Estimating the nitrate concentration from the dissolved oxygen concentration and seawater temperature in the Kuroshio extension,Oyashio, and mixed water regions     

Miho Ishizu  Chiho Sukigara  Toshio Suga  Kelvin J. Richards 《Journal of Oceanography》2015,71(1):19-26

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Geologic and Economic Criteria for Siting Clean-Coal Facilities in the Texas Gulf Coast, USA     

W. A. Ambrose  C. Breton  V. Núñez-López  G. Gülen 《Natural Resources Research》2012,21(4):461-482

The Texas Gulf Coast (TGC) contains the greatest number of favorably co-located CO₂ sources and sinks in Texas that favor new potential clean-coal facilities. Areas in the TGC with clean-coal potential were delineated by mapping spatial linkages between coal- and lignite-bearing formations and geologic and infrastructure factors that include proximity to existing fields from mine-mouth power plants for enhanced oil recovery (EOR), length of new pipelines to transport CO₂ from new clean-coal facilities to either EOR fields or to brine formations for deep storage, proximity to centers of electric load, and depth to subsurface coal for enhanced coalbed methane recovery. Other factors include thickness of brine formations for deep storage of CO₂, groundwater and surface-water availability, and proximity to railroads for haulage of western U.S. coal feedstock. Geospatial analysis of maps portraying the distribution of these factors, together with data on volumes of oil recoverable from miscible CO₂ flooding of oil fields, indicates that optimal areas for new clean-coal sites in the TGC are in east and southeast Texas. CO₂ pipeline networks linking these sites to EOR fields are integral components of systems that can typically recover 5–50 million stock tank barrels from miscible CO₂ flooding from each EOR field. Many of these fields with EOR potential (for example, Neches, Long Lake, Conroe, and Livingston) have a great potential for stacked CO₂ storage, in which multiple reservoir zones can undergo EOR development and deeper zones in the field can accommodate excess CO₂ from EOR operations.  相似文献   

Regional assessment of climate change impacts on coastal and fluvial ecosystems and the scope for adaptation     

J. A. Richards  M. Mokrech  P. M. Berry  R. J. Nicholls 《Climatic change》2008,90(1-2):141-167

Ecosystem changes in floodplains could be a major issue during the twenty-first century as designated habitat areas are affected by climate change and floodplain management options. As part of the RegIS project, a Regional Impact Simulator has been developed to investigate these potential changes. This paper presents the methodologies and results of biodiversity metamodels used within the Regional Impact Simulator for two regions of the UK: East Anglia and North West England. Potential impacts and adaptations to future climate and socio-economic scenarios are analysed for three habitat types in floodplains (saltmarsh, coastal grazing marsh and fluvial grazing marsh) and selected species. An important finding is that management choices, which can be linked to socio-economic futures have a greater potential impact on habitat viability than climate change. The choices society makes will therefore be key to protection and conservation of biodiversity. The analyses also show that coastal grazing marsh is the most vulnerable habitat to sea-level rise, although there is a scope for substituting losses with fluvial grazing marsh. These results indicate that these methods provide a useful approach for assessing potential biodiversity changes at the regional scale, including the effect of different policies.  相似文献   

Is there a win–win scenario for marine nature conservation? A case study of Lyme Bay,England     

Siân E. Rees  Martin J. Attrill  Melanie C. Austen  Steven C. Mangi  Jo P. Richards  Lynda D. Rodwell 《Ocean & Coastal Management》2010,53(3):135-145

A statutory two hundred and six square kilometre ‘closed area’ in Lyme Bay, South West England entered into force on the 11 July 2008 to protect the reef substrate and the associated biodiversity from the impacts of trawling and dredging with heavy demersal fishing gear. This case study provides an example of how the ecosystem approach has been incorporated into decision making for marine nature conservation and shows that despite sound ecological knowledge of a marine area, the current reliance on traditional neo-classical economic valuations for marine spatial planning can obscure other issues pertinent to the ecosystem approach. With the Government seeking win–win scenarios for stakeholders in the designation of Marine Conservation Zones under the Marine and Coastal Access Act, experience of marine spatial planning in Lyme Bay has revealed that a win–win must be a long-term goal based on a thorough evaluation of the environmental, social and economic values of marine biodiversity.  相似文献   

