Südchina, insbes. die Provinz Guandong, ist eines der am dichtesten besiedelten Gebiete der Erde. Positive Konsequenz dieser Ballung ist eine äußerst dynamische Wirtschaftsentwicklung, aber gerade diese von subtropischem Monsunklima geprägte Region ist auch immer wieder Ausgangspunkt für sich schnell und zunehmend global ausbreitende epidemische Krankheiten wie zuletzt SARS. Mit der globalen Erwärmung einhergehende Klimaveränderungen könnten sich für diese Region insbesondere durch Veränderungen der Häufigkeit und Intensität tropischer Wirbelstürme, aber auch Änderungen der Niederschlagsmenge- und Intensität bemerkbar machen. Im Gegensatz zu den schon recht umfangreichen Datensätzen aus der Südchinesischen See (SCS) gibt es bisher jedoch nur sehr wenige terrestrische Paläoklimaarchive aus der Region, die Klimaveränderungen während des Holozäns, des Spätglazials oder Glazials hochauflösend dokumentieren. Wir haben deshalb einen an der nördlichen Küste der SCS gelegenen Maarsee ausgewählt, um über die Analyse von Proxydaten aus Seesedimenten solche Paläo-Klimavariationen zu untersuchen. Aus dem Sediment des Huguang-Maarsees wurden mittels Usinger-Präzisionsstechtechnik von einem Floss aus insgesamt 7 Sedimentsequenzen gewonnen, von denen die tiefste bis 57 m unter den Seeboden reicht. Die zeitliche Einstufung der Profile wurde mit Hilfe von 17 Radiokohlenstoff-Datierungen vorgenommen und ergab ein extrapoliertes Maximalalter von ca. 78.000 Jahren. Ein breites Spektrum aus sedimentologischen, geochemischen, paläo- und gesteinsmagnetischen sowie palynologischen Methoden kam sodann zum Einsatz, um die Paläo-Umweltbedingungen, die natürlich immer das entsprechende Klima widerspiegeln, während dieses Zeitraumes zu rekonstruieren. Überraschenderweise ergab sich ein von vielen bekannten Klimaprofilen der Nordhemisphäre (insbes. des Atlantikraumes, aber auch mariner Kerne aus dem Indik und Südostasien) abweichendes Muster. Im Gegensatz zu dem bekannten Grundmuster eines vergleichsweise stabilen Klimas während des Holozäns und stärkerer Schwankungen während des letzten Glazials weisen die Daten aus dem Huguang-Maarsee für das letzte Glazial im Zeitraum zwischen 15.000 und 40.000 Jahren auf relativ stabile Umweltbedingungen hin. Die älteren Bereiche zwischen 40.000 und ca. 78.000 Jahren haben durch Eintrag von umgelagertem Torf eine eher lokale Komponente und sind somit für den regionalen und globalen Vergleich ungeeignet. Das Holozän hingegen zeichnet sich durch hohe Schwankungsamplituden vieler Proxydaten (Karbonatgehalt, magnetische Suszeptibilität, organischer Kohlenstoff, Trockendichte, gesteinsmagnetische Parameter, Redox-Verhältnisse) aus, die auf ein recht variables Klima hinweisen. Besonders interessant ist die Übergangsphase vom Glazial zum Holozän, die bei etwa 15.000 Jahren vor heute in etwa zeitgleich mit dem beobachteten stärksten Meeresspiegelanstieg der Südchinesischen See einsetzt und eine abrupte Intensitätszunahme des Sommermonsuns anzeigt
Identification the risks and benefits associated with the use of untreated wastewater in urban and peri-urban fodder and vegetable cropping systems in India and Pakistan, with a particular focus on livelihoods, livestock and food safety. The project activities are in Hyderabad (India) and Faisalabad (Pakistan). Main task is the creation of a project GIS database and field mapping.
