西南印度洋深海散射层昼夜垂直迁移特征研究

本研究根据2011−2020年西南印度洋56个声学断面数据观察到的深海散射层201次昼夜垂直迁移现象,分析了其昼夜垂直迁移特征及时空差异。研究结果表明,该海域散射层具有分层现象,第一散射层位于200 m以浅水层,其海洋面积散射系数(NASC)峰值的平均水深为(58.66±24.63)m,夏季和冬季之间存在显著性差异(p<0.001);第二散射层位于400~700 m水层,其NASC峰值的平均水深为(589.02±66.33)m,夏季和冬季之间无显著性差异(p=0.51)。散射层向上迁移的开始时间平均为16:20,结束迁移的平均时间为18:31,迁移的平均速率为(5.28±1.53)cm/s;向下迁移的开始时间平均为4:38,结束迁移的平均时间为6:52,迁移的平均速率为(5.56±2.13)cm/s。随着纬度的增加,散射层向下迁移的开始时间变晚,迁移速率变慢;随着经度的增加,散射层迁移速率变慢,且不同经度海域之间存在显著性差异(p<0.001)。分析认为,研究海域理化环境的季节性变化以及散射层中生物的不同生活史阶段是造成散射层垂直结构和昼夜垂直迁移特征时空差异的主要原因,其对解释金枪鱼的昼夜垂直迁移行为和指示金枪鱼渔场分布等具有重要意义。

塞拉利昂海域雨季深海声学散射层生物垂直迁移现象分析

应用2021年5月西北非塞拉利昂海域中上层渔业资源与环境调查的船载Simrad EK60科学渔探仪(38 kHz)数据,对深海声学散射层生物的垂直迁移过程和迁移量进行分析研究。结果表明:EK60探测范围内,277~563 m水层存在深海声学散射层;该层部分生物日落时分上升、日出时分下降,上升和下降活动持续时间均约为3.10 h;迁移活动以变速运动形式分2~5层进行,且迁移中会发生层间的分离与聚合现象;净垂直下降速率均值为4.30 cm·s^(-1),大于净垂直上升速率均值3.41 cm·s^(-1);上升后,深海声学散射层内NASC值减少62.63%~92.70%,绝大部分进入96 m以浅的浅水层中;下降后,深海声学散射层内NASC值增加45.59%~79.79%,占浅水层内减少NASC值的32.71%~98.67%。

南海深海声学散射层垂直分布和昼夜变化初步研究

2013-09利用船载Simrad EK60科学鱼探仪（38kHz）对南海深海声学散射层进行了连续监测,并结合变水层拖网采样分析了其垂直分布和昼夜变化。结果表明,南海深海存在2个明显的声学散射层,特征深度分别为0-100m和350-700m,并且2个散射层间存在较为明显的昼夜垂直移动现象。其随时间变化情况为：16∶00-19∶00,350-700m散射层中的部分生物逐渐向上移动到0-100m散射层;04∶00-07∶00,这部分上升的生物又逐渐移回至350-700m散射层。变水层拖网采样结果发现,白天0-100m散射层内渔获物数量较少,夜间0-100m散射层内渔获物较多,验证了声学映像所检测到的2个散射层间确实存在昼夜移动的现象。

深海浅层非成岩天然气水合物喷射破碎压控滑套的研制

为了解决海洋天然气水合物固态流化开采过程中射流喷头作业过程不可控、不可重复使用且需要多次起下钻柱等问题,基于节流压降原理与天然气水合物固态流化开采工艺,针对深海浅层非成岩天然气水合物的特点,设计出了一种可控制射流喷头开启与关闭且作业过程不受水深和井深影响的压控滑套,并对其进行了仿真分析与室内实验评价。研究结果表明:①所研制的压控滑套入口处锥面角度越大,滑套所产生的压降与轴向力越大,但钻井液对锥面的冲蚀越严重,因此综合考虑上述因素,滑套锥部角度选择30°为最佳;②钻井液通过滑套的流量越大,滑套内部产生的压降与滑套轴向力越大;③验证实验表明,在钻井液的作用下滑套能够滑动并开启射流喷头,喷头的全开启流量为833 L/min,与设计流量的误差值为4.13%;④试压实验表明,压力滑套内部压力的变化不能驱使滑套运动,有效地验证了其工作状态不受环境压力的影响。结论认为,该工具的研制和应用将有助于促进海洋天然气水合物固态流化开采技术的进步。

