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1.
双台子河口重金属污染的沉积记录 总被引：3，自引：0，他引：3
根据双台子河口沉积柱中微量金属的含量及沉积物的粒度参数,结合137Cs放射性比活度精确定年,研究了双台子河口的沉积速率和重金属的污染变化特征,并利用地累积指数法评价了重金属的污染程度。137Cs计年的结果表明,沉积柱的平均沉积速率为1.3cm/a。沉积物的粒径从底层向表层逐渐变细,反映了水动力条件的减弱。绝大多数重金属的含量基本上都是自底部向上逐渐增加。重金属元素与细粒沉积物(63μm)均具有较好的正相关性,说明细粒物质对重金属具有较高的吸附能力。采用地累积指数对沉积柱中重金属元素的垂向变化进行了评价,发现除Cd元素外,大部分元素均未受到污染(Igeo0)。推测Cd的污染可能主要与20世纪90年代起至今人类活动对双台子河口产生的影响逐渐增加有关。 相似文献
2.
长江口泥质区18#柱样的现代沉积速率及其环境 指示意义 总被引：1，自引：0，他引：1
通过对长江口泥质区18#柱样进行137Cs和210Pb同位素测年分析,得到了柱样站点的现代沉积速率。结果表明,近50多年来沉积速率较大,且呈现阶段性差异：由137Cs时标计年法得到柱样1954—1964年的沉积速率为5.9 cm/yr,1964—2006年减小为 3.36 cm/yr;沉积柱样的210Pb剖面呈两段分布,由此得到沉积速率120～225 cm为5.47 cm/yr,对应于18～100 cm减小为4.58 cm/yr。对比分析两种方法得出沉积速率开始减小的时间为1968—1972年,并且采样点区域表层可能出现侵蚀现象,为研究长江口泥质区环境演变提供了依据。 相似文献
3.
对珠江口内伶仃洋不同海域3个柱状样沉积物进行的210 Pb测年和重金属分布特征垂向变化分析;研究了近百年来珠江口沉积速率时空变化;探讨了在自然作用和人类活动影响下重金属分布特点和累积因素。结果表明,珠江口内伶仃洋海域东西两岸的沉积物平均粒径4~7.5Φ,横门和深圳海域沉积物敏感组分呈现出显著双峰分布,粗细组分分界线为5.25Φ,淇澳岛沉积物敏感组分不明显,沉积环境较为稳定。基于210Pb测年的CIC模式,获得了各个岩心的现代沉积速率,横门海域沉积速率1.6cm/a,淇澳岛海域沉积速率4.08cm/a,0~70cm深度内深圳西海岸海域沉积速率2.58cm/a,70cm以深沉积速率为4.47cm/a。重金属含量分析表明,Cr、Ni、Cu、Zn和Pb含量从1923—1986年维持较高水平,但是变化不大;1967—1983年的深圳海域和1983—2004年的淇澳岛海域,各重金属元素含量快速上升;进入2000年以后,2003—2005年和2008—2012年,重金属含量呈现逐年减小趋势,2005—2008年则表现为逐年上升;这些变化与沿岸的社会经济发展、重金属入海量紧密相关。 相似文献
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海州湾南部近岸现代沉积速率及其沉积通量 总被引：1，自引：0，他引：1
对海州湾南部近岸3个柱状岩芯进行了210Pb的测定,绘制了岩芯中210Pb的垂直分布图。结果表明,柱-1岩芯表现为2个明显的沉积阶段,1-12 cm平均沉积速率为0.51 cm/a,12-57 cm的为0.18 cm/a,沉积通量分别为0.69和0.24 g/（cm^2·a）;柱-2岩芯平均沉积速率为0.64 cm/a,沉积通量为0.68 g/（cm^2·a）;柱-3岩芯平均沉积速率为0.67 cm/a,沉积通量为0.76 g/（cm^2·a）。沉积速率从北往南逐渐增大。造成这种空间分布规律的主要因素是沉积环境和物质来源,其次可能同海域位置、沉积物组分特征和海底地形有关。 相似文献
6.
