透明胞外聚合颗粒物碳输运新途径   总被引：2，自引：1，他引：1  

孙军  郭聪聪  张桂成 《海洋学报》2019,41(8):125-130

目前大家普遍认为，透明胞外聚合颗粒物(Transparent Exopolymer Particles，TEP)因其独特的凝聚效应导致碳通量向海底输出。但是，近几年的研究表明TEP不仅影响了碳沉降途径，其本身能够悬浮甚至向海水表层迁移，导致其在海洋微表层(Surface Micro-layer, SML)积累，最终显著影响海洋表层碳通量。TEP和其他颗粒物聚集形成凝聚物后，其运动趋势则由凝聚物中TEP的含量占比，即最终颗粒物密度所决定。一个新的值得注意的现象是，密度低的TEP通过与其他微粒聚合形成表面活性物质(Surface-active Substances, SAS)，会在海洋–大气界面形成薄膜，显著影响海–气CO₂交换通量，甚至对全球气候变化造成影响。  相似文献   

南海大洋钻探及海洋地质与地球物理前沿研究新突破   总被引：2，自引：2，他引：0  

林间  李家彪  徐义刚  孙珍  夏少红  黄小龙  解习农  李春峰  丁巍伟  周志远  张帆  罗怡鸣 《海洋学报》2019,41(10):125-140

南海是西太平洋地区规模最大且具有代表性的边缘海盆地之一。经过近几十年的研究积累，尤其是通过实施5个国际大洋钻探航次(1999–2018年)与国家自然科学基金委“南海深海过程演变”重大研究计划(2011–2019年)，我国科学家获得了大量宝贵的第一手资料，取得了一系列创新进展与重大突破，标志着南海海洋地质与地球物理研究正走向国际前沿。重要研究成果包括:(1)新提出南海是“板缘张裂”盆地，与经典的大西洋型陆缘模式不同；(2)大洋钻探首次获取了基底玄武岩样品，结合中国在南海首次深拖地磁测量实验，精确测定了南海海盆玄武岩年龄，揭示南海海盆从东向西分段扩张；(3)大洋钻探结果发现南海陆缘岩石圈减薄之初岩浆迅速出现，未发现缓慢破裂造成的蛇纹岩出露；(4)发现南海扩张结束后仍存在大量岩浆活动，可能受控于多种构造与地幔因素；(5)地球化学证据与地球动力学模拟都显示南海岩浆的形成受到周边俯冲带的影响。目前我国的海洋地球科学正在进入崭新的发展阶段，有望以南海为基点，开始拓展到周边大洋，通过主导大型研究计划以及建设我国大洋钻探平台，以提升我国在南海、西太平洋与印度洋海洋地质科学研究的实质性影响力与引领地位。  相似文献   

北部湾灯光罩网渔场时空分布与海洋环境关系分析 *   总被引：1，自引：0，他引：1  

王言丰  余景  陈丕茂  于杰  刘祝楠 《热带海洋学报》2019,38(5):68-76

文章根据大型灯光罩网渔船调查数据和卫星遥感海面风场(Sea Surface Wind, SSW)、海表温度(Sea Surface Temperature, SST)和叶绿素a浓度(Chlorophyll a concentration, Chl a)资料, 基于广义线性模型(Generalized Linear Model, GLM)对北部湾渔业资源单位捕捞努力量渔获量(Catch Per Unit Effort, CPUE)进行标准化, 应用多元线性回归等方法, 对北部湾灯光罩网渔场的时空分布及其与海洋环境的关系进行了分析。结果表明, 北部湾灯光罩网渔场适宜SST为27~29℃, Chl a为0.5~1.5mg·m ^-3。较高资源量出现在10月份中上旬, 分布在18°—19°N及20°—21°N海域。北部湾灯光罩网渔场的时空分布与季风、19°N附近的暖水池和Chl a等环境因素有关。  相似文献   

基于航空重、磁数据的南黄海海相地层分布特征识别     

佟晶  张婉  张玄杰  熊盛青 《中国地质调查》2020,7(5):95-106

基于南黄海海域实测高精度航空重、磁数据,结合航空重、磁场及物性特征,通过平均对数功率谱分析匹配滤波方法技术,对南黄海海相地层界面起伏引起的重、磁异常特征进行分离、提取,采用切线法和外奎尔法计算海相地层界面的深度,经地质和地球物理综合解释,编制了南黄海海相地层底界面、顶界面深度图及海相地层厚度图。在此基础上,初步划分了南黄海海相地层构造单元,探讨了南黄海海相地层的分布特征。苏北—南黄海坳陷区的中部坳陷和南部坳陷均发育在强磁性基底之上,构造变形较弱,海相地层保存完整,埋藏浅,厚度为4~8 km,是南黄海地区具有较大资源潜力的油气勘探区。  相似文献   

