, A.T., and K. Becker, Channelized fluid flow in oceanic crust reconciles heat-flow and permeability data, Nature, 403, 71-74, 2000.
46. Fisher, A.T., E.E. Davis, M. Hutnak, V. Spiess, L. Ziihlsdorff, A. Cherkaoui, L. Christiansen, K. M. Edwards, R. Macdonald, H. Villinger, M.J. Mottl, C.G. Wheat, and K. Becker, Hydrothermal recharge and discharge across 50 km guided by seamounts on a young ridge flank, Nature, 421, 618-621, 2003.
47. Fomari, D.J., R.M. Haymon, M.R. Perfit, T.K.P. Gregg, and M.H. Edwards, Axial summit trough of the East Pacific Rise 9°-10°: Geological characteristics and evolution of the axial zone on fast spreading mid-ocean ridges, J. Geophys. Res., 103, 9827-9855, 1998a.
48. Fomari, D.J., T. Shank, K.L. Von-Damm, T.K.P. Gregg, M. Lilley, G. Levai, A. Bray, R.M. Haymon, M.R. Perfit, and R. Lutz, Time series temperature measurements at high temperature hydrothermal vents, East Pacific Rise 9° 49,-51TST; Evidence for monitoring a crustal cracking event., Earth Planet Sci. Lett., 160, 419-431, 1998b.
49. Fox, C.G., Special collection on the June 1993 volcanic eruption on the Co Axial segment, Juan de Fuca Ridge, Geophys. Res. Lett., 22, 129-130, 1995.
50. Fujimoto, H., N. Seama, J. Lin, T. Matsumoto, T. Tanaka, and K. Fujioka, Gravity anomalies of the Mid-Atlantic Ridge north of Kane Fracture Zone, Geophys. Res. Lett., 23, 3421-3434, 1996.
51. Gelhar, L., and C.L. Axness, Three-dimensional stochastic analysis of macrodispersion in aquifers, Wat. Resour. Res., 19, 161-180, 1983.
52. Gregory, R. T., and H. P. Taylor, An oxygen isotope profile in a section of Cretaceous oceanic crust, Samail ophiolite, Oman: Evidence for DlsO buffering of oceans by deep (>5 km) seawater-hydrothermal circulation at mid-ocean ridges, J. Geophys. Res., 86, 2737-2755, 1981.
53. Hannington, M.D., A.G. Galley, P.M. Herzig, and S. Petersen, Comparison of the TAG mound and stockwork complex with Cyprus-type massive sulfide deposits, in Proceedings of the Ocean Drilling Program, scientific results, Leg 158, edited by P.M. Herzig, S.E. Humphris, D.J. Miller, and R.A. Zierenberg, pp. 389-417, Ocean Drilling Program, College Station, TX, 1998.
54. Haymon, R.M., The response of ridge-crest hydrothermal systems to segmented episodic magma supply, in Tectonic, magmatic, hydrothermal, and biological segmentation of mid-ocean ridges, edited by C.J. MacLeod, P.A. Tyler, and C.L. Walker, pp. 157-168, 1996.
55. Haymon, R.M., D.J. Fomari, M.H. Edwards, S. Carbotte, D. Wright, and K.C. Macdonald, Hydrothermal vent distribution along the East Pacific Rise crest (9°09'-54'N) and its relationship to magmatic and tectonic processes on fast-spreading mid-ocean ridges, Earth Planet. Sci. Lett., 102, 513-534, 1991.
56. Haymon, R.M., D.J. Fomari, K.L. Von Damm, M.D. Lilley, M.R. Perfit, J.M. Edmond, W.C. Shanks III, R.A. Lutz, J.M. Grebmeier, Carbotte S., D. Wright, E. McLaughlin, M. Smith, B.N., and E. Olson, Volcanic eruption of the mid-ocean ridge along the East Pacific Rise crest at 9°45-52'N: Direct submersible observations of seafloor phenomena associated with an eruption event in April, 1991, Earth Planet. Sci. Lett., 119, 85-101, 1993.
57. Herzig, P.M., S.E. Humphris, D. J. Miller, and R.A. Zierenberg (Eds.), Proc. ODP, Sci. Res., Leg 158, 427 pp., Ocean Drilling Program, College Station, TX, 1998.
