南海北部陆坡深水区浅层天然气藏特征     

钟广见  张如伟  易海  冯常茂  赵忠泉 《热带海洋学报》2018,37(3):80-85

南海北部陆坡深水区的浅层天然气藏是一种伴随天然气水合物的新型油气藏, 具有埋藏浅、规模大的特点, 其埋藏深度一般小于300m。浅层天然气藏由深部裂解气沿断裂上升被天然气水合物封盖而形成, 识别似海底反射(BSR)是寻找浅层天然气藏有效方法。浅层天然气藏的气源主要有热解气、生物气和混合气, 陆坡张性断裂是气体运移的主要通道, 水合物下部的砂层是浅层天然气藏的主要储集层, 水合物层则是封盖层。从南海发现的天然气水合物分布特征看, 浅层天然气藏在陆坡深水区广泛分布且气藏厚度大, 潜在资源量非常可观, 是一种新型的开采成本相对低廉的油气藏。  相似文献   

Spatial Variations of b-Values in the Coastal Area of Guangdong     

ZHOU Pengxiang  XIA Shaohong  SUN Jinlong  CAO Jinghe  XU Huilong  ZHAO Fang  CHEN Chuanxu 《中国海洋大学学报(英文版)》2018,(1)

We used earthquake catalogs recorded by Guangdong Seismological Network from 2008 to 2014 to resolve the spatial variations of b-values in the coastal area of Guangdong, particularly in three key research areas(Yangjiang, Heyuan, and offshore Nanao Island) with strong seismicity. Our results revealed that b-values exhibited significant spatial variations, and zones with low b-values could indicate the most likely seismogenic area of large earthquakes. We observed three clear low b-value patches in the offshore Nanao Island. We found a distinct high b-value peak at the depth of 11 km and two minimum peaks at about 14 and 7–8 km in the Yangjiang area. The overall b-values generally decrease with depth in the Heyuan area. The spatial variations of b-values reflect tectonic anomalies; that is, the ‘low-high-low' distribution of b-values in the offshore Nanao Island and the Yangjiang area may indicate the anomaly of the crustal structure with a weak layer. The b-values of reservoir-induced seismicity are obviously lower than that induced by tectonism. This finding indicates that the reservoir area is generally at high stress state under the condition of high pore pressure. We inferred that large earthquakes might be prone to occur at 10–12 km depth in the offshore Nanao Island, at 12–15 km depth in the Yangjiang area, and at the lower part of the seismic activity zone in the Heyuan area. Moreover, the upstream area of the Xinfengjiang reservoir is the most likely area of future large earthquakes in the Heyuan area.  相似文献   

多遮挡环境下BDS/GPS组合动态差分处理算法及性能分析     

王云鹏  石波  王胜利  刘猛奎  张倩  高 《大地测量与地球动力学》2018,38(3):276-281

研究BDS/GPS组合载波相位动态差分定位算法，讨论加入BDS后对模糊度固定的影响，针对部分区域有较严重信号遮挡的实测动态数据，分别进行单GPS和BDS/GPS组合解算。结果表明，相比单GPS，加入BDS后增加了共视卫星数目，改善了卫星几何结构，模糊度解算成功率和可靠性得到明显提高。多遮挡环境下测试数据显示，BDS/GPS组合的定位精度远高于单GPS，东向和北向精度优于8 mm、天向为16 mm，而单GPS东向仅为3 cm、北向和天向约8 cm。  相似文献   

Carbon pools and fluxes in the China Seas and adjacent oceans     

Nianzhi Jiao  Yantao Liang  Yongyu Zhang  Jihua Liu  Yao Zhang  Rui Zhang  Meixun Zhao  Minhan Dai  Weidong Zhai  Kunshan Gao  Jinming Song  Dongliang Yuan  Chao Li  Guanghui Lin  Xiaoping Huang  Hongqiang Yan  Limin Hu  Zenghu Zhang  Long Wang  Chunjie Cao  Yawei Luo  Tingwei Luo  Nannan Wang  Hongyue Dang  Dongxiao Wang  Si Zhang 《中国科学:地球科学(英文版)》2018,61(11):1535-1563

