pure and applied geophysics

, Volume 117, Issue 6, pp 1082–1147 | Cite as

Seismic gaps and plate tectonics: Seismic potential for major boundaries

  • W. R. McCann
  • S. P. Nishenko
  • L. R. Sykes
  • J. Krause


The theory of plate tectonics provides a basic framework for evaluating the potential for future great earthquakes to occur along major plate boundaries. Along most of the transform and convergent plate boundaries considered in this paper, the majority of seismic slip occurs during large earthquakes, i.e., those of magnitude 7 or greater. The concepts that rupture zones, as delineated by aftershocks, tend to abut rather than overlap, and large events occur in regions with histories of both long- and short-term seismic quiescence are used in this paper to delineate major seismic gaps.

In detail, however, the distribution of large shallow earthquakes along convergent plate margins is not always consistent with a simple model derived from plate tectonics. Certain plate boundaries, for example, appear in the long term to be nearly aseismic with respect to large earthquakes. The identification of specific tectonic regimes, as defined by dip of the inclined seismic zone, the presence or absence of aseismic ridges and seamounts on the downgoing lithospheric plate, the age contrast between the overthrust and underthrust plates, and the presence or absence of back-arc spreading, have led to a refinement in the application of plate tectonic theory to the evaluation of seismic potential.

The term seismic gap is taken to refer to any region along an active plate boundary that has not experienced a large thrust or strike-slip earthquake for more than 30 years. A region of high seismic potential is a seismic gap that, for historic or tectonic reasons, is considered likely to produce a large shock during the next few decades. The seismic gap technique provides estimates of the location, size of future events and origin time to within a few tens of years at best.

The accompanying map summarizes six categories of seismic potential for major plate boundaries in and around the margins of the Pacific Ocean and the Caribbean, South Sandwich and Sunda (Indonesia) regions for the next few decades. These categories range from what we consider high to low potential for being the site of large earthquakes during that period of time. Categories 1, 2 and 6 define a time-dependent potential based on the amount of time elapsed since the last large earthquake. The remaining categories, 3, 4, and 5, are used for areas that have ambiguous histories for large earthquakes; their seismic potential is inferred from various tectonic criteria. These six categories are meant to be interpreted as forecasts of the location and size of future large shocks and should not be considered to be predictions in which a precise estimate of the time of occurrence is specified.

Several of the segments of major plate boundaries that are assigned the highest potential, i.e., category 1, are located along continental margins, adjacent to centers of population. Some of them are hundreds of kilometers long. High priority should be given to instrumenting and studying several of these major seismic gaps since many are now poorly instrumented. The categories of potential assigned here provide a rationale for assigning prorities for instrumentation, for future studies aimed at predicting large earthquakes and for making estimates of tsunami potential.

