Maximum seismic depth versus thermal parameter of subducted slab: application to deep earthquakes in Chile and Bolivia
Main Article Content
Abstract
The maximum seismic depth (Dm) depends on the thermal parameter of the descending slab (cp), which is a product of the age of the subducted lithosphere (A) and the vertical component of convergence rate (V 1.). We analyze seismicity profiles across the subduction zones of Mexico, Chile, Kamchatka, Kuriles, Japan, Sumatra, New Hebrides and Aleutians. The quasilinear part of the dependence (Dm ~ 240 km, and cp~20x102 km) corresponds to relatively young and slowly descending slab and is in general agreement with the "critical temperature" models of deep earthquakes. For cp >20x 102 km, which corresponds to the relatively older lithosphere subducting at a higher rate, the D m = f ( cp) dependence is essentially nonlinear. The flattening of the empirical Dm = f(cp) curve in the range of 20x102 km < cp < 35xl02 km is found to be a direct indication of the influence of the equilibrium 0!-Sp phase transition on Dm. Models invoking the metastable 01-Sp phase transition as a mechanism which controls the deepest seismicity can not be constrained by the results of this study. Deep focus earthquakes of the Chilean subduction zone and the strong event of June 9, 1994 in Bolivia (Mw = 8.2), were analyzed using ~he general standard dependence Dm = f (cp). A group of Chilean deep events south of 26°S has occurred inside the detached fragment of the subducted slab. D m values corresponding to these deep events lie outside D m = f (cp) curve. All other events, including the Bolivian earthquake, fit the curve within the uncertainty estimate. Thus the northern group of Chilean events does not necessarily pertain to the detached slab, and the Bolivian earthquake probably occurred at the northernmost deep edge of the oldest segment of the subducted Nazca plate.
Article Details
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
References
AKAOGI, M., E. ITO and A. NAVROTSKY, 1989. Olivine-modified Spinel-Spinel Transitions in the System Mg2SiO4-Fe2SiO4: Calorimetric Measurements, Thermochemical Calculation, and Geophysical Application. J. Geoph. Res., 94, B11, 15671-15685. DOI: https://doi.org/10.1029/JB094iB11p15671
ATWATER, T., 1989. Plate tectonic history of the northeast Pacific and western North America. In: The Eastern Pacific Ocean and Hawaii, The Geology of North America, edited by E. L. Winterer, D. M. Hussong, and R. W. Decker, v. N., pp. 21-71, Geol. Soc. of Am., Boulder, Co. DOI: https://doi.org/10.1130/DNAG-GNA-N.21
BEVINGTON, P. R., 1969. Data Reduction and Error Analysis for the Physical Sciences, 336 pp., McGraw-Hill, N. Y.
CIRCUM-PACIFIC COUNCIL FOR ENERGY AND MINERALS RESOURCES, 1981. Plate-Tectonic Map of the Circum-Pacific Region, Am. Assoc. Petrol. Geol., Tulsa, Okla.
DeMETS, C., R. G. GORDON, D. F. ARGUS and S. STEIN, 1994. Effects of recent revisions to the geomagnetic reversal time scale on estimates of current plate motions. Geophys. Res. Lett., 21, 2191-2194. DOI: https://doi.org/10.1029/94GL02118
ENGEBRETSON, D. and S. KIRBY, 1992. Deep Nazca slab seismicity: Why is it so anomalous? AGU 1992 Fall Meeting. EOS Trans. Am. Geophys. Un., 397.
FROHLICH, C., 1989. The nature of deep-focus earthquakes. Ann. Rev. Earth Planet. Sci., 17, 227-254. DOI: https://doi.org/10.1146/annurev.ea.17.050189.001303
GOTO, K., H. HAMAGUCHI and Z. SUZUKI, 1983. Distribution of stress in descending plate in special reference to intermediate and deep focus earthquakes. I. Characteristics of thermal stress distribution, Tohoku Geophys. J. (The science reports of the Tohoku University, Series 5), 29, 81-105.
GOTO, K., H. HAMAGUCHI and Z. SUZUKI, 1985. Earthquake generating stresses in a descending slab. Tectonophysics, 112, 111-128. DOI: https://doi.org/10.1016/0040-1951(85)90175-1
GREEN, H. W., 1994. Solving the Paradox of deep earthquakes, Scientific American, 50-57.