《海洋地质与第四纪地质》2016,(1)
对珠江口内伶仃洋不同海域3个柱状样沉积物进行的210 Pb测年和重金属分布特征垂向变化分析;研究了近百年来珠江口沉积速率时空变化;探讨了在自然作用和人类活动影响下重金属分布特点和累积因素。结果表明,珠江口内伶仃洋海域东西两岸的沉积物平均粒径4~7.5Φ,横门和深圳海域沉积物敏感组分呈现出显著双峰分布,粗细组分分界线为5.25Φ,淇澳岛沉积物敏感组分不明显,沉积环境较为稳定。基于210Pb测年的CIC模式,获得了各个岩心的现代沉积速率,横门海域沉积速率1.6cm/a,淇澳岛海域沉积速率4.08cm/a,0~70cm深度内深圳西海岸海域沉积速率2.58cm/a,70cm以深沉积速率为4.47cm/a。重金属含量分析表明,Cr、Ni、Cu、Zn和Pb含量从1923—1986年维持较高水平,但是变化不大;1967—1983年的深圳海域和1983—2004年的淇澳岛海域,各重金属元素含量快速上升;进入2000年以后,2003—2005年和2008—2012年,重金属含量呈现逐年减小趋势,2005—2008年则表现为逐年上升;这些变化与沿岸的社会经济发展、重金属入海量紧密相关。 相似文献
7.
以南黄海西部中陆架区SYS-0701钻孔顶部102.5 cm岩心为研究对象,通过对岩心沉积物的210Pb、137Cs同位素测年和重金属元素(Cu、Pb、Zn、Cr、Hg、As、Cd)含量分析,研究了该孔0～102.5 cm岩心的沉积速率及其重金属元素地球化学特征.结果表明,岩心沉积物的平均沉积速率为2.16 cm/a;重金属含量在1961-1970年含量较低,1970-2004年呈上升趋势,随后开始减少,这与人类活动密切相关.SYS-0701孔顶部102.5 cm岩心未明显受重金属污染,且与黄渤海其他海域相比重金属含量偏低,其原因可解释为该钻孔岩心沉积物主要为老黄河沉积物(1128-1855年)在1855年之后被海流侵蚀并搬运而来,来自苏北岸外的现代沉积含量较低. 相似文献
8.
闽北近海柱状沉积物粒度特征及沉积速率研究 总被引：1，自引：0，他引：1
通过对闽北近海柱状沉积物的粒度频率曲线、粒度参数、粒度组成和沉积速率变化等特征分析,探讨闽北近海现代沉积环境条件变化.结果显示,闽北近海沉积物类型单一,以粘土质粉砂为主,粒级变化不大,粒度组成相对集中,粉砂级占绝对优势.频率曲线主要以主次双峰型为主,Zk1、Zk2柱样局部层位为主次三峰形态.Zk1、Zk2、Zk3柱样分别在78、69、87 cm处有不太明显的分段特征,上段平均粒径均略大于下段.研究表明潮流作用是该海域主沉积动力,沉积物主要以陆源物质为主,研究海域的水深整体略有变浅.研究区现代平均沉积速率为1.18～1.23 cm/a,里山湾和台山列岛附近海域沉积物平均沉积速率较快,分别为1.23、1.20 cm/a,大于七星列岛附近海域的沉积速率1.18 cm/a.海水动力条件是主要的控制因素,百年以来里山湾和台山列岛附近海域的水动力大小逐渐减弱,沉积物的沉积速率减小,台山列岛附近海域沉积速率减小幅度比较大;七星列岛附近海域水动力条件逐渐增强,沉积速率缓慢增加. 相似文献
9.
