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1.
Tide gauge data are used to investigate sea level variability off the northwest coast of the South China Sea (SCS) in 2012, and a significant sea level elevation with a magnitude approaching 79 mm is observed. Analysis suggests that an abnormal sea surface heat flux and freshwater flux may have contributed to this abnormal rise in sea level, together with the remote influence of an ENSO event. Further investigation shows that the event was dominated by the positive freshwater flux, where large volumes of water entered the ocean, and a maximum is centered to the south of Guangdong province, China. Simultaneously, a positive anomalous heat flux occurred in the northwestern part of the SCS, which is considered to have made a positive contribution to the high local sea level elevation. In addition to the heat flux, the ENSO event also had a significant effect on the event, where the La Niña-induced northwest Pacific cyclone contributed to sea level rise over the northwestern SCS through dynamic and thermodynamic interactions. 相似文献
2.
An approach to the age of Huanghe River in shelf regions of Yellow Sea and Bohai Sea 总被引：2，自引：0，他引：2
There are two different opinions on the formation history of Huanghe （Yellow） River. One postulates that Huanghe River might have come into existence before Tertiary. The other supposes that it joined up into a long river only in the last stage of Late Pleistocene. The appearance of Huanghe River is believed to have close relation to the uplifting of Tibetan Plateau. It is not likely that it could have come into being before its high elevation riverhead was formed. Today Huanghe River occurred probably during the recession of the sea in glacial periods. In the last glacial age, the climate was very harsh in the area north of the modern estuary of Changjiang （Yangtse） River; some areas were permafrost and the others barren deserts. At that time, eolation was the major exogenic force on exposed shelf. Beginning from 12 Ka BP, the global climate warmed up, resulting in gradual disappearance of continental mountain glaciers retreated, and sea level rose. Consequently, Huanghe River was replenished with water to become modern river system. With continued rising of sea level, Huanghe River delta moved continuously eastward. 相似文献
3.
Type and evolution of landscapes of Nansha Islands 总被引：1，自引：0，他引：1
赵焕庭 《中国地理科学(英文版)》1998,8(2):144-151
ＴＹＰＥＡＮＤＥＶＯＬＵＴＩＯＮＯＦＬＡＮＤＳＣＡＰＥＳＯＦＮＡＮＳＨＡＩＳＬＡＮＤＳＺｈａｏＨｕａｎｔｉｎｇ（赵焕庭）ＳｏｕｔｈＣｈｉｎａＳｅａＩｎｓｔｉｔｕｔｅｏｆＯｃｅａｎｏｌｏｇｙ,ｔｈｅＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳｃｉｅｎｃｅｓ,Ｇｕ... 相似文献
4.
Zhao Huanting 《中国地理科学(英文版)》1997,8(2):144-151
Landscapes of the Nansha Islands may be divided into five types: tropical marine organism-breeding landscape of reef knoll
like Zengmu Shoal, Wan’an Bank and so on; tropical marine organism-breeding landscape of atoll including all emerged reefs
and most submerged reefs; tropical evergreen arbor-bush forest and phosphorous lime soil landscape of limesand Islets like
Taiping Islet, Nanwei islet and so on; tropical shallow sea marine organism-breeding landscape of southern continental shelf;
tropical oceanic and deep-sea marine organism landscape in middle and north parts of the Nansha Islands area. These five landscape
types may be also summed up as two categories, one is tropical sea landscape including those in shallow and deep sea, the
other is tropical coral reef landscape including those of reef knoll, atoll and limesand islet. This paper outlines the evolutional
model of landscapes of the Nansha Islands. The distribution and evolution of landscape types are related with palaeogeography
and modern environmental conditions. The former shallow sea of the Nansha islands was coastal zone in the Late Pleistocene
epoch. Deep sea is evolved from shallow sea due to long and slow subsidence of crust. Modern coral reefs develop on old reef
top of the Late pleistocene epoch or on baserock of continental shelf in the Holocene due to the rise of sea level in postglacial.
Limesand islet is in the peak of developmental stage. 相似文献
5.