应用水声方法考察底栖鱼类和DSL(深海散射层)的垂直移动

利用彩色显示回声探测仪在南海北部水域中测到的图象进行调查底栖鱼 类和ＤＳＬ的垂直移动；仪器的量程扩展功能用子考察底栖鱼类的贴海底、起浮、聚 薄层和扩散等情景。ＤＳＬ在黄昏时期的聚层起浮，午夜出现集群最密，黎时下降、解 体；示出ＤＳＬ聚层的厚度及垂直移动的速度。

环形探测仪在深海浅层土中的工作机理研究

环形探测仪是海洋工程中一种新型的用于描述海底结构物与海床相互作用的原位探测设备。论文建立了环形探测仪工作时剪切地基土的有限元模型,海床地基土采用修正的剑桥模型。分析了探测仪在不同剪切速率下的环向阻力、法向接触力及地基土中超孔压等参数的变化规律,还考虑了埋深和过载比的影响。研究发现,超孔压ΔUN是决定阻力变化的主要因素,其产生与消散的过程与剪切速率、埋深、过载比等因素有关。随着过载比的增加,超孔压从正变为负。

深海视像采样系统和深海浅层岩心取样钻机通过验收

从国家海洋局获悉，由北京先驱高技术开发公司与有关海洋科研单位联合研制生产的两套大型深海勘探设备深海视像采样系统和深海浅层岩心取样钻机，近日同时通过了有关部门的验收并正式交付使用。专家认为，这两套设备技术设计合理，性能可靠，取样成功率高，操作方便，实用性强，是深海资源与地质调查取样作业的重要工具，为今年我国开展深海地质调查和资源评估提供了良好的技术支撑。

Variations of SST and Thermocline Depth in the Tropical Indian Ocean During Indian Ocean Dipole Events

Interannual variations in the surface and subsurface tropical Indian Ocean were studied using HadlSST and SODA datasets. Wind and heat flux datasets were used to discuss the mechanisms for these variations. Our results indicate that the surface and subsurface variations of the tropical Indian Ocean during Indian Ocean Dipole （IOD） events are significantly different. A prominent characteristic of the eastern pole is the SSTA rebound after a cooling process, which does not take place at the subsurface layer. In the western pole, the surface anomalies last longer than the subsurface anomalies. The subsurface anomalies are strongly correlated with ENSO, while the relationship between the surface anomalies and ENSO is much weaker. And the subsurface anomalies of the two poles are negatively correlated while they are positively correlated at the surface layer. The wind and surface heat flux analysis suggests that the thermocline depth variations are mainly determined by wind stress fields, while the heat flux effect is important on SST.

What Depth Should Deep-Sea Water be Pumped up from in the South China Sea for Medicinal Research?

In this study, seawater was pumped up from 150, 200, 300, 500 and 1000 m in the South China Sea and analyzed to make certain what depth should deep-sea water (DSW) be pumped up for medicinal usage. The pumping depth of DSW was determined on the basis of chemical ingredients. The analyses of inorganic elements and dissolved organic matter (DOM) were performed by inductively coupled plasma mass spectrometry (ICP-MS) and ultra performance liquid chromatography-mass spectrometry (UPLC-MS) respectively. The raw data were used for hierarchical cluster analysis (HCA) and principal component analysis (PCA). The results showed that seawater pumped up from 500 m and 1000 m was similar in their chemical ingredients, and was different from the seawater pumped up from other depths. These results indicated that seawater from more than 500 m depth had relatively stable chemical ingredients and could be used as DSW in the South China Sea.

Decadal variability of chlorophyll α in the South China Sea: a possible mechanism

Four climatologies on a monthly scale (January, April, May and November) of chlorophyll a within the South China Sea (SCS) were calculated using a Coastal Zone Color Scanner (CZCS) (1979-1983) and the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) (1998-2002). We analyzed decadal variability of chlorophyll a by comparing the products of the two observation periods. The relationships of variability in chlorophyll a with sea surface wind speed (SSW), sea surface temperature (SST), wind stress (WS), and mixed layer depth (MLD) were determined. The results indicate that there is obvious chlorophyll a decadal variability in the SCS. The decadal chlorophyll a presents distinct seasonal variability in characteristics, which may be as a result of various different dynamic processes. The negative chlorophyll a concentration anomaly in January was associated with the warming of SST and a shallower MLD. Generally, there were higher chlorophyll a concentrations in spring during the SeaWiFS period compared with the CZCS period. However, the chlorophyll a concentration exhibits some regional differences during this season, leading to an explanation being difficult. The deepened MLD may have contributed to the positive chlorophyll a concentration anomalies from the northwestern Luzon Island to the northeastern region of Vietnam during April and May. The increases of chlorophyll a concentration in northwestern Borneo during May may be because the stronger SSW and higher WS produce a deeper mixed layer and convective mixing, leading to high levels of nutrient concentrations. The higher chlorophyll a off southeastern Vietnam may be associated with the advective transport of the colder water extending from the Karimata Strait to southeastern Vietnam.