为研究百年人类活动对广西防城江口沉积物的影响,依据2014-08取得的广西防城江口HSL柱的210Pb、粒度、常量元素、重金属元素数据,建立210Pb年代序列,对其重金属环境背景进行构建,对HSL柱的重金属元素富集系数进行计算,对人类活动影响下的重金属元素进行潜在生态危害评价。结果表明,HSL柱210Pb年代拟合系数在0.9以上,该柱沉积速率约为0.37 cm/a。以沉积物粒度中<32μm体积分数为参比元素构建的防城江口的重金属环境背景显示:HSL柱20 cm以深为"清洁样品";10 cm(约1990年)以浅开始显著受人类活动影响;5 cm(约2000年)以浅各重金属富集系数均显著受工业活动影响,Cd单因子危害系数达到强生态危害程度,Hg达到中等生态危害程度,潜在生态危害指数也达到强生态危害程度。受防城港市产业结构调整的影响,2010年之后潜在生态危害指数有所降低,但部分重金属(Cd和Hg)的潜在生态危害依然较为严峻。 相似文献
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This paper analyses the global tendency of the sea level rise (SLR) and its long term influence on the sea level upstream drainage cascade based on the example of the level’s variation in the Vistula Lagoon of the Baltic Sea compared to the other lagoons and coastal regions of the southeastern part of the Baltic Sea. A steady positive trend in the water level variations was revealed; its magnitude varies significantly depending on the time period. In general, during the 100–150 year period, the rate of the SLR in the lagoons and coastal areas of the Baltic Sea (1.7–1.8 mm per year) is close to the SLR rate in the World Ocean. In the second half of the 20th century, the increased rate of the SLR in the lagoons and marine areas became stronger (up to 3.6 mm per year in the Vistula Lagoon and in 1959–2006 in the sea and exceeded the rate of global ocean SLR). It dramatically increased at the end of the last century both in the lagoons and in the sea (up to 10.0–15.0 mm per year). This is the response not only to the global climate warming but it is likely that it is also a response to the changes of the climate driving forces that influence the regimes of the local wind and precipitation in the catchment. 相似文献
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Distribution of Pacific-origin water in the region of the Chukchi Plateau in the Arctic Ocean in the summer of 2003 总被引：6，自引：1，他引：6
1Introduction Besidestheprecipitationandriverdischarges,the watersinthePacificOceanandtheAtlanticOceanare thesourcesoftheArcticOceanwater.TheAtlantic waterenterstheArcticOceanviatheFramStraitand theBarentsSea.Foritsdenserfeatureduetohigh salinity,mostofitsinkstothenorthofSvaldbardand circulatesinallthedeepbasinsintheArcticOcean, formingthedeepandbottomwatersoftheArcticO- cean(Aagaardetal.,1985;Rudelsetal.,1999).The BeringStraitistheonlychannelforthePacificwater toflowintotheArcticOce… 相似文献
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1 古新-下渐新统含油气层系 古新-始新统母岩形成于滨海和湖泊沉积环境中,并在大量冲积源的参与之下,促进了含分散有机质混合类型砂-黏土质陆源岩层的堆积。在中国东北诸盆地中,含工业油气的白垩-早第三纪建造形成于开阔的浅水和深水湖泊环境中。与中国的盆地类似,在下第三系下部 相似文献
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Izvestiya, Atmospheric and Oceanic Physics - The Great Andaman–Sumatra earthquake (GASE) on December 26, 2004, with magnitude Mw of 9.2, occurred in the Indian Ocean near the northwestern... 相似文献
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Data on the contents and compositions of the hydrocarbons (HCs)—aliphatic (AHCs) and polycyclic aromatic (PAHs)—are provided
in comparison with the contents of the total organic carbon (Corg), the lipids in the particulates, and the Corg in bottom sediments. Particular attention has been paid to the distribution of the HCs in the water area of the Kravtsov
oil field. It has been established that the concentrations of AHCs in the water are governed by the content of particulates,
and the elevated AHC concentrations are confined to the coastal areas. In the water area of platform D-6, the sandy bottom
sediments were notable for the great variability of the HC concentrations, both laterally and from year to year. In the summer
of 2010, the content of AHCs averaged 40 μg/g (19% in the Corg), and that of PAHs, 23 ng/g. Natural seepage from the sediment mass is considered to be a source of HCs along with oil contamination. 相似文献
16.