目前研究表明,深水环境缺氧团向浅水扩散是导致二叠纪末生物危机事件的重要诱因,然而其作用过程仍存在较大争议。四川盆地东部晚二叠世长兴期主要为台地环境,通过对研究区内卧龙河构造连续沉积的井剖面对比研究发现,在二叠纪末生物大灭绝界线之前的碳酸盐岩地层中自然伽马值整体出现异常正偏。当碳酸盐岩地层中泥质含量、钍和钾的含量相对较少时,自然伽马主要反映铀含量变化,进而指示海水氧化还原条件。长兴晚期区内台地环境显现出不同程度的缺氧效应,并持续发展直至生物大灭绝的来临。区内长兴组自然伽马值异常记录了长兴晚期海洋氧化还原过程,同时也见证了重大地质转折期将至时环境的不稳定性。 相似文献
6.
山东半岛海域成矿区带划分以往研究程度较低。该文利用海域重磁资料,在研究区梳理了渤海和黄海的重磁异常特征,渤海和北黄海呈负布格重力异常,南黄海北部与之相反;渤海为正磁异常,黄海与之相反。以重磁异常为基础,基于陆域构造单元划分,对海域构造单元划分至Ⅲ级10个构造单元,海域构造单元多为陆域向海域的延伸,仅渤中坳陷和北黄海盆地为独立的海域构造单元。参照陆域成矿区带划分,以构造单元边界为界线,海域成矿区带划分至Ⅳ级6个成矿区,各成矿区特征不同,坳陷构造单元内成矿区富集油气矿产,隆起构造单元内成矿区表现为埕宁隆起富集煤矿,胶北隆起富集金、菱镁矿、煤、灰岩矿,千里隆起富集岩金、蛇纹岩、石棉、花岗石矿。 相似文献
7.
莱州湾南岸潍河下游地区咸水入侵灾害成因及特征 总被引：8，自引：1，他引：7
通过对莱州湾南岸咸水入侵较严重地潍河下游地区晚更新世以来沉积特征及现代自然环境条件变化的分析，探讨了沉积相对咸水入侵产生及空间范围特征的环境机理。晚更新世以来的三次海平面升降变化造成了潍河下游地区海陆沉积环境交替，形成了巨厚的海陆交互相沉积层。海进时期，大面积的滨海平原被淹没，在近海平原洼地滞留的海水经过蒸发、浓缩变为卤水，成为咸水入侵的物源；海退后陆源碎屑在滨海地区沉积形成了巨厚的古河道砂层。20世纪70年代末期以来，随着对地下淡水的过度开采，淡咸水水头压力差减小．卤水通过古河道砂层快速南侵。通过对潍河下游地区100余个地质钻孔水化学连续监测资料分析，阐明了咸水入侵的特征，有针对性地提出了咸水入侵的防治措施。 相似文献
8.
Regular distribution patterns of elements Ca, Sr, K, Na, Mg, Fe, Mn, Ti, Cu, Co, Ni, Zn, Pb, Cr, Rb, Ba, Cd, and U in Late
Quaternary strata have been studied in detail. The regional variation patterns of elements in these strata are similar to
those in recent surface sediments, showing that the sedimentary environment has been relatively stable since Late Quaternary.
Element distribution changes with the variations of lithological characters. Contents of Ca and Sr increase in coarse sediments,
while those of other elements decrease. Na content increases in the pumice layer. Mn, content tends to increase sharply towards
the surface layer. Ca content decreases sharply in strata where water depth is more than 2,000 m. The strata can be divided
based on the distribution curves of element assemblages. The variations in contents of most elements in Holocene Series are
smaller than those in Late Pleistocene Series, which might be related to the factors of glacial and interglacial changes,
sea level fluctuations and material source differences.
Contribution No. 1488 from Institute of Oceanology, Academia Sinica 相似文献
9.
