Interannual variation of rare earth element abundances in corals from northern coast of the South China Sea and its relation with sea-level change and human activities     

Liu Y  Peng Z  Wei G  Chen T  Sun W  He J  Liu G  Chou CL  Shen CC 《Marine environmental research》2011,71(1):62-69

Here we present interannual rare earth element (REE) records spanning the last two decades of the 20th century in two living Porites corals, collected from Longwan Bay, close to the estuarine zones off Wanquan River of Hainan Island and Hong Kong off the Pearl River Delta of Guangdong Province in the northern South China Sea. The results show that both coral REE contents (0.5-40 ng g?1 in Longwan Bay and 2-250 ng g?1 in Hong Kong for La-Lu) are characterized with a declining trend, which are significantly negative correlated with regional sea-level rise (9.4 mm a?1) from 1981 to 1996 in Longwan Bay, 13.7 mm a?1 from 1991 to 2001 in Hong Kong). The REE features are proposed to be resulted from seawater intrusion into the estuaries in response to contemporary sea-level rise. However, the tendency for the coral Er/Nd time series at Hong Kong site is absent and there is no significant relation between Er/Nd and total REEs as found for the coral at Longwan Bay site. The observations are likely attributed to changes of the water discharge and sediment load of Pearl River, which have been significantly affected by intense human activities, such as the construction of dams/reservoirs and riverbed sediment mining, in past decades. The riverine sediment load/discharge ratio of the Pearl River decreased sharply with a rate of 0.02 kg m?3 a?1, which could make significant contribution to the declining trend of coral REE. We propose that coastal corals in Longwan Bay and similar unexplored sites with little influences of river discharge and anthropogenic disruption are ideal candidates to investigate the influence of sea-level change on seawater/coral REE.  相似文献   

Phenotypic and genetic differentiation in young-of-the-year common sole (Solea solea) at differentially contaminated nursery grounds     

Guinand B  Durieux ED  Dupuy C  Cerqueira F  Bégout ML 《Marine environmental research》2011,71(3):195-206

Growth-related characters, condition factor, and genetic differentiation were investigated for a single cohort of young-of-the-year (YOY) sole within and among nurseries with differing levels of heavy metals (Cd, Cu and Zn) contamination in the two Charentais Straits, Bay of Biscay, France. Analyses were performed when individuals recruited (May), then after a full summer spent in each nursery (October). Levels of phenotypic and genetic diversity were compared, together with genetic differentiation at a candidate metallothionein (MT) locus and three putatively neutral microsatellite loci. No phenotypic or genetic differentiation was detected among nurseries in May, but significant variation at each phenotypic trait and at the multilocus level in October (P < 0.001). Single locus analysis demonstrated that only the MT locus was significantly differentiated among nurseries, whether corrected for null alleles or not (θ=0.0401 and θ(corr.FreeNA)=0.0326, respectively; P < 0.001). Results indicate that phenotypic differences among YOY sole nurseries present a molecular correlate acting at identical spatio-temporal scales among nurseries, potentially reflecting differential selective pressure among nurseries in response to contamination.  相似文献   

A Potential Flood Hazard Caused by Tianchi Volcano Eruption in Changbai Mountain, Northeast China     

Neil B. McLaughlin 《山地科学学报》2011,(5)

Geohazards appear to be increasing in frequency globally. It is of necessity to actively manage these natural hazards to minimize loss of life and property. From an early warning perspective, this paper stresses the potential fatal flood hazard represented by the huge volume of water in Tianchi Lake, the unique geography of Changbai Mountain, and the limited flood control ability in the upstream of the Songhua River. Northeast Asian countries should keep a watchful eye on the Changbai volcano cooperatively,...  相似文献   