Relationship between the path of the Kuroshio in the south of Japan and the path of the Kuroshio Extension in the east 总被引：2，自引：0，他引：2
A relationship between paths of the Kuroshio and Kuroshio Extension (KE) is investigated, using the satellite-derived altimetry
dataset of 1993–2008. When the Kuroshio takes the nearshore nonlarge meander path or typical large meander path and resultantly
goes through the deeper channel (about 2500 m) of the Izu-Ogasawara Ridge, the KE path adopts a relatively stable state with
the two quasi-stationary meanders. On the other hand, when the Kuroshio takes the offshore nonlarge meander path and then
passes over the shallower part of the Ridge (about 1000 m), the KE path tends to be convoluted, i.e., an unstable state. 相似文献
17.
Causes of the bottom hypoxia in the eastern part of the Gulf of Finland in the baltic sea 总被引：1，自引：0，他引：1
A. A. Maximov 《Oceanology》2006,46(2):185-191
The data on the bottom concentrations of dissolved oxygen in the eastern part of the Gulf of Finland obtained in 1923–1939 and in 1962–1989 were analyzed. No statistically reliable differences were found between the two periods studied. It was found that, during the 20th century, the fluctuations in the oxygen concentration were caused by the interannual variability of the winter severity and water salinity. A strong oxygen deficit in the summer was recorded after cold winters, when early freezing suppressed the vertical mixing, and/or in the years of a significant inflow of salt waters from the Baltic Sea with low oxygen contents. It is likely that the long-term dynamics of the oxygen concentration near the bottom in the open parts of the bay is determined by the large-scale variability of the hydrometeorological parameters. 相似文献
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The role of the small-size (SF; 0.1–0.5 mm) and large-size (LF; 0.5–20.0 mm) fractions in the biomass and abundance of mesozooplankton
(0.1–20.0 mm) was assessed using the database of samples obtained during the cruises of RV Akvanavt in the northeastern Black Sea in November 2000 and October 2006. The mesozooplankton was collected by means of Juday nets
(37/50, filtering gauze 160 μm) and Niskin bottles in two areas: (1) the shelf and continental slope (30–1480 m depth) and
(2) the deep sea (depths of more than 1500 m). The plankton net was considerably less effective in collecting the SF of the
mesozooplankton (by a factor of 30–36) than the Niskin bottles. When comparing the SF and LF, we estimated the abundance and
biomass of the SF in the samples obtained with the Niskin bottles. The abundance of the SF in the deep-sea area was 2.5 times
lower compared to the shelf and continental slope, and the LF abundance was 5.0 times lower in the same way. The abundance
of the SF constituted 88% of the total mesozooplankton on the shelf and continental slope, and 78% in the deep-sea area. The
biomass of the SF was higher as well on the shelf and continental slope. Meroplankton played a significant role in the SF
zooplankton abundance (0.5 × 103 + 0.16 ind. m−3) in this area. The SF grazing impact was 10% of the total mesozooplankton grazing on the shelf and continental slope, and
17% in the deepsea area. Appendicularia and nauplii of copepods had the greatest contribution to the mesozooplankton grazing
among the SF group. 相似文献
20.
Evaluation of the effectiveness of the regulatory regime in the management of oil pollution in Kenya
Boaz O. Ohowa 《Ocean & Coastal Management》2009,52(1):17-21
This paper presents an evaluation of the effectiveness of the regulatory regime in the management of oil pollution on Kenya's marine and coastal environment. The prospect of chronic oil pollution along the Kenyan coastline and the port of Mombasa is discussed. A review of the vulnerable marine and coastal resources, commonly used indicators of effectiveness in oil pollution management and the legislation governing oil pollution is given. The author concludes by emphasising that despite having the right legislation in place, there is need for the establishment of criteria and indicators necessary for evaluation of policy effectiveness. 相似文献