海底沙波特征线的最优方向剖面自动识别方法   总被引：2，自引：2，他引：0  

周洁琼  吴自银  赵荻能  尚继宏  李守军  梁裕杨  周勐佳 《海洋学报》2015,37(7):97-107

海底沙波是发育在近海陆架上的一种常见海底地貌类型,海底沙波特征与运动规律的研究具有重要的科学意义与工程应用价值,沙波脊线与谷线是表征海底沙波的最基本特征,也是精确描述沙波运动的基本参量。本文提出了一种基于复合数字水深模型的沙波特征线自动识别方法——最优方向剖面法,基于水深曲面归算得到最优剖面方向,再依据最优剖面方向求导并判定极值,自动提取沙波形态特征点,最终形成沙波脊线和谷线。以台湾浅滩复合型沙波为例进行对比实验研究,结果表明,该方法能基于不同分辨率的数字水深模型自动准确地提取海底沙波脊线与谷线,勿需设置阈值,地形自动化识别程度得到进一步提升,具有重要的实际应用价值。  相似文献   

基于Argo 观测的太平洋温、盐度 分布与变化（2）：盐度     

张春玲  许建平 《海洋通报》2015,34(1):21-31

利用基于客观分析方法重构的Argo网格资料（未同化其他观测资料）,分析探讨了2004年1月-2011年12月期间太平洋海域（60°S-60°N、120°E-80°W）盐度气候态分布特征与变化规律。结果表明,分别位于南、北亚热带海域的两个高盐（北部约为35.2,南部为36.4左右）中心,呈马鞍形的双峰分布,对称中心不在赤道,而是偏北12个纬度;在南、北纬40°附近海域,盐度等值线十分密集,形成“极锋”;在新西兰东南海域存在低盐水由南向北的入侵现象,且由表层至1000 m深层终年存在。盐度在亚极地海域每年大致呈一高一低的周期性变化,亚北极海域更明显,最高盐度值出现在每年的4月份,最低盐度值则出现在每年的9月份,高低盐度差在0.30~0.45之间。表层以下,盐度的周期性变化远不如表层明显,至500 m中层,整个太平洋海域的盐度最大变幅不超过0.10。赤道海域的表层盐度在2007年和2010年分别有明显的异常减小,最大振幅约为0.8,年际变化周期约为3年;北副热带和亚北极海域的表层,盐度表现出3-6个月的年际振荡,振幅约为0.2;中层盐度几乎没有明显的异常变化。  相似文献   

Detecting Regional Deep Ocean Warming below 2000 Meter Based on Altimetry,GRACE, Argo,and CTD Data     

Yuanyuan YANG  Min ZHONG  Wei FENG  Dapeng MU 《大气科学进展》2021,38(10):1778-1790

The deep ocean below 2000 m is a large water body with the sparsest data coverage, challenging the closure of the sea-level budget and the estimation of the Earth's energy imbalance. Whether the deep ocean below 2000 m is warming globally has been debated in the recent decade. However, as the regional signals are generally larger than the global average, it is intriguing to investigate the regional temperature changes. Here, we adopt an indirect method that combines altimetry, GRACE, and Argo data to examine the global and regional deep ocean temperature changes below 2000 m. The consistency between high-quality conductivity-temperature-depth (CTD) data from repeated hydrographic sections and our results confirms the validity of the indirect method. We find that the deep oceans are warming in the Middle East Indian Ocean, the subtropical North and Southwest Pacific, and the Northeast Atlantic, but cooling in the Northwest Atlantic and Southern oceans from 2005 to 2015.  相似文献   

Early Cretaceous Thrust and Nappe Tectonics in North Qilian Shan,Northern Tibetan Plateau: Evidence from Field Mapping,Geochronology, and Deep Structural Analysis     

HAN Lele  DING Weicui  CHEN Xuanhu  SHAO Zhaogang  ZHANG D  XIAO Yongjun  HE Chengguang  WANG Zengzhen  LI Bing  ZHANG Yiping  XU Shenglin  WANG Ye 《《地质学报》英文版》2023,97(4):1058-1077

The North Qilian Shan fold and thrust belt, located at the northern Tibetan Plateau and southern margin of the Hexi Corridor, is a key tectonic unit to decode the formation and expansion of the plateau. Previous studies emphasize the Cenozoic deformation due to the far-field response to the Indo–Asian collision, but the Mesozoic deformations are poorly constrained in this area. We conducted detailed field mapping, structural analysis, geochronology, and structural interpretation of deep seismic ...  相似文献   

Deep seismic reflection profiling across the Ou Backbone range, northern Honshu Island, Japan     