58. Holmes, M.L., and H.P. Johnson, Upper crustal densities derived from bottom gravity measurements: Northern Juan de Fuca Ridge, Geophys. Res. Lett., 20, 1871-1874, 1993.
59. Houtz, R., and J. Ewing, Upper crustal structure as a function of plate age, J. Geophys. Res., 81, 2490-2498, 1976.
60. Humphris, S.E., and J.R. Cann, Constraints on the energy and chemical balances of the modem TAG and ancient Cyprus seafloor sulfide deposits, J. Geophys. Res., 105, 28477-28488, 2000.
61. Humphris, S.E., and M.K. Tivey, A synthesis of geological and geochemical investigations of the TAG hydrothermal field: Insights into fluid flow and mixing processes in the hydrothermal system, in Ophiolites and oceanic crust: New insights from field studies and the Ocean Drilling Program, edited by Y. Dilek, E.M. Moores, D. Elthon, and A. Nicolas, pp. 213-239, Geological Society of America, Boulder, Colorado, 2000.
62. Ingebritsen, S.E., and W.E. Sanford, Groundwater in Geological Processes, 341 pp., Cambridge University Press, Cambridge, United Kingdom, 1998.
63. Jacobson, R.S., The impact of crustal evolution on changes of the seismic properties of the uppermost ocean crust, Rev. Geophys., 30, 23-42, 1992.
64. Johnson, H.P., K. Becker, and R. Von Herzen, Near-axis heat flow measurements on the northern Juan de Fuca Ridge: Implications for fluid circulation in oceanic crust, Geophys. Res. Lett., 20, 1875-1878, 1993.
65. Johnson, H.P., and M. Hutnak, Conductive heat loss in recent eruptions at mid-ocean ridges, Geophys. Res. Lett., 24, 3089-3092, 1997.
66. Johnson, H.P., M. Hutnak, R.P. Dziak, C.G. Fox, I. Urcuyo, J.P. Cowen, J. Nabalek, and C. Fisher, Earthquake-induced changes in a hydrothermal system on the Juan de Fuca Ridge mid-ocean ridge, Nature, 407, 174-177, 2000a.
67. Johnson, H.P., M.J. Pruis, D. Van Patten, and M.A. Tivey, Density and porosity of the upper oceanic crust from seafloor gravity measurements, Geophys Res. Lett., 27, 1053-1056, 2000b.
68. Jupp, T.E., Fluid flow processes at mid-ocean ridge hydrothermal systems, PhD thesis, Cambridge University, England, 2000.
69. Karson, J.A., and P.A. Rona, Block-tilting, transfer faults, and structural control of magmatic and hydrothermal processes in the TAG area, Mid-Atlantic Ridge 26°N, Geol. Soc. Am. Bull., 102, 1635-1645, 1990.
70. Karsten, J.L., S.R. Hammond, E.E. Davis, and R.G. Currie, Detailed geomorphology and neotectonics of the Endeavour segment, Juan de Fuca Ridge: New results from Seabeam swath mapping, Geol. Soc. Am. Bull., 97, 213-221, 1986.
71. Kent, G.M., A.J. Harding, and J.A. Orcutt, Distribution of magma beneath the East Pacific Rise between the Clipperton Transform and the 9°17'N Deval from forward modeling of common depth point data, J. Geophys. Res., 98, 13945-13969, 1993.
72. Kleinrock, M.C., and S.E. Humphris, Structural control on seafloor hydrothermal activity at the TAG active mound, Nature, 382, 149-153, 1996.
73. Kong, L.S.L., S.C. Solomon, and G.M. Purdy, Microearthquake characteristics of a mid-ocean ridge along-axis high, J. Geophys. Res., 91, 1659-1685, 1992.
74. Lilley, M.D., D.A. Butterfield, E.J. Olson, J.E. Lupton, S.A. Macko, and R.E. McDuff, Anomalous CH4 and NH4+ concentrations at an unsedimented mid-ocean ridge hydrothermal system, Nature, 364, 45-47, 1993.
75. Lilley, M.D., D.A. Butterfield, J.E. Lupton, and E.J. Olson, Magmatic events can produce rapid changes in hydrothermal vent chemistry, Nature, 422, 878-881, 2003.
76. Lister, C.R.B., On the penetration of water into hot rock, Geophys. J. R. Astron. Soc., 39, 465-509, 1974.
77. Lister, C.R.B., The basic physics of water penetration into hot rocks, in Hydrothermal Processes at Seafloor Spreading Centers, edited by P.A. Rona, K. Bostrom, L. Laubier, and K.L. Smith, Jr., pp. 141-168, Plenum, New York, 1983.
