Deglaciation and proglacial lakes

Glaciers and ice sheets are important constituents of the Earth's land surface. Current worldwide retreat of glaciers has implications for the environment and for civilisation. There are a range of geomorphic changes occurring in cold environments and it is anticipated that these will be accentuated as a consequence of climate change. In particular, the number and size of proglacial lakes is currently increasing as a result of deglaciation and their significance for the physical environment and for society is becoming increasingly apparent. This article provides an overview of the major interdependent relationships between climate change, glaciers and proglacial lake development. In particular, it describes the key processes and impacts associated with proglacial lake evolution with reference to examples drawn from the European Alps, North America, the Himalayas, the Andes, Greenland, New Zealand and Iceland.     

The impact of the Habitats Directive on European port operations and management

Thirteen years since the EU Habitats Directive (1992/43/EEC) became a binding legal agreement, this paper considers the implementation of this important European environmental legislation as it applies to the coastal activities of seaports and harbours. The paper examines the relationship between environmental legislation and ports policy, and seeks to provide a comprehensive assessment of the policy and science that has been developed in relation to protected areas and port management. The paper reports the results of a survey of European port professionals, and their perception of the successes and challenges of the management regimes that have been established, as well as their opinions on how these have influenced the management within ports. The paper also provides a detailed examination of the scientific and technical developments with particular regard to dredging and habitat management in European ports. Key research gaps are identified, including: practical approaches to licensing procedures; lack of baseline information, especially with regard to in-combination effects; the efficacy of techniques for mitigating the impacts of dredging; and greater understanding on how more resilient models for collaborative action can be developed. The paper will be of use to environmental planners, scientists, regulators, conservationists, and port managers, as they consider how to apply science and management to the sustainable development and environmental protection of coastal areas.     

GEO LOGIC

Let me begin by outlining the role of this column. It is aimed at European geoscientists who use personal computers. Rather than duplicating what is already discussed in the hundreds of computer magazines that can be found at any newsagent, I will concentrate on those products and services that have a particular application in the Earth Sciences. This is not to say that only those products with a specific Earth Science application will be discussed. Instead, anything that a practising geoscientist might find useful will be a candidate for review; a software package for compiling reference lists in the many styles demanded by different journals would be an example. The column will devote itself to products for IBM-PC and Mac users. I apologise in advance for the UK perspective offered in the first few articles; this reflects my ignorance of the European scene and the difficulties I have faced in overcoming it. I look forward to feedback from continental geoscientists who, I hope, will bring me up to date regarding the truly European picture.     

Too‐low magnetic inclinations in central Asia: an indication of a long‐term Tertiary non‐dipole field?

Observed Tertiary palaeolatitudes in central Asia are more southerly (by about 1600 km on average) than those predicted from the Eurasian reference palaeopoles. Subsequent northward displacements of the central Asian terranes are unlikely to have been this large. In this study we analyse to what extent non-dipole fields, especially octupole fields, can explain this phenomenon. A global (zonal) octupole field manifests itself in two ways. (1) Because the reference APWP is based mostly on results from the UK and North America, its palaeopoles will be far-sided as seen from the North Atlantic, but near-sided as seen from eastern Asia, giving predicted palaeolatitudes that are too high. (2) An octupole field contribution produces observed palaeolatitudes, as calculated with the dipole formula for central Asia, that are too low. Both effects therefore increase the palaeolatitude anomalies in Asia. We find that an octupole/dipole field ratio (G3) of 0.06 or greater will reduce the palaeolatitude discrepancies significantly and is of the same magnitude as the G3 estimate of a recent analysis of Early Tertiary European and North American data.     

