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Stochastic Analysis of Tsunami Hazard of the 1945 Makran Subduction Zone Mw 8.1–8.3 Earthquakes. GEOSCIENCES 2020. [DOI: 10.3390/geosciences10110452] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Historical records of major earthquakes in the northwestern Indian Ocean along the Makran Subduction Zone (MSZ) indicate high potential tsunami hazards for coastal regions of Pakistan, Iran, Oman, and western India. There are fast-growing and populous cities and ports that are economically important, such as Chabahar (Iran), Gwadar (Pakistan), Muscat (Oman), and Mumbai (India). In this study, we assess the tsunami hazard of the 1945 MSZ event (fatalities ≈300 people) using stochastic earthquake rupture models of Mw 8.1–8.3 by considering uncertainties related to rupture geometry and slip heterogeneity. To quantify the uncertainty of earthquake source characteristics in tsunami hazard analysis, 1000 stochastic tsunami scenarios are generated via a stochastic source modeling approach. There are main objectives of this study: (1) developing stochastic earthquake slip models for the MSZ, (2) comparing results of the simulation with the existing observations of the 1945 event, and (3) evaluating the effect of uncertain fault geometry and earthquake slip based on simulated near-shore wave profiles. The 1945 Makran earthquake is focused upon by comparing model predictions with existing observations, consisting of far-field tsunami waveforms recorded on tide gauges in Karachi and Mumbai and coseismic deformation along the Pakistani coast. The results identify the source model that matches the existing observations of the 1945 Makran event best among the stochastic sources. The length, width, mean slip, and maximum slip of the identified source model are 270 km, 130 km, 2.9 m, and 19.3 m, respectively. Moreover, the sensitivity of the maximum tsunami heights along the coastline to the location of a large-slip area is highlighted. The maximum heights of the tsunami and coseismic deformation results at Ormara are in the range of 0.3–7.0 m and −2.7 to 1.1 m, respectively, for the 1000 stochastic source models.
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Geodynamic subduction models constrained by deep earthquakes beneath the Japan Sea and eastern China. Sci Rep 2020; 10:5440. [PMID: 32214161 PMCID: PMC7096453 DOI: 10.1038/s41598-020-62238-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 03/11/2020] [Indexed: 11/09/2022] Open
Abstract
Details of Pacific plate subduction under the Japan Sea and associated current seismicity remain challenging. Seismic tomography reveals a continuous slab dipping at ~30° down to ~600 km, and earthquake mechanisms point to down-dip compression. Further, the slab is lying at the 660-km discontinuity, and this zone is aseismic. We suggest that this pattern results from the slab's negative thermal buoyancy, resistance of the viscous lower mantle, and buoyancy forces associated with the phase transitions at 410 km and 660 km. Our model comprises an ageing subducting plate, nonlinear rheology and major phase transitions. The model explains the observed low dip angle of the slab and predicts a detailed stress pattern related to bending down to 450 km, followed by unbending as the slab is laid flat upon the 660 km boundary. Remarkably, in the bending/unbending regions, down-dip compression occurs close to the slab top/bottom, respectively. As only down-dip compression is observed, we argue that the earthquakes are mapping the top and bottom of the slab. The absence of seismicity in the flat-lying slab is explained by significantly lower stresses and higher temperatures. With this new knowledge, increasingly accurate seismic locations will considerably improve images of finite-extent slab geometry.
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Hayes GP, Moore GL, Portner DE, Hearne M, Flamme H, Furtney M, Smoczyk GM. Slab2, a comprehensive subduction zone geometry model. Science 2018; 362:58-61. [PMID: 30093602 DOI: 10.1126/science.aat4723] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 07/31/2018] [Indexed: 11/02/2022]
Abstract
Subduction zones are home to the most seismically active faults on the planet. The shallow megathrust interfaces of subduction zones host Earth's largest earthquakes and are likely the only faults capable of magnitude 9+ ruptures. Despite these facts, our knowledge of subduction zone geometry-which likely plays a key role in determining the spatial extent and ultimately the size of subduction zone earthquakes-is incomplete. We calculated the three-dimensional geometries of all seismically active global subduction zones. The resulting model, called Slab2, provides a uniform geometrical analysis of all currently subducting slabs.