Key Words

Seismic gaps Earthquake prediction Plate tectonics 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Algue, Rv. Jose (1909),Mirador Observatory Baguio, Benguet: A new meterological-geodynamic station of the weather bureau, Manila, Philippines, Bureau of Printing, 26-27.Google Scholar
  2. Allen, C. R. (1962),Circum-Pacific faulting in the Philippines-Taiwan region, J. Geophys. Res.67, 4795–4812.Google Scholar
  3. Allen, C. R. (1968),The tectonic environments of seismically active and inactive areas along the San Andreas fault system, Proceedings of a conference ‘Geological Problems of the San Andreas Fault’, Stanford Univ. Publs. Geol. Sci.11, 70–83.Google Scholar
  4. Allen, C. R., St. Armand, P., Richter, C. F. andNordquist, J. M. (1965),Relationships between seismicity and geologic structure in the southern California region, Bull. Seism Soc. Amer.55, 753–797.Google Scholar
  5. Ando, M. (1975),Source mechanisms and tectonic significance of historical earthquakes along the Nankai Trough, Japan, Tectonophys,27, 119–140.Google Scholar
  6. Archambeau, C. (1978),Estimation of non-hydrostatic stress in the earth by seismic methods: Lithospheric stress levels along Pacific and Nazca plate subduction zones, this volume.Google Scholar
  7. Barazangi, M. andIsacks, B. L. (1976),Spatial distribution of earthquakes and subduction of the Nazca plate beneath South America, Geology4, 686–692.Google Scholar
  8. Brune, J. (1968),Seismic moment, seismicity and rate of slip along major fault zones, J. Geophys. Res.73, 777–784.Google Scholar
  9. Cardwell, R. K. andIsacks, B. L., (1978),Geometry of the subducted lithosphere beneath the Banda Sea in eastern Indonesia from seismicity and fault plane solutions, J. Geophys. Res.83, 2825–2838.Google Scholar
  10. Carr, M. J. (1974),Tectonics of the Pacific margin of northern Central America Ph. D. dissertation, Dartmouth College, Hanover, N.H. 159 pp.Google Scholar
  11. Carr, M. J. (1977),Volcanic activity and great earthquakes at convergent plate margins, Science197, 655–657.Google Scholar
  12. Carr, M. J. Stoiber, R. E. andDrake, C. L. (1974),The segmented nature of some continental margins, in C. A. Burk and C. L. Drake, eds.,The Geology of Continental Margins, Springer-Verlag, 105–114.Google Scholar
  13. Carr, M. J. andStoiber, R. E. (1977),Geologic setting of some destructive earthquakes in Central America, Geol. Soc. Amer. Bull.88, 151–156.Google Scholar
  14. Chase, C., Menard, H. andMammerickx J. (1970),Bathymetry of the North Pacific, Charts 1–6, Scrips Inst. of Oceanogr. Inst. of Mar. Resour, LaJolla, Calif.Google Scholar
  15. Cooper, A. K., Marlow, M. S. andScholl, D. W. (1977),The Bering Sea — A multifarious marginal basin, Maurice Ewing Series No. 1, Amer. Geophys. Union, Washington, D.C., 437–450.Google Scholar
  16. Cormter, V. (1975),Tectonics near the junction of the Aleutian and Kuril-Kamchatka arcs and a mechanism for middle Tertiary magmatism in the Kamchatka Basin, Geol. Soc. Amer. Bull.86, 443–453.Google Scholar
  17. Cox, D. andPararas-Caryannis, G. (1976), Catalog of Tsunamis in Alaska, U.S. Dept. of Commerce, NOAA/EDS, Asheville, N.C., 78 pp.Google Scholar
  18. Davies, J. N. andHouse, L. (1979),Aleutian subduction zone seismicity, volcano-trench separation, and their relation to great thrust-type earthquakes, in preparation.Google Scholar
  19. Dean, B. W. andDrake, C. L. (1978)Focal mechanism solutions and tectonics of the Middle America arc, J. Geol.86, 111–128.Google Scholar
  20. De Loczy, L. (1968),Geotectonic evolution of the Amazon, Parnaiba and Parna basins, An. Acad. brasil. Cieńc,40, 231–249.Google Scholar
  21. Ella, Rv. Samuel (1890),Some physical phenomena of the South Pacific Islands, in Report of the Second Meeting of the Australian Association for the Advancement of Science, Melbourne, Australia, 559–572.Google Scholar
