东海内陆架表层沉积物粒度及其净输运模式   总被引：4，自引：0，他引：4  

刘升发  刘焱光  朱爱美  李朝新  石学法 《海洋地质与第四纪地质》2009,(1)

根据对东海内陆架海底沉积物的粒度测试,运用Gao-Collins"粒度趋势分析"方法,探讨了东海内陆架海底表层沉积物的粒度分布特征和净输运趋势。结果表明,研究区表层沉积物可以分为两类:细颗粒(>5Φ)和粗颗粒(<5Φ);细颗粒分布于研究区的大部分区域,而粗颗粒主要分布在闽江、瓯江等入海河流口门以及马祖等海岛附近;表层沉积物的平均粒径、分选系数、偏态等粒度参数对应性较好,总体特征为粒径越粗,分选越差,偏态更正偏,而粒径越细,分选越好,偏态也较低;粒径趋势分析显示东海陆架表层沉积物的运移模式总体为NE—WS方向运移,而研究区边缘在运移过程中发生向左右两侧的偏移,南部闽江河口区沉积物由近岸向海方向辐射运移,研究区表层沉积物的净输运模式主要受控于流系和地形等多种因素。  相似文献   

ChinaFLUX CO2通量数据处理系统与应用   总被引：4，自引：0，他引：4  

李春  何洪林  刘敏  苏文  伏玉玲  张雷明  温学发  于贵瑞 《地球信息科学学报》2008,10(5):557-565

CO₂通量观测数据的规范处理及其高质量数据产品的发布,是CO₂通量及其相关领域研究的前提和基础。为解决目前通量观测数据处理工作中存在的过程繁琐、方法不统一、处理不及时等问题,本研究以MATLAB为开发工具,利用其强大的数学计算功能和可视化GUI技术,集成目前主要的通量数据处理方法,开发了一套具有自主知识产权的中国通量网(ChinaFLUX)通量观测数据处理系统。该系统的处理对象为30min的CO₂通量观测数据,其主要处理步骤包括湍流通量计算、观测数据的质量控制/质量保证、缺失观测数据的插补,以及不同时间尺度下碳交换量的分解和计算等。该系统自动化程度高、可视化程度强,为ChinaFLUX通量观测数据处理及服务提供了一个良好的平台。  相似文献   

西菲律宾海沉积物铁族元素地球化学   总被引：5，自引：1，他引：5  

石学法  陈丽蓉 《海洋地质与第四纪地质》1993,13(1):73-84

本文对取自西菲律宾海区的三个柱状沉积物岩芯的铁族元素地球化学行为进行了系统的研究。从元素的含量及剖面变化、元素的相关性及组合特征,铁族元素与主元素的关系以及元素的赋存状态等方面探讨了物质来源、沉积作用和古气候,并据此进行了地层划分。沉积物有4种来源:海底火山源、生物源、自生源和陆源。海底火山物质提供了较多的铁族元素,相形之下,自生沉积作用较弱。元素地层学研究表明,在全新世温暖期和晚更新世寒冷期铁族元素表现出不同的地球化学行为,尤以Mn和亲生物(Ca)元素对气候的反映灵敏。WP_2孔和WP_(40)孔铁族元素特征相似,与WP_1孔差别较大。  相似文献   

Concentration distribution and assessment of heavy metals in the surface sediments of the western Gulf of Thailand     

Shengfa Liu  Xuefa Shi  Gang Yang  Somkiat Khokiattiwong  Narumol Kornkanitnan 《Environmental Earth Sciences》2016,75(4):346

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Influence of Leaf Area Index on the Radiometric Resistance to Heat Transfer     

Lei Zhao  Xuhui Lee  Andrew E. Suyker  Xuefa Wen 《Boundary-Layer Meteorology》2016,158(1):105-123

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Lead,Sulfur, and Oxygen Isotope Systematics in Hydrothermal Precipitates from the 14°S Hydrothermal Field,South Mid‐Atlantic Ridge          下载免费PDF全文

