A sub-salt structural model of the Kelasu structure in the Kuqa foreland basin,northwest China

The Kuqa foreland basin, adjacent to the South Tianshan Mountains, is a major hydrocarbon accumulation basin in Western China. The Kelasu structural belt is the focus for hydrocarbon exploration in the basin due to the presence of ramp-related anticline traps and a thick salt seal. The model of the Kelasu sub-salt structure is still contentious because of the structural complexity and poor seismic imaging below the salt layer. The area–depth–strain (ADS) method is applied to the southern part of the Kelasu Fault, a regional fault that cuts basement rocks. The ADS results are consistent with the seismic data, which indicate that both thin-skinned thrusting and basement-involved deformation occur within the Kelasu structure, with the Kelasu Fault acting as the boundary between the two regions of contrasting deformation. The ADS results also suggest that the depth of the lower detachment of the thin-skinned thrust belt is 9.5–10 km, which may correspond to the base of the Triassic. The Kelasu structure has undergone approximately 8.15–10.76 km of horizontal shortening in the east and 16.34 km in the west of the structure.     

1:5万基础地理信息综合判调更新系统的设计与实现

针对“十一五”我国1∶5万基础地理信息更新的任务需求,研究了基于影像综合判调的一体化更新作业模式,并设计开发了1∶5万基础地理信息综合判调更新软件系统。目前,该软件已应用于我国1∶5万地理信息更新工程,有效地提高了更新生产的效率,控制了作业质量、降低了作业成本,为我国1∶5万基础地理信息综合判调更新提供了高效的作业平台,也为1∶1万甚至大比例尺的数据更新提供了很好的借鉴。     

国家城镇生态环境综合监测技术体系构建

近年来,我国城镇突出的生态环境问题受到社会广泛关注,作为生态环境保护工作的重要组成部分,随着城镇化的快速发展,城镇生态环境监测任务也越来越重、要求越来越高,对结合空间信息的天地一体综合监测的需求非常迫切,急需建立其技术体系,以指导城镇生态环境综合监测工作的开展。本文面向城镇生态环境综合监测的需求,从城镇污染气体、水体水质、生态资源3个方面出发,通过梳理城镇生态环境综合监测中的关键科学技术问题,结合开展的关键技术攻关研究,经过分析论证,构建了城镇生态环境综合监测技术体系框架、指标体系框架以及标准体系框架。在此基础上,根据遥感数据特点及国家生态环境监测需求,提出城镇生态环境综合监测业务应用方案,为国家和省市地方下一步有效开展城镇生态环境监测、管理等工作提供重要指导和支撑。     

优选土层锚杆围护体设计方案的计算机实现

介绍了土层锚杆围护体（包括墙体和锚杆支护结构）的方案优选计算机系统的功能和特色,讨论了其计算机实现方法,以及利用系统进行以工程要求和工程成本为目标的土层锚杆围护体设计方案优选的思路和方法     

Analyse isotopique de l'air piégé dans la glace pour quantifier les variations de température

Isotopic measurements in polar ice core have shown a succession of rapid warming periods during the last glacial period over Greenland. However, this method underestimates the surface temperature variations. A new method based on gas thermal diffusion in the firn manages to quantify surface temperature variations through associated isotopic fractionations. We developed a method to extract air from the ice and to perform isotopic measurements to reduce analytical uncertainties to 0.006 and 0.020$\text{‰}$ for δ¹⁵N and δ⁴⁰Ar. It led to a 16±1.5 °C surface temperature variation during a rapid warming ($\text{?70}\text{000}$ yr). To cite this article: A. Landais et al., C. R. Geoscience 336 (2004).     

Geomorphological evolution and sediment stratigraphy of numerically simulated alluvial fans