  22. Eppley, R. A. (1965),Earthquake History of the United States Part 1, U. S. Dept. of Commerce, Env. Sci. Serv. Admin. Coast and Geod. Surv., 120 pp.Google Scholar
  23. Fedotov, S. A. (1965),Regularities of the distribution of strong earthquakes in Kamchatka, the Kuril Islands, and northeast Japan, Trudy Inst. Fiz Zemli., Acad. Nauk. SSSR36, 66–93.Google Scholar
  24. Fisher, R. L. (1961).Middle America trench: Topography and Structure. Geol. Soc. Amer. Bull.72, 703–720.Google Scholar
  25. Fitch, T. J. (1972),Plate convergence, transcurrent faults, and internal deformation adjacent to Southeast Asia and the Western Pacific, J. Geophys. Res.77, 4432–4460.Google Scholar
  26. Fitch, T. J. andMolnar, P. (1970),Focal mechanisms along inclined earthquake zones in the Indonesian-Philippine region, J. Geophys. Res.75, 1431–1444.Google Scholar
  27. Forsyth, D. W. (1975),Fault-plane solutions and tectonics of the South Atlantic and Scotia Sea, J. Geophys. Res.80, 1429–1443.Google Scholar
  28. Frankel, A. andMcCann, W. (1979),Seismicity of the South Sandwich arc: Consequences of a ridge-trench collision, J. Geophys. Res. (in press).Google Scholar
  29. Gansser, A. (1973),Facts and theories on the Andes, J. Geol. Soc. London,129, 93–131.Google Scholar
  30. Garza, T. andLomnitz, C. (1978),The Oaxaca gap: A case history, in this volume.Google Scholar
  31. Geller, R. andKanamori, H. (1977),Magnitudes of great shallow earthquakes from 1904 to 1952, Bull. Seism Soc. Amer.67, 587–598.Google Scholar
  32. Gutenberg, B. andRichter, C. F. (1954),Seismicity of the Earth (2nd edit. Princeton Univ. Press, New Jersey 1954), pp. 161–234.Google Scholar
  33. Hatori, T. (1979),Dimensions and geographical distribution of tsunami sources near Japan, Bull. Earthq. Res. Inst., Univ. Tokyo,47, 185–214.Google Scholar
  34. Herron, E. M. andTucholke B. E. (1976),Sea-floor magnetic patterns and basement structure in the southeastern Pacific in Initial Reports of the Deep Sea Drilling Project35 (U.S. Govt. Printing Office, Washington, D.C. 1976), pp. 263–278.Google Scholar
  35. House, L. andBoatwright, J. (1979),Investigation of two high-stress drop earthquakes in the Shumagin seismic gap, Alaska (in preparation).Google Scholar
  36. International Seismological Summary (Kew Observatory, Richmond, Surrey, England, 1950).Google Scholar
  37. Isacks, B., Oliver, J., andSykes, L. (1968)Seismology and the new global tectonics, J. Geophys. Res.73, 5855–5899.Google Scholar
  38. Isacks, B., andMolnar, P. (1971),Distribution of stresses in the descending lithosphere from a global survey of focal mechanism solutions of mantle earthquakes, Rev. Geophys. Space Phys.,9, 103–174.Google Scholar
  39. Jacob, K., Nakamura, K. andDavies, J. N. (1977),Trench-volcano gap along the Alaska-Aleutian arc: Facts and speculations on the role of terrigenous sediments for subduction in Island Arcs, Deep Sea Trenches and Back-Arc Basins (Talwani, M. and Pitman III, W. C., eds., Maurice Ewing Series I, Amer. Geophys. Union), pp. 243–258.Google Scholar
  40. Jahns, R. (1977),Study of Holocene displacement history along the south-central reach of the San Andreas fault, USGS Final Report #14-08-0001-15225, 1–219.Google Scholar
  41. Johnson, T. andMolnar, P. (1972),Focal mechanisms and plate tectonics of the southwest Pacific, J. Geophys. Res.,77, 5000–5032.Google Scholar
  42. Jordan, T. (1975),The present-day motions of the Caribbean plate, J. Geophys. Res.80, 4433–4439.Google Scholar
  43. Kanamori H. (1971),Great earthquakes at island arcs and the lithosphere, Tectonophysics,12, 187–198.Google Scholar
  44. Kanamori, H. (1977a),Seismic and aseismic slip along subduction zones and their tectonic implications inIslands Arcs, Deep Sea Trenches and Back-Arc Basins (Talwani, M. and Pitman III, W. C., eds., Maurice Ewing Series I, Amer. Geophys. Union), pp. 273–284.Google Scholar
