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991.
马都拉海峡盆地北部外陆架台地发育有E-W向一字排列的颗粒灰岩生物礁体。该生物礁是有孔虫(主要为抱球虫目)壳体经过各种沉积作用形成的堆积体,发育于早上新世挤压反转期盆地北部边缘区。由于生物礁生长发育所经历的特殊性,其岩石学特征等信息常常具有标志性的反映,因此礁体的剖面反射特征和地震属性相比于围岩会存在不小的差异。这些差异为人们利用地震解释和地震属性提取技术识别生物礁奠定了基础,如在地震剖面上,生物礁往往出现对称丘状外形反射、礁前斜坡前积反射、礁内部杂乱反射和不连续强反射的特征等等。以O-2井钻遇的存在抱球虫化石的马都拉海峡盆地上新统芒杜组沉积地层为研究对象,从地质背景入手,描述了盆地的新生代构造特征和发育各时期所对应的地层。通过进行层位标定和三维地震解释,结合地震属性提取技术,同时考虑到生物礁的发育形态与环境,最终获得了盆地抱球虫颗粒灰岩生物礁在空间上的分布。最后,本文结合盆地历史上的沉积构造活动,提出反转断裂带活动是研究区控制生物礁生长的重要因素,并据此总结了马都拉海峡盆地芒杜组台地边缘生物礁的发育模式。 相似文献
992.
台湾及其邻近地区的海啸 总被引:6,自引:0,他引:6
台湾位于环太平洋地震带,不仅陆上地震频繁,发生在海外的地震也不少,但其中仅有极少数的海底地震曾引起海啸。然而,由于台湾北部及西部水深极浅,近距离海底地震所引起的海啸有可能会造成重大灾害,对1867年发生在台湾基隆附近的海啸曾造成数百人死伤。 相似文献
993.
鲸豚类是大型的海洋哺乳动物,是海洋中的重点保护生物。在制定相应的保护政策前,应较为充分地了解其种群特征。而分析一个地区的鲸豚搁浅等信息,则能够为该地区提供其组成和物种多样性等基本信息。本研究收集了2010-2015年台湾海峡西岸发生的鲸豚类的搁浅、误捕和救护等资料和样本。结果共记录了48例事件,其中包括37例搁浅事件,8例误捕事件和3例救护事件,共涵盖了13个鲸豚物种。其中,中华白海豚和江豚占较大比例,分别为31.3%和25%。值得注意的是,其中10起事件(20.8%)发生在平潭岛,而且包含了3种须鲸和4种齿鲸。另外,我们还比较了台湾海峡东西两侧鲸豚物种的组成,发现共有31种鲸豚物种生活在台湾海峡,说明该地区的鲸豚物种丰富度较高。通过这些信息的收集和分析,我们基本摸清了台湾海峡的鲸豚物种分布。今后,我们将通过开展野外调查来系统地分析台湾海峡的鲸类物种组成,种群大小和栖息地状况等基础资料,为提供更好的保护管理打下良好基础。 相似文献
994.
Temim Deli Mohamed Hbib Ben Atti Rym Zitari-Chatti Khaled Sai Noureddine Chatti 《海洋学报(英文版)》2017,36(12):52-66
The present investigation focuses on population structure analysis of the purple sea urchin Paracentrotus lividus across the African Mediterranean coast, with the main aim of assessing the influence of the Siculo-Tunisian Strait on gene flow disruption in this highly dispersive echinoid species. For this purpose, patterns of morphological and genetic variation were assessed among its populations from the western and eastern Mediterranean coasts. A total of 302 specimens from seven Tunisian sites were collected and examined for morphometric variability at twelve morphometric traits. Concordant results, inferred from CDA (canonical discriminant analyses), pairwise NPMANOVA (non parametric multivariate analysis of variance) comparisons and MDS (multidimensional scaling) plot, unveiled significant inter-population differences in the measured traits among the studied populations. Furthermore, the combined use of the one way ANOSIM (analysis of similarities) and the Discriminant/Hotelling analysis allowed unravelling two morphologically differentiated groups assigned to both western and eastern Mediterranean basins. The SIMPER (similarity percentages) routine analysis showed that total dry weight, test diameter and spine length were major contributors to the morphometric separation between locations and between groups. Pattern of phenotypic divergence discerned in P. lividus across the Siculo-Tunisian Strait is interestingly in congruence with that inferred from the genetic investigation of the purple sea urchin populations from the same region based on the analysis of the mtDNA COI (cytochrome oxidase I) gene in 314 specimens from nineteen locations covering a wider geographic transect, streching westward to the Algerian coast and eastward to the Libyan littoral. The specific haplotypic composition characterizing each Mediterranean basin, as inferred from the minimum spanning network, confirmed the geographic partioning of genetic variation, as revealed by F-statistics and AMOVA (analysis of molecular variance) analyses, yielding significant genetic differentiation between eastern and western Mediterranean populations. The newly detected phylogeographic patterns, observed for the first time in P. lividus throughout the explored distribution range, suggest the involvement of different biotic and abiotic processes in shaping such variation, and provide evidence that a large and geographically exhaustive dataset is necessary to unveil phylogeographic structure within widespread marine species, previously cathegorized as panmictic in part of their distribution range. 相似文献
995.
