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  • Within the framework of DOVE, the project Chatseis combines two seismic methods to increase resolution and reliability of the seismic data; i.e. reflection imaging and full-waveform inversion. To acquire the optimal data for the tasks in the project Chatseis, the German Federal Institute for Geosciences and Resources conducted two seismic surveys together with the Leibniz Institute for Applied Geophysics and the Bayerisches Landesamt für Umwelt. At the DOVE-site 5068_3 (Schäftlarn), the project team registered seismic P-wave data with explosive and vibration sources and different geophones as well as S-wave data with a small-scale vibratory source and a landstreamer system on three profiles (in total ca 3.8 km, 100 GB for P-wave and ca 2.6 km, 16 GB for S-wave).

  • A global Earth Magnetic Anomaly Grid (EMAG2) was compiled from satellite, ship and airborne magnetic measurements. (Maus et al., 2009) Over the continents and the Arctic we made use of exisiting magnetic anomaly grids, whereas original ship and airborne trackline data were processed over the rest of the oceans, wherever available. CHAMP satellite magnetic measurements provided the magnetic field at wavelengths above 330 km. The EMAG2 grid is available at http://geomag.org and http://ngdc.noaa.gov. Directional gridding Due to the sparsity of magnetic field measurements in the southern oceans, it is necessary to interpolate the magnetic field between tracklines. Our interpolation algorithm takes the direction of the magnetic lineations into account. Tje lineations are parallel to the isochrons, which are perpendicular to the gradient of the age of teh oceanic crust. We use the age grid of Müller et al. (2008). The magnetic field ad a given grid point is computet by Least Squares Collocation from the surrounding measurements. If the point is on land, we use an isotropic correlation function with Rc = 14 km correlation length. Over the oceans we use Rc = 56 km parallel to the isochrons and Rc = 14 km in the spreading direction. Measurements seperated from the grid point by an age discontinuity or a topographic feature are excluded from the collation.

  • Die Anwendung dient zur Verwaltung von Daten aus der Geophysik. Inhalt: Daten geophysikalischer Untersuchungen Fomen: Verarbeitungs- und Auskunftssystem

  • The 3rd cooperative BGR/SMNG Arctic cruise was designed to acquire new scietific data for a better understanding of temporal and spatial lithospheric variations during rifting and its influence on the tectonic and structural evolution of the continental crust of the Laptev Sea undergoing extension since at least the Early Tertiary, and for tackling open questions regarding the evolution of the submarine permafrost zone. Although conditions for seismic measurements were worse in 1997 than in 1993 and 1994, along 4,622 km of seismic traverses reflection seismic data and wide angle reflection/refraction data from 23 OBH-(ocean bottom hydrophone) stations were collected in the Laptev and East Siberian Sea. The most prominent rift basin is the Ust' Lena Rift, which is at least 300 km wide at latitude 75°N. The Cenozoic sedimentary cover exceeds 3 km everywhere, increasing up to 14 km at two locations. In the northern part of the shelf, the complex mainly N–S-trending Anisin Basin has a basin fill of up to 10 km thickness. The New Siberian Basin which is located in the northwestern part of the study area shows an up to 9 km thick graben fill. The Laptev Horst crust is locally subdivided into several tilted blocks by deep-reaching faults and there are several half grabens of smaller extent which divide the Laptev Horst into three parts: the North, the South and the East Laptev Horst. A major west dipping listric fault of at least 250 km length separates the Laptev Horst from the Ust' Lena Rift. Results from the seismological investigation indicate that recent extension is concentrated within the narrow rift basins of the eastern Laptev Sea. From wide-angle reflection/refraction seismic measurements the seismic velocities of the crustal layers were estimated along five profiles. The layers with velocities of up to 3.5 km/s apparently consist of predominantly Cenozoic sediments. The sedimentary section showing relatively high seismic velocities of 4.5 to 5.2 km/s might be interpreted as Late Paleozoic to Mesozoic deposits or overcompacted/cemented syn-rift deposits. In the eastern shelf area a layer beneath the acoustic basement was interpreted to represent Ordovician to Early Mesozoic carbonates. The lower crust in the area under study shows relatively uniform seismic velocities of about 6.0-6.8 km/s and the velocities estimated for the crust-mantle transition are in the range of 8.0 to 8.2 km/s. The origin of a several 100 m thick layer with a relative high velocity of 3 to 3.5 km/s directly beneath the seafloor was inferred as sub-sea permafrost.

