Book Review     

N. Barton 《Rock Mechanics and Rock Engineering》1985,18(2):141-143

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Crustal structure of the Madeira–Tore Rise, eastern North Atlantic—results of a DOBS wide-angle and normal incidence seismic experiment in the Josephine Seamount region     

C. Peirce  P. J. Barton 《Geophysical Journal International》1991,106(2):357-378

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Hydrological impacts of climate change on a data-scarce Greek catchment     

Venetsanou  P.  Anagnostopoulou  C.  Loukas  A.  Voudouris  K. 《Theoretical and Applied Climatology》2020,140(3):1017-1030

Theoretical and Applied Climatology - This paper demonstrates a climate change impact study on the hydrological process of a data-scarce Greek watershed. The Soil and Water Assessment Tool (SWAT)...  相似文献   

Adaptive traveltime tomography of densely sampled seismic data   总被引：1，自引：0，他引：1  

Immo Trinks  Satish C. Singh  Chris H. Chapman  Penny J. Barton  Miguel Bosch  Adam Cherrett 《Geophysical Journal International》2005,160(3):925-938

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Pulsed Air Sparging in Aquifers Contaminated with Dense Nonaqueous Phase Liquids   总被引：3，自引：0，他引：3  

Gorm Heron  John S. Gierke  Barton Faulkner  Susan Mravik  Lynn Wood  Carl G. Enfield 《Ground Water Monitoring & Remediation》2002,22(4):73-82

Air sparging was evaluated for remediation of tetrachloroethylene (PCE) present as dense nonaqueous phase liquid (DNAPL) in aquifers. A two-dimensional laboratory tank with a transparent front wall allowed for visual observation of DNAPL mobilization. A DNAPL zone 50 cm high was created, with a PCE pool accumulating on an aquitard. Detailed process control and analysis yielded accurate mass balances and insight into the mass-transfer limitations during air sparging. Initial PCE recovery rates were high, corresponding to fast removal of residual DNAPL within the zone influenced directly by air channels. The vadose zone DNAPL was removed within a few days, and the recovery in the extracted soil vapors decreased to low values. Increasing the sparge rate and pulsing the air injection led to improved mass recovery, as the pulsing induced water circulation and increased the DNAPL dissolution rate. Dissolved PCE concentrations both within and outside the zone of air channels were affected by the pulsing. Inside the sparge zone, aqueous concentrations decreased rapidly, matching the declining effluent PCE flux. Outside the sparge zone, PCE concentrations increased because highly contaminated water was pushed away from the air injection point. This overall circulation of water may lead to limited spreading of the contaminant, but accelerated the time-weighted average mass removal by 40% to 600%, depending on the aggressiveness of the pulsing. For field applications, pulsing with a daily or diurnal cycling time may increase the average mass removal rate, thus reducing the treatment time and saving in the order of 40% to 80% of the energy cost used to run the blowers. However, air sparging will always fail to remove DNAPL pools located below the sparge point because the air will rise upward from the top of a screen, unless very localized geological layers force the air to migrate horizontally. Unrecognized presence of DNAPL at chlorinated solvent sites residual and pools could potentially hamper success of air sparging cleanups, since the presence of small DNAPL pools, ganglia or droplets can greatly extend the treatment time.  相似文献   

Inclination shallowing and preferred transitional VGP paths     

C.E. Barton  P.L. McFadden 《Earth and Planetary Science Letters》1996,140(1-4):147-157

Transitional VGP paths recorded in sediments cluster into two antipodal preferred longitude bands that tend to lie 90° away from their site longitudes, the latter also being clustered. VGP paths obtained from lava flow sequences, though much fewer, appear not to show these biases, suggesting a rock-magnetic influence on VGP paths recorded in sediments. Inclination shallowing of detrital magnetic remanence, enhanced under low transitional field strengths, is the most likely candidate.

We illustrate the effects of inclination shallowing by applying a simple shallowing model (tan I_R = f tan I_A, where I_A is the inclination of the magnetic remanence and I_A is the inclination of the ambient field) with field variation to hypothetical data sets. Shallowing-induced clustering increases as f decreases and becomes extreme as f approaches 0.1.

