A5003304953- Geophysical and Geoelectrical Methods
- Geological and Geophysical Studies
- Geophysical Methods and Applications
- Seismic Waves and Analysis
- earthquake and tectonic studies
- Seismic Imaging and Inversion Techniques
- Earthquake Detection and Analysis
- Geochemistry and Geologic Mapping
- Geological Studies and Exploration
- Geomagnetism and Paleomagnetism Studies
- NMR spectroscopy and applications
- Geological and Tectonic Studies in Latin America
- Reservoir Engineering and Simulation Methods
- Marine and environmental studies
- Hydrocarbon exploration and reservoir analysis
- Seismology and Earthquake Studies
- Methane Hydrates and Related Phenomena
- Geological and Geochemical Analysis
- Nonlinear Waves and Solitons
- Geological Modeling and Analysis
- Geological formations and processes
- Geophysics and Gravity Measurements
- CO2 Sequestration and Geologic Interactions
- Quantum chaos and dynamical systems
- Non-Destructive Testing Techniques
GFZ Helmholtz Centre for Geosciences
2011-2022
Freie Universität Berlin
1989-2022
Reservoir Labs (United States)
2021-2022
Time Domain (United States)
2021
Geomechanica (Canada)
2019-2020
Institute of Seismology
2018-2020
Alexion Pharma (Switzerland)
2019
Lufthansa (Germany)
2018
Centre de Géosciences
2018
Geriatrische Gesundheitszentren
2016
For 3-D inversion of controlled-source electromagnetic (CSEM) data, increasing availability high-performance computers enables us to apply techniques that are theoretically favourable, yet have previously been considered be computationally too demanding. We present a newly developed parallel distributed algorithm for interpreting CSEM data in the frequency domain. Our scheme is based on direct forward solver and uses Gauss–Newton minimization with explicit formation Jacobian. This...
3-D inversion techniques have become a widely used tool in magnetotelluric (MT) data interpretation. However, with real sets, many of the controlling factors for outcome are little explored, such as alignment coordinate system, handling and influence errors model regularization. Here we present results 169 MT sites from central San Andreas Fault California. Previous extensive 2-D forward modelling set revealed significant along-strike variation electrical conductivity structure. can recover...
Magnetotelluric (MT) response function estimates can be severely disturbed by the effects of cultural noise. Methods to isolate and remove these disturbances are typically based on time-series editing, robust statistics, remote reference processing, or some combination above. Robust processing improve data quality at a local site, but only if synchronous recordings least one additional site available electromagnetic noise between sites is uncorrelated. If prerequisites not met, we suggest an...
To address one of the central questions plate tectonics—How do large transform systems work and what are their typical features?—seismic investigations across Dead Sea Transform (DST), boundary between African Arabian plates in Middle East, were conducted for first time. A major component these was a combined reflection/refraction survey territories Palestine, Israel Jordan. The main results this study are: (1) seismic basement is offset by 3–5 km under DST, (2) DST cuts through entire...
We evaluated 3D inversion of land controlled-source electromagnetic (CSEM) data collected across the Ketzin [Formula: see text] storage formation. A newly developed, parallel and distributed code, which is based on a direct forward solver, has been used. This scheme allowed us to calculate Jacobian matrix explicitly within reasonable time use it regularization parameters, inspect survey coverage, carry out resolution analysis. After demonstrating that magnetic field components are sensitive...
ABSTRACT To advance and optimize secondary tertiary oil recovery techniques, it is essential to know the areal propagation distribution of injected fluids in subsurface. We investigate applicability controlled‐source electromagnetic methods monitor fluid movements a German oilfield (Bockstedt, onshore Northwest Germany) as brines (highly saline formation water) have much lower electrical resistivity than within reservoir. The main focus this study on simulations test sensitivity various...
Robust estimates of magnetotelluric and geomagnetic response functions are determined using the coherency expected uniformity magnetic source field as quality criteria. The method is applied on data sets three simultaneously recording sites. For acquisition we used a new generation geophysical equipment (S.P.A.M. MkIII), which comprises novel concepts parallel computing networked, digital transmission. data-processing results show that amount noise horizontal components varies considerably...
Magnetotelluric (MT) data from 66 sites along a 45-km-long profile across the San Andreas Fault (SAF) were inverted to obtain 2-D electrical resistivity structure of crust near Observatory at Depth (SAFOD). The most intriguing feature model is steeply dipping upper crustal high-conductivity zone flanking seismically defined SAF NE, that widens into lower and appears be connected broad conductivity anomaly in mantle. Hypothesis tests inversion suggest upper-mantle anomalies may...