  • The multidisciplinary marine geoscientific expedition ARK-25/3 was focused on the Greenland part of northern Baffin Bay and was aimed to acquire new geoscientific data to be used for modelling the evolution of the Greenland continental margin and its hydrocarbon prospective. The data format is Society of Exploration Geophysicists SEG Y. The cruise was performed under the direction of the Federal Institute for Geosciences and Natural Resources Hannover in cooperation with the Alfred-Wegener-Institute for Polar and Marine Research, Bremerhaven. Using 70 days of ship time onboard the research icebreaker R/V POLARSTERN a comprehensive data set was acquired along profiles extending from the deep oceanic basin in the central part of North Baffin Bay onto the Greenland continental margin in an area which was bordered by the Kane Basin in the North and Disko Island in the South. By means of multi-channel seismic, wide angle seismic, gravimetric and magnetic methods the structural inventory of the crust in the NW Baffin Bay was investigated. Additionally, heat flow data and sediment cores were collected along lines crossing the Greenland continental margin. The cores were extracted for geochemical and geomicrobiological analysis to be used for basin modelling, studying the hydrocarbon potential, and the hydrocarbon degradation by microorganisms under polar conditions. Geological sampling in the coastal area was done between Melville Bay and Washington Land. The collected rock material will be used to derive constraints on the erosion history of the coastal area. Aeromagnetic data was acquired covering a substantial part of the marine survey area to investigate magnetic signatures of the oceanic crust and the continental margin. This report summarizes the working programme and contains the documentation of acquired data and first results of the expedition.

  • In May/June 2001, as part of the expedition NARES I, an aeromagnetic survey was carried out in the area of the eastern Kane Basin in cooperation with the Canadian GSC, in addition to the survey over the Robeson Channel and parallel to marine geophysical investigations with the Canadian icebreaker Louis S. St. Laurent. Another survey, NARES II, was conducted from Alexandra Fiord in 2003 and covered coastal areas of Ellesmere Island and the western Kane Basin. The aim of the research was to detect and localize the Wegener Fault, a transform fault between Ellesmere Island and NW Greenland, which is closely linked to the opening of the North Atlantic and the Arctic Ocean. The helicopter-borne magnetic surveys NARES I + II (Kane Basin) were carried out with a flight line spacing of 2 km, and control profiles were flown every 10 km. During the two expeditions, 11806 km of line data were collected (3573 km in 2001, and 8333 km in 2003), covering an area of approximately 20000 km². The aeromagnetic data were recorded by a magnetometer, which was towed approx. 25 m beneath the helicopter.

  • Regarding the use of renewable energy and the reduction of greenhouse-gas emissions, the geological storage of fluids is of particular interest. Therefore, reservoir and barrier formations in the German North Sea come into focus. Due to the widespread distribution of storage and barrier rocks at suitable depths and in combination with a relatively low tectonic overprint, the West Schleswig Block region in the German North Sea shows a high prospectivity for CO2 storage. By means of this high-resolution 2D reflection seismic survey, we want to investigate the potential impairment of geological barriers at the top of geological storage formations (i.e. claystones/mudstones and salt of the Upper Buntsandstein, mudstone dominated formations of the Lower Cretaceous and of the Tertiary). The seismic acquisition setup with a 2400 m active streamer cable with 384 channels will allow a precise image of near-surface structures, such as Quaternary channels, seismic pipe structures, chimneys, polygonal fault systems and crestal faults. In the time period between Nov. 13th and Nov. 24th we acquired 32 lines 2D seismic reflection data (about 1500 km in total) in combination with gravity data, multibeam data and sediment echosounder data. The seismic data resolve the sediments from the seafloor down to the base of the Zechstein. With the acquired data, the sediments of the Mesozoic and Cenozoic up to the seafloor (2-3 seconds of twoway-traveltime) will be imaged in high-resolution for the first time. The imaged fault systems will be investigated regarding their ability to build seal bypass systems. In addition, we acquired seismic data across the Figge Maar blowout crater and we intend to compare these data with the seismic data from the West Schleswig Block.

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