The relatively rapid recession of glaciers in the Himalayas and formation of moraine dammed glacial lakes(MDGLs) in the recent past have increased the risk of glacier lake outburst floods(GLOF) in the countries of Nepal and Bhutan and in the mountainous territory of Sikkim in India. As a product of climate change and global warming, such a risk has not only raised the level of threats to the habitation and infrastructure of the region, but has also contributed to the worsening of the balance of the unique ecosystem that exists in this domain that sustains several of the highest mountain peaks of the world. This study attempts to present an up to date mapping of the MDGLs in the central and eastern Himalayan regions using remote sensing data, with an objective to analyse their surface area variations with time from 1990 through 2015, disaggregated over six episodes. The study also includes the evaluation for susceptibility of MDGLs to GLOF with the least criteria decision analysis(LCDA). Forty two major MDGLs, each having a lake surface area greater than 0.2 km2, that were identified in the Himalayan ranges of Nepal, Bhutan, and Sikkim, have been categorized according to their surface area expansion rates in space and time. The lakes have been identified as located within the elevation range of 3800 m and6800 m above mean sea level(a msl). With a total surface area of 37.9 km2, these MDGLs as a whole were observed to have expanded by an astonishing 43.6% in area over the 25 year period of this study. A factor is introduced to numerically sort the lakes in terms of their relative yearly expansion rates, based on their interpretation of their surface area extents from satellite imageries. Verification of predicted GLOF events in the past using this factor with the limited field data as reported in literature indicates that the present analysis may be considered a sufficiently reliable and rapid technique for assessing the potential bursting susceptibility of the MDGLs. The analysis also indicates that, as of now, there are eight MDGLs in the region which appear to be in highly vulnerable states and have high chances in causing potential GLOF events anytime in the recent future. 相似文献
10.
Ibrahim Zia Hina Zafar Muhammad I. Shahzad Mohsin Meraj Jamil H. Kazmi 《中国海洋大学学报(英文版)》2017,16(6):1055-1060
Indus Deltaic Region (IDR) in Pakistan is an erosion vulnerable coast due to the high deep water wave energy. Livelihood of millions of people depends on the fisheries and mangrove forests in IDR. IDR consists of many creeks where Daboo is a major creek located at southeast of the largest city of Pakistan, Karachi. Unfortunately, there has been no detailed study to analyze the damages of sea water intrusion at a large temporal and spatial scale. Therefore, this study is designed to estimate the effects of sea water inundation based on changing sea water surface salinity and sea surface temperature (SST). Sea surface salinity and SST data from two different surveys in Daboo creek during 1986 and 2010 are analyzed to estimate the damages and extent of sea water intrusion. Mean salinity has increased 33.33% whereas mean SST decreased 13.79% from 1987 to 2010. Spatio-temporal analysis of creek area using LANDSAT 5 Thematic mapper (TM) data for the years 1987 and 2010 shows significant amount of erosion at macro scale. Creek area has increased approximately 9.93% (260.86 m2 per year) which is roughly equal to 60 extensive sized shrimp farms. Further Land Use Land Cover (LULC) analyses for years 2001 and 2014 using LANDSAT 7 Enhanced Thematic Mapper Plus (ETM+) has indicated 42.3% decrease in cultivated land. Wet mud flats have spread out at the inner mouth of creek with enormous increase of 123.3%. Significant sea water intrusion has increased the area of barren land by 37.9%. This also resulted in overall decrease of 6.7% in area covered by mangroves. Therefore, this study recorded a significant evidence of sea water intrusion in IDR that has caused serious damages to community living in the area, economical losses. Additionally, it has also changed the environment by reducing creek biological productivity as reported by earlier studies over other regions of the world. 相似文献
11.
