Seismological constraints on magmatic and hydrothermal processes at mid-ocean ridges

Geophysical Monograph Series

Volumn 178, Issue , 2008, Pages 75-96

  Tolstoy, Maya ^a  

^a Department of Earth and Environmental Sciences   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 79251536592     PISSN: 00658448     EISSN: 23288779     Source Type: Book Series    
DOI: 10.1029/178GM05     Document Type: Conference Paper

References (141)

1. Almendros, J., A. H. Barclay, W. S. D. Wilcock, and G. M. Purdy (2000), Seismic anisotropy of the shallow crust at the Juan de Fuca Ridge, Geophys. Res. Lett., 27, 3109-3112.
2. Baker, E. T., and T. Urabe (1996), Extensive distribution of hydrothermal plumes along the superfast spreading East Pacific Rise, 13°30'-18°40' S. J. Geophys. Res., 101, 8685-8695.
3. Bakun, W. H., and W. B. Joyner (1984), The ML scale in central California, Bull. Seismol. Soc. Am., 74, 1827-1843.
4. Baran, J. M., J. R. Cochran, S. M. Carbotte, and M. R. Nedimovic´ (2005), Variations in upper crustal structure due to variable mantle temperature along the Southeast Indian Ridge, Geochem., Geophys. Geosyst., 6, Q11002, doi: 10.1029/2005GC000943.
5. Barclay, A. H., D. R. Toomey, and S. C. Solomon (1998), Seismic structure and crustal magmatism at the Mid-Atlantic Ridge, 35° N, J. Geophys. Res., 103, 17,827-17,844.
6. Biondi, B. (2006), 3-D seismic imaging, in Society of Exploration Geophysicists, Series: Investigations in Geophysics, edited by G. Gardner, Covington Group, Kansas City, Missouri, 240.
7. Bohnenstiehl, D. R., and M. Tolstoy (2003), Comparison of teleseismically and hydroacoustically derived earthquake locations along the north-central Mid-Atlantic Ridge and Equatorial East Pacific Rise, Seismol. Res. Lett., 74, 790-801.
8. Bohnenstiehl, D. R., M. Tolstoy, D. K. Smith, C. G. Fox, and R. Dziak (2002), Aftershock sequences in the mid-ocean ridge environment: An analysis using hydroacoustic data, Tectonophysics, 354, 49-70.
9. Bohnenstiehl, D. R., et al. (2003), Anomalous seismic activity at 8°37-42’N on the East Pacific Rise: Hydroacoustic detection and site investigation, Ridge2000 Events Newsl., 1(1), 18-20.
10. Bohnenstiehl, D. R., R. P. Dziak, M. Tolstoy, C. G. Fox, and M. Fowler (2004), Temporal and spatial history of the 1999-2000 Endeavour Segment seismic series, Juan de Fuca Ridge, Geochem., Geophys. Geosyst., 5, Q09003, doi:10.1029/2004GC000735.
11. Bosch, D., M. Jamais, F. Boudier, A. Nicolas, J. M. Dautria, and P. Agrinier (2004), Deep and high-temperature hydrothermal circulation in the Oman ophiolite—Petrological and isotopic evidence, J. Petrol., 6, 1181-1208.
12. Bunch, A. W. H., and B. L. N. Kennett (1980), The crustal structure of the Reykjanes Ridge at 59°30'N, Geophys. J. R. Astron. Soc., 61, 141-166.
13. Canales, J. P., J. A. Collins, J. Escartín, and R. S. Detrick (2000), Seismic structure across the rift valley of the Mid-Atlantic Rise at 23°20’ (MARK area): Implications for crustal accretion processes at slow spreading ridges, J. Geophys. Res., 105, 28,411-28,425.
14. Canales, J. P., R. A. Sohn, and B. J. deMartin (2007), Crustal structure of the Trans-Atlantic Geotraverse (TAG) segment (Mid-Atlantic Ride, 26°10’N): Implications for the nature of hydrothermal circulation and detachment faulting at slow spreading ridges, Geochem., Geophys. Geosyst., 8, Q08004, doi:10.1029/2007GC001629.
15. Cannat, M., et al. (1999), Mid-Atlantic Ridge-Azores hotspot interactions: Along-axis migration of a hotspot-derived event of enhanced magmatism 10 to 3 Ma ago, Earth Planet. Sci. Lett., 173, 257-269.