Seismic stratigraphy of the Qiongdongnan deep sea channel system,northwest South China Sea

Based on more than 4000 km 2D seismic data and seismic stratigraphic analysis, we discussed the extent and formation mechanism of the Qiongdongnan deep sea channel. The Qiongdongnan deep sea channel is a large incised channel which extends from the east boundary of the Yinggehai Basin, through the whole Qiongdongnan and the Xisha trough, and terminates in the western part of the northwest subbasin of South China Sea. It is more than 570 km long and 4–8 km wide. The chaotic (or continuous) middle (or high) amplitude, middle (or high) continuity seismic facies of the channel reflect the different lithological distribution of the channel. The channel formed as a complex result of global sea level drop during early Pliocene, large scale of sediment supply to the Yinggehai Basin, inversion event of the Red River strike-slip fault, and tilted direction of the Qiongdongnan Basin. The large scale of sediment supply from Red River caused the shelf break of the Yinggehai Basin to move torwards the S and SE direction and developed large scale of prograding wedge from the Miocene, and the inversion of the Red River strike-slip fault induced the sediment slump which formed the Qiongdongnan deep sea channel.

Subduction/obduction rate in the North Pacific diagnosed by an eddy-resolving model

Ventilation in the North Pacifi c is examined using data from the eddy-resolving 1/12° global HYbrid Coordinate Ocean Model(HYCOM) and Quik SCAT wind stress data. For the period January 2004 to December 2006 and area 20°–40°N, the total annual subduction rate is estimated at 79 Sv, and the obduction rate 41 Sv. Resolving the small-scale and high-frequency components of the eddy fi eld can increase the subduction rate by 42 Sv, and obduction by 31 Sv. Lateral induction is the dominant contributor to enhancement of subduction/obduction, and temporal change of mixed layer depth has a secondary role. Further analysis indicates that the high-frequency components of the eddy fi eld, especially those with timescale shorter than 10 days, are the most critical factor enhancing subduction/obduction.

Optimal Precursor Perturbations of El Ni?o in the Zebiak-Cane Model for Different Cost Functions

Optimal precursor perturbations of El Nino in the Zebiak-Cane model were explored for three different cost functions. For the different characteristics of the eastern-Pacific （EP） El Nino and the central-Pacific （CP） El Nino, three cost functions were defined as the sea surface temperature anomaly （SSTA） evolutions at prediction time in the whole tropical Pacific, the Nino3 area, and the Nino4 area. For all three cost functions, there were two optimal precursors that developed into El Nino events, called Precursor Ⅰ and Precursor Ⅱ. For Precursor Ⅰ, the SSTA component consisted of an east-west （positive-negative） dipole spanning the entire tropical Pacific basin and the thermocline depth anomaly pattern exhibited a tendency of deepening for the whole of the equatorial Pacific. Precursor Ⅰ can develop into an EP-El Nino event, with the warmest SSTA occurring in the eastern tropical Pacific or into a mixed El Nino event that has features between EP-El Nino and CP-El Nino events. For Precursor Ⅱ, the thermocline deepened anomalously in the eastern equatorial Pacific and the amplitude of deepening was obviously larger than that of shoaling in the central and western equatorial Pacific. Precursor Ⅱ developed into a mixed El Nino event. Both the thermocline depth and wind anomaly played important roles in the development of Precursor Ⅰ and Precursor Ⅱ.

Composition and Distribution of Planktonic Ciliates in the Southern South China Sea During Late Summer： Comparison Between Surface and 75 m Deep Layer

Ciliates are very important components in most marine ecosystem. They are trophic link between the microbial food web and grazing food chain. In this study, ciliates were collected from 11 sites in the southern South China Sea （SCS） during August 25 to September 28, 2011. Their composition and distribution at the surface and 75m deep depth of the ocean were studied. A total of 30 species belonging to 22 genera were identified, and 22 species of 15 genera were Tintinnids. Eutintinnusfraknoii and E. stramentus were the most common species. The other dominants were strombidiids ciliates including Strombidium conicum and S. globosaneum, which were followed by the tide form, Mesodinium pulex. Ciliates abundance ranged from 46 indL-1 to 368 indL-1 in the open sites, 46-368indL-1 at surface and 73-198indL-1 at 75m deep layer. In the Yongshu reef, ciliates abundance ranged from 167indL-1 to 365 ind L-1 in the water colunm, similar to that in Sanya coral reef waters. Ciliates composition showed obvious difference between surface and 75m deep layer at station S2 （P〈0.05）, while no similar result was observed at other sites. At 75m deep layer, salinity was negatively related to mixed layer depth （P〈 0.05）, but positively to chlorophyll a concentration （P〈 0.05）, indicating that the change of vertical mixing in water column influenced vertical distribution of ciliates in the southern SCS.