The objective of this project is to quantify near-surface processes for predicting soil degradation by erosion and changes in the water balance, in the context of dry environmental conditions. Field and laboratory experiments, remote sensing observations, and hydrological and erosion modelling are combined to improve process understanding and to further develop prognostic methods for the assessment of soil degradation. The study area is located in refilled landscapes left over from the Niederlausitzer coal-mining industry (Brandenburg region, Eastern Germany ). The area is particularly suitable for this study because it is characterised by exceptionally dry climate conditions for Central European standards, and because it is free of vegetation or covered by sparse vegetation only. Specific goals of the study are: Monitoring and modelling of near-surface processes to predict runoff generation and erosion by water. Coupling of remote sensing data with field measurements to derive information about soil surface characteristics, erosion status and near-surface soil moisture content. Examining the influence of soil moisture / dryness on soil-physical and hydrological parameters, such as hydrophobicity, surface crusts, infiltration capacity, water storage capacity. Study area: The study area in Welzow-Süd (South-East of Germany, close to the town of Cottbus) of 4 ha in size was refilled in 2001 after mining by sediments of different origin and properties, with the major contributions being composed of two different sandy materials of Tertiary and Quaternary origin and, third, by clay deposits. The focus of the this study is on the sandy areas. While the Tertiary deposits are free of vegetation, an initial sparse vegetation cover of grasses has developed on the other areas. Runoff from the test site is episodic. These conditions, together with low annual rainfall volumes, make the test site a valuable pilot study area for the development of monitoring and modelling approaches to assess erosion and soil degradation processes in dryland areas.
Convergent continental margins are the site of large earthquakes originating along the interface between the subducting and overriding plates. The site of the strongest historically recorded earthquake (Mw=9.5, 1960) is the study area of the ongoing TIPTEQ project (2004-2007) in Chile. Here, in southern central Chile the project investigates the controlling parameters of processes leading to earthquakes in the seismogenic coupling zones (add link to more detailed TIPTEQ pages). Along the plate margin the oceanic Nazca plate subducts below the South American continent. Thereby, material is accreted and folded, faults are generated, material is transported to large depths where it is possibly accreteded at the base of the upper plate. These structures and processes are the targets of geophysical imaging and - together with geological surface observations- form the basis for numerical and analog simulations of active margin deformation and the the processes leading to mega-thrust earthquakes. First pilot studies in 2001 (project SPOC) have shown that the target area is well suited for our investigations. Our contributions to TIPTEQ: Seismic and structural image of the plate interface, Co-seismic mass transfer and surface processes, Experimental and numerical analysis of deformation processes Simulation of surface deformation during subduction earthquakes.
High-quality chronologies of late Pleistocene tropical climate have become increasingly important in discussions concerning tropical forcing of deglaciation, i.e., the transition from a glacial to an interglacial. The key argument of this hypothesis is that tropical climate leads high-latitude ice volumes by several thousand years. A tropical forcing of deglaciation would also help to explain why ice ages occur in both hemispheres simultaneously, although the changes in solar irradiance from orbital variations have opposite effects in the two hemispheres. Lake Naivasha provides a unique opportunity to study a continuous record of tropical climate changes during the last two glacial-interglacial cycles (approximately 175 kyr) through sedimentologic and paleoecologic changes reflected in the sediments. We propose a two-step strategy to reconstruct the lake history during this period: (A) a high-resolution seismic survey to characterize the depositional setting, lake-level fluctuations and neotectonics in the Naivasha basin. This survey will also guide up to the best sites for (B) two 50- and 40-m-long sediment cores from the present lake area. These sediment records are expected to fill the gap between a well-studied section exposed south of the present lake (175 to 60 kyr before present) and two sediment cores studied in the 1960's (25 kyr to present).
Wasser- und Stofftransport in Böden werden durch Gefügeinhomogenitäten in strukturierten Böden, eine kleinräumige Variabilität im Profilaufbau, die Korngrößenzusammensetzung, die Oberflächenbeschaffenheit und unterschiedliche Niederschlagsintensität beeinflusst. Viele Modellierungsansätze berücksichtigen und beschreiben den Einfluss dieser Faktoren auf den zeitlichen Verlauf des Transportes. Im Gegensatz dazu gibt es noch wenig Erfahrungen, wie die räumliche Variabilität der Fließprozesse quantifiziert werden kann. Unser Verständnis für Ursachen und Effekte präferentieller Fließprozesse muss durch Feldexperimente vertieft werden, um die Vorhersage und Abschätzung von Stoffverlagerungen und Kontaminationen des Bodens und Grundwassers zu verbessern. Ziel dieses Projektes war, die räumlichen Muster des Stofftransportes unter Berücksichtigung der Bodenoberflächenbeschaffenheit und des Bodengefüges in Abhängigkeit von der Beregnungsintensität auf unterschiedlich strukturierten Böden zu untersuchen. Ein einheitliches Tracerexperiment wurde auf sandigen und tonigen Böden in South Carolina und Brandenburg unter Feldbedingungen durchgeführt. Neben klassischen statistischen Verfahren werden geostatistische Verfahren eingesetzt, um die räumliche Variabilität zu bestimmen.
