Zhang, Y. C., C. Shen, Z. X. Liu, Z. Y. Pu, I. Dandouras, A. Marchaudon, C. M. Carr, and E. Lucek. (2011). Magnetopause response to variations in the solar wind: Conjunction observations between Cluster, TC‐1, and SuperDARN. J. Geophys. Res., 116, A08209.
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Zhang Yang, Ritsema Jeroen, Thorne Michael S, . (2009). Modeling the ratios of SKKS and SKS amplitudes with ultra-low velocity zones at the core-mantle boundary
. Geophys. Res. Lett., 36(19), L19303–.
Keywords: core-mantle boundary, SKS waves, amplitudes, 7203 Seismology: Body waves, 7208 Seismology: Mantle, 0545 Computational Geophysics: Modeling,
Programme: 133
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Zhang Yang, Ritsema Jeroen, Thorne Michael S, . (2009). Modeling the ratios of SKKS and SKS amplitudes with ultra-low velocity zones at the core-mantle boundary
. Geophysical Research Letters, 36(19), L19303–.
Abstract: Between 105115° degrees, the SKS waveform is complicated by the formation of SPdKS, a wave that has segments of P diffraction along the core mantle boundary. While previous studies have primarily focused on the move-out of SPdKS from SKS, we analyze the concomitant reduction of the SKS amplitude. Long-period SKKS/SKS amplitude ratios present a coherent global pattern. SKKS/SKS is relatively large in North and South American recordings of deep Tonga-Fiji earthquakes but PREM-like in European recordings of earthquakes in South America and North American recordings of earthquakes in Indonesia. Modeling of SKKS/SKS indicate that Ultra-Low Velocity Zones (ULVZs), layers at the base of the mantle with a thickness of about 1020 km and a shear velocity reduction between 2030%, are required to explain high SKKS/SKS ratios and the early move-out of SPdKS.
Keywords: core-mantle boundary, SKS waves, amplitudes, 0545 Modeling, 7203 Body waves, 7208 Mantle,
Programme: 133
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Zhang K, Feichter J, Kazil J, Wan H, Zhuo W, Griffiths A D, Sartorius H, Zahorowski W, Ramonet M, Schmidt M, Yver C, Neubert R E M, Brunke E-G, . (2011). Radon activity in the lower troposphere and its impact on ionization rate: a global estimate using different radon emissions
. Atmos. Chem. Phys., 11(15), 7817–7838.
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Zerath E., Holy X., Gaud R. & Schmitt D. (1999). Decreased serum levels of 1,25-(OH)² vitamin D during 1 year of sunlight deprivation in the Antarctic. Eur. J. Appl. Physiol., 79, 141–147.
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Zecchinon, L., Oriol, A., Netzel, U., Svennberg, J., Gerrdin-Otthiers, N. & Feller, G. (2005). Stability domains, substrate-induced conformational changes, and hinge-bending motions in a psychrophilic phosphoglycerate kinase. J. Biol. Chem., 280, 41307–41314.
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Zecchinon L., Claverie P., Collins T., D'amico S., Delille D., Feller G., Georlette D., Gratia E., Hoyoux A., Meuwis M.A. & 1.a.l. (2001). Did psychrophilic enzymes really win the challenge? Extremophiles, 5, 313–321.
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Zdzitowiecki K., Rocka A., Pisano E. & Ozouf Costaz C. (1998). A list of parasitic worms collected off adelie Land (antarctica). Acta Parasitol., 43(2), 71–74.
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Zdzitowiecki K. (1998). Helicometra pisanoae sp. n.(Diogenea, opecoelidae), a parasire of a fish, Trematomus hansoni, in the Eastern Antarctic. Acta Parasitol., 43(1), 26–29.
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Zaroli Christophe, Debayle Eric, Sambridge Malcolm, . (2010). Frequency-dependent effects on global S-wave traveltimes: wavefront-healing, scattering and attenuation
. Geophysical Journal International , 182 (2 ), 1025–1042 .
Abstract: We present a globally distributed data set of 400 000 frequency-dependent SH-wave traveltimes. An automated technique is used to measure teleseismic S, ScS and SS traveltimes at several periods ranging from 10 to 51 s. The targeted seismic phases are first extracted from the observed and synthetic seismograms using an automated time window algorithm. Traveltimes are then measured at several periods, by cross-correlation between the selected observed and synthetic filtered waveforms. Frequency-dependent effects due to crustal reverberations beneath each receiver are handled by incorporating crustal phases into WKBJ synthetic waveforms.After correction for physical dispersion due to intrinsic anelastic processes, we observe a residual traveltime dispersion on the order of 12 s in the period range of analysis. This dispersion occurs differently for S, ScS and SS, which is presumably related to their differing paths through the Earth. We find that: (1) Wavefront-healing phenomenon is observed for S and to a lesser extent SS waves having passed through very low velocity anomalies. (2) A preferred sampling of high velocity scatterers located at the CMB may explain our observation that ScS waves travel faster at low-frequency than at high-frequency. (3) A frequency-dependent attenuation q() q0×, with 0.2, is compatible with the globally averaged dispersion observed for S waves.
Programme: 133
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