陆架沙丘(波)活动量级和稳定性标志研究

陆架底流包含定时变向的潮流、定时定向的洋流和偶发性的暴风浪流,水下沙丘的塑造和运动是潮、浪动力共同作用的结果.用水文计算法计算沙丘迁移速率时应充分考虑陆架各动力要素的作用,并与定位观测速率相对照.按陆架水下沙丘的运动量级和发育过程可划分为强运动、弱运动、不运动(残留)和消亡(或埋藏)沙丘等4种类型,它们的稳定性标志,表现于海底状况、外部形态、粒度结构、水动力和迁移速率等方面.     

南海东北部表层沉积的孢粉与陆缘植被关系的研究

通过对南海东北部表层沉积的孢粉分析，根据孢粉分布的规律，结合多元变量数理统计分析方法-因子分析法，将研究区划分为四个孢粉区：松-水龙骨科-里白、桫椤-凤尾蕨孢粉区，松-栎、栲-水龙骨科-凤尾蕨孢粉区，松-罗汉松、泪杉-水龙骨科-凤尾蕨孢粉区，松-草本植物花粉-桫椤、里白-水龙骨科孢粉区；深入探讨了南海东北部表层沉积孢粉分布格局与陆缘植被的关系。     

Crustal Structure of the High Magnetic Anomaly Belt, Western Taiwan, and its Implications for Continental Margin Deformation

A joint analysis of gravity anomaly and seismic travel-time data has been used to construct a three-dimensional velocity structure for the northeastern extension of the northern South China Sea’s high-magnetic belt in the Taiwan region. The earthquake data used in this study was collected by the Central Weather Bureau Seismological Network from 1991 to 2002, while the gravity data around Taiwan was compiled by Hsu et al. (1998), Terr. Atmos. Oceanic. Sci., 9, 509–532, and Wang et al. (2002), >Terr. Atmos. Oceanic. Sc., 13, 339–354. A modified velocity model obtained by local earthquake tomography was used to construct an initial three-dimensional gravity model, using a linear velocity–density relationship. To derive a crustal velocity–density model that accounts for both types of observations, this study performed a sequential inversion of travel-time and gravity data. The main features of our three-dimensional velocity model are:(1) an uplifted zone with velocity greater than 6.5 km/s being observed in the lower crust, (2) the width and the shape of the uplifted zone being found to be strongly correlated with the high-magnetic belt, (3) a trend by which the lower crustal high-velocity zone turns from northeast to north in central Taiwan, where the high-magnetic zone was truncated. A combination of seismic, gravity, and structural interpretations suggests that the crustal deformation relating to the magnetic truncation observed in northwestern Taiwan could be correlated closely with the collision between the Philippine Sea plate and the Asian continental margin.     

大陆架地质和法律概念的异同探讨

大陆架资源丰富,对大陆架的划分和主权权利的拥有,是国际上十分重视和争论激烈的问题。地质和法律上的大陆架是两层有关联而含义不同的概念：法律上的大陆架以地质概念的大陆架为基础,地质上的大陆架是客观存在的,而法律上的大陆架增加了其社会属性,地质上大陆架的自然延伸受海底有关地质和地貌因素的限制,法律上大陆架除自然延伸标准外,还明确了宽度的人为控制数量。由于大陆架构造的多样性和复杂性,法律和地质概念的大陆架范围也不同。     

Slumping and shallow faulting related to the presence of salt on the Continental Slope and Rise off North Carolina

Seismic reflection profiles and long- and medium-range sidescan sonar were used to investigate a salt diapir complex and area of slope instability near the base of the Continental Slope off North Carolina. Within the area of investigation three diapirs are bounded on their upslope side by a scarp 60 m high and 50 km long. The slope above the scarp is characterized by a series of shallow rotational normal faults. The bottom below the scarp is furrowed by slide tracks, which were probably carved by large blocks that broke off the scarp face and slid downslope leaving rubble and scree lobes.Extensive slumping in this area appears to be a result of uplift and faulting associated with salt intrusion, which has fractured and oversteepened the slope leading to instability and failure. Sharply defined slide tracks suggest that slope failure above the breached diapir complex is a continuing process, in contrast to much of the surrounding slope area where few instability features were observed.     