In this study, we used Landsat images and meteorological data to examine the spatiotemporal distribution and variability of sea ice in Jiaozhou Bay(JZB) between 1986 and 2016. The results show that JZB is not always covered by sea ice in winter, but in some extreme cases, sea ice has covered more than one-third of the sea area of the bay. Sea ice in JZB has generally formed between January 1 and February 5, primarily along the coast, and gradually expanding to the central area of the bay. Both meteorological and artificial factors have played important roles in modulating the sea ice distribution. We found sea ice coverage to have been strongly correlated with the accumulated freezing-degree days nine days before the occurrence of sea ice(R2 = 0.767). North-northwest surface winds have dominated the freezing period of sea water in the JZB, and wind speed has exerted a more significant influence on the formation of sea ice when the sea ice coverage has been generally small. Additionally, artificial factors began to affect the expansion of sea ice in JZB since 2007. The construction of the Jiao-Zhou-Bay Bridge(JZBB) is believed to have retarded water flow and reduced the tidal prism, thereby leading to the formation of an ice bridge along the JZBB, which effectively prevents the southward expansion of sea ice. 相似文献
12.
1 Introduction Nowadaysglobalclimatechangehasbeenanimportantissueintheworld.Antarctic areaisjustthekeyandsensitiveregion,fromwhichscientistsaretryingtheirbesttofind theomenofglobalclimatechange.Andfortherevolvingglobalatmosphere,PolarRegions arecoldsource.TheoceanicandatmosphericconditionofPolarRegionsisimportantto globalatmosphericcirculationandclimatechange.Antarcticareaisoneofthecoldsources ofglobalearth atmospheresystem,whileequatorialareaisitsmainheatsource(seeZhou andLuetal.1996).… 相似文献
13.
Using a regional atmospheric model for Arctic climate simulation, two groups of numerical experiments were carried out to study the inlfuence of changes in the underlying surface (land surface, sea sur... 相似文献
14.
桂西南喀斯特-北部湾海岸带生态环境脆弱性时空分异与驱动机制研究 总被引：2，自引：0，他引：2
为揭示生态环境脆弱性的时空分异和驱动因子,本研究在山江海视角下,以桂西南喀斯特-北部湾海岸带为典型研究区,运用空间主成分分析法,地理探测器模型,结合生态环境脆弱性综合指数,系统分析桂西南喀斯特-北部湾海岸带生态环境脆弱性的时空分异特征及驱动机制。结果表明：① 研究区2008、2013、2018年脆弱性指数分别为0.54、0.61、0.69,多年平均值为0.61,整体处于中度脆弱,在空间上,由城市中心向四周逐渐降低的趋势;在时间上,生态环境脆弱等级呈微恶化趋势; ② 在单因子作用中6个驱动因子对生态环境脆弱性的解释力强度为汛期降雨量（0.457）>植被覆盖度（0.384）>高温季节温度（0.311）>废水入海量（0.248）>NPP（0.184）>人口密度（0.036）。在多因子交互中,只有汛期降水量和NPP, NPP和高温季节温度、废水入海量和NPP呈非线性增强,其余的交互作用均为双线性增强,而且汛期降水量和植被覆盖度的单因子影响较强,交互作用后影响也是最强（0.679）,说明了汛期降水量和植被覆盖度为该区域的主要驱动因子。 相似文献
15.
A marine geomagnetic survey was conducted over Red Bay, a broad shallow sea area in the southern part of the Shandong Peninsula,
to obtain geological information to meet the needs of an underwater engineering project. Analyses of magnetic data revealed
the fault structure of the bedrock and differences in lithology. At the proposed offshore dam site, the magnetic survey results
indicated the position of faults which have since been confirmed by other geophysical surveys. 相似文献
16.
GPS����λˮ 总被引：2，自引：9，他引：2
魏子卿 《大地测量与地球动力学》2007,27(4):1-7
????????????θ?????????GPS????λ??,????????????????????????GPS???????EIGEN-CG03C????????λ?????е?????????????????????GPS????λ???????θ??????????0.5 m???????θ??????????????????????????10 cm?? ????????λ??????????????θ??????????, GPS???????????????????????????θ???????????????GPS????λ?????????????????????? 相似文献
17.