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Affiliation(s)
- Gavin P Hayes
- U.S. Geological Survey National Earthquake Information Center, Golden, CO, USA.
| | - Ginevra L Moore
- U.S. Geological Survey National Earthquake Information Center, Golden, CO, USA.,Department of Geophysics, Colorado School of Mines, Golden, CO, USA
| | - Daniel E Portner
- U.S. Geological Survey National Earthquake Information Center, Golden, CO, USA.,Department of Geosciences, University of Arizona, Tucson, AZ, USA
| | - Mike Hearne
- U.S. Geological Survey National Earthquake Information Center, Golden, CO, USA
| | - Hanna Flamme
- U.S. Geological Survey National Earthquake Information Center, Golden, CO, USA.,Department of Geophysics, Colorado School of Mines, Golden, CO, USA
| | - Maria Furtney
- U.S. Geological Survey National Earthquake Information Center, Golden, CO, USA
| | - Gregory M Smoczyk
- U.S. Geological Survey National Earthquake Information Center, Golden, CO, USA
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Yoshida M. Three-dimensional visualization of numerically simulated, present-day global mantle flow. J Vis (Tokyo) 2013. [DOI: 10.1007/s12650-013-0160-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Lay T, Kanamori H, Ammon CJ, Koper KD, Hutko AR, Ye L, Yue H, Rushing TM. Depth-varying rupture properties of subduction zone megathrust faults. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jb009133] [Citation(s) in RCA: 348] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Jadamec MA, Billen MI. The role of rheology and slab shape on rapid mantle flow: Three-dimensional numerical models of the Alaska slab edge. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jb008563] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Hayes GP, Wald DJ, Johnson RL. Slab1.0: A three-dimensional model of global subduction zone geometries. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jb008524] [Citation(s) in RCA: 738] [Impact Index Per Article: 61.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Gavin P. Hayes
- National Earthquake Information Center, U.S. Geological Survey; Golden Colorado USA
| | - David J. Wald
- National Earthquake Information Center, U.S. Geological Survey; Golden Colorado USA
| | - Rebecca L. Johnson
- National Earthquake Information Center, U.S. Geological Survey; Golden Colorado USA
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Shen X, Zhou H. The low-velocity layer at the depth of 620 km beneath Northeast China. ACTA ACUST UNITED AC 2009. [DOI: 10.1007/s11434-008-0559-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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9
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Crystallographic preferred orientation of akimotoite and seismic anisotropy of Tonga slab. Nature 2008; 455:657-60. [DOI: 10.1038/nature07301] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2007] [Accepted: 08/01/2008] [Indexed: 11/08/2022]
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Chlieh M, Avouac JP, Sieh K, Natawidjaja DH, Galetzka J. Heterogeneous coupling of the Sumatran megathrust constrained by geodetic and paleogeodetic measurements. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007jb004981] [Citation(s) in RCA: 215] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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11
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Ichinose G, Somerville P, Thio HK, Graves R, O'Connell D. Rupture process of the 1964 Prince William Sound, Alaska, earthquake from the combined inversion of seismic, tsunami, and geodetic data. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jb004728] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Borrero JC, Sieh K, Chlieh M, Synolakis CE. Tsunami inundation modeling for western Sumatra. Proc Natl Acad Sci U S A 2006; 103:19673-7. [PMID: 17170141 PMCID: PMC1750885 DOI: 10.1073/pnas.0604069103] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A long section of the Sunda megathrust south of the great tsunamigenic earthquakes of 2004 and 2005 is well advanced in its seismic cycle and a plausible candidate for rupture in the next few decades. Our computations of tsunami propagation and inundation yield model flow depths and inundations consistent with sparse historical accounts for the last great earthquakes there, in 1797 and 1833. Numerical model results from plausible future ruptures produce flow depths of several meters and inundation up to several kilometers inland near the most populous coastal cities. Our models of historical and future tsunamis confirm a substantial exposure of coastal Sumatran communities to tsunami surges. Potential losses could be as great as those that occurred in Aceh in 2004.
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Affiliation(s)
- José C Borrero
- Department of Civil and Environmental Engineering, University of Southern California, Los Angeles, CA 90089-2531, USA.