Seawater samples are collected in the spring of 2013 from the Taiwan Strait for the analysis of uranium(U)concentrations and isotopic compositions using MC-ICP-MS, and the geochemical behavior patterns of U in the Taiwan Strait are then investigated. Average concentrations of individual U isotopes are(3.23±0.14) μg/kg for 238 U,(2.34±0.09)×10~(–2) μg/kg for ~(235)U and(2.05±0.07)×10~(–4) μg/kg for 234 U. Correspondingly, the U isotopic compositions are 155±18 for δ234U and 138±2 for 238U:235U. The U concentrations and isotopic ratios in the Taiwan Strait are similar to those of open ocean seawater, suggesting the dominance of the open ocean input to the strait's U pool.However, river input, as suggested by the slightly lower salinity than that of the open ocean, also affected the U concentrations and isotopic compositions in the strait. From a compilation of U concentrations in the Taiwan Strait and adjacent areas, including the Jiulong Estuary and Zhujiang Estuary, the Xiamen Bay and the northern South China Sea, a strong and significant relationship between U concentration and salinity [U:S; U=(0.093 4±0.002 4)S+(0.092 0±0.061 5)] is revealed, suggesting conservative mixing of U in the Taiwan Strait. To better understand the U geochemistry in the Taiwan Strait, a multiple endmembers mixing model is applied to estimate the contributions of potential sources. The open ocean seawater contributed 69%–95% of U in the Taiwan Strait, with river water approximately 2%, and dust deposition only around 0.13%. Therefore, the model results supported the open ocean input source and the conservative mixing behavior of U derived from the observation of U concentrations and isotopic ratios and U:S ratios. The sediment interstitial water may be an important source of U to the Taiwan Strait with a possible contribution of 3%–29%, consistent with previous investigations based on radium isotopes.However, further investigations are warranted to examine the U concentration in the sediment interstitial water and its input to the overlying seawater in the Taiwan Strait. 相似文献
996.
A numerical study of the summertime flow around the Luzon Strait 总被引:3,自引:0,他引:3
Luzon Strait, a wide channel between Taiwan and Luzon islands, connects the northern South China Sea and the Philippine Sea.
The Kuroshio, South China Sea gyre, monsoon and local topography influence circulation in the Luzon Strait area. In addition,
the fact that the South China Sea is a fairly isolated basin accounts for why its water property differs markedly from the
Kuroshio water east of Luzon. This work applies a numerical model to examine the influence of the difference in the vertical
stratification between the South China Sea and Kuroshio waters on the loop current of Kuroshio in the Luzon Strait during
summer. According to model results, the loop current’s strength in the strait reduces as the strongly stratified South China
Sea water is driven northward by the southwest winds. Numerical results also indicate that Kuroshio is separated by a nearly
meridional ridge east of Luzon Strait. The two velocity core structures of Kuroshio can also be observed in eastern Taiwan.
Moreover, the water flowing from the South China Sea contributes primarily to the near shore core of Kuroshio. 相似文献
997.
调查及综合研究了台湾海峡表层沉积物中底栖有孔虫的分布特征,调查海区根据优势种类组成可以划分出10个底栖有孔虫动物群,其经峡东侧所划分的6个义栖有孔虫生物相有机相连。动物群的分布与现代海洋环境有密切关系,从而对台湾海峡的古地理环境研究提供了依据。 相似文献
998.
1987年8月—31日在剑桥大学地球科学院分别举行了地质及固体地球物理工作组会议及混合会议.两天的会议主席都由新西兰人担任.地质工作组会议内容包括:1.开幕.自我介绍;2.圣迭戈会议提案采纳及执行情况;3.本次会议新议题:a.地质制图,主要确认专家组会议提出的协调分工、统一图例、在大剖面协作中统一比例尺等事项;b.地圈—生物计划设想;c.南极地球科学研究回顾与展望;d.工作组向SCAR的年度报告;4.第5届国际地球科学讨论会总结;5.第6届国际南极地球科学讨论会,审议了日本在圣迭戈会议上提出的建议,经表决同意下届讨论会将于1991年在日本东京或其他城市举行(原建议为1992年),并通过了讨论会内容及分组方法;6.各成员国国家年度报告;中 相似文献
999.
台湾海峡野生牙鲆人工繁殖和育苗技术研究 总被引:4,自引:0,他引:4
2003年12月至2004年5月对台湾海峡的野生牙鲆进行了亲鱼的驯养、促熟产卵及人工育苗技术研究.结果表明,活的鲻鱼苗可用于牙鲆亲鱼的诱食;当水温达到16.2~19.5℃时,牙鲆可自然产卵,产卵盛期为3月中旬至4月上旬.4月份受精率高达86%.在驯养过程中亲鱼未发生死亡.本实验共用受精卵约153万粒,孵出仔鱼140.8万尾,孵化率达92%.经63d培育,育出全长3.8~5.5cm幼鱼53.4万尾,成活率37.9%.育苗水温为20~24℃,海水盐度为26~31. 相似文献
1000.
环台湾岛海域全日分潮的特征和潮汐、潮流的综合性质 总被引:6,自引:0,他引:6
用97版POC海洋模式,对环台湾岛海域的全日分潮和整个潮汐,潮流综合特征进行三维数值研究。研究海域全日分潮是由太平洋传入的,且来自台湾岛北部海区传入的潮波穿越海峡。由吕宋海峡传入的全日分潮对维持南海的潮运动起着重要作用。全日分潮最大流同时线分布表层有5个圆流点,其中4个本文首次得到。台湾海峡及其以北海区和台湾东部洋区为不规则半日潮区,台湾东南为全日分潮为主的混合潮区。台湾岛北部为气旋式余流涡旋区,环绕台浅滩为反气旋余流涡旋区,澎湖水道开始的转向流预示着海峡及其邻近海区的涨潮流或落潮流的来临。 相似文献