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胶州湾现代沉积速率和沉积通量研究 总被引：19，自引：0，他引：19
对胶州湾沉积岩心J39、J37和J94进行了210Pb的测定,绘制了岩心中210Pb的垂直分布图,岩心J37和J94的210Pb呈两段分布模式,岩心J39的210Pb呈三段分布模式。胶州湾西北部大沽河口外海域近百年来沉积速率为0 768cm/a,沉积通量为0 7716g/(cm2·a)。胶州湾中部沉积速率为0 64cm/a,沉积通量为0 65g/(cm2·a)。胶州湾口外J94站沉积速率为0 54cm/a,沉积通量为0 81g/(cm2·a)。结果表明,胶州湾海域210Pb活度与悬浮体含量密切相关,悬浮体含量高的区域,210Pb活度高;反之,悬浮体含量低的区域,210Pb活度低。根据210Pb的垂直分布、活度和沉积速率及悬浮体含量,结合历史资料,对胶州湾近百年来的沉积环境和物质扩散进行了探讨。 相似文献
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杭州湾近期环境演变与沉积速率 总被引：3，自引：0，他引：3
本文追述了杭州湾4万年来的沉积环境演变,论述了近期湾内沉积环境的差异,以及不同时间尺度的沉积速率。从钻孔样品的综合分析得知,4万年来杭州湾和东海大陆架一样亦二经沧桑。陆海变迁不仅在岩性组合、微体古生物诸方面留下确凿证据,而且有确切地貌部位样品~(14)C测年印证。杭州湾3～5m厚的沉积结构特征,显示出其各沉积区环境的明显差异和数百年来的继承性。从全新世沉积层的厚度与年代推算,8000～9000a来其沉积速率一般平均为0.11～0.25cm/a;其口门段中北部细粒沉积物区(锋面活动区),近百年来的沉积速率(~(210)Pb)为1.0～1.2cm/a;有机农药以及风暴层比对的沉积速率与其吻合。 相似文献
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南海,南黄海,渤海^210Pb垂直分布模式 总被引：5，自引：0，他引：5
利用~(210)Pb同位素地质学技术测定了我国南海,南黄海和渤海26个岩心现代沉积速率和沉积通量。发现采样点岩心中~(210)Pb的放射性强度随深度衰减呈现出五种垂直分布模式,利用其分布模式,分析研究了采样点海区沉积作用强度、物质来源和沉积环境。~(210)Pb资料表明我国陆架浅海采样点、尤其象黄河三角洲高速沉积区近百年来的沉积速率和沉积格局有显著的差异和独特的沉积特征。 相似文献
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《应用海洋学学报》2015,(4)
沉积物粒度是反应区域自然环境和人类活动变化的敏感参数之一.粒度分析结果表明,厦门大嶝海域表层沉积物以粘土质粉砂为主,其次为粉砂质砂;中值粒径范围为-0.16~7.17φ.~(210)Pb年代学分析结果显示,大嶝岛西南侧靠近五沙水道附近浅海区平均沉积速率最小(仅为0.36 cm/a),大嶝岛西南侧近岸潮间带平均沉积速率最高(可达3.94 cm/a),大嶝岛南侧近岸和北侧大嶝水道顶端海域平均沉积速率分别为1.26、1.14 cm/a.大嶝海域现代沉积过程主要受沉积动力过程和高强度人类活动控制.在潮流输沙的作用下,大量悬沙在大嶝岛西南侧海域沉积从而导致该海域沉积速率最高,而大嶝岛东侧近岸由于海底经常发生侵蚀,故沉积速率较低(仅为0.58 cm/a).近年来的高强度围填海活动及海堤建造等都明显加速了大嶝海域的沉积过程,其中因人类活动导致大嶝岛西南侧浅滩地区的沉积速率提高了4倍;围填海活动导致大量泥沙入海,对大嶝岛与小嶝岛之间海域的现代沉积过程产生重要影响. 相似文献
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对"中国第五次北极科考"和"中国第六次北极科考"采集的楚科奇海陆架、海台及海盆区的5个多管样品进行210 Pb、粒度、有机碳(OC)和总氮(TN)含量及有机碳同位素(δ13 C)、总氮同位素组成(δ15 N)分析,初步获得5个多管样品近百年来的沉积速率,陆架区沉积速率为0.19~0.41cm/a,海台和海盆区沉积速率为0.03~0.04cm/a;近百年来陆架有机碳、总氮含量分别为1.21%~1.62%、0.17%~0.21%,有机碳、总氮同位素组成分别为-22.30‰~-22.25‰PDB、7.24‰~8.12‰;海台与海盆区有机碳、总氮含量分别为0.80%~1.26%、0.13%~0.16%,有机碳、总氮同位素组成分别为-22.52‰~-22.07‰PDB、7.38‰~7.81‰。陆架与海台和海盆相比,具有沉积速率高、沉积物颗粒粗、有机碳和总氮含量高的特点。近百年来楚科奇海域陆架、海台和海盆区有机碳以海洋生源输入为主,反映了北极气候变暖,水体初级生产力增加。 相似文献
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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
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1Introduction Tracking the history of man s impact on the en-vironment, it is clear that in many places the periodof greatest impact and most dramatic transformationlies within the last 150 a (Oldfield and Appleby,1984). Many aspects of this impact can be… 相似文献
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近70年胶州湾水动力变化的数值模拟研究 总被引：2，自引：1，他引：1
采用无结构三角形网格海洋模式FVCOM,基于胶州湾不同年代的岸线和水深地形条件,建立胶州湾及其邻近海域各年代的三维潮汐潮流数值模型,从数值模拟角度分析和比较胶州湾不同年代纳潮量、潮汐潮流、水交换率等水动力参数的变化。结果表明:随着胶州湾水域总面积不断缩小,纳潮量在逐渐减小,2008年全湾的纳潮量相对于1935年减少了31.5%,约合3.9×108 m3;海湾流场结构变化很小,流速呈减小趋势;胶州湾欧拉余流"团团转"的多涡结构基本保持不变,最大值都发生在团岛附近;海湾的水交换能力趋弱,对整个胶州湾水体的半交换时间进行海湾平均,不同年代5套岸线下海湾的水体半交换时间分别是37.0 d,36.7 d,39.2 d,39.7 d和40.8 d。 相似文献