Yongcun Cheng Qing Xu Yuguang Liu Chongyin Li Zengzui Rong Haibo Zong Xiu Peng Xiaobin Yin 《中国海洋大学学报(英文版)》2008,7(4):379-384
Time series of sea surface temperature (SST),wind speed and significant wave height (SWH) from meteorologicalbuoys of the National Data Buoy Center (NDBC) are useful for studying the interannual variability and trend of these quantities at the buoy areas.The measurements from 4 buoys (B51001,B51002,B51003 and B51004) in the Hawaii area are used to study theresponses of the quantities to EI Nino and Southern Oscillation (ENSO).Long-term averages of these data reflect precise seasonaland climatological characteristics of SST,wind speed and SWH around the Hawaii area.Buoy observations from B51001 suggest asignificant warming trend which is,however,not very clear from the other three buoys.Compared with the variability of SST andSWH,the wind speeds from the buoy observations show an increasing trend.The impacts of El Nifio on SST and wind waves arealso shown.Sea level data observed by altimeter during October 1992 to September 2006 are analyzed to investigate the variabilityof sea level in the Hawaii area.The results also show an increasing trend in sea level anomaly (SLA).The low-passed SLA in theHawaii area is consistent with the inverse phase of the low-passed Sol (Southern Oscillation Index).Compared with the low-passedSOl and PDO (Pacific Decadal Oscillation),the low-passed PNA (Pacific-North America Index) has a better correlation with thelow-passed SLA in the Hawaii area. 相似文献
18.
Influence of sea level rise on Shanghai astronomical tide and storm surge and estimation of probable water level 总被引：3，自引：0，他引：3
reODUCTIONSthtrendanditsinfluencehaveattiactedInanresearchersinrecentyears.He(l994)exPloredthePOssibleeffectofSLRonZhuiang(Pear)fuverdeltaSSbyusingarelativelysimPletecboqUeofcollatingfutUreSthincrementswithrecenily-measuredtidalcharaCteristicvalues.Pengetal.(l994)usedasindlaraPProachtoinvestigatetheSthinf[uenceonTianinSS.SthhasqUitepronouncedimPatontheinteractionbetweenSSandATinshallowwater-SSandATgenesisaxegrealyinfluencedbylocalwaterdepthandtOpography-TocoPewiththenonlinearr… 相似文献
19.
根据1997年8月～1998年11月的调查数据,本文分析和评价了红海湾4个不同水域营养水平的时空分布特点.红海湾水域E值的空间分布从北向南呈逐渐递减的趋势,即长沙湾滩涂养殖区＞长沙湾浅海养殖区＞自然水域、龟龄岛水域,其中长沙湾滩涂养殖区和长沙湾浅海养殖区有机污染十分明显,达高富营养化程度和富营养化程度,自然水域和龟龄岛水域则营养状况相似,基本上未受到明显的有机污染.E值的季节变化趋势为春季＞秋季＞夏季＞冬季,除冬季处于贫营养状况外,其余3个季节均达富营养化程度,其中以春季有机污染最为严重,达高富营养化程度. 相似文献
20.
A typhoon-induced storm surge simulation system was developed for the Qingdao area, including a typhoon diagnostic model for the generation of wind and pressure fields and a 2D Advanced Circulation (ADCIRC) model for simulating the associated storm surge with a 200 m resolution along the Qingdao coastline. The system was validated by an extreme surge event Typhoon Mamie (8509) and the parameters of Typhoon Mamie were used to investigate the sensitivity of typhoon paths to Qingdao storm surges with four selected paths: the paths of Typhoons Mamie (8509), Opal, 3921 and 2413, the selection being made according to their relative position to Qingdao. Experiments based on the Typhoon Mamie (8509) storm surge were also conducted to study the possible influences of future climate changes, including the sea level rise and sea surface temperature (SST) rise, on storm surges along the Qingdao coast. Storm surge conditions under both present day and future (the end of the 21st century) climate scenarios associated with the four selected paths were simulated. The results show that with the same intensity, when typhoons follow the paths of 3921 and 2413, they would lead to the most serious disasters in different areas of Qingdao. Sea level and SST affect storm surges in different ways: sea level rise affects storm surge mainly through its influence on the tide amplitude, while the increased SST has direct impact on the intensity of the surges. The possible maximum risk of storm surges in 2100 in the Qingdao area caused by typhoons like Mamie (8509) was also estimated in this study. 相似文献