16. Carbotte, S. M., and K. C. Macdonald (1994), Comparison of seafloor tectonic fabric at intermediate, fast, and super fast spreading ridges: Influence of spreading rate, plate motions, and ridge segmentation on fault patterns, J. Geophys. Res., 99, 13,609-13,631.
17. Carbotte, S. M., and D. S. Scheirer (2004), Variability of ocean crustal structure created along the global mid-ocean ridge, in Hydrology of the Oceanic Lithosphere, edited by E. E. Davis and H. Elderfield, pp. 59-107, Cambridge Univ. Press, New York.
18. Carbotte, S. M., C. Z. Mutter, J. Mutter, and L. Wu (1998), Insights from a fast-intermediate spreading ridge on the influence of magma supply and spreading rate on crustal magma bodies and emplacement of the extrusive layer, Geology, 26, 455-458.
19. Carbotte, S. M., R. S. Detrick, A. Harding, J. P. Canales, J. Babcock, G. Kent, E. Van Ark, M. Nedimovic, and J. Diebold (2006), Rift topography linked to magmatism at the intermediate spreading Juan de Fuca Ridge, Geology, 34, 209-212.
20. Chapman, C. H. (1985), Ray theory and its extensions—WKBJ and Maslov seismograms, J. Geophys., 58, 27-43.
21. Cherkaoui, A. S. M., W. S. D. Wilcock, R. A. Dunn, and D. R. Toomey (2003), 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.
22. Christensen, N. I. (1979), Compressional wave velocities in rocks at high temperatures and pressures, critical thermal gradients, and low-velocity zones, J. Geophys. Res., 84, 6849-6857.
23. Christeson, G. L., P. R. Shaw, and J. D. Garmany (1997), Shear and compressional wave structure of the East Pacific Rise, 9°-10°N, J. Geophys. Res., 102, 7821-7835.
24. Christeson, G. L., K. D. McIntosh, and J. A. Karson (2007), Inconsistent correlation of seismic layer 2a and lava layer thickness in oceanic crust, Nature, 445, doi:10.1038/nature05517.
25. Collier, J., and M. C. Sinha (1990), Seismic images of a magma chamber beneath the Lau Basin back-arc spreading center, Nature, 346(6285), 646-648.
26. Cowen, J. P., et al. (2007), Volcanic eruptions at East Pacific Rise near 9°50’N, Eos Trans. AGU, 88(7), 81.
27. Cowie, P. A., C. H. Scholz, M. Edwards, and A. Malinverno (1993), Fault strain and seismic coupling on mid-ocean ridges, J. Geophys. Res., 98, 17,911-17,920.
28. Crawford, W. C., S. C. Webb, and J. A. Hildebrand (1999), Constraints on melt in the lower crust and Moho at the East Pacific Rise, 9°48’N, using seafloor compliance measurements, J. Geophys. Res., 104, 2923-2939.
29. Crone, T. J., and W. S. D. Wilcock (2005), Modeling the effects of tidal loading on mid-ocean ridge hydrothermal systems, Geochem. Geophys. Geosyst., 6, Q07001, doi:10.1029/2004GC000905.
30. Crone, T. J., W. S. D. Wilcock, A. H. Barclay, and J. D. Parsons (2006), The sound generated by Mid-Ocean Ridge black smoker hydrothermal vents, PLoS ONE, 1(1), e133, doi:10.1371/journal.pone.0000133.
31. Davis, E. E., K. Wang, R. E. Thomson, K. Becker, and J. F. Cassidy (2001), An episode of seafloor spreading and associated plate deformation inferred from crustal fluid pressure transients, J. Geophys. Res., 106, 21,953-21,963.
32. deMartin, B. J., R. A. Sohn, J. P. Canales, and S. E. Humphris (2007), Kinematics and geometry of active detachment faulting beneath the TAG hydrothermal field on the Mid-Atlantic Ridge, Geology, 35(8), 711.
33. DeMets, C., R. G. Gordon, D. F. Argus, and S. Stein (1994), Effect of recent revision to the geomagnetic reversal time scale on estimates of current plate motions, Geophys. Res. Lett., 21, 2192-2194.
34. Detrick, R. S., P. Buhl, E. Vera, J. Mutter, J. Orcutt, J. Madsen, and T. Brocher (1987), Multichannel seismic imaging of a crustal magma chamber along the East Pacific Rise, Nature, 326, 35-41.