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Geochemical records of phosphorus in Jiaozhou Bay sediments-Implications for environmental changes in recent hundred years 总被引：2，自引：1，他引：2
Phosphorus is a key element and plays an important role in global biogeochemical cycles. The evolution of sedimentary environment is also influenced by phosphorus concentrations and fractions as well as phosphate sorption characteristics of the marine sediments. The geochemical characteristics of phosphorus and their environmental records were presented in Jiaozhou Bay sediments. Profiles of different forms of phosphorus were measured as well as the roles and vertical distributions of phosphorus forms in response to sedimentary environment changes were investigated. The results showed that inorganic phosphorus (IP) was the major fraction of total phosphorus (TP); phosphorus which is bound to calcium, iron and occluded phosphorus, as well as the exchangeable phosphorus were the main forms of IP, especially calcium-phosphorus, including detrital carbonate-bound phosphorus (Det-P) and authigenic apatite-bound phosphorus (ACa-P), are the uppermost constituent of IP in Jiaozhou Bay sediments. Moreover, the lead-210 chronology technology was employed to estimate how much phosphorus was buried ultimately in sediments. And the research showed that the impacts of human activities have increased remarkably in recent years especially between the 1980s and 2000. According to research, the development of Jiaozhou Bay environment in the past hundred years can be divided into three stages: (1) before the 1980s characterized by the relatively low sedimentation rate, weak land-derived phosphorus inputs and low anthropogenic impacts; (2) from the 1980s to around 2000, accelerating in the 1990s, during which high sedimentation rates, high phosphorus abundance and burial fluxes due to the severe human activities impacted on the whole environmental system; (3) after 2000, the period of the improvement of environment, the whole system has been improved including the decreasing sedimentation rates, concentration and the burial fluxes of phosphorus. 相似文献
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胶州湾大型底栖动物的丰度、生物量和生产量研究 总被引：3，自引：1，他引：2
为了研究胶州湾大型底栖动物的丰度、生物量和生产量,于2002年3月、6月、8月和12月,在胶州湾北部软底区、大沽河口、黄岛养殖区及养殖区邻域选取4个站位进行采样,对大型底栖动物进行了定量研究。共采到大型底栖动物138种,总平均丰度、平均生物量(湿质量)和年生产量(有机碳)分别为1 719个/m2,27 g/m2,2.2 g/(m2.a),初步估算,胶州湾大型底栖动物的总次级生产量为2.8万t/a。与渤海和南黄海大型底栖动物的丰度和生物量比较,丰度和生物量均低于这两个海域,但是胶州湾大型底栖动物的总次级生产量高于渤海。本研究对于了解胶州湾大型底栖动物现状及湾内养殖对大型底栖动物的影响具有重要的意义。 相似文献
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Bacterial and cyanobacterial diversities determined by T-RFLP analyses in the Jiaozhou Bay 总被引：2，自引：0，他引：2