Orbits of Ten Visual Binary Stars     

B. Novakovic 《中国天文和天体物理学报》2007,7(3):415-420

We present the orbits of ten visual binary stars: WDS 01015 6922, WDS 01424– 0645, WDS 01461 6349, WDS 04374–0951, WDS 04478 5318, WDS 05255–0033, WDS 05491 6248, WDS 06404 4058, WDS 07479–1212, and WDS 18384 0850. We have also determined their masses, dynamical parallaxes and ephemerides.  相似文献   

自主控制的GIS技术与制图学远程教育:GITTA工程     

Werner M  Stern B  王荣彬  刘宇 《测绘文摘》2004,(1)

“瑞士虚拟校园(SVC)”是瑞士联邦1999年发起,2000年启动的项目,主要是应用新的信息与网络技术,使G-IS技术得到广泛传播。现在人们对相关教育素材的需求不断上升。GITTA项  相似文献   

佛罗里达和大巴哈马滩上新世—更新世低水位大气成岩作用的限制条件:海平面变动模型的意义     

傅文敏  LeslieA．Melim 《海洋地质前沿》1997,(6)

业已证实，潜水大气透镜体内更新世浅水碳酸盐岩中广泛发育成岩作用．且有人推测在更新世大规模低水位期间连续发生这种交代作用，其根据来自出现广布的埋藏洞穴（大于5000m；Spencer，1967），但是，所有的这些洞穴发现在浅水岩相中，在沉积作用之后不久开始重复地出露，因此，洞穴形成的原始深度仍然存在问题．为了正确确定大规模低水位期间出现的大气水成岩作用，蓄意在沉积作用时期存在一个未重复的与大气流体接触的层段，并且目前存在于海面之下80－120m，这样的一个较深水岩相上覆有浅水岩相，在佛罗里达南部和大巴哈马滩前积边缘（C…  相似文献   

Fe-Mn nodules associated with hydrocarbon seeps： A new discovery in the Gulf of Cadiz （eastern central Atlantic）     

FJ．Gonzdlez L．Somoza R．Lunar J.Marffnez-Frias J.A．MarffnRubi T.Torres J．E．oniz V.Diaz-del-Rio 《《幕》》2007,30(3):187-196

  相似文献   

地球化学“景观”的分形特性     

Bolvi.  B 施俊法 《物探化探译丛》1993,(2):44-50

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地核探索——一项并不过分的建议     

D．J．Stevenson朱大庆  范国华陈运泰 《世界地震译丛》2004,(2):85-86

对我们这颗行星的内部运作情况进行探索——这不是科幻小说，而是一项在技术上行得通的方案。  相似文献   

Grain-size end-members and environmentally sensitive grain-size components: A comparative study in the mud shelf depocenters off southern Brazil     

Michel Michaelovitch de Mahiques  Samara Cazzoli y Goya  Maria Carolina da Silva Nogueira de Matos  Rodrigo Augusto Udenal de Oliveira  Bianca Sung Mi Kim  Paulo Alves de Lima Ferreira  Rubens Cesar Lopes Figueira  Marcia Caruso Bícego 《国际泥沙研究》2021,36(2):317-327

The current study aims to do a comparative analysis of the results obtained with two End-Member(EM)grain-size modeling techniques(AnalySize and BasEMMA)and the Environmental Sensitive Grain-Size(ESGS)modeling for sediment samples collected in the mudbelts of the southern Brazilian shelf.The methods were compared using grain-size data from the south Brazilian shelf,and the results are discussed here.It is the first time that the concept of ESGS,in its present form,is utilized outside China.The results show that despite its relative ease of use,the ESGS is not fully comparable to the EM analyses,and only two grain-size ESGS classes were recognized as analogous to EMs.The comparison of the AnalySize and BasEMMA procedures also revealed significant differences between the techniques.A comparative analysis between the two EM techniques revealed advantages in the BasEMMA,especially in the better correlation of the end-members with the original grain size distribution.The analysis of the geographical distribution of the EM abundances allowed point sources of sandy populations to be recognized as well as the contribution of the Rio de la Plata as a source of silty sediments to be inferred.  相似文献