35. Detrick, R. S., A. J. Harding, G. M. Kent, J. A. Orcutt, J. C. Mutter, and P. Buhl (1993), Seismic structure of the southern East Pacific Rise, Science, 259, 499-503.
36. Detrick, R. S., J. Collins, R. Stephen, and S. Swift (1994), In-situ evidence for the nature of the seismic layer 2/3 boundary in oceanic-crust, Nature, 370, 288-290.
37. Detrick, R. S., D. R. Toomey, and J. A. Collins (1998), Threedimensional upper crustal heterogeneity and anisotropy around Hole 504B from seismic tomography, J. Geophys. Res., 103, 30,485-30,504.
38. Detrick, R. S., J. M. Sinton, G. Ito, J. P. Canales, M. Behn, T. Blacic, B. Cushman, J. E. Dixon, D. W. Graham, and J. J. Mahoney (2002), Correlated geophysical, geochemical, and volcanological manifestations of plume-ridge interaction along the Galápagos Spreading Center, Geochem. Geophys. Geosyst., 3(10), 8501, doi:10.1029/2002GC000350.
39. Dunn, R. A., D. R. Toomey, and S. C. Solomon (2000), Threedimensional seismic structure and physical properties of the crust and shallow mantle beneath the East Pacific Rise at 9°30'N, J. Geophys. Res., 105, 23,537-23,555.
40. Dunn, R. A., V. Lekic´, R. S. Detrick, and D. R. Toomey (2005), Three-dimensional seismic structure of the Mid-Atlantic Ridge (35°N): Evidence for focused melt supply and lower crustal dike injection, J. Geophys. Res., 110, B09101, doi: 10.1029/2004JB003473.
41. Dziak, R. P., and Time Critical Studies Committee Members (2007), Time critical studies update, Ridge2000 Events Newsl., in press.
42. Dziak, R. P., C. G. Fox, and A. E. Schreiner (1995), The June-July 1993 Seismo-acoustic event at CoAxial segment, Juan de Fuca Ridge: Evidence for a lateral dike injection, Geophys. Res. Lett., 22, 135-138.
43. Dziak, R. P., and C. G. Fox (1999), The January 1998 earthquake swarm at Axial Volcano, Juan de Fuca Ridge: Hydroacoustic evidence of seafloor volcanic activity, Geophys. Res. Lett., 26, 3429-3432.
44. Dziak, R. P., W. W. Chadwick, C. G. Fox, and R. W. Embley (2003), Hydrothermal temperature changes at the southern Juan de Fuca Ridge associated with Mw 6.2 Blanco Transform earthquake, Geology, 31, 119-122.
45. Dziak, R. P., D. K. Smith, D. R. Bohnenstiehl, C. G. Fox, D. Desbruyeres, H. Matsumoto, M. Tolstoy, and D. J. Fornari (2004), Evidence of a recent magma dike intrusion at the slow spreading Lucky Strike segment, Mid-Atlantic Ridge, J. Geophys. Res., 109, B12102, doi:10.1029/2004JB003141.
46. Dziak, R., B. Chadwick, J. Cowen, E. Baker, R. Embley, D. Bohnenstiehl, and J. Resing (2006), Detecting volcanic events in the Northeast Pacific, Eos Trans. Am. Geophys. Union, 87(4), 37.
47. Edwards, M. H., G. J. Kurras, M. Tolstoy, D. R. Bohnenstiehl, B. J. Coakley, and J. R. Cochran (2001), Evidence of recent volcanic activity on the ultra-slow spreading Gakkel Ridge, Nature, 409, 808-812.
48. Embley, R. W., W. W. Chadwick Jr., I. R. Jonasson, D. A. Butterfield, and E. T. Baker (1995), Initial results of the rapid response to the 1993 CoAxial event: Relationships between hydrothermal and volcanic processes, Geophys. Res. Lett., 22, 143-146.
49. Embley, R. W., W. W. Chadwick Jr., D. Clague, and D. Stakes (1999), 1998 eruption of Axial Volcano: Multibeam anomalies and sea-floor observations, Geophys. Res. Lett., 26, 3425-3428.
50. Ewing, J., and M. Ewing (1959), Seismic refraction measurements in the Atlantic Ocean Basins, in the Mediterranean Sea, on the Mid-Atlantic Ridge, and in the Norwegian Sea, Geol. Soc. Am. Bull., 70, 291.