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Miller MS, Kennett BLN, Toy VG. Spatial and temporal evolution of the subducting Pacific plate structure along the western Pacific margin. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2005jb003705] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- M. S. Miller
- Research School of Earth Sciences; Australian National University; Canberra, ACT Australia
| | - B. L. N. Kennett
- Research School of Earth Sciences; Australian National University; Canberra, ACT Australia
| | - V. G. Toy
- Research School of Earth Sciences; Australian National University; Canberra, ACT Australia
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Banerjee P, Pollitz FF, Bürgmann R. The Size and Duration of the Sumatra-Andaman Earthquake from Far-Field Static Offsets. Science 2005; 308:1769-72. [PMID: 15905364 DOI: 10.1126/science.1113746] [Citation(s) in RCA: 171] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The 26 December 2004 Sumatra earthquake produced static offsets at continuously operating GPS stations at distances of up to 4500 kilometers from the epicenter. We used these displacements to model the earthquake and include consideration of the Earth's shape and depth-varying rigidity. The results imply that the average slip was >5 meters along the full length of the rupture, including the approximately 650-kilometer-long Andaman segment. Comparison of the source derived from the far-field static offsets with seismically derived estimates suggests that 25 to 35% of the total moment release occurred at periods greater than 1 hour. Taking into consideration the strong dip dependence of moment estimates, the magnitude of the earthquake did not exceed Mw = 9.2.
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Affiliation(s)
- P Banerjee
- Wadia Institute of Himalayan Geology, Dehra Dun, 248001, India
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Ammon CJ, Ji C, Thio HK, Robinson D, Ni S, Hjorleifsdottir V, Kanamori H, Lay T, Das S, Helmberger D, Ichinose G, Polet J, Wald D. Rupture Process of the 2004 Sumatra-Andaman Earthquake. Science 2005; 308:1133-9. [PMID: 15905393 DOI: 10.1126/science.1112260] [Citation(s) in RCA: 527] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The 26 December 2004 Sumatra-Andaman earthquake initiated slowly, with small slip and a slow rupture speed for the first 40 to 60 seconds. Then the rupture expanded at a speed of about 2.5 kilometers per second toward the north northwest, extending 1200 to 1300 kilometers along the Andaman trough. Peak displacements reached approximately 15 meters along a 600-kilometer segment of the plate boundary offshore of northwestern Sumatra and the southern Nicobar islands. Slip was less in the northern 400 to 500 kilometers of the aftershock zone, and at least some slip in that region may have occurred on a time scale beyond the seismic band.
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Affiliation(s)
- Charles J Ammon
- Department of Geosciences, Pennsylvania State University, 440 Deike Building, University Park, PA 16802, USA.
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Debayle E, Sambridge M. Inversion of massive surface wave data sets: Model construction and resolution assessment. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/2003jb002652] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Eric Debayle
- Institut de Physique du Globe de Strasbourg, Ecole et Observatoire des Sciences de la Terre; Centre National de la Recherche Scientifique, and Université Louis Pasteur; Strasbourg France
| | - Malcolm Sambridge
- Centre for Advance Data Inference; Research School of Earth Sciences, Australian National University; Canberra Australia
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Tibi R, Wiens DA, Inoue H. Remote triggering of deep earthquakes in the 2002 Tonga sequences. Nature 2003; 424:921-5. [PMID: 12931183 DOI: 10.1038/nature01903] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2003] [Accepted: 07/14/2003] [Indexed: 11/09/2022]
Abstract
It is well established that an earthquake in the Earth's crust can trigger subsequent earthquakes, but such triggering has not been documented for deeper earthquakes. Models for shallow fault interactions suggest that static (permanent) stress changes can trigger nearby earthquakes, within a few fault lengths from the causative earthquake, whereas dynamic (transient) stresses carried by seismic waves may trigger earthquakes both nearby and at remote distances. Here we present a detailed analysis of the 19 August 2002 Tonga deep earthquake sequences and show evidence for both static and dynamic triggering. Seven minutes after a magnitude 7.6 earthquake occurred at a depth of 598 km, a magnitude 7.7 earthquake (664 km depth) occurred 300 km away, in a previously aseismic region. We found that nearby aftershocks of the first mainshock are preferentially located in regions where static stresses are predicted to have been enhanced by the mainshock. But the second mainshock and other triggered events are located at larger distances where static stress increases should be negligible, thus suggesting dynamic triggering. The origin times of the triggered events do not correspond to arrival times of the main seismic waves from the mainshocks and the dynamically triggered earthquakes frequently occur in aseismic regions below or adjacent to the seismic zone. We propose that these events are triggered by transient effects in regions near criticality, but where earthquakes have difficulty nucleating without external influences.
