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Norman H Sleep - One of the best experts on this subject based on the ideXlab platform.
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nonlinear SuppreSSion of high frequency S waveS by Strong rayleigh waveS
Bulletin of the Seismological Society of America, 2016Co-Authors: Norman H Sleep, Nori NakataAbstract:Strong Rayleigh waveS are expected to bring the Shallow SubSurface into frictional failure. They may nonlinearly interact with high‐frequency S waveS. The widely applied Drucker and Prager (1952) rheology predictS that horizontal compreSSion half‐cycle of Strong Rayleigh waveS will increaSe the Strength of the SubSurface for S waveS and predictS that S waveS with dynamic accelerationS >1 g will reach the Surface. We did not obServe thiS effect. Rather, we obServed that Strong high‐frequency S waveS arrived at timeS of low Rayleigh‐wave particle velocity. PhySically, high‐frequency S waveS cauSe failure on horizontal fractureS in which Rayleigh waveS do not change the normal traction. Failure then may depend on the ratio of the Shear invariant to the ambient vertical StreSS. The Shear invariant iS the Square root of the Sum of the SquareS of termS proportional to the reSolved horizontal velocity from Rayleigh waveS and to the reSolved high‐frequency dynamic acceleration from S waveS. That iS, an ellipSe Should bound reSolved dynamic acceleration verSuS reSolved particle velocity. RecordS from Seven StationS from the 2011 Tohoku earthquake and El Pedregal Station during the 2015 Coquimbo Chilean earthquake exhibit thiS expected effect of thiS nonlinear interaction.
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nonlinear attenuation from the interaction between different typeS of SeiSmic waveS and interaction of SeiSmic waveS with Shallow ambient tectonic StreSS
Geochemistry Geophysics Geosystems, 2015Co-Authors: Norman H Sleep, Nori NakataAbstract:Strong SeiSmic waveS bring rock into frictional failure at the uppermoSt few hundred meterS. NumerouS Small fractureS Slip with the cumulative effect of anelaStic Strain and nonlinear attenuation; theSe fractureS Should not diStinguiSh between remote SourceS of StreSS. Still, frictional failure criteria are not evident eSpecially when SeiSmic waveS change the normal traction on fractureS. We identify three earthquakeS aS exampleS where conSideration of interaction among dynamic StreSSeS from different wave typeS and ambient tectonic StreSS provideS theoretical predictionS of nonlinear attenuation that are potentially teStable with Single Station SeiSmogramS. For example, becauSe Rayleigh waveS produce Shallow horizontal dynamic tenSion and compreSSion, frictional failure Should preferentially occur on the tenSile half-cycle if no Shallow tectonic StreSS iS preSent and on the compreSSional half-cycle if the tectonic StreSS iS already near thruSt-faulting failure. We obServed neither effect on recordS from the 2011 Mw 9.0 Great Tohoku earthquake. However, Rayleigh waveS from thiS event appear to have brought rock beneath MYGH05 Station into frictional failure at ∼10 m depth and thuS SuppreSSed high-frequency S-waveS. The tenSile half-cycle of high frequency P-waveS reduced normal traction on horizontal planeS beneath Station IWTH25 during the 2008 Mw 6.9 Iwate-Miyagi earthquake, weakening the rock in Shear and SuppreSSing high-frequency S-waveS. The near-field velocity pulSe from the 1992 Mw 7.3 LanderS earthquake brought the uppermoSt few hundred meterS of granite beneath Lucerne Station into frictional failure, SuppreSSing high frequency S-waveS. TheSe mildly poSitive exampleS Support the reality of nonlinear wave interaction, warranting Study future Strong ground motionS. ThiS article iS protected by copyright. All rightS reServed.
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nonlinear attenuation of S waveS and love waveS within ambient rock
Geochemistry Geophysics Geosystems, 2014Co-Authors: Norman H Sleep, Brittany A EricksonAbstract:We obtain Scaling relationShipS for nonlinear attenuation of S-waveS and Love waveS within Sedimentary baSinS to aSSiSt numerical modeling. TheSe relationShipS conStrain the paSt peak ground velocity (PGV) of Strong 3–4 S Love waveS from San AndreaS eventS within Greater LoS AngeleS, aS well aS the maximum PGV of future waveS that can propagate without Strong nonlinear attenuation. During each event, the Shaking epiSode crackS the Stiff, Shallow rock. Over multiple eventS, thiS repeated damage in the upper few hundred meterS leadS to Self-organization of the Shear moduluS. Dynamic Strain iS PGV divided by phaSe velocity, and dynamic StreSS iS Strain timeS the Shear moduluS. The frictional yield StreSS iS proportional to depth timeS the effective coefficient of friction. At the eventual quaSi-Steady Self-organized State, the Shear moduluS increaSeS linearly with depth allowing inference of paSt typical PGV where rock over the damaged depth range barely reacheS frictional failure. Still greater future PGV would cauSe frictional failure throughout the damaged zone, nonlinearly attenuating the wave. ASSuming Self-organization haS taken place, eStimated maximum paSt PGV within Greater LoS AngeleS BaSinS iS 0.4–2.6 m S−1. The upper part of thiS range includeS regionS of accumulating SedimentS with low S-wave velocity that may have not yet compacted, rather than having been damaged by Strong Shaking. PubliShed numerical modelS indicate that Strong Love waveS from the San AndreaS Fault paSS through Whittier NarrowS. Within thiS corridor, deep drawdown of the water table from itS currently Shallow and preinduStrial levelS would nearly double PGV of Love waveS reaching Downtown LoS AngeleS.
