Event sedimentation in low‐latitude deep‐water carbonate basins,Anegada passage,northeast Caribbean          下载免费PDF全文

Jason D. Chaytor  Uri S. ten Brink 《Basin Research》2015,27(3):310-335

The Virgin Islands and Whiting basins in the Northeast Caribbean are deep, structurally controlled depocentres partially bound by shallow‐water carbonate platforms. Closed basins such as these are thought to document earthquake and hurricane events through the accumulation of event layers such as debris flow and turbidity current deposits and the internal deformation of deposited material. Event layers in the Virgin Islands and Whiting basins are predominantly thin and discontinuous, containing varying amounts of reef‐ and slope‐derived material. Three turbidites/sandy intervals in the upper 2 m of sediment in the eastern Virgin Islands Basin were deposited between ca. 2000 and 13 600 years ago, but do not extend across the basin. In the central and western Virgin Islands Basin, a structureless clay‐rich interval is interpreted to be a unifite. Within the Whiting Basin, several discontinuous turbidites and other sand‐rich intervals are primarily deposited in base of slope fans. The youngest of these turbidites is ca. 2600 years old. Sediment accumulation in these basins is low (<0.1 mm year^?1) for basin adjacent to carbonate platform, possibly due to limited sediment input during highstand sea‐level conditions, sediment trapping and/or cohesive basin walls. We find no evidence of recent sediment transport (turbidites or debris flows) or sediment deformation that can be attributed to the ca. M7.2 1867 Virgin Islands earthquake whose epicentre was located on the north wall of the Virgin Islands Basin or to recent hurricanes that have impacted the region. The lack of significant appreciable pebble or greater size carbonate material in any of the available cores suggests that submarine landslide and basin‐wide blocky debris flows have not been a significant mechanism of basin margin modification in the last several thousand years. Thus, basins such as those described here may be poor recorders of past natural hazards, but may provide a long‐term record of past oceanographic conditions in ocean passages.  相似文献   

Trends in CO2 emissions in Israel—an international perspective     

Moshe Yanai  Jean Koch  Uri Dayan 《Climatic change》2010,101(3-4):555-563

As a Party to the United Nations Framework Convention on Climate Change, Israel conducts a periodical inventory of greenhouse gases emissions. These data allowed the generation of time series of CO₂ emissions per capita and per GDP for the period 1990–2004. It was found that CO₂ emissions per capita increased dramatically from 1990 to 2000, reflecting the rapid economic growth that was initiated by the massive immigration wave at the beginning of the nineties. These emissions remained stable between 2000 and 2004, reflecting the economic stagnation caused by the uprising in the Palestinian Territories, as well as stagnation in the global economy. CO₂ emissions per GDP (CO₂ intensity) remained stable along the whole reviewed period. This stability can be explained by a shift in electricity consumption from the industrial sector towards the commercial and the residential sectors, corresponding to an increase in the standard of living in the same period. A comparison was held with countries considered as developed for many years represented by the five largest economies (G-5) and recently developed countries (RDCs). Although Israel exhibits emission levels within the range of the G-5 countries, it does not fit the patterns demonstrated by these countries. Trends observed in Israel resemble these observed in other RDCs, such as Spain or Greece, confirming the classification of Israel in this category.  相似文献   

The location of deep salinity sources in the Israeli Coastal aquifer     

Uri Shavit  Alex Furman 《Journal of Hydrology》2001,250(1-4):63-77

The salinization process of the Israeli Coastal aquifer has led to an average concentration of about 200 mgCl/l with a significant number of discrete salinity plumes in the middle and southern regions. The salinity of these plumes is high (500–1000 mgCl/l) and is increasing rapidly. Geochemical evidence has suggested that the salinity source in the Be'er Tuvia plume (in the south part of the aquifer) is at the bottom of the aquifer. This paper describes a solution of the source inverse problem and its application in the Be'er Tuvia plume. A transient two-dimensional finite element model was solved and the source terms were computed at each node in a 14×14 km² area. An error analysis has shown that when no errors are introduced in the input data the reconstruction is perfect. The results of a sensitivity analysis are presented and the actual reconstruction errors are estimated. Applying the model in the Be'er Tuvia region indicates that a salinity source exists about 1 km to the west and 1.5 km to the north of the center of the salinity plume. This source is believed to be the plume source.  相似文献   

The geochemistry of groundwater resources in the Jordan Valley: The impact of the Rift Valley brines     

Efrat Farber  Avner Vengosh  Ittai Gavrieli  Amer Marie  Thomas D. Bullen  Bernhard Mayer  Amir Polak  Uri Shavit 《Applied Geochemistry》2007

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Environmental considerations in the fertilizer use decision   总被引：1，自引：0，他引：1  