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Affiliation(s)
- Rigobert Tibi
- Department of Earth and Planetary Sciences, Washington University, St. Louis, Missouri 63130, USA.
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Song TRA, Simons M. Large trench-parallel gravity variations predict seismogenic behavior in subduction zones. Science 2003; 301:630-3. [PMID: 12893939 DOI: 10.1126/science.1085557] [Citation(s) in RCA: 215] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We demonstrate that great earthquakes occur predominantly in regions with a strongly negative trench-parallel gravity anomaly (TPGA), whereas regions with strongly positive TPGA are relatively aseismic. These observations suggest that, over time scales up to at least 1 million years, spatial variations of seismogenic behavior within a given subduction zone are stationary and linked to the geological structure of the fore-arc. The correlations we observe are consistent with a model in which spatial variations in frictional properties on the plate interface control trench-parellel variations in fore-arc topography, gravity, and seismogenic behavior.
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Affiliation(s)
- Teh-Ru Alex Song
- Seismological Laboratory, Division of Geological and Planetary Science, California Institute of Technology, Pasadena, CA 91125, USA.
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Lebedev S, Nolet G. Upper mantle beneath Southeast Asia fromSvelocity tomography. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2000jb000073] [Citation(s) in RCA: 217] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Sergei Lebedev
- Department of Geosciences; Princeton University; Princeton New Jersey USA
| | - Guust Nolet
- Department of Geosciences; Princeton University; Princeton New Jersey USA
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20
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Tibi R. Seismic body wave constraint on mechanisms of intermediate-depth earthquakes. ACTA ACUST UNITED AC 2002. [DOI: 10.1029/2001jb000361] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
Data from earthquakes in the Tonga-Fiji region recorded at a seismic array in northern Australia show evidence for rigid zones at the top of the outer core. The ScP waveforms can be modeled by thin (0.12 to 0.18 kilometer) zones of molten iron mixed with solid material with a small, but positive, S-wave velocity (0.6 to 0.8 kilometer per second) that enables the propagation of S-waves in the outermost core. The zones may be topographic highs of the core-mantle boundary filled by light core sediments and might be important for variation of Earth's nutation and for convection of the outer core.
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Affiliation(s)
- S Rost
- Department of Earth Sciences, University of California, Santa Cruz, CA 95064, USA.
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Castle JC, Creager KC, Winchester JP, van der Hilst RD. Shear wave speeds at the base of the mantle. ACTA ACUST UNITED AC 2000. [DOI: 10.1029/2000jb900193] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Kárason H, van der Hilst RD. Constraints on Mantle Convection From Seismic Tomography. GEOPHYSICAL MONOGRAPH SERIES 2000. [DOI: 10.1029/gm121p0277] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Müller RD, Gaina C, Tikku A, Mihut D, Cande SC, Stock JM. Mesozoic/Cenozoic tectonic events around Australia. GEOPHYSICAL MONOGRAPH SERIES 2000. [DOI: 10.1029/gm121p0161] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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25
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Graeber FM, Asch G. Three-dimensional models ofPwave velocity andP-to-Svelocity ratio in the southern central Andes by simultaneous inversion of local earthquake data. ACTA ACUST UNITED AC 1999. [DOI: 10.1029/1999jb900037] [Citation(s) in RCA: 131] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Flanagan MP, Shearer PM. Topography on the 410-km seismic velocity discontinuity near subduction zones from stacking ofsS,sP, andpPprecursors. ACTA ACUST UNITED AC 1998. [DOI: 10.1029/98jb00595] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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27
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Sambridge M, Guđmundsson Ó. Tomographic systems of equations with irregular cells. ACTA ACUST UNITED AC 1998. [DOI: 10.1029/97jb02602] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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