John Katsaras - One of the best experts on this subject based on the ideXlab platform.
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diffraction pattern from thermal neutron incoherent elaStic Scattering and the holographic reconStruction of the coherent Scattering length diStribution
Physical Review B, 2005Co-Authors: B Sur, Vinicius N P Anghel, R B Rogge, John KatsarasAbstract:The diffraction of Spherical waveS (S waveS) interacting with a periodic Scattering length diStribution produceS characteriStic intenSity patternS known aS KoSSel and Kikuchi lineS (collectively called K lineS). The K-line Signal can be inverted to give the three-dimenSional Structure of the coherent Scattering length diStribution Surrounding the Source of S waveS - a proceSS known aS 'Gabor holography' or, Simply, 'holography'. ThiS paper outlineS a kinematical formulation for the diffraction pattern of monochromatic plane waveS Scattering from a mixed incoherent and coherent S-wave Scattering length diStribution. The formulation demonStrateS that the diffraction pattern of plane waveS incident on a Sample with a uniformly random diStribution of incoherent ScattererS iS the Same aS that from a Sample with a Single incoherent Scatterer per unit cell. In practice, one can therefore reconStruct the holographic data from SampleS with numerouS incoherent S-wave ScattererS per unit cell. ThuS atomic reSolution thermal neutron holography iS poSSible for materialS naturally rich in incoherent thermal neutron ScattererS, Such aS hydrogen (e.g., biological and polymeric materialS). Additionally, holographic inverSionS from Single-wavelength data have Suffered from the So-called conjugate or twin-image problem. The formulation preSented for holographic inverSion - different from thoSe uSed previouSly [e.g., T. Gog et al.,more » PhyS. Rev. Lett. 76, 3132 (1996)] - eliminateS the twin-image problem for Single-wavelength data.« leSS
Nori Nakata - One of the best experts on this subject based on the ideXlab platform.
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nonlinear SuppreSSion of high frequency S waveS by Strong rayleigh waveS
Bulletin of the Seismological Society of America, 2016Co-Authors: Norman H Sleep, Nori NakataAbstract:Strong Rayleigh waveS are expected to bring the Shallow SubSurface into frictional failure. They may nonlinearly interact with high‐frequency S waveS. The widely applied Drucker and Prager (1952) rheology predictS that horizontal compreSSion half‐cycle of Strong Rayleigh waveS will increaSe the Strength of the SubSurface for S waveS and predictS that S waveS with dynamic accelerationS >1 g will reach the Surface. We did not obServe thiS effect. Rather, we obServed that Strong high‐frequency S waveS arrived at timeS of low Rayleigh‐wave particle velocity. PhySically, high‐frequency S waveS cauSe failure on horizontal fractureS in which Rayleigh waveS do not change the normal traction. Failure then may depend on the ratio of the Shear invariant to the ambient vertical StreSS. The Shear invariant iS the Square root of the Sum of the SquareS of termS proportional to the reSolved horizontal velocity from Rayleigh waveS and to the reSolved high‐frequency dynamic acceleration from S waveS. That iS, an ellipSe Should bound reSolved dynamic acceleration verSuS reSolved particle velocity. RecordS from Seven StationS from the 2011 Tohoku earthquake and El Pedregal Station during the 2015 Coquimbo Chilean earthquake exhibit thiS expected effect of thiS nonlinear interaction.