Noel D. Uri 《Environmental Geology》1998,34(2-3):103-110

 The increase in the use of fertilizer in agricultural production has been associated with a substantial increase in agricultural productivity in the United States. This increase in fertilizer use has been driven by a variety of economic forces including variations in the price of output and changing relative factor prices. Associated with the increase in the use of fertilizer have been adverse environmental consequences that are not reflected in the costs and returns of agricultural production. That is, externalities exist whose cost need to be internalized. Because the use of fertilizer has been shown to respond to market forces, it is efficient to use the market to control the use of fertilizer. This can be done through, for example, the use of a fertilizer tax. Received: 31 December 1996 · Accepted: 13 May 1997  相似文献   

Integrated analysis of policy options for protection of groundwater quality     

Noel D. Uri  Wen-Yuan Huang 《Environmental Geology》1990,15(3):233-241

This paper is directed at providing an integrated framework that a regional authority should use when assessing the potential impacts of any policy initiative directed at improving groundwater quality. In particular, a policy model is developed relying on three decision components (a farm-level production decisions model, a household decisions model and a regional policy decision model) where the objective is one of identifying the trade-offs that a regional authority will be confronted with as it strives to balance the preferences of farmers and households while endeavoring to maximize net economic welfare. The basic rule developed indicates that the regional authority must choose a policy whereby any increase (decrease) in regional income is just equal to the decrease (increase) in net benefits to households.The views expressed are those of the authors and do not necessarily represent the policies of the U.S. Department of Agriculture or the views of other U.S. Department of Agriculture staff members.  相似文献   

Does a ‘two-stream’ flow model apply to wakes of large bodies in space?     

Uri Samir  N. H. Stone  W. A. Oran 《Astrophysics and Space Science》1974,31(1):L1-L8

Structural patterns of ion and electron currents observed on the wake axes of the Ariel J and the Gemini 10 space vehicles are re-examined, together with relevant theoretical and laboratory ‘simulation’, studies. Some insight into existingin-situ data is provided. The possibility that ‘converging-stream’ models describe structural features of current enhancements in the wake region of large spacecraft is discussed.  相似文献   

Statistical analysis of multiple absorption spectra in QSO     

Giora Shaviv  Uri Feldman  Ben-Zion Koslovsky 《Astrophysics and Space Science》1972,19(1):159-163

A detailed statistical analysis was carried out for several quasars with multiple red-shifts systems. The most important results are (a) The statistical test of the reliability of az-system is very sensitive toz, the total number of absorption lines, the selected set of reference lines and the number of identified lines (b) The standard deviation from , the average number of randomz-systems per random spectra is larger than . Consequently, the reliability of any system depends predominately on and not on .  相似文献   

Drainage response to Arabia–Eurasia collision: Insights from provenance examination of the Cyprian Kythrea flysch (Eastern Mediterranean Basin)     

Uri Shaanan  Dov Avigad  Navot Morag  Talip Güngr  Axel Gerdes 《Basin Research》2021,33(1):26-47

The Cenozoic geodynamics of the north‐eastern Mediterranean Basin have been dominated by the subduction of the African Plate under Eurasia. A trench‐parallel crustal‐scale thrust system (Misis–Kyrenia Thrust System) dissects the southern margin of the overriding plate and forms the structural grain and surface expression of northern Cyprus. Late Eocene to Miocene flysch of the Kythrea (De?irmenlik) Group is exposed throughout northern Cyprus, both at the hanging‐wall and foot‐wall of the thrust system, permitting access to an extensive Cenozoic sedimentary record of the basin. We report the results of a combined examination of detrital zircon and rutile U–Pb geochronology (572 concordant ages), coupled with Th/U ratios, Hf isotopic data and quantitative assessment of grain morphology of detrital zircon from four formations (5 samples) from the Kythrea flysch. These data provide a line of independent evidence for the existence of two different sediment transportation systems that discharged detritus into the basin between the late Eocene and late Miocene. Unique characteristics of each transport system are defined and a sediment unmixing calculation is demonstrated and explained. The first system transported almost exclusively North Gondwana‐type, Precambrian‐aged detrital zircon sourced from siliciclastic rock units in southern Anatolia. A different drainage system is revealed by the middle to late Miocene flysch sequence that is dominated by Late Cretaceous–Cenozoic‐aged detrital zircon, whose age range is consistent with the magmatic episodicity of southeast Anatolia, along the Arabia–Eurasia suture zone. Deposition of these late Miocene strata took place thereupon closure of the Tethyan Seaway and African–Eurasian faunal exchange, and overlap in time with a pronounced uplift of eastern Anatolia. Our analytical data indicate the onset of prominent suture‐parallel sediment transport from the collision zone of south‐eastern Anatolia into the Kyrenia Range of northern Cyprus, marking the drainage response to the continental collision between Arabia and Eurasia.  相似文献   

Footprint Estimation for Multi-Layered Sources and Sinks Inside Canopies in Open and Protected Environments     

Tomer Duman  Josef Tanny  Uri Dicken  Mario B. Siqueira  Gabriel G. Katul 《Boundary-Layer Meteorology》2015,155(2):229-248

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