Full Access
A Kinematic Thermal Model for Descending Slabs with Velocity Boundary Layers: A Case Study for the Tonga Subducting Slab
ZHANG Keliang,
WEI Dongping,
ZHANG Keliang
College of Earth Science, Graduate University of the Chinese Academy of Sciences, Beijing 100049, China
Search for more papers by this authorCorresponding Author
WEI Dongping
College of Earth Science, Graduate University of the Chinese Academy of Sciences, Beijing 100049, China
Corresponding author. E-mail: [email protected]Search for more papers by this authorZHANG Keliang,
WEI Dongping,
ZHANG Keliang
College of Earth Science, Graduate University of the Chinese Academy of Sciences, Beijing 100049, China
Search for more papers by this authorCorresponding Author
WEI Dongping
College of Earth Science, Graduate University of the Chinese Academy of Sciences, Beijing 100049, China
Corresponding author. E-mail: [email protected]Search for more papers by this authorAbstract:
For the purpose of investigating the influence of metastable olivine (MO) phase transformations on both deep seismicity and stagnation of slabs, we constructed a 2-dimensional finite element thermal model for a 120 Ma-old 50° dipping oceanic lithosphere descending at 10 cm/yr with velocity boundary layers, which would mitigate the interference of constant velocity field for the slab. The resulting temperatures show that most of intermediate and deep earthquakes occurring within the Tonga slab are occurring inside the 800°C and 1200°C isotherm, respectively. The elevation of olivine transformation near ∼410 km and respective persistence of metastable olivine and spinel within the transition zone and beneath 660 km would thus result in bimodal positive, zonal, negative density anomalies, respectively. These results together with the resulting pressure anomalies may reflect the stress pattern of the Tonga slab: (i) slab pull force exerts above a depth of ∼230 km; (ii) MO existence changes the buoyancy force within the transition zone and facilitates slab stagnation at a depth of 660 km; (iii) as the subducting materials accumulated over 660 km, deepest earthquakes occur due to MO transformation; (iv) a flattened ‘slab’ may penetrate into the lower mantle due to the density increment of Sp transformation.
References
- Bina, C.R., 1996. Phase transition buoyancy contributions to stresses in the subducting lithosphere. Geophys. Res. Lett., 23 (24): 3563–3566.
- Bina, C.R., 1997. Patterns of deep seismicity reflect buoyancy stresses due to phase transitions. Geophys. Res. Lett., 24(24): 3301–3304.
- Bina, C.R., Stein, S., Marton, F.C., and Van Ark, E.M., 2001. Implications of slab mineralogy for subduction dynamics. Phys. Earth Planet. Interiors, 127: 51–66.
- Bird, P., 2003. An updated digital model of plate boundaries. Geochem. Geophys. Geosyst., 4(3), 1027, doi: 10.10292001GC000252.
- Brudzinski, M.R., and Chen, W.P., 2005. Earthquakes and strain in the subhorizontal slabs. J. Geophys. Res., 110 (B08303), doi: 10.10292004JB003470.
- Castle, J.C., and Creager, K.C., 1998. NW Pacific slab rheology, the seismicity cutoff, and the olivine to spinel phase change. Earth Planets Space, 50: 977–985.
- Chambers, K., and Pysklywec, R.N., 2003. The influence of phase boundary deflection on the velocity anomalies of stagnant slabs in the transition zone. Geophys. Res. Lett., 30 (18): doi: 10.10292003GL017754.
- Chen, P.F., Bina, C.R., and Okal, E.A., 2004. A global survey of stress orientations in subducting slabs as revealed by intermediate depth earthquakes. Geophys. J. Intel., 159: 721–733.
- Chen, W.P., and Brudzinski, M.R., 2001. Evidence for a large-scale remnant of subducted lithosphere beneath Fiji. Science, 292: 2475–2479.
- Chen Yuejun, Sun Chunlin, Sun Yuewu and Sun Wei, 2008. Cretaceous volcanic events in Southeastern Jilin Province, China: Evidence from single Zircon U-Pb Ages. Acta Geologica Sinica (English edition), 82(6): 1194–1200.
- Fukao, Y., Widiyantoro, S., and Obayashi, M., 2001. Stagnant slabs in the upper and lower mantle transition region. Rev. Geophys., 39(3): 291–323.
- Ganguly, J., Freed, A.M., and Saxena, S.K., 2009. Density profiles of oceanic slabs and surrounding mantle: Integrated thermodynamic and thermal modeling, and implications for the fate of slab at the 660 km discontinuity. Phys. Earth Planet. Interiors, 172: 257–267.
