Investigation of Dynamic Crack Coalescence Using a Gypsum-Like 3D Printing Material     

Chao Jiang  Gao-Feng Zhao  Jianbo Zhu  Yi-Xin Zhao  Luming Shen 《Rock Mechanics and Rock Engineering》2016,49(10):3983-3998

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Effects of low- to high-angle normal faults on sedimentary architectures in the Eocene Wenchang Formation,Enping Sag,Pearl River Mouth Basin,South China Sea     

Q. H. Liu  Y. Shu  X. M. Zhu  X. H. Yang  M. Tan 《Australian Journal of Earth Sciences》2016,63(7):903-922

The effects of low- to high-angle (>30°) normal faults on sedimentary architectural units in the Eocene Wenchang Formation, Enping Sag, Pearl River Mouth Basin (PRMB), South China Sea were investigated utilising a high-quality 3D seismic data set and restored paleogeomorphology. It has been shown that sequence stratigraphic units and sedimentary architecture are significantly controlled by the low- to high-angle normal faults. The Wenchang Formation, a second-order sequence, can be subdivided into two para-second-sequences (the Lower and Upper Wenchang sequences, E₂W^L and E₂W^U) and seven third-order sequences (from base to top: SQ1～SQ7). The low-angle fault confined sequence architecture of the Wenchang Formation is mainly characterised by lateral stacking with the ratio of the vertical subsidence (V) to horizontal slip (H) being reduced from 1/2 for E₂W^L to 1/6 for E₂W^U. In contrast, the high-angle fault confined sequence is characterised by vertical stacking with the ratio of V/H close to 1 for sequences SQ1 to SQ7. In the 3D seismic area, the features of sediment-dispersal pattern were interpreted based on an integrated analysis of paleogeomorphology, seismic reflection characteristics, stratal thickness distribution and multiple attribute clustering. The results show that the large-scale fan delta, belt-shape lacustrine deposit and bird-foot braided delta systems mainly developed in the low-angle fault confined sequences, whereas small-scale fan delta, rhombus-shaped lacustrine deposit and lobe-shaped braided delta systems inherited tectono-sedimentary architectures in the high-angle fault confined sequences.  相似文献   

The Mesozoic structural evolution of the Gorgon Platform,North Carnarvon Basin,Australia     

X.-M. Yang 《Australian Journal of Earth Sciences》2016,63(6):755-770

The Gorgon Platform is located on the southeastern edge of the Exmouth Plateau in the North Carnarvon Basin, North West Shelf, Australia. A structural analysis using three-dimensional (3D) seismic data has revealed four major sets of extensional faults, namely, (1) the Exmouth Plateau extensional fault system, (2) the basin bounding fault system (Exmouth Plateau–Gorgon Platform Boundary Fault), (3) an intra-rift fault system in the graben between the Exmouth Plateau and the Gorgon Platform and (4) an intra-rift fault system within the graben between the Exmouth Plateau and the Exmouth Sub-basin. Fault throw-length analyses imply that the initial fault segments, which formed the Exmouth Plateau–Gorgon Platform Boundary Fault (EG Boundary Fault), were subsequently connected vertically and laterally by both soft- and hard-linked structures. These major extensional fault systems were controlled by three different extensional events during the Early and Middle Jurassic, Late Jurassic and Early Cretaceous, and illustrate the strong role of structural inheritance in determining fault orientation and linkage. The Lower and Middle Jurassic and Upper Jurassic to Lower Cretaceous syn-kinematic sequences are separated by unconformities.  相似文献   

Origin of the alkali tonsteins from southwest China: Implications for alkaline magmatism associated with the waning stages of the Emeishan Large Igneous Province     