页岩岩相分类表征及对建产区产能的影响     

欧成华  梁成钢  罗利  杨晓  李丹  李兆亮 《沉积学报》2021,39(2):269-280

单井产气能力差异大,导致持续稳产困难是页岩气建产区面临的关键难题。围绕页岩气建产区特点,建立了考虑建产区产气能力影响的优质海相页岩岩相分类表征技术流程。首先,分析了建产区优质页岩产气能力差异主控因素,制定了建产区优质页岩岩相分类方案;然后,建立了TOC含量,孔隙度,泥质、硅质、钙质矿物含量等关键参数测井计算模型,结合页岩成因类型,完成了建产区单井参数计算及岩相识别,在实例页岩气建产区识别出10类页岩岩相,揭示了页岩岩相类型与产气能力差异间的对应关系;最后,采用沉积微相约束岩相的策略,运用截断高斯模拟算法建立起实例页岩气建产区岩相三维模型,展示了每类岩相的空间分布特征,揭示了区内五峰组—龙马溪组海相黑色页岩内部产气能力差异特征,与此同时,按照满足在三维空间中所占体积比例大、产气能力大的条件,确定区内产气能力最优的岩相类型为:富碳高孔含钙泥质硅质页岩、富碳富孔混合页岩和高碳中—高孔含钙含泥硅质页岩。上述成果有利于解释建产区不同空间位置产气能力存在较大差异的本质原因,为页岩气建产区精细化生产管理提供技术支撑。  相似文献   

Pattern,style and timing of British–Irish Ice Sheet advance and retreat over the last 45 000 years: evidence from NW Scotland and the adjacent continental shelf     

Tom Bradwell  Derek Fabel  Chris D. Clark  Richard C. Chiverrell  David Small  Rachel K. Smedley  Margot H. Saher  Steven G. Moreton  Dayton Dove  S. Louise Callard  Geoff A. T. Duller  Alicia Medialdea  Mark D. Bateman  Matthew J. Burke  Neil McDonald  Sean Gilgannon  Sally Morgan  David H. Roberts  Colm ó Cofaigh 《第四纪科学杂志》2021,36(5):871-933