51. Fornari, 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 (1998), Time-series temperature measurements at high-temperature hydrothermal vents, East Pacific Rise 9 degrees 49’-51’N: Evidence for monitoring a crustal cracking event, Earth Planet. Sci. Lett., 160, 419-431.
52. Foulger, G. R., and R. E. Long (1984), Anomalous focal mechanism solutions: Evidence for tensile crack formation on an accreting plate boundary, Nature, 310, 43-45.
53. Fox, C. G. (1995), Special collection on the June 1993 volcanic eruption on the CoAxial segment, Juan de Fuca Ridge, Geophys. Res. Lett., 22, 129-130.
54. Fox, C. G., and R. P. Dziak (1998), Hydroacoustic detection of volcanic activity on the Gorda Ridge, February-March 1996, Deep-Sea Res. Part II, 45, 2513-2530.
55. Fox, C. G., R. P. Dziak, H. Matsumoto, and A. E. Schreiner (1993), Potential for monitoring low-level seismicity on the Juan de Fuca Ridge using military hydrophone arrays, Mar. Technol. Soc. J., 27, 22-30.
56. Fox, C. G., W. E. Radford, R. P. Dziak, T.-K. Lau, H. Matsumoto, and A. E. Schreiner (1995), Acoustic detection of a seafloor spreading episode on the Juan de Fuca Rise using military hydrophone arrays, Geophys. Res. Lett., 22, 131-134.
57. Fox, C. G., H. Matsumoto, and T.-K. A. Lau (2001), Monitoring Pacific Ocean seismicity from an autonomous hydrophone array, J. Geophys. Res., 106, 4183-4206.
58. Gaherty, J. B., D. Lizarralde, J. A. Collins, G. Hirth, and S. Kim (2004), Mantle deformation during slow seafloor spreading constrained by observations of seismic anisotropy in the western Atlantic, Earth Planet. Sci. Lett., 228, 255-265.
59. Garrido, C. J., P. B. Kelemen, and G. Hirth (2001), Variation of cool rate with depth in lower crust formed at an oceanic spreading ridge: Plagioclase crystal size distributions in gabbros from the Oman ophiolite, Geochem., Geophys. Geosyst., 2(10), doi:10.1029/2000GC000136.
60. German, C. R., and J. Lin (2004), The thermal structure of the oceanic crust, ridge-spreading and hydrothermal circulation: How well do we understand their inter-connections? in Mid-Ocean Ridges: Hydrothermal Interactions Between the Lithosphere and Oceans, Geophys. Monogr. Ser., vol. 148, edited by C. R. German, J. Lin, and L. M. Parson, pp. 1-18, AGU, Washington, D. C.
61. Golden, C. E., S. C. Webb, and R. A. Sohn (2003), Hydrothermal microearthquake swarms beneath active vents at Middle Valley, northern Juan de Fuca Ridge, J. Geophys. Res., 108(B1), 2027, doi: 10.1029/2001JB000226.
62. Gregory, R. T., and H. P. Taylor Jr. (1981), An oxygen isotope profile in a section of Cretaceous oceanic crust, Samail ophiolite, Oman: Evidence for s18O buffering of oceans by deep (>5 km) seawater-hydrothermal circulation at mid-ocean ridges, J. Geophys. Res., 86, 2737-2755.
63. Gutenberg, B., and C. F. Richter (1944), Frequency of earthquakes in California, Bull. Seismol. Soc. Am., 34, 185-188.
64. Holmes, R., M. Tolstoy, J. R. Cochran, and J. S. Floyd (2005), Crustal structure along the Southeast Indian Ridge from seismic refraction data, Eos Trans. AGU, 86(52), Fall Meet Suppl., Abstract T33A-0513.
65. Humphris, S. E., and J. R. Cann (2000), Constraints on the energy and chemical balances of the modern TAG and ancient Cyprus seafloor sulfide deposits, J. Geophys. Res., 105, 28,477-28,488.
66. Hussenoeder, S. A., J. A. Collins, G. M. Kent, R. S. Detrick, and the TERA Group (1996), Seismic analysis of the axial magma chamber reflector along the southern East Pacific Rise from conventional reflection profiling, J. Geophys. Res., 101, 22,087-22,105.
67. Johnson, H. P., M. Hutnak, R. P. Dziak, C. G. Fox, I. Urcuyo, J. P. Cowen, J. Nabelek, and C. Fisher (2000), Earthquake-induced changes in the hydrothermal system on the Juan de Fuca midocean ridge, Nature, 407, 174-177.
