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141.
142.
Consistency Analysis of Subsurface Fracture Characterization Using Different Polarimetry Techniques by a Borehole Radar 总被引:1,自引:0,他引:1
We present a fully polarimetric borehole radar in conjunction with radar polarimetry, Pauli decomposition, and H-alpha decomposition techniques to carry out physical characterization of subsurface fractures. Further tests are needed to validate the applicability of radar polarimetry analysis for physical characterization of subsurface targets. Toward this goal, we present the implementation of two other decomposition techniques, namely: (1) the Durden-Freeman decomposition and (2) polarimetric anisotropy parameter methods, in the context of previous research and examine the consistency of results using various polarimetric decomposition techniques. While results from the radar polarimetry decomposition were found to depend greatly upon the kind of physical or mathematical models, these techniques seem to provide comparable performances in terms of fracture characterization and classification. 相似文献
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Masayuki Ehiro Satoru Kojima Tadashi Sato Talat Ahmad Tomoyuki Ohtani 《Island Arc》2007,16(1):124-132
Abstract Callovian (late Middle Jurassic) ammonoids Macrocephalites and Jeanneticeras were recovered from the Shyok suture zone, northeast of Chang La Pass, Ladakh, northwest India. They are the first reliable Jurassic fossils and the oldest chronologic data from the Shyok suture zone. The ammonoid-bearing Jurassic strata, newly defined as the Tsoltak Formation, consist largely of terrigenous mudstone with thin sandstone beds and were probably a part of the continental basement to the Cretaceous Ladakh Arc. 相似文献
145.
The 1995 Northern Niigata Earthquake (M 6.0) occurred at a shallow depth in the Niigata seismic gap. The anomaly areas in temperature, electrical conductivity and Cl- concentration of groundwater trend northeast as linear distribution in the epicentral area and are approximately coincident with the area of the seismic intensity 6 (JMA scale). The distributions of seismic intensity 6 and groundwater anomalies convincingly imaged the presence of a buried active fault beneath the epicentral area. The occurrence of this earthquake and the anomalies of groundwater were related to the expulsion of geopressured hydrothermal system (GHS). All epicenters of the destructive earthquakes along the Shinanogawa seismic belt are actually located in the buried active fault zones characterized by the areas of temperature and geochemical anomalies of groundwater. These earthquakes might have been triggered by the activity of GHS. The expulsion of GHS along an active fault in combination with the thermal softening of fault 相似文献
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Astrophysics and Space Science - Analysis of the radial velocity curves of 12 DD Lacertae showns that the primary period is decreasing and the secondary is almost constant, confirming the... 相似文献
149.
Influence of water saturation on horizontal and vertical motion at a porous soil interface induced by incident SV wave 总被引:1,自引:0,他引:1
Recent field observations have indicated that water saturation of soils may strongly affect the vertical ground motion. A study is therefore carried out to investigate the effect of saturation on horizontal and vertical motion at an interface of porous soils with potential contributions directed to site evaluation based on field observations of both the horizontal and vertical motion. The problem described in this paper corresponds to an SV wave incident at the interface between the overlying soil and the underlying rock formation. The soils are modeled as partially water-saturated porous material with a small amount of air inclusions, while the rock are approximately regarded as ordinary one-phase solid. Theoretical formulation is developed for the computation of amplitudes of horizontal and vertical interface motion, which are expressed as functions of the degree of saturation, the angle of incidence as well as the frequency. Numerical results are given for a typical sand to illustrate the influence of saturation on the interface motion in two directions and their ratios. The present study demonstrates that the effect of water saturation may be substantial on both the horizontal and vertical motion as well as on their ratios, implying the importance of such effects in the interpretation of field observations. 相似文献
150.
Assessment of the vertical distribution on seismic ground motion 总被引:1,自引:0,他引:1
It is very important for the facilities such as nuclear power plants to infer seismic force loading on the earthquake stability assessment of the building foundation and the surrounding slope. The purpose of this paper was to propose a method to evaluate underground seismic coefficients, taking into account dynamic response along the depth in horizontally multi-layered ground. The dynamic property of the seismic coefficient was analyzed on the basis of earthquake records observed at hard and soft rock sites mostly found in Tertiary deposits and sedimentary ground sites of the Pleistocene and Holocene epoch. The evaluation methods of a vertical distribution on underground seismic coefficients were proposed for a few calculation methods on the classified layered ground. Extended evaluation for underground seismic coefficients was confirmed with respect to some multi-layered ground during strong motion. 相似文献