Bing Li  Xuefa Shi  Chuanshun Li  Jixin Wang  Yanliang Pei  Jun Ye 《Resource Geology》2016,66(3):274-285

At the inside corner between the South Mid‐Atlantic Ridge (SMAR) and the Cardno fracture zone, the 14°S hydrothermal field, with its abundant silica‐rich sulfides, was identified as a volcanic massif, which provided the first opportunity to study inside corner‐related hydrothermal mineralization. S, Pb, and O isotopes were measured in hydrothermal sulfide samples from the two sites (volcanic top and slope sites) in the 14°S field. The homogeneous Pb isotope values (²⁰⁷Pb/²⁰⁴Pb = 15.466 ? 15.472; ²⁰⁶Pb/²⁰⁴Pb = 18.242 ? 18.252) and the δ³⁴S values (top site, +6.3 to +6.85‰; slope site, +2.37 to +3.36‰) suggest that the source of metals and most of the sulfur is the upper crust, whereas some sulfur is sourced from downward‐penetrating seawater, especially in the top site. The calculated oxygen isotope equilibration temperatures from quartz and seawater are between 94 and 144°C for the top site and between 179 and 196°C for the slope site. These isotopic proxies, together with geological background survey data, have an important implication: Discrepancies between the sites may result from variations in crust permeability, which also affect the mixing level between downward‐penetrating seawater and upward hydrothermal end‐member fluids and determine the various mineralization types.  相似文献   

中国喀斯特关键带岩石风化碳汇评估及其生态服务功能   总被引：7，自引：2，他引：5  

宋贤威  高扬  温学发  郭大立  于贵瑞  何念鹏  张进忠 《地理学报》2016,71(11):1926-1938

喀斯特地区的岩石风化固碳被认为是全球遗漏碳汇之一,中国喀斯特地区的分布面积达344万km²,目前对其岩溶碳汇缺乏精确、系统的评估,对碳汇产生的机制仍存在争议。本文通过对喀斯特地区碳汇研究的回顾,详细介绍了适用于喀斯特地区固碳速率的估算方法,并对喀斯特地区的岩石风化碳汇进行再评估,然后将地球关键带科学概念引入喀斯特生态系统,阐述喀斯特关键带碳汇研究对生态系统服务和功能的意义。研究结果表明,中国喀斯特地区每年因岩溶作用产生的碳汇为4.74 Tg C yr^-1,未来中国需要加强岩石—土壤—水体—生物—大气复杂交互系统的基础数据收集,以明确各界面碳通量,对喀斯特关键带碳汇进行多尺度、多方法、全方位联合评估,在改善喀斯特生态系统功能、科学管理区域和国家碳收支及全球变化研究等方面为政府和学者提供参考。  相似文献   

西菲律宾海晚第四纪沉积地球化学特征   总被引：7，自引：3，他引：7  

石学法  陈丽蓉 《海洋与湖沼》1995,26(2):124-131

对１９８８对取自西菲律宾海区的３个沉积物柱样进行系统的地球化学研究。结果表明，本区的沉积物属半远洋沉积物，其地球化学特征受控于陆源沉积作用、海洋生物沉积作用和海底火山常积作用。据主要化学元素和ＣａＣＯ５的柱状变化进行地层划分和古气候的恢复，区分出末次冰期的亚间冰期沉积、冰期最盛期沉积和全新世沉积。本区的ＣａＣＯ３变化表现出两种类型，ＷＰ１柱样属大西洋型溶解旋回；ＷＰ２和ＷＰ４０柱样属太平洋型溶解旋  相似文献   

37 ka以来日本海沉积物有机质碳和氮稳定同位素变化及其古海洋学意义     

邹建军  宗娴  朱爱美  豆汝席  林锦辉  冯旭光  董智  Sergey A. GORBARENKO  郑立伟  石学法 《地学前缘》2022,29(4):123-135