We have used the model to ‘de-shallow’ the available set of transitional VGP sediment records for various values of f. The probability that the observations arise from inclination shallowing of a uniform random distribution of paths increases as f decreases. When f drops to 0.13 there is a 50% chance of getting at least as much grouping as observed. To decide if inclination shallowing is a dominant factor in the clustering, we need to know whether such extreme shallowing is widespread in sedimentary records under transitional field conditions. Field and laboratory redeposition data are not yet adequate to resolve this question.  相似文献   

Twenty-Seven Years of Manual Fresh Snowfall Density Measurements on Whistler Mountain,British Columbia     

Mark Barton 《大气与海洋》2017,55(3):144-154

Snow density is important information for a wide range of activities including avalanche control, marketing, building-code development, weather forecasting, and water supply forecasting. Extended recent high-quality datasets from the mountainous regions of the Pacific Northwest coastal area are rare. This paper presents a study of an unusually long and continuous (January 1990 to April 2016) manually collected dataset of fresh snowfall measurements for Whistler Mountain, British Columbia, Canada. The dataset consists of snowboard core measurements that were collected by Whistler–Blackcomb ski patrol staff twice daily for avalanche control and resort-marketing purposes. These records were collated, transcribed, quality controlled, and made computer accessible in this study. A discussion of the characteristics of the data collection site and an assessment of data reliability are presented. Two examples of the many purposes to which this high-quality dataset might be put were studied. Climatic teleconnections to winter (December–February) mean snow density were examined, which revealed a positive relationship to the quadratic form of the Pacific Decadal Oscillation pattern (i.e., PDO²). In addition, an analysis of daily snow density relationships to air mass types was performed, which suggested that higher (lower) densities are associated with maritime inflow (arctic outflow) conditions. Both of these relationships appear to be mediated by the positive correlation between snow density and air temperature.

Based on the full dataset (N?=?1275 individual snow density measurements) for all months with measured snowfall, annual snowfall season (November to May) mean snow densities ranged from 77?kg?m^?3 to 109?kg?m^?3 with an overall mean of 91?kg?m^?3, giving an overall snow-depth to water-depth ratio of 11:1.  相似文献   

Machine learning predictions of passive microwave brightness temperature over snow-covered land using the special sensor microwave imager (SSM/I)     

Barton A. Forman  Yuan Xue 《自然地理学》2017,38(2):176-196

Abstract

Two different forms of machine learning – an artificial neural network (ANN) and a support vector machine (SVM) – are used to estimate passive microwave (PMW) brightness temperatures (Tb) as observed by the special sensor microwave imager (SSM/I) satellite sensor over snow- covered land in North America. Both techniques reasonably reproduce unbiased estimates of SSM/I observations at 19.35 and 37.0 GHz for both vertically- and horizontally-polarized channels. When compared against SSM/I observations not used during training, domain-averaged statistics from 1 September 1987 to 1 September 2002 yielded a root mean squared error (RMSE) of less than 9 K for all frequency and polarization combinations examined in this study. Even though both ML techniques reasonably reproduced SSM/I Tb observations, the SVM outperformed the ANN because the SVM: (1) better captured the high-frequency (i.e. day-to-day) temporal characteristics in the Tb observations across the majority of the study domain, (2) better reproduced the spatial variability as a function of snow classification, and (3) yielded greater sensitivity to snow-related input variables during the estimation of PMW Tb. These findings reinforce previous research of SVM-based estimation of PMW Tb employing observations from the advanced microwave scanning radiometer.  相似文献   

Pāwehe Ke Kai a‘o Hā‘ena: Creating State Law based on Customary Indigenous Norms of Coastal Management     

Mehana Blaich Vaughan  Barton Thompson  Adam L. Ayers 《社会与自然资源》2017,30(1):31-46

Much research has demonstrated the effectiveness of customary indigenous management at conserving natural resources. However, little is known about integrating customary management with state-level institutions. We present a model case study of collaborative rulemaking based upon customary norms for interacting with resources. We explore the efforts of one Hawai‘i community to create formal state law based on customary norms to understand: (1) What is needed to integrate customary norms into state law? (2) What factors influence this integration? (3) What lessons emerge for similar efforts in other locations? First, we find that implementing some norms of customary management requires fundamental changes to state-level institutions. Second, communities can overcome institutional constraints by identifying substitutes for those customary norms that cannot be implemented directly. And third, formal regulation must be supplemented with educational and social programs. Based on these findings, we offer suggestions to integrate customary and state management in other geographies.  相似文献   

Exploring the Benefits of Field Trips in a Food Geography Course     

Karen Barton 《The Journal of geography》2017,116(6):237-249

University students often cite field experiences as some of their most important and memorable. Yet research shows that field trips are on the decline in many colleges and universities; this shift may impact geography courses that are traditionally field based. Often cited is the problem of instructor time, increased enrollment, and concerns over liability. However, field experiences give students opportunities to develop competencies, forge community connections, and provide tangible experiences that encourage deep learning. This project employs survey data from a food geography course to understand how field experiences combined with classroom discussion help students internalize and reexamine course content.  相似文献