Derivative‐Assisted Classification of Fractured Zones Crossing a Deep Borehole

In this study, the derivative analysis using the derivative of drawdown with respect to log‐time was utilized to determine candidates for hydraulic conductor domains (HCDs). At a 500‐m deep borehole in the study site, the fractured rocks crossing the borehole were first classified in fractured and nonfractured zones by core logging and geophysical loggings, such as acoustic televiewing, density, and flow loggings. After conducting the hydraulic tests such as constant head withdrawal and recovery tests at the fractured zones and the nonfractured zones, the derivative analyses were carried out, of which the results were evaluated to determine the candidates for HCDs. For the nonfractured zones, the diagnostic plot has only a big hump indicating poor connection of the background fractures to the permeable geologic media, while those of the candidates for HCDs show various flow regimes. On the basis of these results, the candidates for HCDs among the fractured zones were determined. From discussion on the results, the combination of the spacing analysis and derivative analysis following a hydraulic test is recommended for determining the candidates for HCDs rather than other geophysical loggings.     

The ‘Stained Glass Procedure’, a new method to compare classification performance of images acquired with different pixel sizes

Objective comparison of classification performance of earth observation images, acquired at different spatial resolutions (e.g. NOAA-AVHRR, IRS-MOS, IRS-WiFS, Landsat-TM, IRS-LISS), is complicated because both class definition and training site selection are hampered by the inherent scale differences. This paper presents a new, generic method to compare the information content of such a set of images, the “Stained Glass Procedure”. It overcomes the stated problems by computing the scale-dependent, internal spectral variation in an image and by using this as an indicator for land cover information. The Stained Glass Procedure creates segments in the images and calculates the internal spectral variation in a high-spatial-resolution image for each segment. For each image from the set the average variance, weighted to area, is calculated. The Stained Glass Procedure can be used to predict the performance of sensors that are not available, yet, or to roughly determine the optimal spatial resolution for the classification of a specific area.The procedure was applied to images with pixel sizes ranging from 23 to 1100 m. Classification detail of Envisat-MERIS (300 m pixel size), not included in the image set, could be predicted accurately using the Stained Glass Procedure.The Stained Glass Procedure applies one procedure to all images, without any subjective decision during the analysis, thus offering a method to compare images with different pixel sizes in terms of classification detail that is truly objective.     

Parametric studies of physical conditions in the Earth's upper mantle

Seismic body-wave and surface-wave data indicate the existence of a substantial lowvelocity, low-Q zone in the upper mantle beneath western North America. Conditions in this zone are distinctively different from those that are typical of the upper mantle in shield regions. The present study, using Walsh's model for partially melted rock, suggests a common mechanism for low-velocity and low-Q zones. This parametric study also indicates that the pronounced low-velocity, low-Q zone and anomalous travel-time delays of both P and S waves in the Basin and Range Province are consistent with the combined effects of high temperature, chemical composition, phase changes, and partial melting. The observed low P_n velocity in this region is consistent with high temperature, chemical composition, and the presence of a partially molten layer within the upper mantle, but the observed teleseismic delay times result principally from the thickness of the lowvelocity zone. The teleseismic delay-time variations are therefore related to the seismic Q distribution in the asthenosphere. Conditions a few kilometers beneath the Moho boundary influence the P_n velocity; however, the observed correlation among the teleseismic signal amplitudes, travel-time delays, and the upper mantle Q indicates that the P_n velocity is a better indicator of upper mantle Q than suggested by the P_n path alone. This knowledge of the upper mantle seems to account for the anomalous effects of the Basin and Range Province and other regions of similar tectonic nature on observations of teleseismic events. This will provide a practical technique for comparing seismic observations made in unstable tectonic regions with observations made in shield areas.     