South Tirol is an important region for apple production in Europe. The mild climate allows a high productivity but during the last decades, winter damage on apple trees was observed in 3 to 4 year intervals at numerous sites in South Tirol. This winter damage in apple orchards is economically relevant as e.g. in season 2004/2005 costs of more than 6 Mio Euros were caused. There are several indications that the observed dieback of crown parts or even trees was related to frost drought. The situation is comparable to that of trees at the timberline, where winter damage was analysed in previous projects. Based on our experience with trees growing at the alpine timberline, we hypothesize that winter damage in South Tirol apple orchards is strongly influenced by the duration of water uptake blockages, the extent of transpirational water losses, the trees water storage capacity as well as the climatic conditions in autumn. We expect damage in living tissues as well as xylem embolism to cause prolonged drought stress in spring. In the proposed project, these aspects will be analysed and avoidance strategies will be developed. In field measurements at five apple orchards in South Tirol, climatic conditions and effects on tree water relations (water potential, hydraulic conductivity, water storage, transpiration) as well as winter injury will be quantified, and in experimental approaches important parameters will be analysed in detail. These data will be compared with hydraulic characteristics (vulnerability to embolism, drought resistance of living tissues, water storage capacity) of studied varieties. In consequence, numerous varieties will be screened for resistance to frost drought, whereby hydraulic as well as related anatomical parameters will be analysed to develop a valuable screening protocol for variety selection. Cultivation techniques to avoid winter damage will also be tested in thi u.s.w.
At ANDRILL site SMS (Southern McMurdo Sound) an longer than 1000m sediment core will be drilled from a sea-ice platform covering Early/Middle Miocene (ca17 Ma) to Pleistocene strata of McMurdo Sound, Ross Sea, Antarctica. The target sediments were deposited on the western flank of the Victoria Land Basin (VLB), a structural half-graben that forms part of the West Antarctic Rift system, and experienced subsidence since late Eocene times. On this sediment core we propose to combine high-resolution on-ice measurement of chemical element concentrations using XRF core-scanner with off-ice high-precision chemical and sedimentological analysis on bulk samples (XRF, XRD, ICP-MS, biogenic components) and individual lithoclasts (LA-ICP-MS, electron microprobe, microscopy). The resulting multiple dataset will provide detailed information on sediment composition and, thus, contribute to several scientific objectives of ANDRILL such as the history of Ross/West Antarctic ice shelf expansion and retreat since ca17 million years, sea-ice presence/absence in the McMurdo region, and the history of Neogene sediment provenance and accumulation rates in the VLB. Our major goal is to improve our understanding of the Neogene paleoenvironmental evolution of Antarctica with a special focus on the Mid-Miocene climatic optimum (ca17-15 Ma) and the subsequent onset of major cooling (ca14 Ma) along with the key question on the stability of cold-polar climate conditions during the last 14 million years
In the framework of the international ANtarctic DRILLing program (ANDRILL) the 1138 m deep core borehole SMS was drilled in the Southern McMurdo Sound (Ross Sea). The investigations of Antarctic Neogene ice sheet variations, of long-term climate evolutions and of the tectonic history of McMurdo Sound represent the main project aims. One part of the German participation in the ANDRILL project is the extensive geophysical logging of the SMS borehole. It delivers a main basis for answering a lot of questions in the scope of the whole project consisting of about 100 scientists. Interpreting the downhole logging data permits among other things to establish a complete lithological log, to characterize the drilled sediments petrophysically, to determine sedimentary structures and to get evidence about palaeoclimatic conditions during up to 19 Mio years. Seismic experiments in the borehole allow linking detailed geological information with shipborne seismic sections. This way, local results can be transformed into spatial information thus providing an important contribution to the understanding of the tectonic structure of the Ross Sea.
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