The China Seas include the South China Sea, East China Sea, Yellow Sea, and Bohai Sea. Located off the Northwestern Pacific margin, covering 4700000 km~2 from tropical to northern temperate zones, and including a variety of continental margins/basins and depths, the China Seas provide typical cases for carbon budget studies. The South China Sea being a deep basin and part of the Western Pacific Warm Pool is characterized by oceanic features; the East China Sea with a wide continental shelf, enormous terrestrial discharges and open margins to the West Pacific, is featured by strong cross-shelf materials transport; the Yellow Sea is featured by the confluence of cold and warm waters; and the Bohai Sea is a shallow semiclosed gulf with strong impacts of human activities. Three large rivers, the Yangtze River, Yellow River, and Pearl River, flow into the East China Sea, the Bohai Sea, and the South China Sea, respectively. The Kuroshio Current at the outer margin of the Chinese continental shelf is one of the two major western boundary currents of the world oceans and its strength and position directly affect the regional climate of China. These characteristics make the China Seas a typical case of marginal seas to study carbon storage and fluxes. This paper systematically analyzes the literature data on the carbon pools and fluxes of the Bohai Sea,Yellow Sea, East China Sea, and South China Sea, including different interfaces(land-sea, sea-air, sediment-water, and marginal sea-open ocean) and different ecosystems(mangroves, wetland, seagrass beds, macroalgae mariculture, coral reefs, euphotic zones, and water column). Among the four seas, the Bohai Sea and South China Sea are acting as CO_2 sources, releasing about0.22 and 13.86–33.60 Tg C yr~(-1) into the atmosphere, respectively, whereas the Yellow Sea and East China Sea are acting as carbon sinks, absorbing about 1.15 and 6.92–23.30 Tg C yr~(-1) of atmospheric CO_2, respectively. Overall, if only the CO_2 exchange at the sea-air interface is considered, the Chinese marginal seas appear to be a source of atmospheric CO_2, with a net release of 6.01–9.33 Tg C yr~(-1), mainly from the inputs of rivers and adjacent oceans. The riverine dissolved inorganic carbon (DIC) input into the Bohai Sea and Yellow Sea, East China Sea, and South China Sea are 5.04, 14.60, and 40.14 Tg C yr~(-1),respectively. The DIC input from adjacent oceans is as high as 144.81 Tg C yr~(-1), significantly exceeding the carbon released from the seas to the atmosphere. In terms of output, the depositional fluxes of organic carbon in the Bohai Sea, Yellow Sea, East China Sea, and South China Sea are 2.00, 3.60, 7.40, and 5.92 Tg C yr~(-1), respectively. The fluxes of organic carbon from the East China Sea and South China Sea to the adjacent oceans are 15.25–36.70 and 43.93 Tg C yr~(-1), respectively. The annual carbon storage of mangroves, wetlands, and seagrass in Chinese coastal waters is 0.36–1.75 Tg C yr~(-1), with a dissolved organic carbon(DOC) output from seagrass beds of up to 0.59 Tg C yr~(-1). Removable organic carbon flux by Chinese macroalgae mariculture account for 0.68 Tg C yr~(-1) and the associated POC depositional and DOC releasing fluxes are 0.14 and 0.82 Tg C yr~(-1), respectively. Thus, in total, the annual output of organic carbon, which is mainly DOC, in the China Seas is 81.72–104.56 Tg C yr~(-1). The DOC efflux from the East China Sea to the adjacent oceans is 15.00–35.00 Tg C yr~(-1). The DOC efflux from the South China Sea is 31.39 Tg C yr~(-1). Although the marginal China Seas seem to be a source of atmospheric CO_2 based on the CO_2 flux at the sea-air interface, the combined effects of the riverine input in the area, oceanic input, depositional export,and microbial carbon pump(DOC conversion and output) indicate that the China Seas represent an important carbon storage area.  相似文献   

基于HYCOM再分析数据研究琉球海流的形成与起源     

汪敏  刘昭君  朱小华  闫晓梅  张钟哲  赵瑞祥 《海洋学报(英文版)》2019,38(11):1-10

The origin of the Ryukyu Current(RC) and the formation of its subsurface velocity core were investigated using a 23-year(1993–2015) global Hybrid Coordinate Ocean Model(HYCOM) dataset. The volume transport of the RC comes from the Kuroshio eastward branch(KEB) east of Taiwan and part of the North Pacific Subtropical Gyre(pNPSG). From the surface to 2 000 m depth, the KEB(p-NPSG) transport contributes 41.5%(58.5%) to the mean total RC transport. The KEB originally forms the subsurface velocity core of the RC east of Taiwan due to blockage of the subsurface Kuroshio by the Ilan Ridge(sill depth: 700 m). Above 700 m, the Kuroshio can enter the East China Sea(ECS) over the Ilan Ridge, meanwhile, the blocked Kuroshio below 700 m turns to the right and flows along the Ryukyu Islands. With the RC flowing northeastward, the p-NPSG contribution strengthens the subsurface maximum structure of the RC owing to the blockage of the Ryukyu Ridge. In the surface layer, the pNPSG cannot form a stable northeastward current due to frequent disturbance by mesoscale eddies and water exchange through the gaps(with net volume transport into ECS) between the Ryukyu Islands.  相似文献   

卡里马塔海峡水体交换的季节变化   总被引：2，自引：0，他引：2  

王研  徐腾飞  李淑江  Susanto R. Dwi  Agustiadi Teguh  Trenggono Mukti  谭伟  魏泽勋 《海洋学报(英文版)》2019,38(4):47-57