  45. Kanamori, H. (1977b)The energy release in great earthquakes, J. Geophys. Res.82, 2981–2987.Google Scholar
  46. Kanamori, H. (1978),Nature of seismic gaps and foreshocks, in this volume.Google Scholar
  47. Kanamori, H. andAbe, K. (1978),Re-evaluation of the turn-of-the-Century seismicity peak using an undamped Milne seismograph, EOS, Spring AGU Abstracts, April, p. 327.Google Scholar
  48. Karig, D. E. (1973),Plate convergence between the Philippines andthe Ryukyu Islands, Mar. Geol.14, 153–168.Google Scholar
  49. Karig, D. E. andMammerickx, J. (1972),Tectonic framework of the New Hebrides Island arc, Mar. Geol.12, 187–205.Google Scholar
  50. Katili, J. A. (1970),Large transcurrent faults in Southeast Asia with special reference to Indonesia, Geologische Rundschau59, 581–600.Google Scholar
  51. Katsumata, M. andSykes, L. R. (1969),Seismicity and tectonics of the western Pacific: Izu-Mariana-Caroline and Ryukyu-Taiwan regions, J. Geophys. Res.74, 5923–5948.Google Scholar
  52. Katz, H. R. (1964),Some new concepts on geosynclinal development and mountain building of the southern end of South America, Proc. 22nd Internal. Geol. Cong., New Dehli4, 241–255.Google Scholar
  53. Kelleher, J. A. (1970),Space-time seismicity of the Alaska-Aleutian seismic zone. J. Geophys. Res.,75, 5745–5756.Google Scholar
  54. Kelleher, J. A. (1972),Rupture zones of large South American earthquakes and some predictions, J. Geophys. Res.77, 2087–2103.Google Scholar
  55. Kelleher, J. A., Sykes, L. R. andOliver, J. (1973),Possible criteria of predicting earthquake locations and their applications to major plate boundaries of the Pacific and Caribbean, J. Geophys. Res.78, 2547–2585.Google Scholar
  56. Kelleher, J. A., Savino, J., Rowlett, H. andMcCann, W. (1974),Why and where great thrust earthquakes occur along island arcs, J. Geophys. Res.,79, 4889–4899.Google Scholar
  57. Kelleher, J. A. andSavino, J. (1975),Distribution of seismicity before large strike-slip and thrusttype earthquakes, J. Geophys. Res.80, 260–271.Google Scholar
  58. Kelleher, J. A. andMccann, W. (1976),Buoyant zones, great earthquakes and unstable boundaries of subduction, J. Geophys. Res.81, 4885–4908.Google Scholar
  59. Kelleher, J. A. andMcCann, W. (1977),Bathymetric highs and the development of convergent plate boundaries, in (ed. M. Talwani and W. C. Pitman III) Maurice Ewing Series I:Island Arcs, Deep Sea Trenches and Back-Arc Basins, AGU, 115–122.Google Scholar
  60. Kimura, M. (1976)Major magnetic activity as key to predicting large earthquakes along the Sagami trough, Japan, Nature260, 131–133.Google Scholar
  61. Kimura, M. (1978),Relation between great earthquakes and eruptive activity in the circum-Pacific area, J. Phys. Earth26, 557–570.Google Scholar
  62. Kondorskya, N. V. andShebalin, N. V. (eds.) (1977),New Catalog of Strong Earthquakes in the Territory of the USSR, Nauka, Moscow, USSR, pp. 374–433.Google Scholar
  63. Krause, J., McCann, W., Nishenko, S. andSykes, L. (1978),Sumatra: A major seismic gap? (abstract), EOS, Trans. Amer. Geophys. Union59, 1125.Google Scholar
  64. Kulm, L. D., Schweller, W. J. andMasias, A. (1977),A preliminary analysis of the subduction process along the Andean continental margin, 6° to 45°S, in (ed. M. Talwani and W. C. Pitman III) Maurice Ewing Series I:Island Arcs, Deep Sea Trenches and Back-Arc Basins, AGU, 285–302.Google Scholar
  65. LePichon, X. (1968),Sea floor spreading and continental drift, J. Geophys. Res.73, 3661–3697.Google Scholar
  66. Lomnitz, C. (1970),Major earthquakes and tsunamis in Chile during the period 1535 to 1955, Geol. Rundschau59, 938–960.Google Scholar
  67. McCann, W. andNishenko, S. (1978),Large earthquakes and the tectonics of the western Pacificpast, present and future, Internat. Geodynamics Conf. ‘Western Pacific and Magma Genesis’, Tokyo, 100–101.Google Scholar