78. Lowell, R.P., and L.N. Germanovich, On the temporal evolution of high-temperature hydrothermal systems at ocean ridge crests, J. Geophys. Res., 99, 565-575, 1994.
79. Lowell, R.P., P.A. Rona, and R.P. Von Herzen, Seafloor hydrothermal systems, J. Geophys. Res., 100, 327-352, 1995.
80. Lowell, R.P., and W. Xu, Sub-critical two-phase seawater convection near a dike, Earth Planet. Sci. Lett., 174, 385-396, 2000.
81. Lowell, R.P., and Y. Yao, Anhydrite precipitation and the extent of hydrothermal recharge zones at ocean ridge crests, J. Geophys. Res., 107, 2183, doi:10.1029/2001JB001289, 2002.
82. Luyendyk, B. P., On-bottom gravity profile across the East Pacific Rise crest at 21°N, Geophysics, 49, 2166-2177, 1984.
83. Macdonald, K.C., Linkages between faulting, volcanism, hydrothermal activity and segmentation on fast spreading centers, in Faulting and magmatism at mid-ocean ridges, edited by W.R. Buck, P.T. Delaney, J.A. Karson, and Y. Lagabrielle, pp. 27-58, AGU, Washington, D.C., 1998.
84. Manning, C.E., C.J. MacLeod, and P.E. Weston, Lower crustal cracking front at fast-spreading ridges: evidence from the East Pacific Rise and Oman ophiolite, in Ophiolites and Oceanic Crust: New Insights from Field Studies and the Ocean Drilling Program, edited by Y. Dilek, E. Moores, D. Elthon, and A. Nicolas, pp. 261-272, Geological Society of America, Boulder, Colorado, 2000.
85. McCollom, T.M., and E.L. Shock, Fluid-rock interactions in the lower oceanic crust: Thermodynamic models of hydrothermal alteration, J. Geophys. Res., 103, 547-575, 1998.
86. McDuff, R.E., Physical dynamics of deep-sea hydrothermal plumes, in Seafloor Hydrothermal Systems, edited by S.E. Humphris, R.A. Zierenberg, L.S. Mullineaux, and R.E. Thomson, pp. 357-368, AGU, Washington, D.C., 1995.
87. McDuff, R.E., J.R. Delaney, M.D. Lilley, and D.A. Butterfield, Are up flow zones boundaries between adjacent hydrothermal systems?, Eos Trans. AGU, 75, Fall Meeting Suppl., 618, 1994.
88. MacGregor, L.M., S.C. Constable, and M.C. Sinha, The RAMESSES experiment; III, Controlled-source electromagnetic sounding of the Reykjanes Ridge at 57“45'N., Geophys J. Int., 135, 773-789, 1998.
89. McGregor, B.A., C.G.A. Harrison, J.W. Lavelle, and P.A. Rona, Magnetic anomaly pattern on the Mid-Atlantic Ridge crest at 26°N, J. Geophys. Res., 82, 231-238, 1977.
90. Meyer, P.S., and W.B. Bryan, Petrology of basaltic glasses from the TAG segment: implications for deep hydrothermal heat source, Geophys. Res. Lett., 23, 3435-3438, 1996.
91. Moreno, L., and C.-F. Tsang, Flow channeling in strongly heterogeneous porous media: a numerical study, Wat. Resour. Res., 30, 1421-1430, 1994.
92. Noel, M., and M.W. Hounslow, Heat flow evidence for hydrothermal convection in Cretaceous crust of the Madiera Abyssal Plain, Earth Planet Sci. Lett., 90, 77-86, 1988.
93. Novakowski, K.S., P.A. Lapcevic, J. Voralek, and G. Bickerton, Preliminary interpretation of tracer experiments conducted in a discrete rock fracture under conditions of natural flow, Geophys. Res. Lett., 22, 1417-1420, 1995.
94. Oberlander, P.L., Fluid density and gravitational variations in deep boreholes and their effect on fluid potential, Ground Water, 27, 341-350, 1989.
95. Palmer, M.R., and G.G.J. Ernst, Generation of hydrothermal megaplumes by cooling of pillow basalts at mid-ocean ridges, Nature, 393, 643-647, 1998.