地球化学与环境样品分析标准物质和GeoReM数据库

在地球化学和环境样品分析中,标准物质发挥着越来越重要的作用。尽管通常要求分析者必须提供量值溯源的测量过程的信息;但大多数论著都未给出标准物质的数据。文章强调标准物质在地球化学分析工作中的重要性,同时将地球化学与环境样品分析标准物质数据库GeoReM介绍给中国的地质分析工作者。GeoReM数据库收录了1880个地球化学和环境样品分析标准物质的定值数据、汇编数据、分析数据及其他相关信息,其中包括156个由中国制备的标准物质的数据。GeoReM数据库还给出了所收录标准物质推荐使用的首选值及其不确定度。尽管这些首选值大多都不是按照国际标准化组织的有关规定而确定的,但是它们的置信度高,因而被广泛应用于仪器校准和分析数据的质量监控。文章还指出要将中国研制的、发表在中文期刊上的标准物质也收录到GeoReM数据库中,这对于促进中国的相关研究,增加国际认可度具有重要意义。     

A framework for evaluating potential ecological effects of implementing biological control of<Emphasis Type="Italic">Phragmites australis</Emphasis>

The increasing abundance ofPhragmites australis in many North American coastal and inland wetlands is of great concern to many scientists and land managers. While some considered the species native, others considered it an introduced invasive species. Regardless of its origin, control measures using mechanical, physical, and chemical means are implemented widely. With the exception of increased salinity, reductions in the abundance ofP. australis are usually temporary and control measures need to be repeated frequently increasing the cost and the potential for nontarget effects. The failure of traditional control attempts resulted in increased interest to develop a biological control program. Recent research suggests that genetically distinct populations (introduced and native) occur in North America. The native genotypes appear noninvasive and declining while the introduced genotypes are invasive replacing native genotypes where they co-occur. Accidentally introduced European herbivores specialized onP. australis are spreading across North America and can be extremely abundant in the Northeast. Introduction of additional specialized herbivores as biological control agents from the European range ofP. australis, if approved and successful, will result in changes in plant communities, wetland food webs, and management practices. The potential changes associated with introduction of biological control agents to wetland plant communities and their food webs may be more beneficial than current management strategies allowing the introducedP. australis genotypes and its associated herbivores to spread.     

Climate shifts and coastal changes in a geological perspective. A contribution to integrated coastal zone management

This Special Issue deals with the impact of climate change on western European coastal systems. Notwithstanding the inherent problems of studying geological data in terms of climate shifts, the results show that on the meso- and the macroscale of time, climatic forcing is a major drive for coastal change. However, its impact is largely influenced by other factors. Sediment availability plays a dominant role in the evolution of coastal systems and it can be considered one of the most important thresholds at the land-ocean interface. Sea-level changes are expected to have a significant impact on most European coasts. There is particular concern for the tidally influenced flats and marshes, and for those coastal areas known to have already a net sediment deficit and to be threatened by erosion. Areas where isostatic uplift has countered sea-level rise until now, are expected to become subject to coastal erosion in the near future under an accelerated sea-level rise scenario. The sensitivity and vulnerability of coastal systems to climate shifts is shown to be largely controlled by storm magnitude and fetch. A particular case of vulnerability is the impact of tsunamis. Finally, the consequences of human interference have been demonstrated in many cases. The implementation of geoscientific studies for rational, comprehensive and cost-effective strategies on a regional or national level of integrated coastal zone management is reviewed.     

The mutual climatic range method of palaeoclimate reconstruction based on insect fossils: New applications and interhemispheric comparisons

The Mutual Climatic Range (MCR) method of palaeoclimate reconstruction has been employed in Europe for the last decade. A quantitative, calibrated method, MCR has many advantages over qualitative methods. More recent applications deal with eastern and central North America, and the method is also being developed for desert and arctic faunas. The climate envelopes for North American beetles have been compiled using a 25-km gridded North American climate database that pairs climate parameters with modern collection sites. Modern tests of the reliability of the MCR method for North American species yielded similar results to prior European tests. Linear regressions of predicted on observed values yielded equations used to calibrate the MCR estimates. Work is under way to develop MCR estimates of mean annual precipitation for fossil assemblages from the desert southwest, where moisture conditions may play a more important role in determining beetle species' ranges.An examination of British and North American mean July temperature reconstructions during the Late Wisconsinan glacial interval compares and contrasts three sets of records. The North American records show no indication of the Younger Dryas cooling that is clearly marked in records from northwest Europe. The MCR method adds vigour to our reconstructions, and allows us to compare between regions and with other palaeoenvironmental methods.     