68. Johnson, H. P., R. P. Dziak, C. R. Fisher, C. G. Fox, and M. J. Pruis (2001), Earthquakes’ impact on hydrothermal systems may be far-reaching, Eos Trans. AGU, 82(21), 233.
69. Jokat, W., and M. C. Schmidt-Aursch (2007), Geophysical characteristics of the ultraslow spreading Gakkel Ridge, Arctic Ocean, Geophys. J. Int., 168, 983-998.
70. Jupp, T. E., and A. Schultz (2004), A poroelastic model for the tidal modulation of seafloor hydrothermal systems, J. Geophys. Res., 109, B03105, doi:10.1029/2003JB002583.
71. Kelley, D. S., et al. (2005), A serpentinite-hosted ecosystem: The Lost City hydrothermal field, Science, 307, 1428, doi:10.1126/science.1102556.
72. Kent, G. M., A. J. Harding, and J. A. Orcutt (1993), 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, 13,945-13,969.
73. Kent, G. M., et al. (2000), Evidence from three-dimensional seismic reflectivity images for enhanced melt supply beneath midocean ridge discontinuities, Nature, 406, 614-618.
74. Lilley, M. D., D. A. Butterfield, J. E. Lupton, and E. J. Olson (2003), Magmatic events can produce rapid changes in hydrothermal vent chemistry, Nature, 442, 878-881.
75. Lowell, R. P., and Y. Yao (2002), Anhydrite precipitation and the extent of hydrothermal recharge zones at ocean ridge crests, J. Geophys. Res., 107(B9), 2183, doi: 10.1029/2001JB001289.
76. Lowell, R. P., B. W. Crowell, S. R. Gosnell, K. C. Lewis, L. Liu, and Y. Yang (2007), Modeling multiphase, multi-component processes at oceanic spreading centers: Magma to microbe, this volume.
77. Maclennan, J., T. Hulme, and S. C. Singh (2004), Thermal models of oceanic crustal accretion: Linking geophysical, geological and petrological observations, Geochem. Geophys. Geosys., 5, Q02F25, doi:10.1029/2003GC000605.
78. McClain, J. S., M. L. Begnaud, M. A. Wright, J. Fondrk, and G. K. Von Damm (1993), Seismicity and tremor in a submarine hydrothermal field: The northern Juan de Fuca Ridge, Geophys. Res. Lett., 20, 1883-1886.
79. Menke, W., and D. Schaff (2004), Absolute earthquake locations with differential data, Bull. Seismol. Soc. Am., 94, 2254-2264.
80. Michael, P. J., et al. (2003), Magmatic and amagmatic seafloor generation at the ultraslow-spreading Gakkel Ridge, Arctic Ocean, Nature, 423, 956-961.
81. Miller, A. D., B. R. Julian, and G. R. Foulger (1998), Threedimensional seismic structure and moment tensors of non-doublecouple earthquakes at the Hengill-Grensdalur volcanic complex, Iceland, Geophys. J. Int., 133, 309-325.
82. Mogi, K. (1963), Some discussions on aftershocks, foreshocks and earthquake swarms—The fracture of a semi-infinite body caused by an inner stress origin and its relation to the earthquake phenomena, Bull. Earthquake Res. Inst. Univ. Tokyo, 41, 615-658.
83. Morton, J. L., N. H. Sleep, W. R. Normark, and D. H. Tompkins (1987), Structure of the southern Juan de Fuca Ridge from seismic reflection records, J. Geophys. Res., 92, 11,315-11,326.
84. Muller, M. R., T. A. Minshull, and R. S. White (1999), Segmentation and melt supply at the Southwest Indian Ridge, Geology, 10, 867-870.
85. Mutter, J. C., S. M. Carbotte, W. Su, L. Xu, P. Buhl, R. S. Detrick, G. A. Kent, J. A. Orcutt, and A. J. Harding (1995), Seismic images of active magma systems beneath the East Pacific Rise between 17 050 and 17 350S, Science, 268, 391-395.
86. Perfit, M. R., and W. W. Chadwick Jr. (1998), Magmatism at midocean ridges: Constraints from volcanological and geochemical investigations, in Faulting and Magmatism at Mid-Ocean Ridges, Geophys. Monogr. Ser., vol. 106, edited by W. R. Buck et al., pp. 59-115, AGU, Washington, D. C.
