Stress Sensitivity of Seismic and Electric Rock Properties of the Upper Continental Crust at the KTB     

Axel Kaselow  Katharina Becker  Serge A. Shapiro 《Pure and Applied Geophysics》2006,163(5-6):1021-1029

We test the hypothesis that the general trend of P-wave and S-wave sonic log velocities and resistivity with depth in the pilot hole of the KTB site Germany, can be explained by the progressive closure of the compliant porosity with increasingly effective pressure. We introduce a quantity θ_c characterizing the stress sensitivity of the mentioned properties. An analysis of the downhole measurements showed that estimates of the quantitiy θ_c for seismic velocities and electrical formation factor of the in situ formation coincide. Moreover, this quantity is 3.5 to 4.5 times larger than the averaged stress sensitivity obtained from core samples. We conclude that the hypothesis mentioned above is consistent with both data sets. Moreover, since θ_c corresponds approximately to the inverse of the effective crack aspect ratio, larger in situ estimates of θ_c might reflect the influence of fractures and faults on the stress sensitivity of the crystalline formation in contrast to the stress sensitivity of the nearly intact core samples. Finally, because the stress sensitivity is directly related to the elastic nonlinearity we conclude that the elastic nonlinearity (i.e., deviation from linear stress-strain relationship i.e., Hooke's law) of the KTB rocks is significantly larger in situ than in the laboratory.  相似文献   

Miniature interferometer terminals for Earth Surveying     

C. C. Counselman III  I. I. Shapiro 《Journal of Geodesy》1979,53(3):VIII

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Vertical mass- and trace constituent transports in the vicinity of jet streams     

Prof. M. A. Shapiro  Prof. E. R. Reiter  Prof. R. D. Cadle  Dr. W. A. Sedlacek 《Theoretical and Applied Climatology》1980,28(3):193-206

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How Good Are Estimates of Transmissivity from Slug Tests in Fractured Rock?   总被引：6，自引：1，他引：5  

Allen M. Shapiro  Paul A. Hsieh 《Ground water》1998,36(1):37-48

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A synoptic program for large solar telescopes: Cyclic variation of turbulent magnetic fields     

L. Kleint  S.V. Berdyugina  D. Gisler  A.I. Shapiro  M. Bianda 《Astronomische Nachrichten》2010,331(6):644-647

Upcoming large solar telescopes will offer the possibility of unprecedented high resolution observations. However, during periods of non‐ideal seeing such measurements are impossible and alternative programs should be considered to best use the available observing time. We present a synoptic program, currently carried out at the Istituto Ricerche Solari Locarno (IRSOL), to monitor turbulent magnetic fields employing the differential Hanle effect in atomic and molecular lines. This program can be easily adapted for the use at large telescopes exploring new science goals, nowadays impossible to achieve with smaller telescopes. The current, interesting scientific results prove that such programs are worthwhile to be continued and expanded in the future. We calculate the approximately achievable spatial resolution at a large telescope like ATST for polarimetric measurements with a noise level below 5 × 10^‐5 and a temporal resolution which is sufficient to explore variations on the granular scale. We show that it would be important to optimize the system for maximal photon throughput and to install a high‐speed camera system to be able to study turbulent magnetic fields with unprecedented accuracy (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

Publishing our "ugly babies"     

Shapiro AM 《Ground water》2007,45(6):655-655

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Arecibo radar observations of Phobos and Deimos     

Michael W. Busch  Steven J. Ostro  Jon D. Giorgini  Ellen S. Howell  Alice A. Hine  Irwin I. Shapiro 《Icarus》2007,186(2):581-584

In November 2005, we observed the moons of Mars using the Arecibo 2380-MHz (13-cm) radar, obtaining a result for the OC radar albedo of Phobos (0.056±0.014) consistent with its previously reported radar albedo and implying an upper bound on its near-surface bulk density of . We detected Deimos by radar for the first time, finding its OC radar albedo to be 0.021±0.006, implying an upper bound on its near-surface density of , consistent with a high-porosity regolith. We briefly discuss reasons for these low radar albedos, Deimos' being possibly the lowest of any Solar System body yet observed by radar.  相似文献   

A Boundary-Layer Scaling for Turbulent Katabatic Flow   总被引：1，自引：1，他引：0  

Alan Shapiro  Evgeni Fedorovich 《Boundary-Layer Meteorology》2014,153(1):1-17

Scaling relationships are proposed for the turbulent katabatic flow of a stably stratified fluid down a homogeneously cooled planar slope—the turbulent analogue of a Prandtl-type slope flow. The \(\Pi \) Theorem predicts that such flows are controlled by three non-dimensional parameters: the slope angle, the Prandtl number, and a Reynolds number defined in terms of the surface thermal forcing (surface buoyancy or surface buoyancy flux), Brunt-Väisälä frequency, slope angle, and molecular viscosity and diffusivity coefficients. However, by exploiting the structure of the governing differential equations in a boundary-layer form, scaled equations are deduced that involve only two non-dimensional parameters: the Prandtl number and a modified Reynolds number. In the proposed scaling framework, the slope angle does not appear as an independent governing parameter, but merely acts as a stretching factor in the scales for the dependent and independent variables, and appears in the Reynolds number. Based on the boundary-layer analysis, we hypothesize that the full katabatic-flow problem is largely controlled by two rather than three parameters. Preliminary tests of the scaling hypothesis using data from direct numerical simulations provide encouraging results.  相似文献   

Photoevaporation of cosmological minihaloes during reionization   总被引：1，自引：0，他引：1  

Paul R. Shapiro  Ilian T. Iliev †  Alejandro C. Raga 《Monthly notices of the Royal Astronomical Society》2004,348(3):753-782

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Solar Spectral Irradiance Variability in November/December 2012: Comparison of Observations by Instruments on the International Space Station and Models     

G. Thuillier  G. Schmidtke  C. Erhardt  B. Nikutowski  A. I. Shapiro  C. Bolduc  J. Lean  N. Krivova  P. Charbonneau  G. Cessateur  M. Haberreiter  S. Melo  V. Delouille  B. Mampaey  K. L. Yeo  W. Schmutz 《Solar physics》2014,289(12):4433-4452

Onboard the International Space Station (ISS), two instruments are observing the solar spectral irradiance (SSI) at wavelengths from 16 to 2900 nm. Although the ISS platform orientation generally precludes pointing at the Sun more than 10?–?14 days per month, in November/December 2012 a continuous period of measurements was obtained by implementing an ISS ‘bridging’ maneuver. This enabled observations to be made of the solar spectral irradiance (SSI) during a complete solar rotation. We present these measurements, which quantify the impact of active regions on SSI, and compare them with data simultaneously gathered from other platforms, and with models of spectral irradiance variability. Our analysis demonstrates that the instruments onboard the ISS have the capability to measure SSI variations consistent with other instruments in space. A comparison among all available SSI measurements during November–December 2012 in absolute units with reconstructions using solar proxies and observed solar activity features is presented and discussed in terms of accuracy.  相似文献