Surface roughness and geological mapping at subhectometer scale from the High Resolution Stereo Camera onboard Mars Express

The quantitative measurement of surface roughness of planetary surfaces at all scales provides insights into geological processes. A characterization of roughness variations at the scale of a few tens of meters is proposed that complements the analysis of local topographic data of the martian surface at kilometer scale, as achieved from the Mars Orbiter Laser Altimeter (MOLA) data, and at the subcentimeter scale using photometric properties derived from multi-angular observations. Relying on a Gabor filtering process, an algorithm developed in the context of image classification for the purpose of texture analysis has been adapted to handle data from the High Resolution Stereo Camera (HRSC). The derivation of roughness within a wavelength range of tens of meters, combined with analyses at even longer wavelengths, gives an original view of the martian surface. The potential of this approach is evaluated for different examples for which the geological processes are identified and the geological units are mapped and characterized in terms of roughness.     

实时智能地震处理系统在2020年四川石渠M5.6地震序列中的应用

实时智能地震处理系统（RISP）是一套基于深度学习技术的新型地震实时处理系统,于2021年6月在四川开始试运行。为了评估该系统在四川台网稀疏区域的地震检测和处理能力,笔者等采用RISP系统对2020年4月1日四川甘孜州石渠县发生的M5.6级地震序列进行了回溯性分析,获得了较为可靠的自动处理地震序列目录,并与人工目录进行了对比分析。震后10d内,RISP系统自动处理获得了386个地震信号,地震数量是正式地震目录的1.98倍,匹配率为97.43%。分析显示,发震时刻偏差小于±1.0 s的地震占比71.05%,震中位置偏差小于10 km的地震占比96.31%,震级偏差小于±0.3级的地震占比99.47%。根据RISP系统检测地震序列分布特征和震源机制解,认为此次地震的发震断层为五道梁—长沙贡玛断裂北东侧的一条未发现的分支断层。研究结果表明,RISP系统的应用可以提升台网稀疏区域的地震检测能力,可快速产出地震序列目录,对大震应急、震后趋势判定和发震构造研究等具有重要意义。     

Geological evolution of offshore pollution and its long-term potential impacts on marine ecosystems

Populations and metropolitan centers are accumulated in coastal areas around the world. In view of the fact that they are geographically adjacent to coasts and intense anthropogenic activities, increasing global offshore pollution has been an important worldwide concern over the past several decades and has become a very serious problem that needs to be addressed urgently. Due to offshore pollution, various geological disasters occur in high frequency, including intensified erosion and salinization of coastal soils, frequent geological collapses and landslides and increasing seismic activities. Moreover, offshore pollution shows increasingly serious impacts on the topography and geomorphology of offshore and coastal areas, including coastal degradation, retreating coastlines and estuary delta erosion. Offshore sedimentation processes are strongly influenced by the pH changes of terrestrial discharges, and sedimentary dynamics have become extremely acute and complex due to offshore pollution. The seabed topography and hydrodynamic environment determine the fate and transport of pollutants entering offshore regions. Coastal estuaries, port basins and lagoons that have relatively moderate ocean currents and winds are more likely to accumulate pollutants. Offshore regions and undersea canyons can be used as conduits for transporting pollutants from the continent to the seabed. It is particularly noteworthy that the spatial/temporal distribution of species, community structures, and ecological functions in offshore areas have undergone unprecedented changes in recent decades. Due to increasing offshore pollution, the stable succession and development trend of marine ecosystems has been broken. It is thus important to identify and regulate the quantity, composition and transportation of pollutants in offshore regions and their behavior in marine ecosystems. In particular, crucial actions for stabilizing marine ecosystems, including increasing species and biodiversity, should be implemented to enhance their anti-interference capabilities. This review provides an overview of the current situation of offshore pollution, as well as major trends of pollutant fate and transportation from continent to marine ecosystems, transformation of pollutants in sediments, and their bioaccumulation and diffusion. This study retrospectively reviews the long-term geological evolution of offshore pollution from the perspective of marine geology, and analyses their long-term potential impacts on marine ecosystems. Due to ecological risks associated with pollutants released from offshore sediments, more research on the influence of global offshore pollution based on marine geology is undoubtedly needed.     

日本苫小牧CO2海底地质封存监测技术分析及其启示

海洋二氧化碳捕集、利用与封存(CCUS)是应对全球气候变化、减排温室气体CO₂的关键技术之一,也是实现中国碳中和目标愿景解决方案的重要组成部分。中国近海沉积盆地封存潜力巨大,2022年中国首个CO₂海底地质封存示范工程已在南海珠江口盆地咸水层中正式启动。日本苫小牧咸水层封存项目作为迄今为止亚洲最成功的海底封存项目,其CO₂封存监测工作为我国离岸封存项目的开展提供了重要的实践参考及技术指导。文章全面回顾了苫小牧CCS项目案例情况,对项目执行、场地监测内容及布点、监测设施及技术、监测结果等进行分析,总结苫小牧CCS项目的成功经验,以及陆—井—海结合一体化的多层次、全方位的监测体系,旨在助力中国海上CO₂封存项目顺利运行,确保海洋生态环境安全。     