Understanding the human dimensions in the management of coastal and marine resources in the WIO region     

Rosemarie Mwaipopo  Glenn-Marine Lange  Yvan Breton 《Ocean & Coastal Management》2010,53(4):147-149

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Proterozoic low-sulfidation epithermal Au-Ag mineralization in the Mallery Lake area, Nunavut, Canada   总被引：2，自引：0，他引：2  

William Turner  Jeremy Richards  Bruce Nesbitt  Karlis Muehlenbachs  John Biczok 《Mineralium Deposita》2001,36(5):442-457

The Mallery Lake area contains pristine examples of ancient precious metal-bearing low-sulfidation epithermal deposits. The deposits are hosted by rhyolitic flows of the Early Proterozoic Pitz Formation, but are themselves apparently of Middle Proterozoic age. Gold mineralization occurs in stockwork quartz veins that cut the rhyolites, and highest gold grades (up to 24 g/t over 30 cm) occur in the Chalcedonic Stockwork Zone. Quartz veining occurs in two main types: barren A veins, characterized by fine- to coarse-grained comb quartz, with fluorite, calcite, and/or adularia; and mineralized B veins, characterized by banded chalcedonic silica and fine-grained quartz, locally intergrown with fine-grained gold or electrum. A third type of quartz vein (C), which crosscuts B veins at one locality, is characterized by microcrystalline quartz intergrown with fine-grained hematite and rare electrum. Fluid inclusions in the veins occur in two distinct assemblages. Assemblage 1 inclusions represent a moderate temperature (Th=150 to 220 °C), low salinity (~1 eq. wt% NaCl, with trace CO₂), locally boiling fluid; this fluid type is found in both A and B veins and is thought to have been responsible for Au-Ag transport and deposition. Assemblage 2 inclusions represent a lower temperature (Th=90 to 150 °C), high salinity calcic brine (23 to 31 wt% CaCl₂-NaCl), which occurs as primary inclusions only in the barren A veins. Assemblage 1 and 2 inclusions occur in alternating quartz growth bands in the A-type veins, where they appear to represent alternating fluxes of dilute fluid and local saline groundwater. No workable primary fluid inclusions were observed in the C veins. The A-vein quartz yields '¹⁸O values from 8.3 to 14.5‰ (average=10.9ǃ.7‰ [1C], n=30), whereas '¹⁸O values for B-vein quartz range from 11.2 to 14.0‰ (average=13.0ǂ.9‰, n=12). Calculated '¹⁸O_H2O values for the dilute mineralizing fluid from B veins range from -2.6 to 0.2‰ (average=-0.8ǂ.9‰, n=12) and are consistent with a dominantly meteoric origin. No values could be calculated for the brine, however, because all A-vein quartz samples contain mixed fluid inclusion populations. However, the fact that A-vein quartz samples extend to lower '¹⁸O values than the B veins suggests that the brine had a lighter isotopic signature relative to the dilute fluid. Hydrogen isotopic ratios of fluid inclusion waters extracted from eleven quartz samples of both vein types range from 'D_FI=-56 to -134‰, but show no particular correlation with vein type. In most respects, the mineralogical and fluid characteristics of the Mallery Lake system are comparable to those of Phanerozoic low-sulfidation deposits, and although the presence of high salinity brines is unusual in such deposits, it is not unknown (e.g., Creede, Colorado). In addition, one of the few other examples of well-preserved, Precambrian, low-sulfidation epithermal deposits, from the Central Pilbara tectonic zone, Australia, contains a similarly bimodal fluid assemblage. The significance of these saline brines is not clear, but from this study we infer that they were not directly involved with Au-Ag transport or deposition.  相似文献   

A Study of Small Magnitude Seismic Events During 1961–1989 on and near the Semipalatinsk Test Site, Kazakhstan     

V.I. Khalturin  T.G. Rautian  P.G. Richards 《Pure and Applied Geophysics》2001,158(1-2):143-171