87. Phipps Morgan, J., and Y. J. Chen (1993), Dependence of ridgeaxis morphology on magma supply and spreading rate, Nature, 364, 706-708.
88. Purdy, G. M., and R. S. Detrick (1986), Crustal structure of the Mid-Atlantic Ridge at 23°N from seismic refraction studies, J. Geophys. Res., 91, 3739-3762.
89. Purdy, G. M., L. S. L. Kong, G. L. Christeson, and S. C. Solomon (1992), Relation between spreading rate and the seismic structure of mid-ocean ridges, Nature, 355, 815-817.
90. Ramondenc, P., L. N. Germanovich, and R. P. Lowell (2007), Modeling the hydrothermal response to earthquakes with application to the 1995 event at 9°50’N, East Pacific Rise, this volume.
91. Riedesel, M., J. A. Orcutt, K. C. MacDonald, and J. S. McClain (1982), Microearthquakes in the black smoker hydrothermal field, East Pacific Rise at 21°N, J. Geophys. Res., 87, 10,613-10,623.
92. Rubin, A. M. (1992), Dike-induced faulting and graben subsidence in volcanic rift zones, J. Geophys. Res., 97, 1839-1858.
93. Scheirer, D. S., D. J. Fornari, S. E. Humphris, and S. Lerner (2000), High-resolution seafloor mapping using the DSL-120 sonar system: Quantitative assessment of sidescan and phase-bathymetry data from the Lucky Strike Segment of the Mid-Atlantic Ridge, Mar. Geophys. Res., 21, 121-142.
94. Scheirer, D. S., Shank, T. M., and D. J. Fornari (2006), Temperature variations at diffuse and focused flow hydrothermal vent sites along the northern East Pacific Rise. Geochem. Geophys. Geosyst., 7, Q03002, doi:10.1029/2005GC001094.
95. Schreiner, A. E., C. G. Fox, and R. P. Dziak (1995), Spectra and magnitudes of T-waves from the 1993 earthquake swarm on the Juan de Fuca Ridge, Geophys. Res. Lett., 22, 139-142.
96. Schultz, A., and H. Elderfield (1997), Controls on the physics and chemistry of seafloor hydrothermal circulation, Philos. Trans. R. Soc. Lond., 355, 387-425.
97. Seyfried, W. E., Jr., J. S. Seewald, M. E. Berndt, K. Ding, and D. I. Foustoukos (2003), Chemistry of hydrothermal vent fluids from the Main Endeavour Field, northern Juan de Fuca Ridge: Geochemical controls in the aftermath of June 1999 seismic events, J. Geophys. Res., 108(B9), 2429, doi:10.1029/2002JB001957.
98. Shearer, P., and J. A. Orcutt (1985), Anisotropy in the oceanic lithosphere—Theory and observations from the Ngendei seismic refraction experiment in the southwest Pacific, Geophys. J. R. Astron. Soc., 80, 493-526.
99. Shearer, P., and J. A. Orcutt (1986), Compressional and shear-wave anisotropy in the oceanic lithosphere—The Ngendei seismic refraction experiment, Geophys. J. R. Astron. Soc., 87, 967-1003.
100. Shearer, P. M. (1997), Improving local earthquake locations using the L1 norm and waveform cross correlation: Application to the Whittier Narrows, California, aftershock sequence, J. Geophys. Res., 102, 8269-8283.
101. Sheriff, R. E., and L. P. Geldart (1995), Exploration Seismology, Cambridge University Press, Cambridge, U.K.
102. Singh, S. C., G. M. Kent, J. S. Collier, A. J. Harding, and J. A. Orcutt (1998), Melt to mush variations in crustal magma properties along the ridge crest at the southern East Pacific Rise, Nature, 394, 874-878.
103. Singh, S. C., J. S. Collier, A. J. Harding, G. M. Kent, and J. A. Orcutt (1999), Seismic Evidence for a hydrothermal layer above the solid roof of the axial magma chamber at the southern East Pacific Rise, Geology, 27, 219-222.
104. Singh, S. C., W. C. Crawford, H. Carton, T. Seher, V. Combier, M. Canat, J. P. Canales, D. Dusunur, J. Escartin, and J. M. Miranda (2006a), Discovery of a magma chamber and faults beneath a Mid-Atlantic Ridge hydrothermal field, Nature, 442, 1029-1032.
105. Singh, S. C., et al. (2006b), Seismic reflection images of the Moho underlying sills at the East Pacific Rise, Nature, 442, 287-290.
