The geology of continental margins | C.A. Burk and C.L. Drake, (Editors), 1975. Springer,Berlin, 1009 pp., U.S. $34.80     

Harold D. Palmer 《Earth》1976,12(4):423-424

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Germane in the atmosphere of Jupiter     

Uwe Fink  Harold P. Larson  Richard R. Treffers 《Icarus》1978,34(2):344-354

High-altitude spectra of Jupiter obtained from the Kuiper Airborne Observatory are analyzed for the presence of germane (GeH₄) in Jupiter's atmosphere. Comparison with laboratory spectra shows that the strong Q branch of the ν₃ band of germane at 2111 cm^?1 is prominent in the Jovian spectra. The abundance of germane in Jupiter's atmosphere is 0.006 (±0.003) cm-am corresponding to a mixing ratio of 0.6 ppb. This trace amount of germane is consistent with chemical equilibrium calculations if the germane present at ～1000°K is carried up by convection to the spectroscopically observable region at ～300°K.  相似文献   

Late Quaternary barrier and fringing reef development of Bora Bora (Society Islands,south Pacific): First subsurface data from the Darwin‐type barrier‐reef system          下载免费PDF全文

Eberhard Gischler  J. Harold Hudson  Marc Humblet  Juan C. Braga  Anton Eisenhauer  Anja Isaack  Flavio S. Anselmetti  Gilbert F. Camoin 《Sedimentology》2016,63(6):1522-1549

The universally known subsidence theory of Darwin, based on Bora Bora as a model, was developed without information from the subsurface. To evaluate the influence of environmental factors on reef development, two traverses with three cores, each on the barrier and the fringing reefs of Bora Bora, were drilled and 34 uranium‐series dates obtained and subsequently analysed. Sea‐level rise and, to a lesser degree, subsidence were crucial for Holocene reef development in that they have created accommodation space and controlled reef architecture. Antecedent topography played a role as well, because the Holocene barrier reef is located on a Pleistocene barrier reef forming a topographic high. The pedestal of the fringing reef was Pleistocene soil and basalt. Barrier and fringing reefs developed contemporaneously during the Holocene. The occurrence of five coralgal assemblages indicates an upcore increase in wave energy. Age–depth plots suggest that barrier and fringing reefs have prograded during the Holocene. The Holocene fringing reef is up to 20 m thick and comprises coralgal and microbial reef sections and abundant unconsolidated sediment. Fringing reef growth started 8780 ± 50 yr bp ; accretion rates average 5·65 m kyr^?1. The barrier reef consists of >30 m thick Holocene coralgal and microbial successions. Holocene barrier‐reef growth began 10 030 ± 50 yr bp and accretion rates average 6·15 m kyr^?1. The underlying Pleistocene reef formed 116 900 ± 1100 yr bp , i.e. during marine isotope stage 5e. Based on Pleistocene age, depth and coralgal palaeobathymetry, the subsidence rate of Bora Bora was estimated to be 0·05 to 0·14 m kyr^?1. In addition to subsidence, reef development on shorter timescales like in the late Pleistocene and Holocene has been driven by glacioeustatic sea‐level changes causing alternations of periods of flooding and subaerial exposure. Comparisons with other oceanic barrier‐reef systems in Tahiti and Mayotte exhibit more differences than similarities.  相似文献   

Ecologies of actor-networks and (non)social labor within the urban political economies of nature     

Harold A. Perkins   《Geoforum》2007,38(6):1152-1162

On September 16th, 2005 the United States began restricting the entry of commodities shipped from abroad in wood packaging materials that do not conform to phytosanitation measures meant to prevent the spread of pests and pathogens. This action results from expensive lessons learned as global commerce facilitates pandemics like Dutch elm disease. Marxist political ecology is well suited to investigate such scenarios with its emphasis on the social production of nature within accumulation regimes. Some scholars contend, however, that Marxist accounts of the contradictions that result from nature’s commodification relegate nonhuman organisms to an apolitical role in environmental transformation while reinforcing the nature/society dichotomy. Often viewed as antithetical to Marxism, actor-network theory or ANT emphasizes the ability of actants (both human and nonhuman) to enroll other actants into heterogeneous assemblages or networks. Thus, it is claimed that nonhuman organisms can be attributed ontological status in processes of environmental change, much like their human counterparts. Despite this apparent theoretical discord, political ecologists are increasingly integrating aspects of both Marx and ANT into their analyses. But a more explicit articulation of the ontological basis and epistemic import of theoretical synthesis is warranted. This paper therefore prioritizes and links the ontological status of labor in both of these theories in order to expand the definition of urban environmental politics to include the role of nonhuman organisms. By demonstrating the laboring capacity of Dutch elm disease within the networks of urban political economy, the epistemology of environmental politics is thus expanded.  相似文献   

A method for estimating casualties due to the tsunami inundation flow     

Shunichi Koshimura  Toshitaka Katada  Harold O. Mofjeld  Yoshiaki Kawata 《Natural Hazards》2006,39(2):265-274

This study develops a method for estimating the number of casualties that may occur while people evacuate from an inundation zone when a tsunami has inundated an area. The method is based on a simple model of hydrodynamic forces as they affect the human body. The method uses a Tsunami casualty index (TCI) computed at each grid point of a numerical tsunami model to determine locations and times within the tsunami inundation zone where evacuation during the tsunami inundation is not possible and therefore where casualties are likely to occur. The locations and times can be combined with information about population density to compute the potential number of casualties. This information is useful in developing tsunami evacuation routes that avoid such locations. To illustrate the method, it is applied to the Seattle waterfront in Washington State, USA, that is under the threat of possible tsunami disasters due to Seattle Fault earthquakes. Preliminary results suggest that the tsunami casualties may occur within the Seattle waterfront for 15 min, during the time interval from 3 to 18 min after a large Seattle Fault tsunami is generated when the background tide level is mean high water.  相似文献   