  68. McCann, W. andKelleher, J. (1976),Large earthquakes along convergent margins of the southwest Pacific (abstract), EOS57, 597.Google Scholar
  69. McCann, W., Murphy, A. andFrankel, A. (1979),Small earthquakes and the tectonics of the Virgin Islands region (in preparation).Google Scholar
  70. Medvedev, S. V. (ed.) (1968),Seismic Zoning of the USSR (Izdatel'stvo Nauka, Moscow 1968), pp. 460–467 (Trans. by Teteruk-Schneider, R. in Hardin, R. (ed.), Israel Progr. Sci. Trans., Jerusalem 1976).Google Scholar
  71. Meyers, H., Brozee, R., Coffman, J. andLessig, S. (1976), An analysis of earthquake intensities and recurrence rates in and near Alaska, NOAA Tech. Rept. EDS-NGSDC-3, 79 pp.Google Scholar
  72. Minster, J. B., Jordan, T. H., Molnar, P. andHaines, E. (1974),Numerical modelling of instantaneous plate tectonics, Geophys. J. Roy. astronom. Soc.36, 541–576.Google Scholar
  73. Mogi, K. (1968),Some features of recent seismic activity in and near Japan (1), Bull. Earthq. Res. Inst., Univ. Tokyo46, 1225–1236.Google Scholar
  74. Mogi, K. (1969),Some features of recent seismic activity in and near Japan (2), Bull. Earthq. Res. Inst., Univ. Tokyo47, 395–417.Google Scholar
  75. Molnar, P. andSykes, L. R. (1969),Tectonics of the Caribbean and Middle America regions from focal mechanisms and seismicity, Geol. Soc. Amer. Bull.,80, 1639–1684.Google Scholar
  76. Morgan, W. J. (1972),Plate motion and deep mantle convection in Studies in Earth and Space Science, GSA Memoir 132, Shagarn, R. (ed.).Google Scholar
  77. Murphy, A. andMcCann, W. (1979),Preliminary results from a new seismic network in the northeast Caribbean (in preparation).Google Scholar
  78. Nakamura, K. (1975),Volcano structure and possible mechanical correlation between volcanic eruptions and earthquakes, Bull. Volcanol. Soc. Japan, Ser. 2,20, 229–240.Google Scholar
  79. Nishenko, S. andMcCann, W. (1977),Deep sea terraces: Indicators of great thrust earthquake history (abstract), EOS, Trans. Amer. Geophys. Union58, 437.Google Scholar
  80. Nishenko, S. andMcCann, W. (1979),Large thrust earthquakes and tsunamis: Implications for the development of fore-arc basins, J. Geophys. Res.84, 573–584.Google Scholar
  81. Ohtake, M., Matumoto, T. andLatham, G. V. (1977),Seismicity gap near Oxaaco, southern Mexico as a probable precursor to a large earthquake, Pure appl. Geophys.115, 375–385.Google Scholar
  82. Reid, H. (1910),The California earthquake of April 18, 1906 inThe Mechanics of the Earthquake, Report of the State Earthquake Investigation Comm. 2, pp. 16–19, Carnegie Inst. Washington, D.C.Google Scholar
  83. Reid, H. andTaber, S. (1920),The Virgin Islands earthquakes of 1867–1868, Bull. Seism. Soc. Amer.10, 9–30.Google Scholar
  84. Reyes, A., Burne, J. N. andLomnitz, C. (1978),Source mechanism and aftershock study of the Colima, Mexico earthquake of January 10, 1973, in this volume.Google Scholar
  85. Richter, C. F. (1958),Elementary Seismology (W. H. Freeman, San Francisco), 768 pp.Google Scholar
  86. Rodolfo, K. S. (1969),Bathymetry and marine geology of the Andaman Basin and tectonic implications for Southeast Asia, Geol. Soc. Amer. Bull.80, 1203–1230.Google Scholar
  87. Roth'e, J. (1969),The Seismicity of the Earth 1953–1965 (Unesco, Paris), p. 336.Google Scholar
  88. Rowlett, H. andKelleher, J. (1976),Evolving seismic and tectonic patterns along the western margin of the Philippine Sea plate, J. Geophys. Res.81, 3518–3524.Google Scholar
  89. Savage, J. C. andBurford, R. O. (1973),Geodetic determination of relative plate motions in central California, J. Geophys. Res.78, 832–845.Google Scholar
  90. Scholz, C. H., Barazangi, M. andSbar, M. L. (1971),Late Cenozoic evolution of the Great Basin western United States as an ensialic inter-arc basin, Geol. Soc. Amer. Bull.82, 2979–2990.Google Scholar