106. Sinha, M. C., D. A. Navin, L. M. MacGregor, S. Constable, C. Pierce, A. White, G. Heinson, and M. A. Inglis (1997), Evidence for accumulated melt beneath the slow spreading Mid-Atlantic Ridge, in Mid-Ocean Ridges: Dynamics of Processes Associated With Creation of New Ocean Crust, Philos. Trans. R. Soc. London, Ser. A, vol. 355, edited by J. R. Cann, H. Elderfield, and A. Laughton, pp. 233-253, Cambridge University Press, Cambridge, U.K.
107. Smith, D. K., M. Tolstoy, C. G. Fox, D. R. Bohnenstiehl, H. Matsumoto, and M. J. Fowler (2002), Hydroacoustic monitoring of seismicity at the slow-spreading Mid-Atlantic Ridge, Geophys. Res. Lett., 29(11), 1518, doi:10.1029/2001GL013912.
108. Smith, D. K., J. Escartin, M. Cannat, M. Tolstoy, C. G. Fox, D. R. Bohnenstiehl, and S. Bazin (2003), Spatial and temporal distribution of seismicity along the northern Mid-Atlantic Ridge (15°-35°N), J. Geophys. Res., 108(B3), 2167, doi: 10.1029/2002JB001964.
109. Spudich, P., and J. Orcutt (1980), A new look at the seismic velocity structure of the oceanic crust, Rev. Geophys., 18, 627-645.
110. Sohn, R., D. J. Fornari, K. Von Damm, S. Webb, and J. Hildebrand (1998), Seismic and hydrothermal evidence for a propagating cracking event on the East Pacific Rise crest at 9°50'N, Nature, 396, 159-161.
111. Sohn, R. A. (2007), Stochastic analysis of exit fluid temperature records from the active TAG hydrothermal mound (Mid-Atlantic Ridge, 26°N): 2. Hidden Markov Models of flow episodes, J. Geophys. Res., 112, B09102, doi:10.1029/2007JB004961.
112. Sohn, R. A., J. A. Hildebrand, and S. C. Webb (1999), A microearthquake survey of the high-temperature vent fields on the volcanically active East Pacific Rise (9°50’N), J. Geophs. Res., 104, 25,367-25,377.
113. Sohn, R. A., A. H. Barclay, and S. C. Webb (2004), Microearthquake patterns following the 1998 eruption of Axial Volcano, Juan de Fuca Ridge: Mechanical relaxation and thermal strain, J. Geophys. Res., 109, B01101, doi:10.1029/2003JB002499.
114. Stein, S., and M. Wysession (2003), An Introduction to Seismology, Earthquakes, and Earth Structure, Blackwell Publishing, Oxford, 498 pp., ISBN 0-86542-087-5.
115. Stroup, D. F., D. R. Bohnenstiehl, M. Tolstoy, F. Waldhauser, and R. T. Weekly (2007), Pulse of the seafloor: Tidal triggering of microearthquakes at 9°50’N East Pacific Rise, Geophys. Res. Lett., 34, L15301, doi:10.1029/2007GL030088.
116. Tolstoy, I., and W. M. Ewing (1950), The T phase of shallow-focus earthquakes, Bull. Seismol. Soc. Am., 40, 25-51.
117. Tolstoy, M., A. J. Harding, and J. A. Orcutt (1993), Crustal thickness on the Mid-Atlantic Ridge—Bull’s eye gravity anomalies and focused accretion, Science, 262, 726-729.
118. Tolstoy, M., A. J. Harding, J. A. Orcutt, and TERA Group (1997), Deepening of the axial magma chamber on the southern East Pacific Rise toward the Garret Fracture Zone, J. Geophys. Res., 102, 3097-3108.
119. Tolstoy, M., D. J. Fornari, and C. G. Fox (1999), Detailed Investigation of T-phase swarms on the East Pacific Rise, Eos Trans. AGU.
120. Tolstoy, M., D. Bohnenstiehl, M. Edwards, and G. Kurras (2001), The seismic character of volcanic activity at the ultra-slow spreading Gakkel Ridge, Geology, 29, 1139-1142.
121. Tolstoy, M., F. L. Vernon, J. A. Orcutt, and F. K. Wyatt (2002), The breathing of the seafloor: Tidal correlations of seismicity on Axial volcano, Geology, 30, 503-506.