Hiroshi Sato  Naoshi Hirata  Takaya Iwasaki  Makoto Matsubara  Takeshi Ikawa   《Tectonophysics》2002,355(1-4)

Knowledge of the crustal structure, especially the geometry of seismogenic faults, is key to understanding active tectonic processes and assessing the size and frequency of future earthquakes. To reveal the relationship between crustal structure and earthquake activity in northern Honshu Island, common midpoint (CMP) deep reflection profiling and earthquake observations by densely deployed seismic stations were carried out across the active reverse faults that bound the Ou Backbone range. The 40-km-long CMP profiles portray a relatively simple fault geometry within the seismogenic layer. The reverse faults merge at a midcrustal detachment just below the base of the seismogenic layer, producing a pop-up structure that forms the Ou Backbone range. The top of the reflective middle to lower crust (4.5 s in travel time (TWT)) nearly coincides with the bottom of seismogenic layer. The P-wave velocity structure and surface geology suggest that the bounding faults are Miocene normal faults that have been reactivated as reverse faults.  相似文献   

西北太平洋暖池区台风对海表盐度的影响   总被引：11，自引：0，他引：11  

许东峰  刘增宏  徐晓华  许建平 《海洋学报》2005,27(6):9-15

分析了西北太平洋暖池区2002和2003年夏季ARGO浮标得到的次表层温度和盐度剖面,结果表明大多数台风经过暖池区时,会引起海面盐度下降,这与Kwon和Riser等在大西洋观测到的飓风过后海面盐度上升的结论不同,表明西北太平洋暖池区特有的上层结构以及台风在此海域的降雨与大西洋不同,结果对研究西北太平洋暖池区的混合层混合和热交换过程有重要意义.  相似文献   

利用Argo资料研究2001-2004年期间西北太平洋海洋上层对热带气旋的响应   总被引：9，自引：0，他引：9  

刘增宏  许建平  朱伯康  孙朝辉  张立峰 《热带海洋学报》2006,25(1):1-8

利用Argo剖面浮标观测资料,对2001-2004年11月期间西北太平洋热带气旋经过后海洋上层的响应作了分析研究.结果显示,热带气旋经过后,55.6%的观测剖面其混合层深度会加深,范围在0-60m,并且在气旋过后5d内更为明显;由于混合加剧,大约有77.8%的观测剖面其混合层温度会下降,最多达5℃;61.1%的混合层盐度会下降,平均降盐约0.12;表层流速增大的占54%,平均增大30cm·s,表层流速的变化与风速的大小呈正相关,相关系数仅为0.06;混合层内温度变化与热带气旋风速呈负相关,相关系数为-0.15;混合层温度下降有明显的右偏现象,在气旋路径右侧50-150km处,温度下降尤为明显,而混合层盐度在气旋路径两侧的变化基本呈对称状分布;混合层深度在气旋路径右侧加深更为明显,在右侧100 150km范围内达到最大;混合层深度的变化与气旋经过前混合层的初始深度呈明显的负相关,相关系数达-0.42.  相似文献   

Geological control of shallow gas and pockmarks in the Norwegian Channel; high resolution shallow subbottom profiling of small scale features     

M. D. Max  R. Schreiber  N. Z. Cherkis 《Marine Geophysical Researches》1992,14(1):77-85

High resolution bathymetric and fine-scale parametric subbottom profiling along a line to the SW of Stavanger, Norway near the NE flank of the Norwegian Channel, show pockmarks clustered over neotectonic shallow fold structures in Quaternary sediments. Detailed profiles of the pockmarks indicate that they are collapsed gas seeps, rather than being collapse structures that followed doming and breaching with a more dramatic gas burst. The gentle folding and weak structures along the margin of a Mesozoic through Cenozoic sedimentary basin are probably due to differential uplift generating light compressional strain.  相似文献   

自持式剖面循环探测漂流浮标水下运动过程实例分析     

董涛  杨庆保 《海洋技术学报》2006,25(1):20-23

文章对正在研制中的“自持式剖面循环探测漂流浮标”完成一个剖面测量任务的过程,进行了运动分析和数值计算。数值计算结果与试验数据的对比显示,数值计算结果是可信的,这对了解浮标在水下的运动状态提供直观的帮助,并为浮标的海上试验提供了参考依据。  相似文献   

水下自动监测站的结构设计和试验     

李永军  李飞权 《海洋技术学报》2007,26(1):1-5

介绍了水下自动监测站的结构构成;围绕剖面测量功能的实现,论述了在总体设计、集成框架、浮动平台、驱传动系统、实时数据传输、剖面运动控制、试验和维护等方面应注意的主要问题以及采取的具体措施,供有关人员参考交流.  相似文献