A qualitative approach to electrical resistivity interpretation     

Harold M. Moorey 《Pure and Applied Geophysics》1958,40(1):164-171

Summary The formula for apparent resistivity can be interpreted in terms of two quantities more easily identified with the physical process involved: the distribution of current flow in the earth, as it affects the current density along a line between the potential electrodes, and the true resistivity along this line. The analysis permits a qualitative prediction of resistivity sounding and profiling data over a variety of structures. Examples are given for faults, layers, and a dipping dike.  相似文献   

Organization and objectives of the sanitary engineering profession in the united states of america     

Harold Allen Thomas Jr. 《Aquatic Sciences - Research Across Boundaries》1956,18(1):1-4

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Effect of stratification on tidal circulation over the Scotian Shelf and Gulf of St. Lawrence: a numerical study using a three-dimensional shelf circulation model     

Kyoko Ohashi  Jinyu Sheng  Keith R. Thompson  Charles G. Hannah  Harold Ritchie 《Ocean Dynamics》2009,59(6):809-825

A three-dimensional shelf circulation model is used to examine the effect of seasonal changes in water-column stratification on the tidal circulation over the Scotian Shelf and Gulf of St. Lawrence. The model is driven by tidal forcing specified at the model’s lateral open boundaries in terms of tidal sea surface elevations and depth-averaged currents for five major tidal constituents (M₂, N₂, S₂, K₁, and O₁). Three numerical experiments are conducted to determine the influence of baroclinic pressure gradients and changes in vertical mixing, both associated with stratification, on the seasonal variation of tidal circulation over the study region. The model is initialized with climatological hydrographic fields and integrated for 16 months in each experiment. Model results from the last 12 months are analyzed to determine the dominant semidiurnal and diurnal tidal components, M₂ and K₁. Model results suggest that the seasonal variation in the water-column stratification affects the M₂ tidal circulation most strongly over the shelf break and over the deep waters off the Scotian Shelf (through the development of baroclinic pressure gradients) and along Northumberland Strait in the Gulf of St. Lawrence (through changes in vertical mixing and bottom stress). For the K₁ constituent, the baroclinic pressure gradient and vertical mixing have opposing effects on the tidal circulation over several areas of the study region, while near the bottom, vertical mixing appears to play only a small role in the tidal circulation.  相似文献   

A GIS-based approach to site vegetated buffer strips for erosion control within an agricultural catchment in southern England     

Cat Hudson  Harold Lovell  Alastair W. Pearson  Martin Schaefer  Philip J. Soar 《水文研究》2024,38(5):e15165

Agricultural soil erosion is largely attributed to arable intensification and increased mechanization. Runoff from arable land and intensively managed grassland transports sediment and contaminants across the landscape and into watercourses, causing crop loss, land degradation, and water quality issues. One low-cost and low-maintenance nature-based mitigation approach is the implementation of vegetated buffer strips (VBS): grassland sited along field margins to trap sediment and contaminants, reducing transportation and diffuse pollution rates. GIS modelling using remotely sensed landscape indices and land parcel data can provide an efficient means of identifying priority areas for intervention at sub-catchment or farm system scales. We develop and test a scalable runoff risk model in the lower Rother catchment, West Sussex. The model uses the Normalized Difference Vegetation Index (NDVI) applied to satellite images as an erodibility proxy and identifies locations along pathways that are conceivably at greatest risk of sediment accumulation and transfer, guided by field observations. We assess current and historical field boundaries near high-risk locations, evaluating the potential capacity of their margins to contribute to runoff risk reduction using an innovative ranking system. Recommendations are made for VBS implementation and the value of historical field boundary and margin restoration is discussed. Our method offers a rapid approach with minimal data requirements to identify high-risk sediment runoff locations and priority sites for intervention. The tool has the potential to guide decision-makers responsible for targeting and implementing soil erosion and runoff control measures such as VBS, while also maximizing agri-environmental and cultural benefits.  相似文献   

A study of the minor element concentrations of spinels from two type B calcium-aluminum-rich inclusions: An investigation into potential formation conditions of calcium-aluminum-rich inclusions     

Harold C. CONNOLLY  D. S. BURNETT 《Meteoritics & planetary science》1999,34(6):829-848

Abstract— We have conducted an electron microprobe study of minor element distributions among spinels from two type B1 calcium-aluminum-rich inclusions (CAIs): Allende TS-23 and Leoville 3537–2. We show that by maintaining the petrologic context (edge, middle, and center of the inclusion plus their host silicate phase), four populations of spinels are resolvable based on their minor element contents. One population resides within the edge area (mainly mantle melilite) and is characterized by the highest V contents. Unlike Leoville 3537–2, many edge grains from Allende TS-23 also have high-Fe contents (up to 4.0 wt%) and low-Cr values. Based on their V and Ti concentrations (which is positively correlated), middle and center grains define a trend that is divided into three populations: spinels enclosed by melilite, fassaite, and anorthite. The overall range in Ti concentration based on fractional crystallization should be much less than a factor of 2; however, the observed range is considerably larger. The minor element contents of these grains are interpreted as recording alteration, primary fractional crystallization, and a complex igneous history that may involve remelting and recrystallization. From our data, Allende TS-23 has experienced more alteration than Leoville 3537–2, which is consistent with previous petrologic studies of silicates within these objects; yet both objects have likely been remelted (at least one additional melting event, possibly two, postdating the initial formation of these CAIs). By invoking a remelting history, the large range ir Ti concentrations and the different populations of spinels can be explained. Although our data suggest that more than one generation of spinels exist within these objects, we are unable to establish any population of relic spinel grains that predate the initial melting event.  相似文献