Magnetotelluric and seismic methods provide complementary information about the resistivity velocity structure of subsurface on similar scales resolutions. No global relation, however, exists between these parameters, correlations are often valid for only a limited target area. Independently derived inverse models from can be combined using classification approach to map geologic structure. The method employed is based solely statistical correlation physical properties in joint parameter...
Fault zones are the locations where motion of tectonic plates, often associated with earthquakes, is accommodated. Despite a rapid increase in understanding faults last decades, our knowledge their geometry, petrophysical properties, and controlling processes remains incomplete. The central questions addressed here study Dead Sea Transform (DST) Middle East as follows: (1) What structure kinematics large fault zone? (2) controls its kinematics? (3) How does DST compare to other plate...
Whereas robust processing techniques are routinely used for estimating high-quality magnetotelluric (MT) transfer functions, such not commonly applied controlled-source electromagnetic (CSEM) processing, although CSEM and MT data suffer from similar noise. We implemented a new scheme that combines CSEM-specific preprocessing with statistically least-squares stacking to extract interpretable ground responses very noisy onshore data. the signals transmitter was equipped three grounded...
We present the crustal resistivity structure of Pamir and Southern Tian Shan orogenic belts at northwestern promontory India–Asia collision zone. The magnetotelluric (MT) data were recorded along a roughly north–south trending, 350 km long corridor from Plateau in southern Tajikistan across frontal ranges, Alai Valley southwestern to Osh Kyrgyz part Fergana Basin. In total, we measured 178 sites, whereof 26 combine broad band period recordings. One most intriguing features 2-D 3-D inversion...
Abstract We present a model of the electrical resistivity structure lithosphere in Central Andes between 20° and 24°S from 3‐D inversion 56 long‐period magnetotelluric sites. Our shows complex with significant variability parallel perpendicular to trench direction. The continental forearc is characterized mainly by high (>1,000 Ωm), suggesting overall low volumes fluids. However, zones (LRZs, <5 Ωm) were found below areas where major trench‐parallel faults systems intersect NW‐SE...
Abstract We compare recent magnetotelluric investigations of four large fault systems: (i) the actively deforming, ocean-continent interplate San Andreas Fault (SAF); (ii) continent-continent Dead Sea Transform (DST); (iii) currently inactive, trench-linked intraplate West (WF) in northern Chile; and (iv) Waterberg Fault/Omaruru Lineament (WF/OL) Namibia, a fossilized shear zone formed during early Proterozoic continental collision. These zones show both similarities marked differences their...
With advancing computational resources, 3-D inversion techniques have become feasible in recent years and are now a more widely used tool for magnetotelluric (MT) data interpretation.Galvanic distortion caused by small-scale near-surface inhomogeneities remains an obstacle MT which so far has experienced little attention.If not considered properly, the effect on can be immense result erroneous subsurface models interpretations.To tackle problem we implemented of distortion-free phase tensor...
Over the last decades, electromagnetic methods have become an accepted tool for a wide range of geophysical exploration purposes and nowadays even monitoring. Application to hydrocarbon monitoring, example enhanced oil recovery, is hampered by steel-cased wells, which typically exist in large numbers producing fields distort subsurface. Steel casings complex geometries as they are very thin but vertically extended; moreover, conductivity contrast steel natural materials six orders magnitude....
High‐resolutionseismictomography and magneto‐telluric (MT) soundings of the shallow crust show strong changes in material properties across Dead Sea Transform Fault (DST) Arava valley Jordan. 2D inversion results MT data indicate that DST is associated with a lateral conductivity contrast highly conductive layer at depth approximately 1.5 km cut‐off position coinciding surface trace DST. At same location, we observe sharp increase P wave velocities from <4 km/s west fault to >5 east....
Magnetotelluric (MT) responses in complex, 3-D terrains are general characterized by (i) elliptical polarization states of horizontal electric and magnetic fields; (ii) the non-orthogonality fields (iii) a coupling anomalous tangential-electric (TE) tangential-magnetic (TM) modes, giving rise to mode-mixed field at surface. These effects propagated into MT impedance tensor, which is derived from fields, recorded earth's The 2 × tensor fully occupied, each its elements quantity. To study...
Research Article| September 01, 2007 The Whitehill Formation – a high conductivity marker horizon in the Karoo Basin Thomas Branch; Branch GeoForschungsZentrum Potsdam, Telegrafenberg, 14473 Germany AEON-Africa Earth Observatory Network and Department of Geological Sciences, University Cape Town, Rondebosch 7700, South Africa., e-mail: tbranch@geology.uct.ac.za Search for other works by this author on: GSW Google Scholar Oliver Ritter; Ritter Germany, oritter@gfz-pozsdam.de (corresponding...