L. Zhao  I. Graham 《Australian Journal of Earth Sciences》2016,63(1):123-128

A unique type of Nb–Zr–REE–Ga-enriched alkali tonstein of pyroclastic origin occurs exclusively within the late Permian coal measures of southwest China. The alkali tonsteins are located within the lowest Xuanwei or Longtan formations of Wuchiapingian age, indicating that their age is later than the main episode of Emeishan Large Igneous Province (ELIP) magmatism. The alkali tonsteins have intermediate–felsic Al₂O₃/TiO₂ values (12.6–34.2, mean 22.0), light rare earth element-enriched chondrite-normalised patterns, negative δEu and incompatible element ratios similar to those of ELIP alkaline Nb–Ta-enriched syenites. All available evidence shows that the alkali tonsteins from southwest China originated from coeval ELIP alkaline magmatism. The enrichment of Nb–Zr–REE–Ga in alkali tonsteins is derived from the ELIP alkaline Nb–Ta-enriched volcanic ashes and may represent the last stage of mineralisation associated with the Emeishan mantle plume activity.  相似文献   

Turbulent transfer coefficient and roughness length in a high-altitude lake,Tibetan Plateau   总被引：1，自引：0，他引：1  

Zhaoguo Li  Shihua Lyu  Lin Zhao  Lijuan Wen  Yinhuan Ao  Shaoying Wang 《Theoretical and Applied Climatology》2016,123(3-4):723-732

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Impact of the Pacific–Japan Teleconnection Pattern on July Sea Fog over the Northwestern Pacific: Interannual Variations and Global Warming Effect     

Jingchao LONG  Suping ZHANG  Yang CHEN  Jingwu LIU  Geng HAN 《大气科学进展》2016,33(4):511-521

The northwestern Pacific(NWP) is a fog-prone area, especially the ocean east of the Kuril Islands. The present study analyzes how the Pacific–Japan(PJ) teleconnection pattern influences July sea fog in the fog-prone area using independent datasets. The covariation between the PJ index and sea fog frequency(SFF) index in July indicates a close correlation, with a coefficient of 0.62 exceeding the 99% confidence level. Composite analysis based on the PJ index, a case study, and model analysis based on GFDL-ESM2 M, show that in high PJ index years the convection over the east of the Philippines strengthens and then triggers a Rossby wave, which propagates northward to maintain an anticyclonic anomaly in the midlatitudes,indicating a northeastward shift of the NWP subtropical high. The anticyclonic anomaly facilitates the formation of relatively stable atmospheric stratification or even an inversion layer in the lower level of the troposphere, and strengthens the horizontal southerly moisture transportation from the tropical–subtropical oceans to the fog-prone area. On the other hand, a greater meridional SST gradient over the cold flank of the Kuroshio Extension, due to ocean downwelling, is produced by the anticyclonic wind stress anomaly. Both of these two aspects are favorable for the warm and humid air to cool, condense, and form fog droplets, when air masses cross the SST front. The opposite circumstances occur in low PJ index years, which are not conducive to the formation of sea fog. Finally, a multi-model ensemble mean projection reveals a prominent downward trend of the PJ index after the 2030 s, implying a possible decline of the SFF in this period.  相似文献   

A modeling study of effective radiative forcing and climate response due to tropospheric ozone     

Bing Xie  Hua Zhang  Zhili Wang  Shuyun Zhao  Qiang Fu 《大气科学进展》2016,33(7):819-828

This study simulates the effective radiative forcing(ERF) of tropospheric ozone from 1850 to 2013 and its effects on global climate using an aerosol–climate coupled model, BCC AGCM2.0.1 CUACE/Aero, in combination with OMI(Ozone Monitoring Instrument) satellite ozone data. According to the OMI observations, the global annual mean tropospheric column ozone(TCO) was 33.9 DU in 2013, and the largest TCO was distributed in the belts between 30°N and 45°N and at approximately 30°S; the annual mean TCO was higher in the Northern Hemisphere than that in the Southern Hemisphere;and in boreal summer and autumn, the global mean TCO was higher than in winter and spring. The simulated ERF due to the change in tropospheric ozone concentration from 1850 to 2013 was 0.46 W m~(-2), thereby causing an increase in the global annual mean surface temperature by 0.36℃, and precipitation by 0.02 mm d~(-1)(the increase of surface temperature had a significance level above 95%). The surface temperature was increased more obviously over the high latitudes in both hemispheres, with the maximum exceeding 1.4?C in Siberia. There were opposite changes in precipitation near the equator,with an increase of 0.5 mm d~(-1)near the Hawaiian Islands and a decrease of about-0.6 mm d~(-1)near the middle of the Indian Ocean.  相似文献   