Molecular expression of opsin gene in growing juvenile mackerel (<Emphasis Type="Italic">Scomber japonicus</Emphasis> Houttuyn)

Fish have developed color vision that is closely adapted to their photic environments, where both spectral sensitivity and the number of visual opsins are influenced. The mackerel used in this study is one of the most important fishery stocks in Korea. The opsin gene of the mackerel juveniles after 20 days in hatching was isolated and characterized based on the molecular study of visual photoreceptor. The full-length mackerel opsin gene was obtained by PCR amplification of genomic DNA, as well as cDNA synthesis. Sequence analysis of the opsin gene showed that it contained a 1,080 bp open reading frame encoding 360 amino acids. Based on Schiff’s base formation (S114, K119), glycosylation (E3, F37) and palmitoylation (S281, 282), the deduced amino acid sequence had a typical rod opsin. The mackerel and Gempylus serpens showed 73.7% DNA homology on opsin gene, which was higher than any other of investigated species. In the analysis of phylogenetic relationship, the genetic placement of the mackerel is closer to that of Scombroidei than Labroidei, with supporting somewhat strong bootstrap value. In the analysis of Northern and RT-PCR, the probed products were observed only in rapidly growing juveniles. These findings indicate that in mackerel opsin mRNA expression can be detected in day-20 hatching larvae. It may play an important role in stimulating growth hormone.     

Resolving climate change in the period 15–23 ka in Greenland ice cores: a new application of spectral trend analysis

Northern Hemisphere climate history through and following the Last Glacial Maximum is recorded in detail in ice cores from Greenland. However, the period between Greenland Interstadials 1 and 2 (15–23 ka), i.e. the period of deglaciation following the last major glaciation, has been difficult to resolve in great detail. We here offer a new subdivision of this in the NGRIP, GRIP and GISP2 ice cores, by newly introducing spectral trend analysis to the study of climate-related data series from ice cores. This analysis reveals patterns of change and discontinuity in the waveform properties of a data series, relating to the environmental (including climatic) history of accumulation of the rock or ice record. The application allows high-resolution correlation between the ice cores, and a greatly improved subdivision of the study interval. Nine climatic phases are recognized, within which more identifiable events can also be correlated between the three locations.     

Source and Formation of the Arsenic in Ground Water in Hanoi,Vietnam

The problem of Arsenic source in groundwater has yet been addressed thoroughly. From the results of the analysis of samples, this article gives the statement that the Arsenic in groundwater of Quaternary sediments in Hanoi has mainly natural source, with the impact of man-made factors (industrial waste water, use of crop protection products, etc.). The article also explains the formation of Arsenic in groundwater in Hanoi area is closely related to the reduction by two main mechanisms, reducing mechanism of oxyhydroxit (Fe3 + OHAs) As liberation by microorganisms and reducing mechanism of As adsorbed on iron oxide or oxyhydroxit replaced by bicarbonate. The process of oxidation of minerals containing As is needed to be researched more.     

Comparison and relative quality assessment of the GLC2000, GLOBCOVER,MODIS and ECOCLIMAP land cover data sets at the African continental scale

Land cover dynamics at the African continental scale is of great importance for global change studies. Actually, four satellite-derived land cover maps of Africa now available, e.g. ECOCLIMAP, GLC2000, MODIS and GLOBCOVER, are based on images acquired in the 2000s. This study aims at stressing the compliances and the discrepancies between these four land cover classifications systems. Each of them used different mapping initiatives and relies on different mapping standards, which supports the present investigation. In order to do a relative comparison of the four maps, a preamble was to reconcile their thematic legends into more aggregated categories after a projection into the same spatial resolution. Results show that the agreement between the four land cover products is between 56 and 69%. While all these land cover datasets show a reasonable agreement in terms of surface types and spatial distribution patterns, mapping of heterogeneous landscapes in the four products is not very successful. Land cover products based on remote sensing imagery can indeed significantly be improved by using smarter algorithms, better timing of image acquisition, improved class definitions. Either will help to improve the accuracy of future land cover maps at the African continental scale. Data producers may use the areas of spatial agreement for training area selection while users might need to verify the information in the areas of disagreement using additional data sources.     

Random vectors and spatial analysis by geostatistics for geotechnical applications

Geostatistics is extended to the spatial analysis of vector variables by defining the estimation variance and vector variogram in terms of the magnitude of difference vectors. Many random variables in geotechnology are in vectorial terms rather than scalars, and its structural analysis requires those sample variable interpolations to construct and characterize structural models. A better local estimator will result in greater quality of input models; geostatistics can provide such estimators: kriging estimators. The efficiency of geostatistics for vector variables is demonstrated in a case study of rock joint orientations in geological formations. The positive cross-validation encourages application of geostatistics to spatial analysis of random vectors in geoscience as well as various geotechnical fields including optimum site characterization, rock mechanics for mining and civil structures, cavability analysis of block cavings, petroleum engineering, and hydrologic and hydraulic modelings.