The key role of supply chain actors in groundwater irrigation development in North Africa

The role played by supply chain actors in the rapid development of groundwater-based irrigated agriculture is analyzed. Agricultural groundwater use has increased tremendously in the past 50 years, leading to the decline of water tables. Groundwater use has enabled intensification of existing farming systems and ensured economic growth. This “groundwater economy” has been growing rapidly due to the initiative of farmers and the involvement of a wide range of supply chain actors, including suppliers of equipment, inputs retailers, and distributors of irrigated agricultural products. In North Africa, the actors in irrigated production chains often operate at the margin of public policies and are usually described as “informal”, “unstructured”, and as participating in “groundwater anarchy”. This paper underlines the crucial role of supply chain actors in the development of groundwater irrigation, a role largely ignored by public policies and rarely studied. The analysis is based on three case studies in Morocco, Tunisia and Algeria, and focuses on the horticultural sub-sector, in particular on onions and tomatoes, which are irrigated high value crops. The study demonstrates that although supply chain actors are catalyzers of the expansion of groundwater irrigation, they could also become actors in adaptation to the declining water tables. Through their informal activities, they help reduce market risks, facilitate credit and access to subsidies, and disseminate innovation. The interest associated with making these actors visible to agricultural institutions is discussed, along with methods of getting them involved in the management of the resource on which they depend.     

Glacier Peak and mid-Lateglacial Katla cryptotephras in Scotland: potential new intercontinental and marine-terrestrial correlations

Using contiguous high resolution sampling methods, we report the detection of a Glacier Peak volcanic ash from North America in Lateglacial Interstadial lake sediments in western Scotland. It occurs in close proximity to the Icelandic Borrobol and Penifiler tephras, but is distinguishable by its rhyolitic major-element composition that is consistent with the earliest set G layer, one of a number of mid-Interstadial Glacier Peak eruptions dated between 13.71 and 13.41 cal ka bp. Another cryptotephra layer present in these same Interstadial sediments has a rhyolitic composition consistent with the Icelandic Katla source. However, it is in a stratigraphic position below the widespread mid-Lateglacial Stadial Vedde Ash from Katla, which is also present in these cores. The Katla layer is stratigraphically well defined, suggesting primary airfall, and is compositionally similar to a mid-Interstadial rhyolitic tephra reported from a North Atlantic marine sequence south of Iceland dated to ~13.6 ka. The detection of Glacier Peak G in the European tephrostratigraphy will permit direct high-precision correlation of mid-Interstadial palaeoenvironments between North American and European terrestrial sequences. Any correlation between the new Katla layer and similar marine layers remains provisional, though if verified would permit similar correlation between North Atlantic marine and European terrestrial records.     

Simulation of the climate of 18,000 years BP: Results for the North American/North Atlantic/European sector and comparison with the geologic record of North America

The large ice sheets in North America and Europe and the extensive sea-ice cover in the North Atlantic at the time of the last glacial maximum must have greatly modified the surface temperature patterns and, in turn, the location and intensity of the surface winds and jet streams. A general circulation model was used to simulate the January and July patterns of temperature, precipitation, and wind for 18 ka BP. Boundary conditions for the model, consisting of ice-sheet location and height, sea-ice location, and sea-surface temperature were prescribed from CLIMAP (1981). The model results are illustrated and described for the North American/North Atlantic/European sector. The jet stream splits around the North American ice-sheet, and the southern branch strengthens considerably (compared to present) over the southern portion of the United States, the sea-ice margin of the North Atlantic, and the southern edge of the European ice-sheet. Geologic evidence, principally from North America, of wind, temperature and moisture conditions is assessed from sand dune and loess records, estimates of snowline depression, pollen records and lake-level studies. The geologic evidence is generally compatible with the model simulation.     