  91. Shimazaki, K. (1976),Intra-plate seismicity gap along the Median Tectonic Line and oblique plate convergence in southwest Japan, Tectonophys.31, 139–156.Google Scholar
  92. Shimazaki, K. (1978),Correlation between intraplate seismicity and interplate earthquakes in Tohoku, northeast Japan, Bull. Seism. Soc. Amer.68, 181–192.Google Scholar
  93. Sieh, K. E. (1978),Prehistoric large earthquakes produced by slip on the San Andreas fault at Pallet Creek, California, J. Geophys. Res.83, 3907–3939.Google Scholar
  94. Sindvahl, H., Khattri, K. N., Rai, K. andGaur, V. K. (1978),Neo-tectonics and space-time seismicity of the Andaman-Nicobar region, Bull. Seism. Soc. Amer.68, 399–409.Google Scholar
  95. Soedati, K. (1962),Seismic zones in Indonesia, Geophys. Notes No. 2, Dept. Perhubungan Udata-Duawatan Meteorologi dan Geofisik, Duakarta, Indonesia 10 pp.Google Scholar
  96. Spence, W. (1977),The Aleutian Arc: Tectonic blocks, episodic subduction, strain diffusions and magma generation, J. Geophys. Res.32, 213–230.Google Scholar
  97. Stauder, W. (1973),Mechanism and spatial distribution of Chilean earthquakes with relation to subduction of the oceanic plate, J. Geophys. Res.78, 5033–5061.Google Scholar
  98. Sykes, L. R. (1971),Aftershock zones of great earthquakes, seismicity gaps and earthquake prediction for Alaska and the Aleutians, J. Geophys. Res.76, 8021–8041.Google Scholar
  99. Taber, S. (1920),Jamaica earthquakes and the Bartlett Trough, Bull. Seism. Soc. Amer.10, 55–89.Google Scholar
  100. Taber, S. (1922),The Great Fault Troughs of the Antilles, J. Geol.30, 89–114.Google Scholar
  101. Tarr, R. andMartin, L. (1912),The earthquakes at Yakutat Bay, Alaska in September, 1899, U. S. Geol. Surv. Prof. Pap.69, 1–131.Google Scholar
  102. Thatcher, W., Hileman, J. andHanks, T. (1975),Seismic slip distribution along the San Jacinto fault zone, Southern California, and its implications, Bull. Geol. Soc. Amer.86, 1140–1146.Google Scholar
  103. Thatcher, W. andG. Plafker (1977),The Yakutat Bay, Alaska, earthquakes: seismograms and crustal deformation, Geol. Soc. Amer. Abs. w. Prog.9, p. 515.Google Scholar
  104. Tobin, D. G. andSykes, L. R. (1968),Seismicity and tectonics of the northeast Pacific Ocean, J. Geophys. Res.73, 3821–3845.Google Scholar
  105. Uyeda, S. andKanamori, H. (1978),Back-arc opening and the mode of subduction, this volume.Google Scholar
  106. Visser, S. W. (1922),Inland and submarine epicenters of Sumatra and Java earthquakes, Koninklijk Magnetisch en Meteorologisch Observatorium te Batavia, Verhandelingen9, 14 pp.Google Scholar
  107. Vogt, P. Lowrie, A., Brace, D. andHey, R. (1976),Subduction of aseismic oceanic ridges: Effects on shape, seismicity, and other characteristics of consuming plate boundaries, Geol. Soc. Amer. Spec. Pap. 172, 59 pp.Google Scholar
  108. Winslow, M. A. (1976),Active transcurrent shear zones in Southern Chile as landword expressions of transform plate boundaries, Geol. Soc. Amer. Abs. w. Prog. 1976 Ann. Meeting, Denver. Col. p. 1173.Google Scholar
  109. Winslow, M. A. (1978),The structural evolution of the Magallanes Basin and neotectonics in the southernmost Andes SCAR-Third Symp. on Antarctic Geol. and Geophys., Madison, Wisc. held Aug. 1977, p. 113.Google Scholar
  110. Winslow, M. A. (1979),Late Cenozoic tectonic history of Tierra del Fuego, Chile, in preparation.Google Scholar
  111. Wyss, M. andBrune, J. (1971),Regional variations of source properties in southern California estimated from the ratio of short to long period amplitudes, Bull. Seism. Soc., Amer.61, 1153.Google Scholar

Copyright information

© Birkhäuser Verlag 1979

Authors and Affiliations

  • W. R. McCann
    • 1
  • S. P. Nishenko
    • 1
  • L. R. Sykes
    • 1
  • J. Krause
    • 1
  1. 1.Lamont-Doherty Geological Observatory of Columbia UniversityPalisadesUSA

Personalised recommendations