96. Perfit, M.R., and W.W. Chadwick Jr., Magmatism at mid-ocean ridges: Constraints from volcanological and geochemical investigations, in Faulting and magmatism at mid-ocean ridges, edited by W.R. Buck, P.T. Delaney, J.A. Karson, and Y. Lagabrielle, American Geophysical Union, Washington, D.C., 1998.
97. Phipps Morgan, J., and Y.J. Chen, The genesis of oceanic crust: Magma injection, hydrothermal circulation, and crustal flow, J. Geophys. Res., 98, 6283-6297, 1993.
98. Phipps Morgan, J., A. Harding, J. Orcutt, G. Kent, and Y.J. Chen, An observational and theoretical synthesis of magma chamber geometry and crustal genesis along a mid-ocean ridge spreading center, in Magmatic Systems, edited by M. P. Ryan, pp. 139-178, Academic Press, San Diego, CA, 1994.
99. Purdy, M., J.C. Sempere, H. Schouten, D.L. Dubois, and R. Goldsmith, Bathymetry of the Mid-Atlantic Ridge, 24°-31°N, Map Series, Mar. Geophys. Res., 12, 247-252, 1990.
100. Raitt, R.W., The crustal rocks, in The Sea, Vol. 3, The Earth Beneath the Sea History, edited by M.N. Hill, pp. 85-102, John Wiley, New York, 1963.
101. Rohr, K.M.M., and K.P. Furlong, Ephemeral plate tectonics at the Queen Charlotte triple junction, Geology, 23, 1035-1038, 1995.
102. Rohr, K.M.M., B. Milkereit, and C.J. Yorath, Asymmetric deep crustal structure across the Juan de Fuca Ridge, Geology, 16, 533-537, 1988.
103. Rona, P.A., M.D. Hannington, C.V. Raman, G. Thompson, M.K. Tivey, S.E. Humphris, C. Lalou, and S. Petersen, Active and relict seafloor hydrothermal mineralization at the TAG hydrothermal field, Mid-Atlantic Ridge, Econ. Geol., 88, 1989-2017, 1993.
104. Salisbury, M.H., N.I. Christensen, and R.H. Wilkens, Nature of the layer 2/3 transition from a comparison of laboratory and logging velocities and petrology at the base of Hole 504B, in Proc. ODP, Sci. Res., Leg 148, edited by J.C. Alt, H. Kinoshita, and L. Stokking, pp. 353-363, Ocean Drilling Program, College Station, Texas, 1996.
105. Schoofs, S., and U. Hansen, Depletion of a brine layer at the base of ridge-crest hydrothermal systems, Earth Planet Sci. Lett., 180, 341-353, 2000.
106. Schultz, A., R. Dickson, and H. Elderfield, Temporal variations in diffuse hydrothermal flow at TAG, Geophys. Res. Lett., 23, 3471-3474, 1996.
107. Sclater, J.G., C. Jaupart, and D. Galson, The heat flow through oceanic and continental crust and the heat loss of the earth, Rev. Geophys. Space Phys., 18, 269-311, 1980.
108. Sohn, R.A., D.J. Fomari, K.L. Von Damm, J.A. Hildebrand, and S.C. Webb, Seismic and hydrothermal evidence for a cracking event on the East Pacific rise crest at 9° 50' N, Nature, 396, 159-161, 1998.
109. Stahr, F.R., R.E. McDuff, S.R. Veirs, D.R. Yoerger, and A.M. Bradley, Vertical heat flux from the Main Endeavour Vent Field on the Juan de Fuca Ridge, Geochem. Geophys. Geosyst., submitted, 2003.
110. Stein, C., and S. Stein, Constraints on hydrothermal heat flux through the oceanic lithosphere from global heat flow, J. Geophys. Res., 99, 3081-3095, 1994.
111. Tivey, M.A., and H.P. Johnson, High-resolution geophysical studies of oceanic hydrothermal systems, Rev. Aquat. Sci., 1, 473-496, 1989.
112. Tivey, M.A., and H.P. Johnson, High-resolution geophysical mapping of the hydrothermal vent systems at Endeavour Ridge, Juan de Fuca (abstract), Eos Trans. AGU, 82 (47), Fall Meet Suppl., Abstract OS21B-0440, 2001.