岩心钻机从事煤层气勘探HSE管理尝试

从事煤层气勘探作业的机台,必须参考石油钻井行业标准《石油天然气钻井健康、安全与环境管理指南》（SY／T6283—1997）对钻探作业进行HSE管理,即通过建立HSE管理体系,对作业机台钻探生产过程中的健康、安全及环境进行动态管理。结合XY-5型岩心钻机在陕北某煤层气勘探孔生产的实际,就该钻机从事煤层气勘探作业时HSE管理办法进行介绍。     

Interregional and Transnational Co-operation in River Basins – Chances to Improve Flood Risk Management?

In European river basins many flood management and protection measures are planned. However, the realisation of effective but space consuming measures such as retention areas and dike relocation mostly lags far behind time schedules. The development and set-up of an interregional and transnational basin-wide co-operation structure (“flood management alliance”) is substantial to realise catchment oriented flood management. In particular, this co-operation structure must involve spatial planning. The interregional and transnational co-operation structure establishes the framework for the joint accomplishment of instruments for flood risk management which is basin-wide agreed on. One of these instruments comprises financial compensations between downstream and upstream regions which shall improve the acceptance and the realisation of measures which bear disadvantages for the regions where measures are located. Existing and planned basin-wide co-operations in large transnational European river catchments demonstrate reasonable developments towards these goals. However, further efforts have to be made to exploit the chances interregional co-operation offers for improved flood risk management.     

Atmospheric deposition of heavy metals to North European marginal seas: Scenarios and trend for lead

The contribution of the atmosphere to the input of heavy metals to marine environments of Northern Europe is determined by applying an EMEP-type Lagrangian trajectory model. The results show that the model is capable of simulating long-range transport of heavy metals from European anthropogenic sources to the North Sea and the Baltic Sea including emission reduction scenarios for lead. Model calculations for lead indicate maximum annual inputs from the atmosphere of more than 2,400 tonnes for the North Sea and 1,300 tonnes for the baltic sea. It was calculated that in the 1985–1990 time period, mainly as a consequence of use of unleaded gasoline, the trend show a pronounced decrease of the deposition fluxes of lead from the atmosphere.     

