Estimating impacts of warming temperatures on California's electricity system     

Jayant A. Sathaye  Larry L. Dale  Peter H. Larsen  Gary A. Fitts  Kevin Koy  Sarah M. Lewis  André Frossard Pereira de Lucena 《Global Environmental Change》2013,23(2):499-511

Despite a clear need, little research has been carried out at the regional-level to quantify potential climate-related impacts to electricity production and delivery systems. This paper introduces a bottom-up study of climate change impacts on California's energy infrastructure, including high temperature effects on power plant capacity, transmission lines, substation capacity, and peak electricity demand. End-of-century impacts were projected using the A2 and B1 Intergovernmental Panel on Climate Change emission scenarios. The study quantifies the effect of high ambient temperatures on electricity generation, the capacity of substations and transmission lines, and the demand for peak power for a set of climate scenarios. Based on these scenarios, atmospheric warming and associated peak demand increases would necessitate up to 38% of additional peak generation capacity and up to 31% additional transmission capacity, assuming current infrastructure. These findings, although based on a limited number of scenarios, suggest that additional funding could be put to good use by supporting R&D into next generation cooling equipment technologies, diversifying the power generation mix without compromising the system's operational flexibility, and designing effective demand side management programs.  相似文献   

Structure and subduction processes along the Oregon-Washington margin     

Guy R. Cochrane  Brian T. R. Lewis  Kevin J. McClain 《Pure and Applied Geophysics》1988,128(3-4):767-800

Seismic reflection and refraction data off Washington and Oregon are used to determine the style of sediment deformation and to infer the physical properties of accreted sediments on the lower slope. Onshore-offshore seismic refraction data off Washington are used to determine the location of the trench, or where the plate bending starts.We find that off Washington the subduction zone is characterized by a trench whose physiographic expression is buried under several kilometers of sediments and is tens of kilometers landward of the lower slope, which is accreting seaward as the result of the offscraping of sediments.Seismic reflection data support previous observations that offscraping occurs along seaward and landward dipping thrust faults. Refraction data indicate that a sediment package thrust up along a seaward dipping fault (off Washington) was not measurably changed in velocity with respect to a Cascadia basin section. However a package uplifted by thrusting along a landward dipping fault (off Oregon) did have increased velocity. It is suggested that the increased velocities off Oregon could be the result of erosion and exposure of more deeply buried and compacted sediments, rather than the result of dewatering due to tectonic stress. Off Washington the sensitivity of velocity to porosity and resolution of the seismic method does not preclude dewatering due to tectonic stress, but it does limit the degree of dewatering.In the deeper parts of the lower slope section off Washington and Oregon velocities as high as 3 to 4 km/sec are found. Heat flow data indicate that the temperatures in this high velocity regime are greater than 100°C. It is hypothesized that lithification related to clay diagenesis may be partly responsible for the high velocities, rather than simply compaction. It also appears that the high velocity sediments are subducted while the unlithified low velocity sediments are offscraped.  相似文献   

Field Comparison of Micropurging vs. Traditional Ground Water Sampling     

Peter M. Kearl  Nic E. Korte  Mike Stites  Joe Baker 《Ground Water Monitoring & Remediation》1994,14(4):183-190

Micropurge sampling of ground water wells has been suggested as a possible replacement to traditional purge and sample methods. To compare methods, duplicate ground water samples were collected at two field sites using iraditional and micropurge methods. Samples were analyzed for selected organic and inorganic constituents, and the results were compared statistically. Analysis of the data using the nonparametric sign test indicates that within a 95 percent confidence interval, there was no significant difference between the two methods for the site contaminants and the majority of analytes. These analytical results were supported by visual observations with the colloidal borescope, which demonstrated impacts on the flow system in the well when using traditional sampling methods. Under selected circumstances, the results suggest replacing traditional sampling with micropurging based on reliability, cost, and waste minimization.  相似文献   

The unique,widely distributed,estuarine sea anemone,Nematostella vectensis Stephenson: A review,new facts,and questions     

Cadet Hand  Kevin R. Uhlinger 《Estuaries and Coasts》1994,17(2):501-508

The small, burrowing, edwardsiid sea anemone Nematostella vectensis is widely distributed in estuaries and bays. Most typically it occurs in pools in marshes though it may occur subtidally as well. We have compiled records of its occurrence in North America from Nova Scotia to Georgia along the shores of the Atlantic Ocean, from Florida to Louisiana in the Gulf of Mexico and from California to Washington on the Pacific coast. To date we have found no records of its presence in Alabama or Texas, though it is present in all other of the contiguous coastal states of the United States. The species also occurs in England. We have obtained living specimens from many locations and have crossed females from England, Maryland, Georgia, California, Oregon, and Washington with males from Nova Scotia, Maryland, Georgia, and Oregon. These 24 crosses all yielded viable first-generation anemones that in turn produced second-generation animals. We accept this as proof that this widely distributed anemone is a single species. We have obtained living N. vectensis from 11 areas. Of these, only samples from Maine, Maryland, Georgia, and Oregon contained both sexes. The sample from Nova Scotia was all male and our samples from England, New Hampshire, California, and Washington were all female. We hypothesize that the unisexual samples were from clones resulting from asexual reproduction in this species. *** DIRECT SUPPORT *** A01BY066 00015  相似文献   

Genetic structure of bay anchovy (Anchoa mitchilli) populations in Chesapeake Bay     

Raymond P. Morgan  Bruce M. Baker  James H. Howard 《Estuaries and Coasts》1995,18(3):482-493

