Book reviews     

Clyde H. Moore  C. W. Grant  S. R. Jacobson 《Geo-Marine Letters》1991,11(1):56-58

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Lightning flash mensuration using video from the space shuttle Columbia (STS‐32)     

David E. Pitts  Clyde A. Sapp  Otha H. Vaughan Jr. 《国际地球制图》2013,28(1):61-68

Abstract

Environmental data are often utilized to guide interpretation of spectral information based on context, however, these are also important in deriving vegetation maps themselves, especially where ecological information can be mapped spatially. A vegetation classification procedure is presented which combines a classification of spectral data from Landsat‐5 Thematic Mapper (TM) and environmental data based on topography and fire history. These data were combined utilizing fuzzy logic where assignment of each pixel to a single vegetation category was derived comparing the partial membership of each vegetation category within spectral and environmental classes. Partial membership was assigned from canopy cover for forest types measured from field sampling. Initial classification of spectral and ecological data produced map accuracies of less than 50% due to overlap between spectrally similar vegetation and limited spatial precision for predicting local vegetation types solely from the ecological information. Combination of environmental data through fuzzy logic increased overall mapping accuracy (70%) in coniferous forest communities of northwestern Montana, USA.  相似文献   

Evaluation,repair and stabilization of the boling sinkhole     

Dreyer  Boyd V.  Schulz  Clyde E. 《Environmental Geology》1986,8(1-2):19-23

Abrupt ground subsidence occurred along FM 442, approximately 3 miles east of Boling, in Wharton County, Texas, in August 1983 The subsidence created a depression of approximately 250 feet in diameter with a maximum depth of about 25 feet. Roadway collapse, pavement breakage, and inundation of the sinkhole by subsurface waters forced the closure of FM 442 to thru-traffic The vicinity of the sinkhole is underlain, by alluvial deposits of the Colorado River drainage basin and unconsolidated Miocene, Pliocene, and Pleistocene sediments to a depth of about 500 feet. The sediments consist largely of sand, silts, clays, and gravels. The Boling Salt Dome and its associated caprock occur directly beneath the section of unconsolidated sediments Major and minor axes of the dome are about 5 miles and 35 miles, respectively, and the sinkhole occurred approximately 1 mile east-northeast of the dome's center An investigation was conducted in the immediate area of the sinkhole to determine the cause of the subsidence and also to determine the feasibility of dewatering the sinkhole Four monitoring wells were installed around the perimeter to evaluate the potential recharge from shallow sand units Two 300-foot holes were drilled and geophysically logged to determine the stratigraphy adjacent to the sinkhole, and two slope indicators were installed in order to evaluate further earth movements A total of six million gallons of saline water were removed and disposed of from the sinkhole Based on information provided by the geologic and dewatering investigation, the Texas State Department of Highways and Public Transportation elected to fill the existing sinkhole and reconstruct the roadway A total of 3,500 cubic yards of rock borrow and 26,000 cubic yards of soil borrow were placed in the depression Construction began in February 1984, and the roadway was completed in May A monitoring program to evaluate subsequent earth movements will continue into 1985  相似文献   

Field Test of the In Situ Permeable Ground Water Flow Sensor   总被引：1，自引：0，他引：1  

Andrew S. Alden  Clyde L. Munster 《Ground Water Monitoring & Remediation》1997,17(4):81-88

Two in situ permeable flow sensors, recently developed at Sandia National Laboratories, were field tested at the Brazos River Hydrologic Field Site near College Station, Texas. The flow sensors use a thermal perturbation technique to quantify the magnitude and direction of ground water flow in three dimensions. Two aquifer pumping tests lasting eight and 13 days were used to field test the flow sensors. Components of ground water flow as determined from piezometer gradient measurements were compared with ground water flow components derived from the 3-D flow sensors. The changes in velocity magnitude and direction of ground water flow induced by the pump were evaluated using flow sensor data and piezometric analyses. Flow sensor performance closely matched piezometric analysis results. Ground water flow direction (azimuth), as measured by the flow sensors and derived in the piezometric analysis, predicted the position of the pumping well accurately. Ground water flow velocities measured by the flow sensors compared well to velocities derived in the piezometric analysis. A significant delay in flow sensor response to relatively rapid changes in ground water flow was observed. Preliminary tests indicate that the in situ permeable flow sensor provides accurate and timely information on the velocity magnitude and direction of ground water flow.  相似文献   

Volcanic and Seismic Swarm Events on the Reykjanes Ridge and Their Similarities to Events on Iceland: Results of a Rapid Response Mission     

Kathleen Crane  Lynn Johnson  Bruce Appelgate  Clyde Nishimura  Roger Buck  Chris Jones  Peter Vogt  Rubin Kos’yan 《Marine Geophysical Researches》1997,19(4):319-338