A Comparative Study of Taoist and Heideggerian Concepts of Nature From Perspectives of Technology and Deep Ecology

With the theory of existentialism, hermeneutics and phenomenology, this paper carries out profound exploration in a comparative study of Heidegger and Taoist＇s concept of nature and the significance of understanding it. It not only plays an important role in comparison and analogy of eastern culture and western culture in the aspect of civilization and cultural communication, but also helps to take advantage of their theories to support the environmental-friendly movement. Moreover, the text also investigates some controversy in this field and how to solve the problems as well as the meaning of solutions. Both of the theories are significant for deep ecology for their opposing modern technology＇s generally reductionistic and materialistic view of nature.

Deep Seismic Exploration in the Taiwan Straits: The HX9 Survey Line Experiment and Preliminary Results

By using an offshore large volume air-gun seismic source, onshore seismic stations( including mobile stations and permanent stations) and ocean bottom seismometers,a deep seismic exploration experiment was carried out for the first time in the Taiwan Straits. Results show that seismic stations can receive seismic signals from the air-gun arrays of the "YANPING Ⅱ"scientific investigation ship from as far as 280 km away.Tens of thousands of high quality seismic data items were obtained successfully and different types of P-wave seismic phases were identified. A one-dimensional crustal structure model of the survey profile HX9 shows that the crustal structure,which is reflected by Pc and Pm P reflection waves from two velocity discontinuities and basement refraction wave( Pg) constitutes the basic characteristic of the crustal structure in this region. The depths of Conrad discontinuity and Moho discontinuity are respectively16. 0km- 17. 5km and 28. 0km- 29. 5km.

Exploration technology and development trend of Daqing Oilfield

Exploration for oil and deep gas in northern Songliao Basin,complex rift basin—Hailaer Basin,and Yi-Shu Graben in peripheral basin has technical challenge.Researches on supporting technology including seismic acquisition,processing and interpretation,logging and drilling are performed to establish high resolution 3D seismic technology for lithologic reservoir,deep volcanic rock and complex rift basin,reservoir evaluation and stimulation technology for low permeability reservoir,volcanic reservoir and complex rift reservoir,and drilling technology for deep volcanic rock,providing technical support for reserves increase in northern Songliao Basin,large gas reservoirs discovery in deep volcanic rock and exploration progress in complex rift basin.Next-step development trend of exploration technology is proposed to meet the demand of more technical challenges in the future.

海洋深处生物的特征

大洋深处，距海面１０００米的地方，一片黑暗。这里缺少氧气，压力很大，没有波浪冲击，没有暴风袭击，也没有阳光照射，水温在０℃左右。看似风平浪静，实则环境严酷，生命似乎已不存在。而实际上在１０００米～４０００米的深海里仍然生活着１００多种动物，只是由于特...

Tracking shallow marine red beds through geological time as exemplified by the lower Telychian (Silurian) in the Upper Yangtze Region,South China

Marine red beds occur frequently in China through geological time.Despite their complex environments,the red beds are found in three depositional settings:1) oceanic,deep water,as in the Upper Cretaceous of southern Tibet;2) outer shelf,deeper water,as in the Lower-Middle Ordovician of South China;and 3) inner shelf,shallow water,as in the Silurian and Triassic in South China.The Silurian marine red beds are recurrent in the lower Telychian,upper Telychian,and upper Ludlow.This paper is to document the marine nature of the lower Telychian red beds (LRBs) in the Upper Yangtze Region and to discuss the spatial and temporal distribution of the LRBs and their depositional environments.The LRBs are best developed on the north side of the Cathaysian Oldland,which can be interpreted as the source area.It is inferred that they were deposited during a marine regression,characterized by the lack of upwelling,low nutrition and organic productivity with a decrease of biodiversity and a high rate of sedimentation.The iron-rich sediments may have been transported by rivers on the oldland into the Upper Yangtze Sea,as rates of deposition were rapid enough to counteract normal reducing effect around sediment-water interface.The LRBs are different from the off-shore,deeper water red beds of lower Telychian in Avalonia and Baltica and further from the oceanic,deep water red beds of Upper Cretaceous in southern Tibet chiefly in palaeogeographic settings,biotic assemblages and marine environments.