Predicting the future response of ice sheets to climate warming and rising global sea level is important but difficult. This is especially so when fast-flowing glaciers or ice streams, buffered by ice shelves, are grounded on beds below sea level. What happens when these ice shelves are removed? And how do the ice stream and the surrounding ice sheet respond to the abruptly altered boundary conditions? To address these questions and others we present new geological, geomorphological, geophysical and geochronological data from the ice-stream-dominated NW sector of the last British–Irish Ice Sheet (BIIS). The study area covers around 45 000 km² of NW Scotland and the surrounding continental shelf. Alongside seabed geomorphological mapping and Quaternary sediment analysis, we use a suite of over 100 new absolute ages (including cosmogenic-nuclide exposure ages, optically stimulated luminescence ages and radiocarbon dates) collected from onshore and offshore, to build a sector-wide ice-sheet reconstruction combining all available evidence with Bayesian chronosequence modelling. Using this information we present a detailed assessment of ice-sheet advance/retreat history, and the glaciological connections between different areas of the NW BIIS sector, at different times during the last glacial cycle. The results show a highly dynamic, partly marine, partly terrestrial, ice-sheet sector undergoing large size variations in response to sub-millennial-scale climatic (Dansgaard–Oeschger) cycles over the last 45 000 years. Superimposed on these trends we identify internally driven instabilities, operating at higher frequency, conditioned by local topographic factors, tidewater dynamics and glaciological feedbacks during deglaciation. Specifically, our new evidence indicates extensive marine-terminating ice-sheet glaciation of the NW BIIS sector during Greenland Stadials 12 to 9 – prior to the main ‘Late Weichselian’ ice-sheet glaciation. After a period of restricted glaciation, in Greenland Interstadials 8 to 6, we find good evidence for rapid renewed ice-sheet build-up in NW Scotland, with the Minch ice-stream terminus reaching the continental shelf edge in Greenland Stadial 5, perhaps only briefly. Deglaciation of the NW sector took place in numerous stages. Several grounding-zone wedges and moraines on the mid- and inner continental shelf attest to significant stabilizations of the ice-sheet grounding line, or ice margin, during overall retreat in Greenland Stadials 3 and 2, and to the development of ice shelves. NW Lewis was the first substantial present-day land area to deglaciate, in the first half of Greenland Stadial 3 at a time of globally reduced sea-level c. 26 kabp , followed by Cape Wrath at c. 24 kabp. The topographic confinement of the Minch straits probably promoted ice-shelf development in early Greenland Stadial 2, providing the ice stream with additional support and buffering it somewhat from external drivers. However, c. 20–19 kabp , as the grounding-line migrated into shoreward deepening water, coinciding with a marked change in marine geology and bed strength, the ice stream became unstable. We find that, once underway, grounding-line retreat proceeded in an uninterrupted fashion with the rapid loss of fronting ice shelves – first in the west, then the east troughs – before eventual glacier stabilization at fjord mouths in NW Scotland by ~17 kabp. Around the same time, ~19–17 kabp , ice-sheet lobes readvanced into the East Minch – possibly a glaciological response to the marine-instability-triggered loss of adjacent ice stream (and/or ice shelf) support in the Minch trough. An independent ice cap on Lewis also experienced margin oscillations during mid-Greenland Stadial 2, with an ice-accumulation centre in West Lewis existing into the latter part of Heinrich Stadial 1. Final ice-sheet deglaciation of NW mainland Scotland was punctuated by at least one other coherent readvance at c. 15.5 kabp , before significant ice-mass losses thereafter. At the glacial termination, c. 14.5 kabp , glaciers fed outwash sediment to now-abandoned coastal deltas in NW mainland Scotland around the time of global Meltwater Pulse 1A. Overall, this work on the BIIS NW sector reconstructs a highly dynamic ice-sheet oscillating in extent and volume for much of the last 45 000 years. Periods of expansive ice-sheet glaciation dominated by ice-streaming were interspersed with periods of much more restricted ice-cap or tidewater/fjordic glaciation. Finally, this work indicates that the role of ice streams in ice-sheet evolution is complex but mechanistically important throughout the lifetime of an ice sheet – with ice streams contributing to the regulation of ice-sheet health but also to the acceleration of ice-sheet demise via marine ice-sheet instabilities.  相似文献   

无隔水管泥浆回收钻井技术控制系统功能设计          下载免费PDF全文

陈浩文  刘晓林  王林清  于彦江  田烈余  王偲  殷国乐 《探矿工程》2021,48(S1):375-380

无隔水管泥浆回收钻井技术（RMR）作为双梯度钻井工艺之一,具有绿色环保、井身结构简易、工程成本低和安全程度高等优点。但是RMR作为新兴钻井工艺,虽然国外应用较为成熟,但国内目前尚无工程应用,缺乏相关使用经验。最关键的是RMR控制系统功能复杂,对可靠性、准确性及灵敏性等要求高,面对复杂工况时,要求控制系统能够及时准确的做出应对处理。因此,为发展国内无隔水管泥浆回收钻井技术（RMR）,拉近甚至超越国外钻井工艺水平,迫切需要对控制系统做出相对完善的设计。本文针对无隔水管泥浆回收钻井过程中的几类典型工况,分析不同工况下控制系统所具备的功能,设计控制功能具体的实现形式。通过对无隔水管泥浆回收钻井技术控制系统的功能设计与实现的研究,以期为今后同类研究提供有益的借鉴。  相似文献   