Four trawl-resistant bottom mounts, with acoustic Doppler current profilers(ADCPs) embedded, were deployed in the Karimata Strait from November 2008 to June 2015 as part of the South China Sea-Indonesian Seas Transport/Exchange and Impact on Seasonal Fish Migration(SITE) Program, to estimate the volume and property transport between the South China Sea and Indonesian seas via the strait. The observed current data reveal that the volume transport through the Karimata Strait exhibits significant seasonal variation. The winteraveraged(from December to February) transport is –1.99 Sv(1 Sv=1×10~6 m~3/s), while in the boreal summer(from June to August), the average transport is 0.69 Sv. Moreover, the average transport from January 2009 to December2014 is –0.74 Sv(the positive/negative value indicates northward/southward transport). May and September are the transition period. In May, the currents in the Karimata Strait turn northward, consistent with the local monsoon. In September, the southeasterly trade wind is still present over the strait, driving surface water northward, whereas the bottom flow reverses direction, possibly because of the pressure gradient across the strait from north to south.  相似文献   

秦皇岛近岸海域绿藻微观繁殖体的分布以及在绿潮形成中的作用   总被引：2，自引：0，他引：2  

韩红宾  宋伟  王宗灵  丁德文  袁超  张学雷  李艳 《海洋学报(英文版)》2019,38(8):72-77

2015年以来，秦皇岛近岸海域暴发了绿潮，对北戴河旅游区的环境和生态系统造成了严重影响。绿藻微观繁殖体在绿潮的形成过程中起到重要作用，主要包括孢子、配子、幼苗和营养片段。绿藻微观繁殖体作为绿潮的“种源”，其分布规律可以反映绿潮的“藻源”位置。本研究于2016年4-9月和2017年1月对秦皇岛近岸海域绿藻微观繁殖体的调查，探究了其分布规律以及生物量变化。结果显示，绿藻微观繁殖体主要分布在近岸海域，由近岸向远岸海域逐渐降低。绿藻微观繁殖体的数量在7、8月份最高，在冬季最低。受绿潮影响严重的海域微观繁殖体数量高于其它海域。秦皇岛近岸海域的绿藻微观繁殖体为该海域绿潮的种源，其分布规律表明秦皇岛近岸海域绿潮起源于本地。  相似文献   

我国海洋保护地现状、问题及发展对策          下载免费PDF全文

赵林林  程梦旎  应佩璇  曲方圆  张朝晖 《海洋开发与管理》2019,36(5):3-7

随着我国海洋经济的不断发展,沿海地区的海洋环境和生态系统面临的压力不断加剧。海洋保护地作为海洋生态环境管理的有效手段,近30年来被广泛应用于海洋生物多样性和生态系统保护,取得了显著的成就和效果。文章通过对我国海洋保护地的建设情况进行系统研究,阐述了海洋保护地的发展现状和管理体制,重点剖析了海洋保护地管理和建设过程中面临的缺乏顶层设计、管理能力和管护条件弱、管理人才和资金少、空间发展不平衡等问题,在建设以国家公园为主体的自然保护地体系的新形势下,为我国海洋保护地的发展提出了健全海洋保护地管理制度体系、构建海洋保护地网络体系、加强海洋保护地管理能力建设和加强海洋保护地宣传教育等对策建议。  相似文献   

机构改革背景下的广东省海洋灾害应急管理          下载免费PDF全文

周圆  赵明辉 《海洋开发与管理》2019,36(8):42-48

为进一步提升广东省海洋灾害应急管理水平和全社会抵御海洋灾害的综合防范能力,文章在广东省机构改革的背景下,概述广东省海洋灾害应急管理"一案三制"体系,查找存在的问题,并提出对策建议。研究结果表明:广东省海洋灾害应急管理已初步建立应急预案以及体制、机制和法制体系,尤其是2018年机构改革后成立广东省应急管理厅,有力促进全灾种、全流程和全方位的应急管理,其中海洋灾害应急管理体制由应急管理领导议事机构、应急管理综合调度机构、海洋灾害专业管理机构和海洋灾害辅助管理机构4个部分组成;在防灾减灾救灾体制机制改革和机构改革的新形势下,广东省海洋灾害应急管理仍存在不足,亟须完善地方性法规等制度、优化管理体制机制、加强技术支撑和成果转化以及提高社会和市场参与度。  相似文献   

海域无人机全景监视监测技术及其应用          下载免费PDF全文

王飞  陈一鹤  赵建华  王鹏  张建丽  景昕蒂 《海洋开发与管理》2019,36(10):65-68

为充分利用先进设备和技术,提高我国海域使用动态监管水平,文章介绍无人机全景技术及其作业流程,并分析大笔架山海域无人机全景监视监测实例。研究结果表明:目前全景图主要利用普通相机拍摄的照片经专业图像软件后期处理生成,在多个行业领域应用,结合无人机的利用可大大扩展视野,具有快速高效、安全可靠和操作简便等优势,但在测量、自动化和视距等方面仍存在局限性;无人机全景图作业主要包括方案制订、数据获取、数据处理和图像发布4个步骤;海域无人机全景监视监测工作的开展为大笔架山海域使用动态监管提供有力的数据支撑。  相似文献