113. Tivey, M.K., et al., The RIDGE Endeavour segment seafloor observatory: Recent successes and an overview of coordinated experiments for Y2K, RIDGE Events, 11 (1), 10-17, 2001.
114. Toomey, D.R., G.M. Purdy, S. C. Solomon, and W.S.D. Wilcock, The three-dimensional seismic velocity structure of the East Pacific Rise near latitude 9°30'N, Nature, 347, 639-645, 1990.
115. Toomey, D.R., S.C. Solomon, and G.M. Purdy, Tomographic imaging of the shallow crustal structure of the East Pacific Rise at 9°30'N, J. Geophys. Res., 99, 24135-24157, 1994.
116. Toomey, D.R., S.C. Solomon, G.M. Purdy, and M.H. Murray, Microearthquakes beneath the median valley of the Mid-Atlantic Ridge near 23°N: Hypocenters and focal mechanisms, J. Geophys. Res., 90, 5443-5458, 1985.
117. Tsang, C.F., and I. Neretnieks, Flow channeling in heterogeneous fractured rocks, Rev. Geophys., 36, 275-298, 1998.
118. Tsang, C.-F., Y.W. Tsang, and F.V. Hale, Tracer transport in fractures: analysis of field data based on a variable-aperture channel model, Wat. Resour. Res., 27, 3095-3106, 1991.
119. Tucholke, B.E., J. Lin, M.C. Kleinrock, M.A. Tivey, T.B. Reed, J. Goff, and G.E. Jaroslow, Segmentation and crustal structure of the western Mid-Atlantic Ridge flank, 25°25'-27°10/N and 0-29 m.y., J. Geophys. Res., 102, 10203-10223, 1997.
120. Vera, E.E., J.C. Mutter, P. Buhl, J.A. Orcutt, A.J. Harding, M.E. Kappus, R.S. Detrick, and T.M. Brocher, The structure of 0-to 0.2-m.y.-old oceanic crust at 9°N on the East Pacific Rise from expanded spread profiles, J. Geophys. Res.,95, 15, 529-15,. 556, 1990.
121. Wang, H.F., Theory of linear poroelasticity and applications to geomechanics and hydrogeology, 287 pp, Princeton University Press, New Jersey, 2000.
122. Wang, K., Understanding processes and estimating parameters using mathematical models, in Hydrogeology of the Oceanic Crust, edited by E.E. Davis, and H. Elderfield, in press, Cambridge University Press, Cambridge, UK, 2004.
123. White, D.J., and R.M. Clowes, Shallow crustal structure beneath the Juan de Fuca Ridge from 2-D seismic refraction tomography, Geophys. J. Int., 100, 349-367, 1990.
124. Wilcock, W.S.D., S.D. Archer, and G.M. Purdy, Microearthquakes on the Endeavour segment of the Juan de Fuca Ridge, J. Geophys. Res. (107), 2336, doi: 10.1029/2001JB000505, 2002.
125. Wilcock, W.S.D., and J.R. Delaney, Mid-ocean ridge sulfide deposits: Evidence for heat extraction from magma chambers or cracking fronts?, Earth Planet. Sci. Lett., 149, 49-64, 1997.
126. Wilcock, W.S.D., and A. McNabb, Estimates of crustal permeability on the Endeavour segment of the Juan de Fuca midocean ridge, Earth Planet. Sci. Lett., 138, 83-91, 1995.
127. Wilcock, W.S.D., S.C. Solomon, G.M. Purdy, and D.R. Toomey, The seismic attenuation structure of the East Pacific Rise near 9°30/N, J. Geophys. Res., 100, 24147-24165, 1995.
128. Wooldridge, A.L., C.G.A. Harrison, M.A. Tivey, P.A. Rona, and H. Schouten, Magnetic modeling near selected areas of hydrothermal activity on the Mid-Atlantic and Gorda Ridges, J. Geophys. Res., 97, 10911-10926, 1992.
129. Wright, D.J., R.M. Haymon, and D.J. Fomari, Crustal Assuring and its relationship to magmatic and hydrothermal processes on the East Pacific Rise crest (9° 12' to 54'N), J. Geophys. Res., 100, 6097-6120, 1995a.
130. Wright, D.J., R.M. Haymon, and K.C. MacDonald, Breaking new ground: Estimates of crack depth along the axial zone of the East Pacific Rise (9°12'-54'N), Earth Planet. Sci. Lett., 134, 441-457, 1995b.