The Upstream “Strong Signals” of the Water Vapor Transport over the Tibetan Plateau during a Heavy Rainfall Event in the Yangtze River Basin   总被引：2，自引：0，他引：2  

Yang Zhao  Xiangde Xu  Bin Chen  Yinjun Wang 《大气科学进展》2016,33(12):1343-1350

A heavy rainfall event that occurred over the middle and lower reaches of the Yangtze River Basin(YRB) during July11–13 2000 is explored in this study. The potential/stream function is used to analyze the upstream "strong signals" of the water vapor transport in the Tibetan Plateau(TP). The studied time period covers from 2000 LST 5 July to 2000 LST 15 July(temporal resolution: 6 hours). By analyzing the three-dimensional structure of the water vapor flux, vorticity and divergence prior to and during the heavy rainfall event, the upstream "strong signals" related to this heavy rainfall event are revealed. A strong correlation exists between the heavy rainfall event in the YRB and the convective clouds over the TP. The "convergence zone" of the water vapor transport is also identified, based on correlation analysis of the water vapor flux two days and one day prior to, and on the day of, the heavy rainfall. And this "convergence zone" coincides with the migration of the maximum rainfall over the YRB. This specific coupled structure actually plays a key role in generating heavy rainfall over the YRB. The eastward movement of the coupled system with a divergence/convergence center of the potential function at the upper/lower level resembles the spatiotemporal evolution of the heavy rainfall event over the YRB. These upstream "strong signals" are clearly traced in this study through analyzing the three-dimensional structure of the potential/stream function of upstream water vapor transport.  相似文献   

A comprehensive classification of anomalous circulation patterns responsible for persistent precipitation extremes in South China          下载免费PDF全文

吴慧  翟盘茂  陈阳 《Acta Meteorologica Sinica》2016,30(4):483-495

Based on observational precipitation at 63 stations in South China and NCEP NCAR reanalysis data during 1951 2010,a cluster analysis is performed to classify large-scale circulation patterns responsible for persistent precipitation extremes(PPEs) that are independent of the influence of tropical cyclones(TCs).Conceptual schematics depicting configurations among planetary-scale systems at different levels are established for each type.The PPEs free from TCs account for 38.6%of total events,and they tend to occur during April August and October,with the highest frequency observed in June.Corresponding circulation patterns during June August can be mainly categorized into two types,i.e.,summer-Ⅰ type and summer-Ⅱtype.In summer-Ⅰ type,the South Asian high takes the form of a zonal-belt type.The axis of upstream westerly jets is northwest-oriented.At the middle level,the westerly jets at midlatitudes extend zonally.Along the southern edge of the westerly jet,synoptic eddies steer cold air to penetrate southward;the Bay of Bengal(BOB) trough is located to the north;a shallow trough resides over coastal areas of western South China;and an intensified western Pacific subtropical high(WPSH) extends westward.The anomalous moisture is mainly contributed by horizontal advection via southwesterlies around 20°N and southeasterlies from the southern flange of the WPSH.Moisture convergence maximizes in coastal regions of eastern South China,which is the very place recording extreme precipitation.In summer-Ⅱ type,the South Asian high behaves as a western-center type.The BOB trough is much deeper,accompanied by a cyclone to its north;and a lower-level trough appears in northwestern parts of South China.Different to summer-Ⅰ type,moisture transport via southwesterlies is mostly responsible for the anomalous moisture in this type.The moisture convergence zones cover Guangdong,Guangxi,and Hainan,matching well with the areas of flooding.It is these set combinations among different systems at different levels that trigger PPEs in South China.  相似文献   

Estimating uncertainty caused by ocean heat transport to the North Sea: experiments downscaling EC-Earth     

T. Tian  J. Su  F. Boberg  S. Yang  T. Schmith 《Climate Dynamics》2016,46(1-2):99-110

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