兴文天坑的崩塌过程     

Tony WALTHAM  张远海 《中国岩溶》2006,25(Z1):79-83

四川兴文喀斯特包括小岩湾天坑和大岩湾退化天坑,以及猪槽井洞穴系统中潜在的洞穴崩塌大厅.这3个地方似乎可以说明天坑的演化顺序,即天坑从多重洞穴崩塌,到最后退化成大型漏斗的过程.  相似文献   

Sources of uncertainty in projections of twenty-first century westerly wind changes over the Amundsen Sea,West Antarctica,in CMIP5 climate models     

Thomas J. Bracegirdle  John Turner  J. Scott Hosking  Tony Phillips 《Climate Dynamics》2014,43(7-8):2093-2104

The influence of changes in winds over the Amundsen Sea has been shown to be a potentially key mechanism in explaining rapid loss of ice from major glaciers in West Antarctica, which is having a significant impact on global sea level. Here, Coupled Model Intercomparison Project Phase 5 (CMIP5) climate model data are used to assess twenty-first century projections in westerly winds over the Amundsen Sea (U _AS ). The importance of model uncertainty and internal climate variability in RCP4.5 and RCP8.5 scenario projections are quantified and potential sources of model uncertainty are considered. For the decade 2090–2099 the CMIP5 models show an ensemble mean twenty-first century response in annual mean U _AS of 0.3 and 0.7 m s^?1 following the RCP4.5 and RCP8.5 scenarios respectively. However, as a consequence of large internal climate variability over the Amundsen Sea, it takes until around 2030 (2065) for the RCP8.5 response to exceed one (two) standard deviation(s) of decadal internal variability. In all scenarios and seasons the model uncertainty is large. However the present-day climatological zonal wind bias over the whole South Pacific, which is important for tropical teleconnections, is strongly related to inter-model differences in projected change in U _AS (more skilful models show larger U _AS increases). This relationship is significant in winter (r = ?0.56) and spring (r = ?0.65), when the influence of the tropics on the Amundsen Sea region is known to be important. Horizontal grid spacing and present day sea ice extent are not significant sources of inter-model spread.  相似文献   

A modeling study of coastal inundation induced by storm surge,sea-level rise,and subsidence in the Gulf of Mexico   总被引：2，自引：2，他引：0  

Zhaoqing Yang  Taiping Wang  Ruby Leung  Kathy Hibbard  Tony Janetos  Ian Kraucunas  Jennie Rice  Benjamin Preston  Tom Wilbanks 《Natural Hazards》2014,71(3):1771-1794

The northern coasts of the Gulf of Mexico (GoM) are highly vulnerable to the direct threats of climate change, such as hurricane-induced storm surge, and such risks are exacerbated by land subsidence and global sea-level rise. This paper presents an application of a coastal storm surge model to study the coastal inundation process induced by tide and storm surge, and its response to the effects of land subsidence and sea-level rise in the northern Gulf coast. The unstructured-grid finite-volume coastal ocean model was used to simulate tides and hurricane-induced storm surges in the GoM. Simulated distributions of co-amplitude and co-phase lines for semi-diurnal and diurnal tides are in good agreement with previous modeling studies. The storm surges induced by four historical hurricanes (Rita, Katrina, Ivan, and Dolly) were simulated and compared to observed water levels at National Oceanic and Atmospheric Administration tide stations. Effects of coastal subsidence and future global sea-level rise on coastal inundation in the Louisiana coast were evaluated using a “change of inundation depth” parameter through sensitivity simulations that were based on a projected future subsidence scenario and 1-m global sea-level rise by the end of the century. Model results suggested that hurricane-induced storm surge height and coastal inundation could be exacerbated by future global sea-level rise and subsidence, and that responses of storm surge and coastal inundation to the effects of sea-level rise and subsidence are highly nonlinear and vary on temporal and spatial scales.  相似文献