共查询到20条相似文献，搜索用时 46 毫秒
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大堡礁位于澳大利亚东北边缘的珊瑚海和塔斯曼海,是世界上最大的珊瑚礁复合体。最近运用磁性地层学和锶同位素测年方法对珊瑚取心进行研究,估计珊瑚礁中央的年龄为(600±280)ka,比布容—松山磁性倒转期(780ka)还年轻。这些结果支持以前依据ODP133航次的地层、同位素和地震数据得出的大堡礁相对年轻(晚更新世)的结论。从ODP133航次的沉积物得到的所有浮游有孔虫氧同位素记录表明其δ18O值在晚更新世有所下降,记录了700～300ka之间温度上升了4～6℃。现代热带珊瑚礁生长需要的最低温度为18℃,在海面温度达到24℃以前珊瑚礁的生长速度都是非… 相似文献
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旧照片显示澳大利亚珊瑚礁的破坏ＩａｎＡｎｄｅｒｓｏｎ澳大利亚大堡礁的许多部分正在以令人吃惊的速度消失。昆士兰州Ｔｏｗｎｓｖｉｌｌｅ的大堡礁海洋公园管理局的科学家把现代大堡礁的照片与早到１８９０年拍摄的照片进行了比较，为其发现深感震惊。“某种东西正在毁... 相似文献
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众所周知 ,最近数十年来 ,珊瑚构筑物深受气候变暖、海水污染和其他因素之害。所有这些给珊瑚礁带来了很大的损失 ,其中包括沿澳大利亚东海岸延伸 2 0 0 0多公里的世界上最大的自然构筑物———大堡礁。澳大利亚海洋科学研究所的生物学家 ,提出了死亡珊瑚礁复生的方法。早在 1 997年他们就注意到在珊瑚湾的试验过程中珊瑚虫的大量繁殖。科学家们用桶从水中舀出微小的珊瑚幼虫 ,并将它们分置到锚泊在珊瑚礁受损位置之上的浮动水池中。将已成熟的幼虫放在瓦片或板上 ,在浅水处将它们沉降至底部并注意它们的发育 ,同时用网盖保护它们不受入侵者… 相似文献
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长棘海星是生活在珊瑚礁中的一种有害动物,它专食珊瑚虫,危害珊瑚礁。远在60年代即在印度洋和太平洋的珊瑚礁中发现过大量长棘海星对珊瑚礁的破坏。70年代和90年代初,世界上最大的珊瑚礁澳大利亚大堡礁曾发生过大量长棘海星对珊瑚礁的毁坏情况。我国西沙群岛的一些岛屿水域也发现过长棘海星。据生物生态学家的研究统计,如果100平方米内有一只长棘海星,就足以造成珊瑚礁的毁 相似文献
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大堡礁是地球上最大的珊瑚礁体系（２５００００ｋｍ２） ,但对其成因和演化仍然不了解 ,主要是因为缺乏通过生物礁的深钻孔。然而 ,外堡礁之外的平顶礁周边沉积物中有３个ＯＤＰ（１３３航次）剖面 ,这些钻孔结果与边缘地震剖面一起 ,可表明该地区陆架边缘珊瑚礁很年轻（更新世）。但是这个假设没有经过验证 ,据推测大堡礁中部开始发育的时间变化很大（Ｄａｖｉｅｓ和ＭｃＫｅｎｚｉｅ认为＜５００ｋａ，１９９３；Ｆｅａｒｙ 等认为大约１Ｍａ，１９９３） ,此外 ,浅水底栖有孔虫分析指出了整个更新世存在着零散的珊瑚礁序列 ,其为现代生… 相似文献
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营口市位于辽宁省的中南部，面对渤海的辽东湾，背依鞍山市平原丘陵，东邻辽东崇山峻岭，西接盘锦市沿海平原，有辽河蜿蜒人海，海岸线绵延曲折。由于受海洋、河流的影响．营口市四季分明，气候宜人，蕴藏着丰富的滨海旅游资源，海蚀景观、地质珍迹、人文景观等资源各显异彩；尤其是海水浴场，条件极为优越，与国际上一流的海水浴场相比．毫不逊色，在某些特征上还稍胜一筹。 相似文献
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A. P. Tolstosheev 《Physical Oceanography》2009,19(6):358-365
A method for the estimation of the results of reconstruction of the trajectories of drifting buoys is proposed. It is based
on the comparison of the estimates of power spectral densities for the components of current velocity computed according to
three data sets: the data set of the coordinates of a drifting buoy with a built-in GPS receiver, the data set of coordinates formed on the basis of the first set but with data missing and observational errors
corresponding to the actual trajectory measurements by the Argos satellite location and data collection system by the Doppler method, and the data set of coordinates obtained as a result
of interpolation of the second set. As an example, we consider the procedure of realization of the proposed method and demonstrate
the efficiency of its application for the improvement of the reliability of reconstruction of the trajectories of drifting
buoys. 相似文献
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I. E. Timchenko A. A. Primalenny V. D. Yarin E. F. Vasechkina E. M. Igumnova 《Physical Oceanography》2001,11(4):367-378
We use many-year archival observations of hydrologic and hydrobiologic state of the Sea of Azov for the identification of
the structure of a model of its ecosystem. The ecosystem model, supplemented with expert estimates of bioresource consumption
(fish reserve), contamination level, and possible ecologic fines for violation of the sea natural state, is formalized by
the method of system dynamics. Hereat, the major part of influence functions is found in terms of observational data with
application of self-organization algorithms. We also present the results of simulated experiments with the model of the ecosystem,
which enable us to analyse scenarios of its behaviour under the influence of various external factors (wind, river discharge,
water exchange with the Black Sea, etc.).