海洋沉积物有机质碳氮稳定同位素(δ¹³C、δ¹⁵N)广泛用于有机质来源示踪、古生产力和古海洋环境重建。日本海沉积物δ¹³C和δ¹⁵N值一个显著特征是在末次冰盛期(LGM)同步负偏,但是对这一现象产生的原因以及他们的演化过程的认识仍然存在明显不足。在本研究中,我们详细调查了37 ka以来日本海中部LV53-23-1岩心沉积物δ¹³C和δ¹⁵N演化历史。结果显示,沉积物δ¹³C和δ¹⁵N分别介于-26.3‰至-22.5‰和1.6‰至6.1‰,低值出现在LGM(26.5~17 ka)暗色层状泥发育时期,指示较强的陆源输入贡献。在Heinrich冰阶1时期(17~14.5 ka),δ¹³C和δ¹⁵N快速正偏,表明日本海海洋环境发生了明显的转换,对应于对马海峡淹没及对马暖流入侵。14.5 ka之后,沉积物δ¹⁵N值恢复到5‰,与开阔大洋海水硝酸盐的δ¹⁵N值近似。我们采用二端员混合模型粗略地估算了有机质来源的相对贡献。LGM时期陆源有机质贡献介于65%至80%,14.5 ka以后海源有机质贡献介于60%至80%。除了增加的陆源有机质贡献以外,LGM时期沉积物δ¹⁵N亏损还涉及如下过程:(1)较高的含Fe沙尘供给提高日本海表层海洋生物固氮效率;(2)缺氧环境盛行减弱成岩作用对沉积物δ¹⁵N影响。37 ka以来,日本海沉积物δ¹³C和δ¹⁵N变化与有机质来源、营养盐的供给、表层生产力和沉积物氧化还原条件相关,实际受海平面和全球气候制约。  相似文献   

Recent progress and future directions of ChinaFLUX     

Yu Guirui  Fu Yuling  Sun Xiaomin  Wen Xuefa  Zhang Leiming 《中国科学D辑(英文版)》2006,49(2):1-23

The eddy covariance technique has emerged as an important tool to directly measure carbon dioxide, water vapor and heat fluxes between the terrestrial ecosystem and the atmosphere after a long history of fundamental research and technological developments. With the realization of regional networks of flux measurements in North American, European, Asia, Brazil, Australia and Africa, a global-scale network of micrometeorological flux measurement (FLUXNET) was established in 1998. FLUXNET has made great progresses in investigating the environmental mechanisms controlling carbon and water cycles, quantifying spatial-temporal patterns of carbon budget and seeking the “missing carbon sink” in global terrestrial ecosystems in the past ten years. The global-scale flux measurement also built a platform for international communication in the fields of resource, ecology and environment sciences. With the continuous development of flux research, FLUXNET will introduce and explore new techniques to extend the application fields of flux measurement and to answer questions in the fields of bio-geography, eco-hydrology, meteorology, climate change, remote sensing and modeling with eddy covariance flux data. As an important part of FLUXNET, ChinaFLUX has made significant progresses in the past three years on the methodology and technique of eddy covariance flux measurement, on the responses of CO₂ and H₂O exchange between the terrestrial ecosystem and the atmosphere to environmental change, and on flux modeling development. Results showed that the major forests on the North-South Transect of Eastern China (NSTEC) were all carbon sinks during 2003 to 2005, and the alpine meadows on the Tibet Plateau were also small carbon sinks. However, the reserved natural grassland, Leymus chinensis steppe in Inner Mongolia, was a carbon source. On a regional scale, temperature and precipitation are the primary climatic factors that determined the carbon balance in major terrestrial ecosystems in China. Finally, the current research emphasis and future directions of ChinaFLUX were presented. By combining flux network and terrestrial transect, ChinaFLUX will develop integrated research with multi-scale, multi-process, multi-subject observations, placing emphasis on the mechanism and coupling relationships between water, carbon and nitrogen cycles in terrestrial ecosystems.  相似文献