When a sediment laden river reaches a flat basin area the coarse fraction of their sediment load is deposited in a cone shaped structure called an alluvial fan. In this article we used the State Space Soil Production and Assessment Model (SSSPAM) coupled landform–soilscape evolution model to simulate the development of alluvial fans in two- and three-dimensional landforms. In SSSPAM the physical processes of erosion and armouring, soil weathering and sediment deposition were modelled using state-space matrices, in both two and three dimensions. The results of the two-dimensional fan showed that the fan grew vertically and laterally keeping a concave up long profile. It also showed a downstream fining of the sediments along the fan profile. Both of these observations are in agreement with available literature concerning natural and experimental fan formations. Simulations with the three-dimensional landform produced a fan with a semicircular shape with concave up long profiles and concave down cross profiles which is typical for fans found in nature and ones developed in laboratory conditions. During the simulation the main channel which brings sediment to the fan structure changed its position constantly leading to the semicircular shape of the fan. This behaviour is similar to the autogenic process of ‘fanhead trenching’ which is the major mechanism of sediment redistribution while the fan is developing. The three-dimensional fan simulation also exhibited the downstream fining of sediments from the fan apex to the peripheries. Further, the simulated fan also developed complex internal sediment stratification which is modelled by SSSPAM. Currently such complex sediment stratification is thought to be a result of allogenic processes. However, this simulation shows that, such complex internal sediment structures can develop through autogenic processes as well. © 2020 John Wiley & Sons, Ltd.     

A Statistically-Based Low-Level Cloud Scheme and Its Tentative Application in a General Circulation Model

1. Introduction Clouds are active factors in the climate system, and have significant influences on the global hydrolog- ical and thermal budgets. More and more the climate model developers and researchers have realized the im- portance to appropriately describe the interactions be- tween cloud and radiation in the atmospheric general circulation model (AGCM). It is well known that cloud is one of the contributing factors to the uncertainties in the simulation of climate by AGCM. Especiall…     

非对称台风风场的动力初始化应用研究

在对比NCAR-AFWA三维Bogus(虚拟)风场及风压场方案的基础上,虚拟台风模型中的水平风场采用考虑台风移速、移向、摩擦等客观因素的非对称方案,垂直风场采用考虑高空反气旋环流的风廓线方案,然后利用Nudging动力初始化技术形成新的模式初始场.最后对云娜台风进行数值模拟,结果表明:通过合理引入客观因子及观测事实对台风Bogus模型进行构建,并利用同化方法使各个物理量相互协调,可以使初始场与实况更加接近,从而在一定程度上提高台风路径及强度的预报水平,并对降水分布的预报效果也有所改善.     

Statistical Evaluation of the Jason-1 Operational Sensor Data Record Special Issue: Jason-1 Calibration/Validation

The Jason-1 satellite altimeter mission represents a first step towards operational oceanography from satellite altimeter missions. An operational data product, the Operational Sensor Data Record (OSDR), provides measurements from the on-board altimeter and radiometer within 3–5 h of real time. This data product is a wind and wave product that is aimed towards near-real–time meteorological applications. A higher accuracy and more detailed data product, the Interim Geophysical Data Record (IGDR), that is better suited to detailed scientific studies of ocean topography, is available no sooner than 2–3 days from real time. The measurements reported on the OSDR primarily differ from those on the IGDR in that the OSDR reports measurements derived from on-board processing of the altimeter waveforms, while ground retracking of the waveforms is performed for the IGDR. The altimeter-derived measurements on the OSDR are validated through a statistical evaluation of the differences between data on the OSDR and IGDR. In doing so, the impact of ground retracking of the altimeter waveforms is also illustrated.     

U–Pb zircon age of the Walloon Coal Measures in the Surat Basin,southeast Queensland: implications for paleogeography and basin subsidence

The Jurassic Walloon Coal Measures of the Surat Basin were previously estimated to be of Middle Jurassic age, ranging from Aalenian to Callovian, based on an uncalibrated eastern Australian biostratigraphic framework. New U–Pb dates of 162.55 ± 0.05 Ma and 158.86 ± 0.04 Ma obtained from zircons in ash-fall volcanic tuffs now place the Walloon Coal Measures of the Surat Basin in the Upper Jurassic Oxfordian. The new dates have several implications for the interpretation of the Jurassic strata in the Surat Basin. First-order subsidence rates of 61 m/Myr for the Walloon Coal Measures are more akin to those of foreland basins than the previously assumed intracratonic setting. The dates also imply deposition of the Walloon coals in substantially higher latitudes than previously assumed and that they accumulated as peats in mires that experienced more than three months’ continual darkness each winter. Zircon dating of tuffs and associated geochemistry should assist with the correlation of the laterally impersistent coals, fluvial sandstone and mudstone of the Walloon Coal Measures, which are currently difficult to correlate over distances of more than a few kilometres. Dating of the palynostratigraphic zones APJ4.2 to APJ5 (Aequitriradites norrisii Association Zone to Murospora florida Association Zone) will also need to be recalibrated.