白垩纪--古近纪边界的残存钙质超微浮游生物

K-T边界可以提供极有价值的生物灭绝事件的证据,但是关于生物消失的强度、速度和选择性仍然存在争论,这些争论的焦点一般是化石记录的准确性以及取样的偏差和再造作用的影响。有证据说明脊椎动物和无脊椎动物化石群分布区的选择性,并且这个事件好像对于食物链中依赖初级生产力的生物优先淘汰。食物链中以碎屑为食的动物以及耐饥饿的种群最有可能生存下来。在初级生产者中,陆地植物和海洋钙质超微浮游生物都遭到了灭绝,但硅藻属和沟鞭藻类浮游植物却有很高的生存比例,这可能是底栖和非浮游生物的包囊或孢子休眠期所致。     

Response of oceanic organisms to abiotic events in the Paleogene

Climate fluctuations with the optimum in the Early Eocene and subsequent cooling were the main abiotic factor that controlled the development of the oceanic biota in the Paleogene. The Paleogene represented the transitional stage from the greenhouse climate of the Mesozoic to the partly glacial Neogene and was characterized by changes in the distribution of the temperatures in the ocean with the replacement of the dominant latitudinal thermal circulation by the largely meridional thermohaline one. The climate changes were also determined by other factors: the opening and closure of seaways between basins, the position of major currents, volcanic activity, the sea-level fluctuations, the composition of the hydro- and atmosphere, and others. These changes were, in turn, determined by factors of higher order, primarily, by tectonic movements: vertical and horizontal (motions of lithospheric plates). The contribution of impact events to this process is also highly probable. All these factors influenced, via the hydrological and hydrochemical parameters of the water column, the evolution of the oceanic biota: their distribution areas, the sizes of the organisms, the diversity of the communities, the bioproductivity, and the mass extinction (for example, the extinction of 30–50% of the benthic foraminifers at the Paleocene-Eocene transition in response to the abrupt temperature increase). The Eocene-Oligocene transition (38 Ma ago) was marked by a global biotic crisis, the most significant one in the Cenozoic, when the abyssal part of the ocean was filled with cold water to form the psychrosphere. At least five major impact events, which preceded the Oligocene mass extinction of the biota, occurred in the terminal Eocene (36–35 Ma ago).     

2009年海洋大事记

<正>一月中国南极长城站卫星网络通讯系统建设成功。1月1日,中国南极长城站卫星网络通讯系统建成并投入使用,同时,中国南极中山站的卫星网络通讯系统也即将建成,这将有效解决我国南极两站接通互联网、电话通讯和科考数据实时传输等方面的难题。     

Response of Temperature Field in the Western Tropical Pacific to El Nino Events

El Nino, Anti-El Nino and normal years are defined in this paper according to time-de-pendent variations of El Nino and Southern Oscillation index. Statistics and analyses have been made of hydrological observation data related to 137°E section (34°N-l°S) from 1967 to 1983. It is shown from the results that there are obvious interannual variabilities of tempera-     

Volcanic and Seismic Swarm Events on the Reykjanes Ridge and Their Similarities to Events on Iceland: Results of a Rapid Response Mission

On 21 May 1989, a major earthquake swarm on the Reykjanes Ridge at59°44 N, 29°32 W at a water depth of about 1000 m andabout 500 km southwest of Iceland was detected on both the WorldwideStandard Seismic Network (WWSSN) and Icelandic seismic networks. As part ofa multi-institutional response to this swarm, the Naval ResearchLaboratory arranged for a P3 Orion Aircraft to deploy sonobuoys and AXBTs inthe immediate vicinity of the swarm activity. The detection of the swarmmotivated a survey of the region in 1990, using the towed SeaMARC IIside-looking sonar system. In 1990–1991 the Russian ShirshovInstitute of Oceanology offered the use of its MIR deep-divingsubmersibles to investigate the rise axis for recent volcanism. During 1992,a scientific team comprised of five US and ten Russian scientists mobilizedthe twin, deep diving Russian submersibles to study the spreading axis ofthe Reykjanes Ridge. The resulting data analyses allows us to conclude thatthe 1989 seismic swarm event occurred adjacent to and east of the largeaxial high in the center of our survey area. The length, width and depthrange of the earthquakes were very similar to major seismic swarm eventsconfined to fissure systems in the Krafla region of Iceland. It is likelythat the earthquake swarm was located on a fresh, well-defined systemof fissures and faults extending south of the northernmost axial highstudied. The earthquake swarm was probably associated with an emanation oflava creating a region of high backscatter, located just to the east of thecentral axial high. In addition, the region of high-backscatterremains unsampled because it lay underneath the nadir of the processedSeaMARC tracks used to plan the submersible survey. However many sampleswere taken and structural studies of the evolving Reykjanes Ridge werecarried out.     

