Depositional history of Franchthi Cave: Sediments,stratigraphy and chronology     

Jamie C. Woodward 《Geoarchaeology》2002,17(7):751-754

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Broad synchrony of a Late-glacial glacier advance and the highstand of palaeolake Tauca in the Bolivian Altiplano     

Jamie D. Clayton  Chalmers M. Clapperton 《第四纪科学杂志》1997,12(3):169-182

The morphology and sedimentology of glacially influenced fan-deltas on massifs at the margin of the southern Altiplano, Bolivia, suggest a broadly synchronous expansion of glaciers and palaeolake Tauca during the late-glacial interval. This is shown by sedimentary successions of glacigenic, glacifluvial and glacideltaic facies linking palaeoglaciers with palaeolake Tauca on the flanks of Cerro Azanaques and Cerro Tunupa at altitudes of 3770–3720 m. Radiocarbon dates from peat overlain by glacial diamict and glacifluvial outwash indicate that glaciers in this area reached their last glacial maximum extent after ca. 13 300 ¹⁴ C yr BP. Glacifluvial fan-deltas contiguous with the moraines confirm that the advance coincided with a highstand of palaeolake Tauca radiocarbon dated to the interval ca. 13 500–11 500 yr BP. Modeling of climatic controls on this glacier advance suggests the primary forcing was increased summer (wet season) moisture, possibly amounting to 600 mm above the modern values of 200–400 mm. Greater cloud cover probably depressed local temperatures and reduced the evaporation rate. The consequent rise in effective annual moisture ( P − E ) comfortably accommodates a palaeolake 48–50 × 10 ³ km ² in area and up to 100 m deep in the southern Altiplano. Because the palaeoglacier equilibrium-line altitudes rose toward the south and west, like the gradient of modern precipitation totals, we conclude that the increased late-glacial moisture was brought by weather systems similar to those of the present, but that atmospheric conditions were cloudier and cooler. © 1997 John Wiley & Sons, Ltd.  相似文献   

Perceived attributes of hurricane-related retrofits and their effect on household adoption     

Zou  Yilin  Stock  Alexia  Davidson  Rachel  Nozick  Linda  Trainor  Joseph  Kruse  Jamie 《Natural Hazards》2020,104(1):201-224

Natural Hazards - Understanding how homeowners make protective action decisions is important for designing policies and programs to encourage those actions and community resilience as a whole. This...  相似文献   

Tracking stormwater discharge plumes and water quality of the Tijuana River with multispectral aerial imagery     

Jan Svejkovsky  Nikolay P. Nezlin  Neomi M. Mustain  Jamie B. Kum 《Estuarine, Coastal and Shelf Science》2010

Spatial–temporal characteristics and environmental factors regulating the behavior of stormwater runoff from the Tijuana River in southern California were analyzed utilizing very high resolution aerial imagery, and time-coincident environmental and bacterial sampling data. Thirty nine multispectral aerial images with 2.1-m spatial resolution were collected after major rainstorms during 2003–2008. Utilizing differences in color reflectance characteristics, the ocean surface was classified into non-plume waters and three components of the runoff plume reflecting differences in age and suspended sediment concentrations. Tijuana River discharge rate was the primary factor regulating the size of the freshest plume component and its shorelong extensions to the north and south. Wave direction was found to affect the shorelong distribution of the shoreline-connected fresh plume components much more strongly than wind direction. Wave-driven sediment resuspension also significantly contributed to the size of the oldest plume component. Surf zone bacterial samples collected near the time of each image acquisition were used to evaluate the contamination characteristics of each plume component. The bacterial contamination of the freshest plume waters was very high (100% of surf zone samples exceeded California standards), but the oldest plume areas were heterogeneous, including both polluted and clean waters. The aerial imagery archive allowed study of river runoff characteristics on a plume component level, not previously done with coarser satellite images. Our findings suggest that high resolution imaging can quickly identify the spatial extents of the most polluted runoff but cannot be relied upon to always identify the entire polluted area. Our results also indicate that wave-driven transport is important in distributing the most contaminated plume areas along the shoreline.  相似文献