中国石炭纪构造—地层区划与地层格架

中国石炭纪构造活跃,在华北地块、扬子地块、塔里木地块等稳定块体间存在着大量造山带,尤其存在着北天山洋、南天山洋、布青山—勉略洋、金沙江洋、甘孜—理塘洋等多个洋盆中的洋板块地层,大地构造分区极为复杂。传统的地层区划主要考虑稳定的地块区,按目前的地理格局来进行地层区划划分。本文通过大地构造单元与构造演化阶段相结合,借鉴目前国内经典的大地构造划分方案,对中国石炭纪构造-地层进行区划,共划分出阿尔泰—兴蒙地层大区、北准噶尔—西拉木伦地层大区、天山—北山地层大区、塔里木—阿拉善地层大区、华北地层大区、秦祁昆地层大区、扬子地层大区、华夏地层大区、北羌塘—三江地层大区、班公湖—怒江地层大区、印度地层大区等11个地层大区及若干地层区。其中阿尔泰—兴蒙地层大区位置相当于阿尔泰—兴蒙多岛弧盆系,发育洋板块地层及大量岛弧火山岩,分为阿尔泰地层区和兴安地层区;北准噶尔—西拉木伦地层大区位置相当于额尔齐斯—西拉木伦大洋盆,包括大量岛弧带地层及洋板块地层,分为北准噶尔地层区及西拉木伦地层区;天山—北山地层大区位置相当于天山—北山造山系,发育大量火山岩,分为南准噶尔地层区、北天山地层区、南天山地层区、伊犁地层区及额济纳—北山地层区;塔里木—阿拉善地层大区位置相当于塔里木陆块、塔东南—敦煌隆起及阿拉善地块,为稳定的滨浅海沉积,局部为海陆交互相沉积,分为塔里木地层区和阿拉善地层区;华北地层大区位置相当于华北陆块及贺兰山陆缘裂陷盆地,主要为稳定的海陆交互相地层,分为贺兰山地层区、华北地层区及华北地块北缘地层区,其中华北地层区缺乏密西西比亚纪地层;秦祁昆地层大区位置相当于秦祁昆造山系,分为祁连地层区、东昆仑—柴达木地层区、西昆仑地层区、秦岭地层区、南秦岭—苏鲁地层区;扬子地层大区位置相当于扬子陆块,分为盐源—丽江地层区、中上扬子地层区、下扬子地层区、湘浙赣地层区及滇黔桂地层区,主要为稳定的碳酸盐沉积,仅湘浙赣地层区见现有较多的海陆交互相沉积;华夏地层大区位置相当于武夷—云开造山系,分为粤闽地层区、粤南地层区、钦防地层区、琼北地层区、琼中南地层区及华夏地层区,除钦防地层区为一套深海—半深海硅泥质沉积外,其他地层区主要为滨浅海沉积及少量海陆交互相沉积;北羌塘—三江地层大区位置相当于北羌塘—三江多岛弧盆系,包括多个稳定的小型地块及其间的蛇绿混杂岩带,洋板块地层发育,分为可可西里—巴颜喀拉—勉略地层区、金沙江—哀牢山地层区、中甸—昌都—思茅地层区、鲜水河—甘孜—理塘地层区、北羌塘地层区及甜水海地层区;班公湖—怒江地层大区位置相当于班公湖—双湖—怒江—孟连大洋盆,主要为洋板块地层;印度地层大区位置相当于印度大陆北部被动大陆边缘,以发育冈瓦纳大陆特有的古生物化石组合及冰成岩为特征,分为冈底斯地层区、北喜马拉雅地层区及保山地层区。简单介绍了各地层大区、地层区及部分地层分区内的岩石组合、古生物组合及地层序列。结合实例提出了中国石炭纪地层格架建立的原则,对各地层区系石炭系进行了系统的地层对比,建立了其地层对比关系。     

西藏喜马拉雅瑞替阶和赫塘阶菊石组合及其生物年代学对比

基于西藏聂拉木拉弄拉地区的格米格剖面新近逐层采集的菊石及缝合线研究,已识别出晚三叠世瑞替阶Choristoceras marshi组合,过渡带Neophyllites-Choristoceras组合,下赫塘阶Psiloceras calliphyllum组合和中赫塘阶Discamphiceras pleuronotum组合。作为东特提斯唯一的三叠系-侏罗系界线地层剖面,格米格菊石组合序列提供了特提斯范围内三叠/侏罗系界线菊石组合(或菊石带)以及地层对比的基础:Choristoceras marshi组合可以和欧洲,南美的秘鲁和智利的MARSHI菊石带,北美的内瓦达,不列颠哥伦比亚(加拿大)等地CRICKMAYI菊石带比较。Neophyllites-Choristoceras组合可和北美的内瓦达侏罗系底部TILMANNI菊石带Neophyllites和Choristoceras共生动物群比较。Psiloceras calliphyllum组合能够和北阿尔卑斯地区CALLIPHYLLUM菊石带比较, 证明北阿尔卑斯地区三叠系和侏罗系之间存在地层缺失。     

Disconnected policies and actors and the missing role of spatial planning throughout the risk management cycle