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
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An attempt has been made to estimate the fishery potentials of the EEZ of India on the basis of data on primary and secondary production. The total column primary production and zooplankton production have been calculated to be 265·9 and 9 million tonnes of carbon per year, respectively. From these values the fishery potential has been estimated as 2·5 million tonnes per year. To this, if we add the estimated demersal fish catch, being 1·2 million tonnes per year, the total potential yield comes to 3·7 million tonnes per year. Since the present average total catch is about 1·6 million tonnes in a year, the fish catch could be doubled. 相似文献
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天然气水合物地球化学特征 总被引：4，自引：0，他引：4
天然气水合物是在低温、高压以及有足够气体供应条件下形成的一种天然气(主要为甲烷)与水组成的似冰状固态化合物。天然气水合物中包含的甲烷碳是全球甲烷资源的重要组成部分,是一种数量巨大的潜在能源[1]。而且由于甲烷的温室效应,天然气水合物分解释放的甲烷进入大气中会严重 相似文献
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1992年，联合国21世纪议程提出了综合管理的概念，并认为它是海岸管理的最重要目标，而海岸管理的目的就是改进业已存在的管理实践的效率和效果。在21世纪议程的实施过程中，沿海国家面临着巨大的困难，即：为了使综合管理在实践中具有可操作性而建立适合的政府机构。韩国正是在国家范围和次一级区域进行这项工作的实验场所。这项工作的最重要成就是在1996年成立了具有综合协调各涉海部门职能的韩国海洋事务与渔业部（MOMAF）。这篇文章的内容主要来自于这些观察，即韩国政府为建立海岸带综合机制而进行了各种努力，特别是1992年联合国环发大会召开后到1997年初海洋事务与渔业部成立了海岸带管理处这段时间里开展的各种工作，文章重点在于评价在建立海岸带综合机制的过程中综合的概念是如何被应用并被挑战的。文章提出了在东亚地区沿海国家开展合作的可能区域的建议。 相似文献
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The analysis of the structure of the cryolithozone, facies, and thicknesses of the Quaternary sediments and the results of the physicochemical mathematical modeling of the modern shelf of the western part of the Laptev Sea support the influence of the Late Pleistocene glaciations on the heat conditions and the distribution of the permafrost in the area. A ～200-m thick glacier formed under aerial conditions from atmospheric precipitation represented the metamorphosed snow cover. According to the modeling, the long-living (from 60?50 to 10?4 ky) glacier reduced the thickness of the permafrost rocks in the reviewed shelf area for 280–360 m. The Holocene marine transgression additionally decreased the thickness from 50–140 m on the inner shelf to 220–350 m on the outer shelf. The modern submarine cryolithozone 450-0 m thick is wide-spread in the studied region from the coast to the shelf boundary (isobaths of 130–140 m), where it pinches out at a distance of ～380 km from the coast at a depth of ～250 m above the sea level. 相似文献
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Values of root mean square slope 0 and its variations -0 are estimated using the brightness field of an image of the surface of the sea near a speck of light. When 0 and -0 are defined it is highly important to take into account direct as well as dissipated solar radiation.The space-time analysis of the structure of the image brightness field is performed. This gives an opportunity to estimate dispersion relationship and the running effect of a brightness contrast packet. Comparison of the parameters obtained with the theoretical dispersion ratio of internal waves (IW) allows one to make a conclusion that IW surface manifestations are recorded in a frame.UDK 551.463.5 相似文献