1Introduction Bacteriaareactivelyinvolvedinthedecomposi tionanddegradationoforganicmatterandxenobiotic compound,biogeochemicaltransformationsandnu trientrecyclingoflife essentialelements.Owingto freshwaterrunoff,wastewaterdischargeandaquacul turalpractice… 相似文献
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胶州湾沉积物中有机质的来源与组成及其对百年尺度环境变化的指示 总被引：4，自引：0，他引：4
The Jiaozhou Bay is characterized by heavy eutrophication that is associated with intensive anthropogenic activities. Four core sediments from the Jiaozhou Bay are analyzed using bulk technologies, including sedimentary total organic carbon(TOC), total nitrogen(TN), the stable carbon(δ~(13)C) and nitrogen(δ~(15) N) isotopic composition to obtain the comprehensive understanding of the source and composition of sedimentary organic matter and further shed light on the environmental changes of the Jiaozhou Bay on a centennial time scale.Results suggest that the TOC and TN concentrations increase in the upper core, having indicated a probable eutrophication process since the 1920 s in the inner bay and the 2000 s in the bay mouth. The TOC and TN concentrations outside the bay have also changed since 1916 owing to the variation of terrigenous input.Considering TOC/TN ratio, δ~(13) C and δ~(15) N, it can be concluded there is a mixture of terrigenous and marine organic matter sources in the study area. A simple two end-member(terrigenous and marine) mixing model usingδ~(13) C indicats that 45%–79% of TOC in the Jiaozhou Bay is from the marine source. The environmental changes of the Jiaozhou Bay are recorded by geochemical proxies, which are influenced by the intensive anthropogenic activities(e.g., extensive use of fertilizers, and discharge of sewage) and climate changes(e.g., rainfall). 相似文献
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在实验室对胶州湾现场水样进行了处理、分析,获得了黄色物质溶液中六种生化成分在胶州湾的水平分布和测定数据,其中测得胶州湾黄色物质溶液中总脂质含量的平均值为21.03mg/dm3,游离氨基酸为1.75mg/dm3,总糖为1.41mg/dm3,氨基多糖为14.23μg/dm3,而胡萝卜素和酚分别为1.13和0.004μg/dm3.黄色物质在胶州湾海水中约为24.20mg/dm3.计算给出了胶州湾黄色物质中总脂质占86.90%,总糖占5.82%,游离氨基酸占7.22%,氨基多糖占0.06%,而胡萝卜素和酚所占比例甚小,与总脂质、氨基酸和总糖相比,约相差几个数量级.分析认为,胶州湾黄色物质以陆源输入为主,其生化成分分布受河流淡水入海流路和湾内环流等影响而被进一步扩散、输送. 相似文献
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This is the first detailed study on the distribution of lead-210 in the Japan Sea water. The content of lead-210 ranged from 9.3±2.1 dph/l in the surface water to 3.4+-0.8 dph/l in the deep water—a quite low content as compared to that in the deep water of the North Pacific. Vertical profiles show that the content of lead-210 abruptly decreases below the seasonal thermocline (10–20 m in depth) and nearly uniform in the deep water. It is suggested that a significant amount of air-borne lead-210 deposited over the Japan Sea is transported along with the Tsushima Current to the open ocean. The budget of lead-210 is calculated by using a simple box-model and the mean residence time of lead-210 in the Japan Sea is estimated to be 15 yr. 相似文献