The present work addresses the problem of lack of coordination between policies and actors with joint competence for risk management, i.e., civil protection, spatial planning, and sectoral planning (e.g., forest policy in the case of forest fire risk). Spatial planning in particular is assigned a minor or no role at all though it might perfectly operate as the coordinating policy platform; the reason is that spatially relevant analysis and policy guidance is an omnipresent component of the risk management cycle. However, disconnected risk relevant policies turning a blind eye to spatial planning might cause several adverse repercussions: Breaks in the response-preparedness-prevention-remediation chain (which should function as a continuum), minimal attention to prevention, risk expansion and growth instead of mitigation, lack of synergies between involved actors as well as duplicated or even diverging measures and funding. The authors bear witness to the above suggestions by examining three cases of European (regional and local) risk management systems faced with failures when confronting natural hazards (floods and forest fires). These three systems are embedded in different types of political-administrative structures, namely those of the city of Dortmund (Germany) facing floods, Eastern Attica region (Greece), and Lazio Region (Italy) facing forest fires.     

Structure of the crust and upper mantle beneath the central european rift system

The crustal structure of the central European rift system has been investigated by seismic methods with varying success. Only a few investigations deal with the upper-mantle structure. Beneath the Rhinegraben the Moho is elevated, with a minimum depth of 25 km. Below the flanks it is a first-order discontinuity, while within the graben it is replaced by a transition zone with the strongest velocity gradient at 20–22 km depth. An anomalously high velocity of up to 8.6 km/s seems to exist within the underlying upper mantle at 40–50 km depth. A similar structure is also found beneath the Limagnegraben and the young volcanic zones within the Massif Central of France, but the velocity within the upper mantle at 40–50 km depth seems to be slightly lower. Here, the total crustal thickness reaches only 25 km. The crystalline crust becomes extremely thin beneath the southern Rhônegraben, where the sediments reach a thickness of about 10 km while the Moho is found at 24 km depth. The pronounced crustal thinning does not continue along the entire graben system. North of the Rhinegraben in particular the typical graben structure is interrupted by the Rhenohercynian zone with a “normal” West-European crust of 30 km thickness evident beneath the north-trending Hessische Senke. A single-ended profile again indicates a graben-like crustal structure west of the Leinegraben north of the Rhenohercynian zone. No details are available for the North German Plain where the central European rift system disappears beneath a sedimentary sequence of more than 10 km thickness.     

The Cenozoic evolution of the Roer Valley Rift System integrated at a European scale

The Roer Valley Rift System (RVRS) is located between the West European rift and the North Sea rift system. During the Cenozoic, the RVRS was characterized by several periods of subsidence and inversion, which are linked to the evolution of the adjacent rift systems. Combination of subsidence analysis and results from the analysis of thickness distributions and fault systems allows the determination of the Cenozoic evolution and quantification of the subsidence. During the Early Paleocene, the RVRS was inverted (Laramide phase). The backstripping method shows that the RVRS was subsequently mainly affected by two periods of subsidence, during the Late Paleocene and the Oligocene–Quaternary time intervals, separated by an inversion phase during the Late Eocene. During the Oligocene and Miocene periods, the thickness of the sediments and the distribution of the active faults reveal a radical rotation of the direction of extension by about 70–80° (counter clockwise). Integration of these results at a European scale indicates that the Late Paleocene subsidence was related to the evolution of the North Sea basins, whereas the Oligocene–Quaternary subsidence is connected to the West European rift evolution. The distribution of the inverted provinces also shows that the Early Paleocene inversion (Laramide phase) has affected the whole European crust, whereas the Late Eocene inversion was restricted to the southern North Sea basins and the Channel area. Finally, comparison of these deformations in the European crust with the evolution of the Alpine chain suggests that the formation of the Alps has controlled the evolution of the European crust since the beginning of the Cenozoic.     

Dimensions of drought: South African case studies

The recent drought in southern Africa has underscored the need for detailed analysis of the phenomenon. While geographers have researched the causes and impacts of drought in many African contexts, South Africa and in particular its Bantustans have not received sufficient similar attention. This paper outlines firstly the dimensions of drought in South Africa, including the biophysical and socio-economic factors. Issues such as land-use management, drought planning and relief are interrogated in the South African context. The final section of the paper highlights these debates with specific reference to case studies of past and present drought initiatives in South Africa.