中国钾盐矿产基地成矿规律与深部探测技术示范     

张永生  郑绵平 《地学前缘》2021,28(6):1-9

本项研究得到国家“十三五”重点研发计划支持,系“深地资源勘探开采专项”2017年启动的重点项目之一,由中国地质调查局中国地质科学院矿产资源研究所牵头,来自自然资源部、中国科学院、教育部、大型石油国企等10家骨干单位以及多家协作单位参加,联合开展协同创新研究,充分体现“产研学用”密切融合。本项研究聚焦“特提斯东段中生代(三叠纪、侏罗纪)海相成钾作用与后期改造、青藏高原北部柴达木盆地深层富钾卤水迁移-分异-汇聚成矿机制”的关键科学问题和“深部含钾盐系‘双复杂’高精度地震成像技术、深部钾盐矿层(富钾卤水层)测井识别与地震预测技术”的关键技术问题,以柴达木西部和川东北两个重点成钾区为资源基地落脚点,兼顾其他含钾盆地研究,建立三维地质模型和成矿模型,完善海、陆相成钾理论,形成3 000 m以浅钾盐勘探成套技术能力,综合评价深部钾盐资源潜力,实施异常验证钻探,新发现1个大型钾盐资源基地,值得综合评价的有利成钾远景区3~4处,实现深部钾盐找矿突破和增储示范。值得强调的是,只有立足国内,突破海相,在中西部大中型叠合盆地古代海相蒸发岩地层中找到大规模海相可溶性固体钾盐矿床,方能从根本上扭转中国钾盐资源严重短缺的被动局面。令人欣慰的是,通过近10年的艰苦努力,我国海相钾盐取得了一系列成矿理论新认识和钾盐找矿新发现:创新提出了滇西南“二层楼”成钾模式,指出侏罗纪海相找钾新方向;在川东北宣汉普光地区发现三叠系海相可溶性“新型杂卤石钾盐矿”,开拓了四川盆地海相找钾新领域和新方向;在新疆库车地区发现埋深超5 000 m的钾石盐矿层,取得了库车坳陷海相找钾的实质性进展;创新提出“W型复底锅”成钾模式,在陕北奥陶纪海相盐盆发现厚层钾石盐矿化段,取得古陆表海型钾盐找矿重要新进展。至此,中国海相钾盐找矿崭露了突破的曙光。如何在这些新发现的基础上,进一步加大投入、深入研究,取得海相可溶性钾盐找矿的实质性突破,落实建成若干大型以上海相钾盐资源基地,将是“十四五”及以后时期中国钾盐的主攻方向。  相似文献   

中国铜矿床成矿系列研究进展     

应立娟  唐菊兴 《矿床地质》2015,34(6):1309-1320

矿床成矿系列理论在中国经过三十多年的发展,已被广泛应用于找矿勘查实践。文章在以往矿床成矿系列研究的基础上,对中国铜矿床的成矿系列进行了补充与完善,厘定出30个以铜为特色的矿床成矿系列。结合全国地质与成矿演化,分析铜矿床成矿系列在主要地质历史时期的特点与时空分布规律,其中,前寒武纪7个铜矿床成矿系列,矿床类型以变质型和岩浆型为主;古生代8个铜矿床成矿系列,矿床类型以海相火山岩型为主;中生代13个铜矿床成矿系列和新生代2个铜矿床成矿系列,矿床类型均以斑岩型和矽卡岩型为主。西藏地区铜矿找矿突破显著,新增2个全国范围的铜矿床成矿系列。矿床成矿系列的复合,是中国铜矿床成矿系列研究的重要成果和特色。  相似文献   

IMPACT OF SSTA OF SOUTHERN HEMISPHERE ON FLOOD SEASON PRECIPITATION ANOMALIES IN YUNNAN     

杨竹云  杨素雨  严华生  张瑾文 《热带气象学报(英文版)》2015,21(3):255-264

Based on the reanalysis data of monthly mean global SST and wind from the NCEP/NCAR and the observation data of rain seasons in 124 stations of Yunnan province from 1961 to 2006, we applied the analytical methods of correlation analysis and composite analysis and a significance testing method to two sets of samples of average differences. The goal is to investigate into the influence of the Southern Hemispheric (SH) SST on the summer precipitation in Yunnan from January to May so as to identify the key time and marine regions. Physical mechanisms are obtained by analyzing the influence of sea level wind and the key marine regions on the precipitation during Yunnan’s rain season. Results show that there is indeed significant relationship between the SST in SH and summer precipitation in Yunnan. The key areas for influencing the summer precipitation are mainly distributed in a region called “West Wind Drift” in the SH, including the Southeast Indian, southern Australia, west coast of eastern Pacific off Chile, Peru and the southwest Atlantic Magellan. Besides, the most significant marine region is the west coast of Chile and Peru (cold-current areas of the eastern Pacific). Diagnostic analysis results also showed that monsoons in the Bay of Bengal, a cross-equatorial flow in the Indian Ocean near the equator and southwest monsoon in India weaken during the warm phase of the Peruvian cold current in the eastern Pacific. Otherwise, they strengthen.  相似文献