We investigate the parallel performance of an iterative solver for 3D heterogeneous Helmholtz problems related to applications in seismic wave propagation. For large 3D problems, the computation is no longer feasible on a single processor, and the memory requirements increase rapidly. Therefore, parallelization of the solver is needed. We employ a complex shifted-Laplace preconditioner combined...

the study area covers the northern part of the baft geological map (scale of 1:100 000 ). several porphyry and vein-type mineralization are reported from this area. a topic that is discussed in the mineral exploration community is the use of remote sensing and airborne geophysics for porphyry type mineralization. which one is more reliable and efficient in hydrothermal alteration mapping? airbo...

S U M M A R Y Geophysical inversion is often ill-posed because of inaccurate and insufficient data. Regularization is often applied to the inversion problem to obtain a stable solution by imposing additional constraints on the model. Common regularization schemes impose isotropic smoothness on solutions and may have difficulties in obtaining geologically reasonable models that are often suppose...

In recent decades, decomposition techniques have enabled increasingly more applications for dimension reduction, as well as extraction of additional information from geophysical time series. Traditionally, the principal component analysis (PCA)/empirical orthogonal function (EOF) method and more recently the independent component analysis (ICA) have been applied to extract, statistical orthogon...

We propose a method for uncoherent noise removal in geophysical data. The Multiple Wavelet Stacking is based on a concurrent use of wavelet-based shrinkage and data and time-scale dependent threshold choice. Since one singular wavelet does not match all the time-varying properties of a signal, the simultaneous use of several wavelets is able to lower some shrinkage shortcomings, such as wavelet...

We present statistical and interval techniques for evaluating the uncertainties associated with geophysical tomographic inversion problems, including estimation of data errors, model errors, and total solution uncertainties. These techniques are applied to the inversion of traveltime data collected in a cross well seismic experiment. The inversion method uses the conjugate gradient technique, i...

Geophysical signals N of interest are often contained in a parent signal G that also contains a seasonal signal X at a known frequency fX. The general issues associated with identifying N and X and their separation from G are considered for the case where G is the Pacific sea surface temperature monthly data, SST3.4; N is the El Niño/La Niña phenomenon and the seasonal signal X is at a frequenc...

We present a method for measuring the characteristic length of sea ice based on fitting to a the recentlyfound solution for the flexural response of a floating ice sheet subject to localized periodic loading. Unlike previous techniques, the method enables localized measurements at single frequencies of geophysical interest and, since the measurements may be synchronously demodulated, gives exce...

[1] We develop a state-space Bayesian framework to combine time-lapse geophysical data with other types of information for quantitative estimation of biogeochemical parameters during bioremediation. We consider characteristics of end products of biogeochemical transformations as state vectors, which evolve under constraints of local environments through evolution equations, and consider time-la...