Extension of the Paraná Basin to offshore Brazil: Implications for coalbed methane evaluation

Coalbed methane (CBM) is a worldwide exploration target of the petroleum industry. In Brazil, the most important coal-bearing succession is associated with the Permian Rio Bonito Formation of the Paraná Basin. The gas-prone areas are located at the southeastern margin of the Paraná Basin and possibly in the offshore region of the northern part of the Pelotas Basin. Coalfields end abruptly at the present day shoreline, a result of rifting of Gondwana and the evolution of the South Atlantic Ocean. All geologic indicators suggest that in pre-rift times the coal seams extended further eastwards, probably now lying deeply buried below the sedimentary succession of the Pelotas Basin. The present paper discusses structural, stratigraphic, seismic and aeromagenetic data that support the preservation of continental crust beneath ocean sediment. If the coal beds had similar lateral extent to known onshore coals, and coal beds extended across the projected extension of the Parana basin, and there was a conservative 5 m of cumulative coal thickness, then a potential methane volume can be estimated for this newly inferred resource. Average onshore coal gas content is 32 scf/ton (1.00 m³/ton). If this is similar in the offshore coal deposits, then the hypothetical methane volume in the offshore area could be in excess of 1.9 × 10¹² scf (56 × 10⁹ m³). Metamorphism from dikes associated with rifting are potential complicating factors in these deposits, and since no borehole reaching the deep-lying strata in the offshore area are available, this is a hypothetical gas resource with a certain level of uncertainty which should be tested in the future by drilling a deep borehole.     

南海北部表层水温变化的幅度和时期:与东亚季风的动态联系

热带和亚热带季风区经历着地球上最大的年内风向逆转,随之而来的是迁移区内的强烈降雨。季风体系从温暖的赤道海洋向高纬度的内陆输送热量和水汽（如Emile-Geay等,2003）。在过去的150ka年间,季风和降雨变化显著,日照量和北半球冰盖面积也随之逐渐变化。这些变化影响了热带太平洋西部边缘盆地的淡水平衡（如Wang等,1999;Oppo等,2003;Rosenthal等,2003）,但是该时期季风对热带太平洋西部边缘盆地海水表层温度（SST）的影响仍然不为人所熟知。我们在此提供南海（西部热带太平洋的一个边缘海）北部过去145ka以来SST变化的第一手资料。     

Behavioural responses to structures on the seafloor by the deep-sea fish Coryphaenoides armatus: Implications for the use of baited landers

Coryphaenoides armatus plays a fundamental role in the dispersal of organic matter on the deep-sea floor by consuming food-falls. The use of baited cameras to study population parameters (e.g. abundances and size frequencies) assumes that members of this species follow odour plumes directly to bait, appear immediately in the field of view, and depart as predicted by optimal foraging theory. Described here are behaviours to the contrary observed during the operation and development of more complex baited camera systems. Of the 247 C. armatus observed by a video lander, 72.5% of the fish explored the structure whilst only 6% fed, and 21.5% were indifferent. This exploratory behaviour increased individual staying time by 38.4% compared to those that just fed. Experiments with several models of in situ fish respirometry lander showed the importance of both equipment design, and an understanding of the behaviour of the target animals in maximising capture success. These results show how previously unexpected aspects of behaviour by C. armatus can greatly affect the chances of capturing members of this species and influence the results of baited camera experiments.     

黄河入海径流量周期变化与东亚夏季风的关系研究

为揭示近 70 年东亚夏季风与黄河夏季入海径流量的多尺度特征以及二者之间的响应关系,本文利用集合经验模态分解 （EEMD） 和小波分析对二者的多尺度特征进行研究,利用交叉小波分析和小波相干性等方法对东亚夏季风和黄河夏季入海径流量在时频域内的共振周期以及相干性进行探究。结果表明：东亚夏季风具有显著的年际、年代际尺度特征,且以年际周期振荡最为显著,其中,2.7 a 左右的周期尺度对东亚夏季风的整体影响程度最高,另外,40 a 左右的年代际周期亦具有较强显著性。黄河夏季入海径流量的年际、年代际尺度周期均通过了 80 %的显著性检验,且以 2.1 a 左右的年际周期为主。东亚夏季风与黄河夏季入海径流量的交叉小波功率谱显示二者在 2 a、6~7 a 左右具有显著的共振周期,且在 1980— 1990 年之间通过了 95 %的显著性检验,由二者的小波相干谱发现,东亚夏季风和径流量的显著性在低能量区大于高能量区,且东亚夏季风提前径流量约 1/4 个周期,另外,1980—2000 年之间在 6~7 a 左右周期尺度上二者的相干性极强。该研究可为黄河下游水资源管理及预测提供一定的理论依据。