On 21 May 1989, a major earthquake swarm on the Reykjanes Ridge at59°44 N, 29°32 W at a water depth of about 1000 m andabout 500 km southwest of Iceland was detected on both the WorldwideStandard Seismic Network (WWSSN) and Icelandic seismic networks. As part ofa multi-institutional response to this swarm, the Naval ResearchLaboratory arranged for a P3 Orion Aircraft to deploy sonobuoys and AXBTs inthe immediate vicinity of the swarm activity. The detection of the swarmmotivated a survey of the region in 1990, using the towed SeaMARC IIside-looking sonar system. In 1990–1991 the Russian ShirshovInstitute of Oceanology offered the use of its MIR deep-divingsubmersibles to investigate the rise axis for recent volcanism. During 1992,a scientific team comprised of five US and ten Russian scientists mobilizedthe twin, deep diving Russian submersibles to study the spreading axis ofthe Reykjanes Ridge. The resulting data analyses allows us to conclude thatthe 1989 seismic swarm event occurred adjacent to and east of the largeaxial high in the center of our survey area. The length, width and depthrange of the earthquakes were very similar to major seismic swarm eventsconfined to fissure systems in the Krafla region of Iceland. It is likelythat the earthquake swarm was located on a fresh, well-defined systemof fissures and faults extending south of the northernmost axial highstudied. The earthquake swarm was probably associated with an emanation oflava creating a region of high backscatter, located just to the east of thecentral axial high. In addition, the region of high-backscatterremains unsampled because it lay underneath the nadir of the processedSeaMARC tracks used to plan the submersible survey. However many sampleswere taken and structural studies of the evolving Reykjanes Ridge werecarried out.  相似文献   

The role of orbit determination in satellite altimeter data analysis     

Bruce C. Douglas  Clyde C. Goad 《Boundary-Layer Meteorology》1978,13(1-4):245-251

The satellite-borne radar altimeters on GEOS 3 and SEASAT produce high-precision measurement of distance from the satellite to the ocean surface. However, the precision of the GEOS 3 altimeter (~50 cm) and especially the forthcoming SEASAT (~10 cm) instrument far exceeds our ability to determine the position of either satellite using conventional electronic or laser-tracking methods. Thus special techniques are required to prevent the uncertainty of the satellite position from degrading the value of the altimeter data. The altimeter data themselves provide a solution to this problem. Using the condition that intersections of passes of altimeter data must measure the same time-invariant part of the sea-surface height, the root-mean-square error of 292 intersections of 47 passes of GEOS 3 altimeter data from the Atlantic Ocean was reduced from 17 m to 44 cm. Simulations of the SEASAT problem also show that altimeter data can aid in determining the satellite orbit, and have their greatest value when radar or laser tracking is sparse.  相似文献   

The great lakes clean-up     

Clyde Sanger 《Marine pollution bulletin》1972

The Great Lakes are at last to be cleaned up. An agreement signed in Canada by President Nixon commits Canada and the US to spend 3,500 million dollars over five years de-polluting the immense lakes—Lake Erie is twice the size of Jamaica and Lake Ontario is twice the size of Cyprus. Currently, Erie has become known as the dead lake—but in a few years game fish could be back in it.  相似文献   

Seasonal variation of infiltration rates through pond bed in a managed aquifer recharge system in St-André, Belgium     

Sayantan Samanta  Zhuping Sheng  Clyde L. Munster  Emmanuel Van Houtte 《水文研究》2020,34(18):3807-3823

In Belgium, IWVA uses managed aquifer recharge (MAR) to recharge the aquifer with treated wastewater generated from the communities to sustain the potable water supply on the Belgian coast. This MAR facility is faced with a challenge of reduced infiltration rates during the winter season when pond water temperatures near 4°C. This study involves the identification of the predominant factor influencing the rate of infiltration through the pond bed. Several factors, including pumping rates, natural recharge, tidal influences of the North Sea and pond-water temperature, were identified as potential causes for variation of the recharge rate. Correlation statistics and linear regression analysis were used to determine the sensitivity of the infiltration rate to the aforementioned factors. Two groundwater flow models were developed in visual MODFLOW to simulate the water movement under the pond bed and to obtain the differences in flux to track the effects of variation of hydraulic conductivity during the two seasons. A 32% reduction in vertical hydraulic gradient in the top portion of the aquifer was observed in winter, causing the recharge rates to fluctuate. Results showed that water temperature caused a 30% increase in hydraulic conductivity in summer as compared with winter and has the maximum impact on infiltration rate. Cyclic variations in water viscosity, occurring because of seasonal temperature changes, influence the saturated hydraulic conductivity of the pond bed. Results from the models confirm the impact on infiltration rate by temperature-influenced hydraulic conductivity.  相似文献   

The use of passive treatment alternatives for the mitigation of acidic drainage at the Williams Brother mine,California: Bench-scale study     

Erin J. Clyde  Pascale Champagne  Heather E. Jamieson 《Applied Geochemistry》2010

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The anisotropic structure of the upper mantle in the Pacific   总被引：4，自引：0，他引：4  

Clyde E. Nishimura  Donald W. Forsyth 《Geophysical Journal International》1989,96(2):203-229

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