GREEN, H. W. and P. C. BURNLEY, 1989. A new self-organizing mechanism for deep-focus earthquakes. Nature, 341, 733-737. DOI: https://doi.org/10.1038/341733a0
GREEN, H. W., T. E. YOUNG, D. WALKER and C. H. SCHOLZ, 1990. Anticrack associated faulting at very high pressure in natural olivine. Nature, 348, 720-722. DOI: https://doi.org/10.1038/348720a0
KALININ, V. A. and M. V. RODKIN, 1982. Physical model for the source of deep focus earthquakes. Izv. Acad. Sci. USSR Geophys., 8, 3-12.
KIRBY, S. H., E. A. OKAL and E. R. ENGDAHL, 1995. The 9 June 94 Bolivian earthquake: An exceptional event in an extraordinary subduction zone. Geophys. Res. Lett., 22, 2233-2236. DOI: https://doi.org/10.1029/95GL01802
KIRBY, S., W. B. DURHAM and L. A. STERN, 1991. Mantle phase changes and deep-earthquake faulting in subduction lithosphere. Science, 252, 216-225. DOI: https://doi.org/10.1126/science.252.5003.216
KLITGORD, K. and J. MAMMERICKX, 1982. East Pacific rise: Magnetic anomaly and bathymetric framework. J. Geophys. Res., 87, 6725-6750. DOI: https://doi.org/10.1029/JB087iB08p06725
KOSTOGLODOV, V. V., 1989. Maximum depth of earthquakes and phase transformation within the litho-spheric slab descending in the mantle. In: Physics and Interior Structure of the Earth, edited by V. A. Magnitsky, Nauka, Moscow.
KOSTOGLODOV, V., 1994. Structure and seismotectonic segmentation of Chilean subduction zone, 7o Congreso Geológico Chileno 1994, Concepción, 17-20 Oct. 1994, Univ. de Concepción, Actas Volumen II, 1383-1387
KOSTOGLODOV, V. and W. BANDY, 1995. Seismotectonic constraints on the convergence rate between the Rivera and North American plates. J. Geophys. Res., 100, 17, 977-17, 989. DOI: https://doi.org/10.1029/95JB01484
LARSON, R. L., W. C. PITMAN III, X. GOLOVCHENCO, C. S. CANDE, J. F. DEWEY, W. F. HAXBY and J. L. LaBRECQUE, 1985. The Bedrock Geology of the World, Freeman and Co., New York.
LARUE, B. M., J. DANIEL, C. JOUANNIC and J. RECY, 1977. The South Rennel trough: evidence for a fossil spreading zone. In: International Symposium on Geodynamics in South-West Pacific, Noumea, 1976., pp. 51-62, Editions Technip, Paris.
LAY, T., 1994. Seismological constraints on the velocity structure and fate of subducting lithospheric slabs: 25 years of progress. Advances in Geophysics, 35, 1-185. DOI: https://doi.org/10.1016/S0065-2687(08)60014-X
LUNDGREN, P. and D. GIARDINI, 1995. The June 9 Bolivia and March 9 Fiji deep earthquakes of 1994: I. Source processes. Geophys. Res. Lett., 22, 2241-2244. DOI: https://doi.org/10.1029/95GL02233
MAMMERICKX, J., 1984. The morphology of propagating spreading ridges. J. Geophys. Res., 89, 1817-1828. DOI: https://doi.org/10.1029/JB089iB03p01817
MAMMERICKX, J. and K. KLITGORD, 1982. Northern East Pacific rise: evolution from 25 m.y. B.P. to the present. J. Geophys. Res., 87, 6751-6759. DOI: https://doi.org/10.1029/JB087iB08p06751
MAMMERICKX, J., D. F. NAAR and R. L. TYCE, 1988. The Mathematician paleoplate. J. Geophys. Res., 93, 3025-3040. DOI: https://doi.org/10.1029/JB093iB04p03025
MAYES, C. L., L. A. LAWVER and D. T. SANDWELL, 1990, Tectonic history and new isochron chart of the South Pacific. J. Geophys. Res., 95, 8543-8567. DOI: https://doi.org/10.1029/JB095iB06p08543
McKENZIE, D. P., 1969. Speculations on the consequence and cause of plate motions. Geophys. J. R. Astron. Soc., 18, 1-32. DOI: https://doi.org/10.1111/j.1365-246X.1969.tb00259.x
McKENZIE, D. P., 1970. Temperature and potential temperature beneath island arcs. Tectonophysics, 10, 357-366. DOI: https://doi.org/10.1016/0040-1951(70)90115-0
MEADE, C. and R. JEANLOZ, 1991. Deep-Focus earthquakes and recycling of water into the Earth's Mantle. Science, 252, 68-72. DOI: https://doi.org/10.1126/science.252.5002.68
MOLNAR, P., D. FREEDMAN and J. S. SHIH, 1979. Length of intermediate and deep seismic zones and temperatures in downgoing slabs of lithosphere. Geophys. J. R. Astron. Soc., 56, 41-54. DOI: https://doi.org/10.1111/j.1365-246X.1979.tb04766.x
MUELLER, R. D., W. R. ROEST, J.-Y. ROYER, L. M. GAHAGAN and J. G. SCLATER, 1993. A digital age map of the oceanic floor. SIO Reference Series No. 93-30, Scripps Inst. of Oceanography, Univ. of California at San Diego, La Jolla, Ca.