EFFECTS OF SST, VWS, AND DCC UPON RAPID INTENSIFICATION OF OFF-SHORE TYPHOONS IN CHINA SEAS

In this study, we employed National Centers for Environmental Prediction(NCEP)/National Center for Atmospheric Research(NCAR) reanalysis data and records from the China Meteorological Administration(CMA)Yearbook of Tropical Cyclones to investigate three factors: sea-surface temperature(SST), vertical wind shear(VWS),and the density of the core convection(DCC), which are responsible for the rapid intensification(RI) of 1949-2013 offshore typhoons. Our analysis results of these composite factors show that in the environmental wind field the typhoons are far away from the outer strong VWS; in the SST field they are in the high SST area; and the core convective activity is robust and takes a bimodal pattern. The difference in RI between typhoons over the East China Sea(ECS) and the South China Sea(SCS) is a smaller VWS for the ECS typhoons, which may be one of the reasons why typhoons in the ECS are more intense than those in the SCS. Our study results indicate that SST, VWS, and DCC can result in an RI after a certain time interval of 36 h, 24 h to 30 h, and 24 h, respectively. The RI indicates a lag in the atmospheric response to oceanic conditions. This lag characteristic makes it possible to predict RI events. In summary, where the SST is high(≥28 ℃), the VWS is small, and the DCC is high, an RI will occur. Where mid-range SSTs occur(26 ℃≤SST≤28 ℃), with small VWS, and high DCC, the RI of typhoons is also likely to occur.     

海上风电勘探装备研发与应用

配置合理的海上风电勘探装备,对海上风电地质钻探至关重要,而配置合理、功能齐备的海上风电勘探平台更是重中之重。为了提升35 m以上水深海上风电勘探作业工效、安全、精度,本文主要从平台运维功能和勘探功能设计为切入点,针对性地开展了平台主要技术规格、升降操控系统、场区设计、现场土工试验室等方面的海上风电勘探自升式勘探平台装备的功能设计与研究,研发了具备双孔勘探能力的自升式勘探平台,并在投产运营2年中,取得了良好的使用效果,勘探工效、安全性大大提升,达到了研发的目标,为海上风电勘探提供了有力的装备支撑。     

Spatio‐temporal variability of zooplankton biomass and environmental control in the Northern Benguela Upwelling System: field investigations and model simulation

Spatial and temporal distribution patterns of zooplankton are highly variable in the Northern Benguela Upwelling System. We studied the distribution of zooplankton (size class ≥ 0.33 mm) and used field data from four cruises that took place between March 2008 and February 2011, as well as simulation results of a regional ecosystem model. Remotely sensed sea surface temperatures (SST) and surface chlorophyll concentrations were analysed to investigate environmental influences on zooplankton biomass. The Intense Benguela Upwelling Index showed a distinct seasonal signal throughout the years and the highest upwelling peaks in August/September. Even though surface chlorophyll concentrations were very variable throughout the year, the highest concentrations were always detected in September, following the upwelling of nutrient‐rich water. In field catches, zooplankton biomass concentration in the upper 200 m was highest above the outer shelf and shelf‐break in December 2010 and February 2011, i.e. 6 months after the upwelling peaks. In contrast, zooplankton biomass simulated by the model in the surface water was highest in September. In March/April, biomass maxima were typically measured in the field at intermediate water depths, but the vertical distribution was also affected by extensive oxygen minimum zones. The ecosystem model reproduced this vertical pattern. Although general trends were similar, simulation data of zooplankton standing stocks overestimated the field data by a factor of 3. In upwelling systems, food webs are generally considered to be short and dominated by large cells. However, our field data indicate more small‐sized zooplankton organisms above the shelf than offshore.     

Experiment Study of Dynamics Response for Wind Turbine System of Floating Foundation

The floating foundation is designed to support a 1.5 MW wind turbine in 30 m water depth. With consideration of the viscous damping of foundation and heave plates, the amplitude-frequency response characteristics of the foundation are studied. By taking into account the elastic effect of blades and tower, the classic quasi-steady blade-element/momentum (BEM) theory is used to calculate the aerodynamic elastic loads. A coupled dynamic model of the turbine-foundation- mooring lines is established to calculate the motion response of floating foundation under Kaimal wind spectrum and regular wave by using the FAST codes. The model experiment is carried out to test damping characteristics and natural motion behaviors of the wind turbine system. The dynamics response is tested by considering only waves and the joint action of wind and waves. It is shown that the wind turbine system can avoid resonances under the action of wind and waves. In addition, the heave motion of the floating foundation is induced by waves and the surge motion is induced by wind. The action of wind and waves is of significance for pitch.     

一种适用于海量多波束测深数据的中值滤波算法

针对CUBE算法中的数据中值滤波排序问题,设计了一种基于堆结构的中值滤波算法。这种方法以初始滤波窗口中间数据为支点,把滤波序列划分为2个堆,进而把查找滤波窗口中间位置数据转化为在两个堆中进行排序并输出根节点的操作。实验结果表明,这种方法的滤波速度约为基于二分查找的中值滤波算法的2~4倍,适合应用于海量数据的滤波处理。     

基于FVCOM的温州近海潮汐潮流数值模拟

基于有限体积法海洋数值模型(FVCOM),构建了温州近海潮汐潮流数值模式,模式模拟区域为(120°24′00″~121°19′12″E,27°21′00″~28°24′00″N),模式水平分辨率由近岸河口区的50m,逐渐增加至开边界附近的2km。模式模拟并分析了温州近海的M2,S2,N2,K1,O1五个主要分潮。利用温州近海实测资料对模拟结果进行了验证,模拟与实测符合良好;其中与4个验潮站资料比较,M2,S2,N2,K1,O1五个主要分潮的振幅绝均差和迟角绝均差分别为4.84cm和5.14°,2.19cm和3.35°,5.18cm和4.38°,0.64cm和3.67°,0.59cm和4.61°;与9个海流连续观测站比较,流速绝均差为11.71cm/s,流向绝均差为9.66°。在模拟结果较好地反映温州近海潮汐、潮流运动状况的基础上,本文给出了各模拟分潮的潮汐同潮图和潮流椭圆分布、潮汐和潮流类型分布以及最大可能潮流分布等。