122. Tolstoy, M., et al. (2006), A seafloor spreading event captured by seismometers, Science, DOI: 10.1126/science.1133950.
123. Tolstoy, M., F. Waldhauser, D. R. Bohnenstiehl, R. T. Weekly, and W.-Y. Kim (2008), Seismic identification of along-axis hydrothermal flow on the East Pacific Rise, Nature, doi:10.1038/nature06424.
124. Toomey, D. R., G. M. Purdy, S. C. Solomon, and W. S. D. Wilcock (1990), The 3-dimensional seismic velocity structure of the East Pacific Rise near latitude 9-degrees-30’N, Nature, 347, 639-645.
125. Toomey, D. R., S. C. Solomon, and G. M. Purdy, (1994), Tomographic imaging of the shallow crustal structure of the East Pacific Rise at 9°30’N, J. Geophys. Res., 99, 24,135-24,157.
126. Tréhu, A. M., and S. C. Solomon (1983), Earthquakes in the Orozco Transform Zone: Seismicity, source mechanisms and tectonics, J. Geophys. Res., 88, 8203-8225.
127. Van Ark, E. M., R. S. Detrick, J. P. Canales, S. M. Carbotte, A. J. Harding, G. M. Kent, M. Nedimovic, W. S. D. Wilcock, J. B. Diebold, and J. M. Babcock (2007), Seismic structure of the Endeavour Segment, Juan de Fuca Ridge: Correlations with seismicity and hydrothermal activity, J. Geophys. Res., 112, B02401, doi:10.1029/2005JB004210.
128. Vera, E. E., J. C. Mutter, P. Buhl, J. A. Orcutt, A. J. Harding, M. E. Kappus, R. S. Detrick, and T. M. Brocher (1990), 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.
129. Waldhauser, F., and W. L. Ellsworth (2000), A double-difference earthquake location algorithm: Method and application to the northern Hayward fault, California, Bull. Seismol. Soc. Am., 6, 1,353-1,368.
130. Waldhauser, F., W. L. Ellsworth, and A. Cole (1999), Slip-parallel seismic lineations on the northern Hayward fault, California, Geophys. Res. Lett., 26, 3525-3528.
131. West, M. E., W. Menke, M. Tolstoy, S. C. Webb, and R. Sohn (2001), Magma storage beneath Axial volcano on the Juan de Fuca mid-ocean ridge, Nature, 413, 833-836.
132. White, R. S., and R. B. Whitmarsh (1984), An investigation of seismic anisotropy due to cracks in the upper oceanic-crust at 45-degrees N, Mid-Atlantic Ridge, Geophys. J. Royal Astron. Soc., 79, 439-467.
133. White, R. S., D. McKenzie, and R. K. O’Nions (1992), Oceanic crustal thickness from seismic measurements and rare earth element inversions, J. Geophys. Res., 97, 19,683-19,715.
134. Wilcock, W. S. D. (2001), Tidal triggering of microearthquakes on the Juan de Fuca Ridge, Geophys. Res. Lett., 28, 3999-4002.
135. Wilcock, W. S. D. (2004), Physical response of mid-ocean ridge hydrothermal systems to local earthquakes, Geochem. Geophys. Geosyst., 5, Q11009, doi:10.1029/2004GC000701.
136. Wilcock, W. S. D., and J. R. Delaney (1996), Mid-ocean ridge sulfide deposits: Evidence for heat extraction from magma chambers or cracking fronts? Earth Planet. Sci. Lett., 145, 49-64.
137. Wilcock, W. S. D., S. D. Archer, and G. M. Purdy (2002), Microearthquakes on the Endeavour segment of the Juan de Fuca Ridge. J. Geophys. Res., 107(B12), 2336, doi:10.1029/2001JB000505.
138. Wilson, D. S. (1993), Confidence intervals for motion and deformation of the Juan de Fuca plate, J. Geophys. Res., 98, 16,053-16,071.
139. Wilson, D. S., et al. (2006), Drilling to gabbro in intact ocean crust, Science, 312, 1016-1020.
140. Wolfe, C. J., G. M. Purdy, D. R. Toomey, and S. C. Solomon (1995), Microearthquake characteristics and crustal velocity structure at 29°N on the Mid-Atlantic Ridge: The architecture of a slow spreading segment, J. Geophys. Res., 100, 24,449-24,472.
141. Wyss, M. (1973), Towards a physical understanding of earthquake frequency distribution, Geophys. J. R. Astron. Soc., 31, 341-359.