- Green II, H.W., 2007. Shearing instabilities accompanying high pressure phase transformations and the mechanics of deep earthquakes. Proceedings National Acad. Sci. United States Am., 104(22): 9133–9138.
- Green II, H.W., and Burnley, P.C., 1989. A new self-organizing mechanism for deep-focus earthquakes. Nature, 341: 733–737.
- Guest, A., Schubert, G., and Gable, C.W., 2004. Stress along the metastable wedge of olivine in a subducting slab: possible explanation for the Tonga double seismic layer. Phys. Earth Planet. Interiors, 141: 253–267.
- Houseman, G.A., and Gubbins, D., 1997. Deformation of subducted oceanic lithosphere. Geophys. J. Interl., 131: 535–551.
- Iidaka, T., and Furukawa, Y., 1994. Double seismic zone for deep earthquakes in the Izu-Bonin subduction zone. Science, 263: 1116–1118.
- Iidaka, T., and Suetsugu, D., 1992. Seismological evidence for metastable olivine inside a subducting slab. Nature, 356: 593–595.
- Isacks, B., and Molnar, P., 1969. Mantle earthquake mechanisms and the sinking of the lithosphere. Nature, 223(5211): 1121–1124.
- Jiang, G., Zhao, D., and Zhang, G., 2008. Seismic evidence for a metastable olivine wedge in the subducting Pacific slab under Japan Sea. Earth Planet. Sci. Lett., 270: 300–307.
- Jiao, W., Silver, P.G., Fei, Y., and Prewitt, C.T., 2000. Do intermediate- and deep-focus earthquakes occur on preexisting weak zones? An examination of the Tonga subduction zone. J. Geophys. Res., 105(B12): 28125–28138.
- Kao, H., and Liu, L., 1995. A hypothesis for the seismogenesis of double seismic zone. Geophys. J. Interl., 123: 71–84.
- Karato, S.I., Riedel, M.R., and Yuen, D.A., 2001. Rheological structure and deformation of subducted slabs in the mantle transition zone: implications for mantle circulation and deep earthquakes. Phys. Earth Planet. Interiors, 127: 83–108.
- Kawakatsu, H., 1986. Double seismic zones: kinematics. J. Geophys. Res., 91(B5): 4811–4825.
- Kirby, S.H., Stein, S., Okal, E., and Rubie, D.C., 1996. Metastable mantle phase transformations and deep earthquakes in subducting oceanic lithosphere. Rev. Geophys., 34: 261–306.
-
Lewis, R.W.,
Nithiarasu, P., and
Seetharamu, K.N., 2004. Fundamentals of the Finite Element Method for Heat and Fluid Flow.
Chichester
: John Wiley and Sons, Ltd.
341.
10.1002/0470014164 Google Scholar
- Li Chaowen, Guo Feng, Fan Weiming and Gao Xiaofeng, 2007. Ar-Ar geochronology of Late Mesozoic volcanic rocks from the Yanji area, NE China and tectonic implications. Sci. China–Earth Science (D Ser.), 50(4): 505–518.
- Li Xiaoming and Song Yougui, 2010. Late Cretaceous-Cenozoic Exhumation History of the Lüliang Mountains, North China Craton: Constraint from Fission-track Thermochronology. Acta Gologica Sinica (English edition), 84(2): 296–305.
- Milsch, H.H., and Scholz, C.H., 2005. Dehydration-induced weakening and fault slip in gypsum: Implications for the faulting process at intermediate depth in subduction zones. J. Geophys. Res., 110, B04202, doi: 10.10292004JB003324.
- Mishra, O.P., and Zhao, D., 2004. Seismic evidence for dehydration embritlement of the subducting Pacific slab. Geophys. Res. Lett., 31, L09610, doi: 10.10292004GL019489.
- Nakajima, J., Tsuji, Y., Hasegawa, A., Kita, S., Okada, T., and Matsuzawa, T., 2009. Tomographic imaging of hydrated crust and mantle in the subducting Pacific slab beneath Hokkaido, Japan: evidence for dehydration embritlement as a cause of intraslab earthquakes. Gondwana Research, doi: 10.1016j.g.r.2008.12.010.
- Negredo, A.M., Valera, J.L., and Carminati, E., 2004. TEMSPOL: a MATLAB thermal model for deep subduction zones including major phase transformations. Computers Geosci., 30: 249–258.