NAKANISHI, M., K. TAMAKI and K. KOBAYASHI, 1992. Magnetic anomaly lineations from Late Jurassic to Early Cretaceous in the west-central Pacific Ocean. Geophys. J. Int., 109, 701-719. DOI: https://doi.org/10.1111/j.1365-246X.1992.tb00126.x
NEPROCHNOV, Y. N., L. R. MERKLIN and A. A. SHREYDER, 1979. New data on the structure and geomagnetic field of the Sunda (Java) trench. Oceanology, Acad. Sci. USSR, Engl. Transl., 19, 3, 281-283.
PARDO, M. and G. SUAREZ, 1993. Steep subduction geometry of the Rivera plate beneath the Jalisco block in Western Mexico. Geophys. Res. Lett., 20, 2391-2394. DOI: https://doi.org/10.1029/93GL02794
PARDO, M. and G. SUAREZ, 1995. Shape of the subducted Rivera and Cocos plates in Southern Mexico: Seismic and Tectonic implications. J. Geophys. Res., 100, B5, 12357-12373. DOI: https://doi.org/10.1029/95JB00919
RENKIN, M. L. and J. G. SCLATER, 1988. Depth and age in the North Pacific. J. Geophys. Res., 93, 2919-2935. DOI: https://doi.org/10.1029/JB093iB04p02919
SHIONO, K. and N. SUGI, 1985. Life of an oceanic plate: cooling time and assimilation time. Tectonophysics, 112, 35-50. DOI: https://doi.org/10.1016/0040-1951(85)90171-4
SPENCER, J. E., 1994. A numerical assessment of slab strength during high-and low-angle subduction and implications for Laramide orogenesis. J. Geophys. Res., 99, 9227-9236. DOI: https://doi.org/10.1029/94JB00503
SUNG, C. M. and R. G. BURNS, 1976. Kinetics of high-pressure phase transformations: implications to the evolution of the olivine-spinel transition in the down-going lithosphere and its consequences on the dynamics of the mantle. Tectonophysics, 31, 1-32. DOI: https://doi.org/10.1016/0040-1951(76)90165-7
SYKES, L., 1966. The seismicity and deep structure of island arcs. J. Geophys. Res., 71, 2981-3006. DOI: https://doi.org/10.1029/JZ071i012p02981
TURCOTTE, D. L. and G. SCHUBERT. Structure of the Olivine-Spinel phase boundary in the descending lithosphere. J. Geophys. Res., 76, 7980-7987. DOI: https://doi.org/10.1029/JB076i032p07980
VON HERZEN, R. P., 1967. Heat flow and some implications for the mantle. In: The Earth's Mantle, edited by T. G. Gaskell, pp. 197-230, Academic, N. Y.
WEISSEL, J. K., A. B. WATTS and A. LAPOUILLE, 1982. Evidence for late Paleocene to late Eocene seafloor in the southern New Hebrides basin. Tectonophysics, 87, 243-2251. DOI: https://doi.org/10.1016/0040-1951(82)90228-1
ZHAO, D., A. HASEGAWA and S. HORIUCHI, 1992. Tomographic imaging of P and S wave velocity structure beneath northeastern Japan. J. Geophys. Res., 97, 19909-19928. DOI: https://doi.org/10.1029/92JB00603