《中华人民共和国海岛保护法》立法大事记

<正>2003年两会期间,全国人大代表和政协委员提出了多项海岛立法的议案和提案,引起了全国人大领导的高度重视,同年11月,海岛保护法列入经党中央批准的《十届全国人大常委会立法规划》,全国人大启动了海岛立法工作。2003年11月,全国人大环境与资源保护委员会成立海岛保护法起草领导小组,着手法律草案起草工作。     

Response of Summer Phytoplankton to Episodic Meteorological Events (Gulf of Trieste, Adriatic Sea)

Abstract. Despite increasing evidence that atmospheric deposition may contribute considerably to new production in coastal seas, the role of this nutrient source in the shallow northern Adriatic ecosystem has remained largely unassessed. This study demonstrates that locally collected rain water significantly stimulates primary production and phytoplankton biomass accumulation in microcosm experiments. The concentration of nutrients in rain water collected during summer storms (11.38–77.19 μmol·1^-1 nitrate. 4.45–36.38 μmol.1·1 ammonium, 0.93–4.75 μmol·1^-1 phosphate) indicated that the precipitation is influenced by anthropogenic emissions from urbanised and industrialised regions of the European continent. Rainfall events delivered relatively large (127 tons nitrogen, 9.5 tons phosphorus in the period 10 June to 10 September, 1993). though episodic, nutrient input into the area. Field measurements showed that storm events were followed by an increase of phytoplankton standing crop and a shift of community structure.     

Investigation and Discussion on the Beach Morphodynamic Response Under Storm Events Based on A Three-Dimensional Numerical Model

A well-established 3D phase-averaged beach morphodynamic model was applied to investigate the morphodynamics of a typical artificial beach,and a series of discussions were made on the surfzone hydro-sedimentological processes under calm and storm events.Model results revealed that the nearshore wave-induced current presents a significant 3D structure under stormy waves,where the undertow and longshore currents exist simultaneously,forming a spirallike circulation system in the surfzone.Continuous longshore sediment transport would shorten the sediment supply in the cross-shore direction,subsequently suppress the formation of sandbars,showing that a typical recovery profile under calm waves does not necessarily develop,but with a competing process of onshore drift,undertow and longshore currents.Sediment transport rate during storms reaches several hundreds of times as those under calm waves,and two storm events contribute approximately 60%to the beach erosion.Sediment transport pattern under calm waves is mainly bed load,but as the fine sands underneath begin to expose,the contribution of suspended load becomes significant.     

The Southern Baltic Seas in the Paleogene according to the study of the foraminifera

The changes in the paleocomplexes of the foraminifera, the remains of other organisms, and the lithological composition of the Paleogene deposits in the Kaliningrad region made it possible to reconstruct the sedimentation conditions during the Paleogene.     

广角地震勘探技术及在南黄海古近系油气勘探中的应用前景

广角地震(WARRP)是一种针对高速屏蔽层下弱反射层地震勘探的有效方法,其特点是大排列(排列长度可达6~30 km)采集、大能量震源激发、特殊的采集装备、广角反射和折射联合观测;处理中采用以正演模拟、多波分离、远道信息提取和VVO(速度随炮检距变化)分析等与常规处理不同的手段。介绍了广角地震的技术方法,在正演模拟的基础上分析了在南黄海前第三系油气勘探中的应用前景。     

Paleogeography of the Norwegian-Greenland and Northwestern European Sea Basins in the Paleogene

Published and original data on the lithology and fauna (mainly foraminifers) of the Paleogene Norwegian-Greenland and Northwestern European Sea Basins are generalized in this article. Their paleogeographic evolution and the character of development of connections with the North Atlantic, Mesotetis, and the Arctic Ocean are established from the moment of generation to their disappearance. It is shown that the paleogeographic conditions of the studied sedimentation basins depend to a great extent on the tectonic movements of lithospheric plates. Iceland Plume volcanism exerted a considerable influence on the paleoenvironment and sedimentogenesis. The paleotectonic and climatic conditions of sedimentation are reconstructed. The occurrence of bauxite-bearing continental residual soil and other data point to a tropical, humid climate in the Early Paleogene, which changed into a moderate humid climate by the end of the Late Paleogene. Terrigenous sediments, including oil-and-gas bearing ones, were formed in the sea basins; they contain products of eroded residual soil, placers of accessory minerals, pyroclastics of volcanoes of the Iceland Plume, and zeolite-bearing, amber-bearing, phosphorite-bearing, and glauconitic horizons that have practical interest.