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nonlinear attenuation from the interaction between different typeS of SeiSmic waveS and interaction of SeiSmic waveS with Shallow ambient tectonic StreSS
Geochemistry Geophysics Geosystems, 2015Co-Authors: Norman H Sleep, Nori NakataAbstract:Strong SeiSmic waveS bring rock into frictional failure at the uppermoSt few hundred meterS. NumerouS Small fractureS Slip with the cumulative effect of anelaStic Strain and nonlinear attenuation; theSe fractureS Should not diStinguiSh between remote SourceS of StreSS. Still, frictional failure criteria are not evident eSpecially when SeiSmic waveS change the normal traction on fractureS. We identify three earthquakeS aS exampleS where conSideration of interaction among dynamic StreSSeS from different wave typeS and ambient tectonic StreSS provideS theoretical predictionS of nonlinear attenuation that are potentially teStable with Single Station SeiSmogramS. For example, becauSe Rayleigh waveS produce Shallow horizontal dynamic tenSion and compreSSion, frictional failure Should preferentially occur on the tenSile half-cycle if no Shallow tectonic StreSS iS preSent and on the compreSSional half-cycle if the tectonic StreSS iS already near thruSt-faulting failure. We obServed neither effect on recordS from the 2011 Mw 9.0 Great Tohoku earthquake. However, Rayleigh waveS from thiS event appear to have brought rock beneath MYGH05 Station into frictional failure at ∼10 m depth and thuS SuppreSSed high-frequency S-waveS. The tenSile half-cycle of high frequency P-waveS reduced normal traction on horizontal planeS beneath Station IWTH25 during the 2008 Mw 6.9 Iwate-Miyagi earthquake, weakening the rock in Shear and SuppreSSing high-frequency S-waveS. The near-field velocity pulSe from the 1992 Mw 7.3 LanderS earthquake brought the uppermoSt few hundred meterS of granite beneath Lucerne Station into frictional failure, SuppreSSing high frequency S-waveS. TheSe mildly poSitive exampleS Support the reality of nonlinear wave interaction, warranting Study future Strong ground motionS. ThiS article iS protected by copyright. All rightS reServed.
B Sur - One of the best experts on this subject based on the ideXlab platform.
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diffraction pattern from thermal neutron incoherent elaStic Scattering and the holographic reconStruction of the coherent Scattering length diStribution
Physical Review B, 2005Co-Authors: B Sur, Vinicius N P Anghel, R B Rogge, John KatsarasAbstract:The diffraction of Spherical waveS (S waveS) interacting with a periodic Scattering length diStribution produceS characteriStic intenSity patternS known aS KoSSel and Kikuchi lineS (collectively called K lineS). The K-line Signal can be inverted to give the three-dimenSional Structure of the coherent Scattering length diStribution Surrounding the Source of S waveS - a proceSS known aS 'Gabor holography' or, Simply, 'holography'. ThiS paper outlineS a kinematical formulation for the diffraction pattern of monochromatic plane waveS Scattering from a mixed incoherent and coherent S-wave Scattering length diStribution. The formulation demonStrateS that the diffraction pattern of plane waveS incident on a Sample with a uniformly random diStribution of incoherent ScattererS iS the Same aS that from a Sample with a Single incoherent Scatterer per unit cell. In practice, one can therefore reconStruct the holographic data from SampleS with numerouS incoherent S-wave ScattererS per unit cell. ThuS atomic reSolution thermal neutron holography iS poSSible for materialS naturally rich in incoherent thermal neutron ScattererS, Such aS hydrogen (e.g., biological and polymeric materialS). Additionally, holographic inverSionS from Single-wavelength data have Suffered from the So-called conjugate or twin-image problem. The formulation preSented for holographic inverSion - different from thoSe uSed previouSly [e.g., T. Gog et al.,more » PhyS. Rev. Lett. 76, 3132 (1996)] - eliminateS the twin-image problem for Single-wavelength data.« leSS
Brittany A Erickson - One of the best experts on this subject based on the ideXlab platform.
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nonlinear attenuation of S waveS and love waveS within ambient rock
Geochemistry Geophysics Geosystems, 2014Co-Authors: Norman H Sleep, Brittany A EricksonAbstract:We obtain Scaling relationShipS for nonlinear attenuation of S-waveS and Love waveS within Sedimentary baSinS to aSSiSt numerical modeling. TheSe relationShipS conStrain the paSt peak ground velocity (PGV) of Strong 3–4 S Love waveS from San AndreaS eventS within Greater LoS AngeleS, aS well aS the maximum PGV of future waveS that can propagate without Strong nonlinear attenuation. During each event, the Shaking epiSode crackS the Stiff, Shallow rock. Over multiple eventS, thiS repeated damage in the upper few hundred meterS leadS to Self-organization of the Shear moduluS. Dynamic Strain iS PGV divided by phaSe velocity, and dynamic StreSS iS Strain timeS the Shear moduluS. The frictional yield StreSS iS proportional to depth timeS the effective coefficient of friction. At the eventual quaSi-Steady Self-organized State, the Shear moduluS increaSeS linearly with depth allowing inference of paSt typical PGV where rock over the damaged depth range barely reacheS frictional failure. Still greater future PGV would cauSe frictional failure throughout the damaged zone, nonlinearly attenuating the wave. ASSuming Self-organization haS taken place, eStimated maximum paSt PGV within Greater LoS AngeleS BaSinS iS 0.4–2.6 m S−1. The upper part of thiS range includeS regionS of accumulating SedimentS with low S-wave velocity that may have not yet compacted, rather than having been damaged by Strong Shaking. PubliShed numerical modelS indicate that Strong Love waveS from the San AndreaS Fault paSS through Whittier NarrowS. Within thiS corridor, deep drawdown of the water table from itS currently Shallow and preinduStrial levelS would nearly double PGV of Love waveS reaching Downtown LoS AngeleS.