—?Official Russian sources in 1996 and 1997 have stated that 340 underground nuclear tests (UNTs) were conducted during 1961–1989 at the Semipalatinsk Test Site (STS) in Eastern Kazakhstan. Only 271 of these nuclear tests appear to have been described with well-determined origin time, coordinates and magnitudes in the openly available technical literature. Thus, good open documentation has been lacking for 69 UNTs at STS.¶The main goal of our study was to provide detections, estimates of origin time and location, and magnitudes, for as many of these previously undocumented events as possible. We used data from temporary and permanent seismographic stations in the former USSR at distances from 500?km to about 1500?km from STS. As a result, we have been able to assign magnitude for eight previously located UNTs whose magnitude was not previously known. For 31 UNTs, we have estimated origin time an d assigned magnitude — and for 19 of these 31 we have obtained locations based on seismic signals. Of the remaining 30 poorly documented UNTs, 15 had announced yields that were less than one ton, and 13 occurred simultaneously with another test which was detected. There are only two UNTs, for which the announced yield exceeds one ton and we have been unable to find seismic signals.¶Most of the newly detected and located events were sub-kiloton. Their magnitudes range from 2.7 up to 5.1 (a multi-kiloton event on 1965 Feb. 4 that was often obscured at teleseismic stations by signals from an earthquake swarm in the Aleutians).¶For 17 small UNTs at STS, we compare the locations (with their uncertainties) that we had earlier determined in 1994 from analysis of regional seismic waves, with ground-truth information obtained in 1998. The average error of the seismically-determined locations is only about 5?km. The ground-truth location is almost alw ays within the predicted small uncertainty of the seismically-determined location.¶Seismically-determined yield estimates are in good agreement with the announced total annual yield of nuclear tests, for each year from 1964 to 1989 at Semipalatinsk.¶We also report the origin time, location, and seismic magnitude of 29 chemical explosions and a few earthquakes on or near STS during the years 1961–1989.¶Our new documentation of STS explosions is important for evaluating the detection, location, and identification capabilities of teleseismic and regional arrays and stations; and how these capabilities have changed with time.  相似文献   

Hydrology,hydraulics, and geomorphology of the Bonneville flood by J.E. O'Connor,Geological Society of America,Boulder, Colorado,Special paper no. 274, 1993. No. of pages: VI + 83. ISBN 0–8137–2274–8     

Keith Richards 《地球表面变化过程与地形》1995,20(4):386-386

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Establishing the role of pedogenesis in changing soil hydraulic properties     

S. M. Brooks  K. S. Richards 《地球表面变化过程与地形》1993,18(6):573-578

Chronosequences provide suitable sources for the study of changes in soil hydraulic behaviour as a result of long-term pedogenesis. For a podsol chronosequence in the Scottish Highlands, data are presented to indicate the changes that have occurred over 13000 years in the saturated hydraulic conductivity (K_sat) in each horizon. As the soil profile has evolved into a differentiated sequence of three horizons, the resulting hydrological changes can be both measured and quantified by relating K_sat to textural properties and bulk density. The results are significant for interpretation of changing runoff processes and slope stability.  相似文献   

The significance of rainstorm variations to shallow translational hillslope failure     

S. M. Brooks  K. S. Richards 《地球表面变化过程与地形》1994,19(1):85-94

Landsliding in eastern Scotland results from high-magnitude rainstorms generated under either cyclonic or anticyclonic conditions, particularly during the summer. Data from Aviemore indicated that cyclonic storms produce higher rainfall totals than anticyclonic storms, as well as being of longer duration and lower intensity. The distribution of rain during individual storms also varies with the synoptic conditions under which the storms are produced. These different rainfall characteristics produce different geomorphic responses, which can be investigated in detail using physical based modelling. In this paper, a physically based coupled hydrology–stability model is used to assess the significance of these rainfall characteristics to soil moisture response and slope instability for mature podsols. The results provide evidence that rainstorms of different synoptic origin produce varying hydrological response, involving both the extent and the timing of moisture content change. This affects the depth and timing of slope failure, with anticyclonic storms promoting a large, rapid response in the factor of safety at shallow depths within the soil. Cyclonic storms produce a more gradual response, with the region of probable failure being deeper. Futhermore, each of these storm types is associated with different rainfall distributions, and this is also shown to have a significant effect on the timing and depth of slope instability.  相似文献