To determine the genetic structure of the bay anchovy (Anchoa mitchilli) within Chesapeake Bay, 16 isozyme systems encoding 21 loci for 20 population were examined using horizontal starch gel electrophoresis. Contingency Chisquare analysis revealed significant allelic frequency differences at nine loci (AAT-1, AAT-2, ALD-1, CPK-2, GAP-1, GLY-1, LDH-1, MDH-1, and MDH-2). Two loci, ALD-1 and MDH-1, were responsible for nine of 14 tests not conforming to Hardy-Weinberg expectations, with some of these deviations attributed to possible scoring and/or sampling error. Estimates for mean average heterozygosity were relatively high, ranging from 0.40 to 0.096, with 33–57% of the loci polymorphic. A low F_st value (0.041) along with high genetic identity estimates (I=0.997) indicated little substructuring of bay anchovy populations within Chesapeake Bay.  相似文献   

Multiple Residence and Cyclical Migration: A Life Course Perspective*   总被引：1，自引：0，他引：1  

Kevin E. McHugh  Timothy D. Hogan  Stephen K. Happel 《The Professional geographer》1995,47(3):251-267

As a result of restrictive time-space bounds in viewing migration, surprisingly little is known about the tempos and rhythms of geographical mobility in America. We discuss limitations of the conventional definition of migration and develop a life course framework of multiple residence and cyclical migration. Results of an Arizona-based case study reveal that multiple residence is common and more diverse than the annual influx of elderly snowbirds. Coming to grips with multiple residence and recurrent mobility in the United States represents a fundamental challenge in population and migration studies.  相似文献   

High-resolution garnet chronometry and the rates of metamorphic processes     

Kevin W. Burton  R. Keith O'Nions 《Earth and Planetary Science Letters》1991,107(3-4)

Garnets in an amphibolite-facies metasediment from Sulitjelma, North Norway yield precise and concordant SmNd, UPb and RbSr ages that relate directly to the pressure (P) and temperature (T) conditions of mineral growth. Differential mineral reaction between graphitic and non-graphitic layers within this sample preserves a record of theP-T and time (t) history experienced during Barrovian regional metamorphism. Garnets in graphitic layers grew during prograde metamorphism at462 ± 16°C and5.2 ± 0.5 kbar under conditions of lowaH₂O, and yield indistinguishable¹⁴⁷Sm¹⁴³Nd and²³⁸U²⁰⁶Pb ages of434.1 ± 1.2 Ma and433.9 ± 1.0 Ma, respectively. In contrast, garnet growth in adjacent graphite-free layers did not occur untilP-T conditions of540 ± 18°C and8.0 ± 1.0 kbar were attained, with continued growth in response to minor heating and decompression with final matrix equilibration at544 ± 16°C and7.0 ± 1.0 kbar. The inclusion-free garnet rims in this assemblage record indistinguishable¹⁴⁷Sm¹⁴³Nd and²³⁸U²⁰⁶Pb ages of424.6 ± 1.2 Ma and423.4± 1.7 Ma, respectively. These results provide precise estimates for average heating and burial rates during prograde metamorphism of 8.6_−4.4^+7.5°C Ma⁻¹ and 0.8_−0.5^+0.9 km Ma⁻¹, respectively. Rb and Sr exchange between coexisting silicates in the graphite-free assemblage continued for some 37 Ma after the “peak” of metamorphism, and require an average cooling rate of about 4.0°C Ma⁻¹ during uplift. These results illustrate a clear relationship between reaction history and the timing of mineral growth and provide definitive constraints on the rates of thermal and tectonic processes accompanying regional metamorphism.  相似文献   

The effect of Tschermak's substitution on assemblages in aluminous dolomites     

Judy Baker  T. J. B. Holland  Roger Powell 《Contributions to Mineralogy and Petrology》1994,118(1):48-59

A calculated petrogenetic grid for the system CaO-MgO-Al₂O₃-SiO₂-CO₂-H₂O (CaMASCH), incorporating Tschermak's substitutions in amphibole, chlorite, talc and clinopyroxene, is used to examine phase relationships in aluminous marbles. A series of diagrams illustrating the effect upon stable mineral assemblages of increasing the aluminium content of a bulk composition is used to show the way aluminous minerals enter mineral assemblages in progressively more aluminous rocks. The effects of changing pressure and the incorporation of Fe into the bulk composition on the stable mineral assemblages are also examined. The calculated equilibria are shown to be in reasonable agreement with natural assemblages, and the incorporation of new experimental data on amphiboles into the existing dataset is shown to improve the agreement between observed and natural amphibole compositions.  相似文献   

210Pb dating of scottish lake sediments,afforestation and accelerated soil erosion     

Richard W. Battarbee  Peter G. Appleby  Kevin Odell  Roger J. Flower 《地球表面变化过程与地形》1985,10(2):137-142

Changes in the rate of soil erosion in lake catchments can be identified from changes in the rate of sediment accumulation in lakes. Here we compare recently afforested sites with non-afforested sites in the Galloway area of Southwest Scotland. We show that lakes with non-afforested catchments have slow, constant sediment accumulation rates, whereas lakes with recently afforested catchments have changes in accumulation that parallel the known history of afforestation. For Loch Grannoch the sediment accumulation rate increases from 0.1 cm yr^?1 to over 2 cm yr^?2 during the disturbance period. Data from L. Skerrow, however, suggest that the rate might decline to predisturbance levels after approximately 10 years as the forest canopy closes and drainage channels stabilize.  相似文献   

Editorial     

Earl W. Baker 《Organic Geochemistry》1985,8(1):vii

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