- Niu Shuyin, Sun Aiqun, Wang Baode, Nie Fengjun, Jiang Sihong, Shao Ji'an, Guo Lijun and Liu Jianming, 2009. Mantle Branch Structure in the South-Central Segment of the Da Hinggan Mts., Inner Mongolia and Its Ore-controlling Role. Acta Gologica Sinica (English edition), 83(6): 1148–1162.
- Okal, E.A., and Kirby, S.H., 1998. Deep earthquakes beneath the Fiji Basin, SW Pacific: Earth's most intense deep seismicity in stagnant slabs. Phys. Earth Planet. Interiors, 109: 25–63.
- Omori, S., Komabayashi, T., and Maruyama, S., 2004. Dehydration and earthquakes in the subducting slab: empirical link in intermediate and deep seismic zones. Phys. Earth Planet. Interiors, 146: 297–311.
- Peacock, S.M., 1996, Thermal and petrologic structure of subduction zones. In: G.E. Bebout, J. Platt, D.W. Scoll, and S. Kirby, (eds.), Subduction: Top to Bottom. American Geophysical Union Geophysical Monograph, 96: 119–133.
- Ray, D., Banerjee, R., Iyer, S.D., and Mukhopadhyay, S., 2008. A new report of serpentine from Northern Central Indian Ridge (at 6°S) – an implication for hydrational activity. Acta Geologica Sinica (English edition), 82(6): 1213–1222.
- Schmeling, H., Monz, R., and Rubie, D.C., 1999. The influence of olivine metastability on the dynamics of subduction. Earth Planet. Sci. Lett., 165: 55–66.
- Stein, S., and Wysession, M., 2003. An Introduction to Seismology, Earthquakes, and Earth Structure. Boston : Blackwell publishing. 512.
- Stein, C.A., and Stein, S., 1992. A model for the global variation in oceanic depth and heat flow with age. Nature, 359: 123–129.
- Stein, S., and Rubie, D.C., 1999. Deep earthquakes in real slabs. Science, 286: 909–910.
- Stern, R.J., 2002. Subduction zones. Rev. Geophys., 40(4): 1012–1049.
- Tetzlaff, M., and Schmeling, H., 2000. The influence of olivine metastability on deep subduction of oceanic lithosphere. Phys. Earth Planet. Interiors, 120: 29–38.
- Torri, Y., and Yoshika, S., 2007. Physical conditions producing slab stagnation: constraints of the Clapeyron slope, mantle viscosity, trench retreat, and dip angles. Tectonophysics, 445: 200–209.
- Turcotte, D.L., and Schubert, G., 2002. Geodynamics ( 2nd Edition). Cambridge : Cambridge University Press. 472.
- Van der Hilst, R., 1995. Complex morphology of subducted lithosphere in the mantle beneath the Tonga trench. Nature, 374: 154–157.
- Vassiliou, M.S., and Hager, B.H., 1988. Subduction zone earthquakes and stress in slabs. Pure Applied Geophysics, 128: 547–624.
- Warren, L.M., Hughes, A.N., and Silver, P.G., 2007. Earthquake mechanics and deformation in the Tonga-Kermadec subduction zone from fault plane orientations of intermediate-and deep-focus earthquakes. J. Geophys. Res. 112(B05314), doi: 10.10292006JB004677.
-
Wessel, E., and
Smith, W.H.F., 1998. New, improved version of the Generic Mapping Tools Released, EOS Trans. AGU, 79: 579.
10.1029/98EO00426 Google Scholar
- Wiens, D.A., McGuire, J.J., and Shore, P.J., 1993. Evidence for transformational faulting from a deep double seismic zone in Tonga. Nature, 364: 790–793.
- Yamasaki, T., and Seno, T., 2003. Double seismic zone and dehydration embrittlement of subducting slab. J. Geophys. Res., 108(B4): 2212–2232.
- Yu Yang, Xu Wenliang, Pei Fuping, Yang Debin and Zhao Quanguo, 2009. Chronology and geochemistry of Mesozoic volcanic rocks in the Linjiang Area, Jilin Province and their tectonic implications. Acta Geologica Sinica (English edition), 83(2): 245–257.
- Zhao, D., Maruyama, S., and Omori, S., 2007. Mantle dynamics of Western Pacific and East Asia: insights from seismic tomography and mineral physics. Gondwana Research, 11: 120–131.
- Zienkiewicz, O.C., Taylor, R.L., and Nithiarasu, P., 2005. The Finite Element Method for Fluid Dynamics ( 6th Edition). Burlington : Elsevier Butterworth-Heinemann. 435.
