Appropriate regularizations of geophysical inverse problems and joint inversion different data types improve models increase their usefulness in hydrogeological studies. We have developed an efficient method to calculate stochastic regularization operators for given geostatistical models. The method, which combines circulant embedding the diagonalization theorem matrices, is applicable stationary when grid discretization, each spatial direction, uniform volume interest. also used a...

Using local earthquakes and explosions recorded on the 3-D seismic network operating in Southwest Iceland, velocity structure has been modelled to depths of 10–15 km. The tomography algorithm simultaneously inverts for both P- S-wave velocities hypocentral locations. Major tectonic features within 224 × 112 km2 rectangular study region include South Iceland Seismic Zone, Hengill volcanic system Reykjanes Volcanic Zone. Reduced from surface as deep we can resolve, or about 9 km, are...

In seismic tomography, the LSQR algorithm is commonly used for solving inverse problem. belongs to family of conjugate gradient methods, so generalized not solved explicitly. Consequently, neither covariance nor resolution matrix are provided by LSQR, which limits one's ability obtain estimates uncertainty and errors in computed models. this paper we present a method, demonstrated synthetic examples, calculating matrices via general LSQR. The extra computational effort limited only few lines...

The structural approach to joint inversion, entailing common boundaries or gradients, offers a flexible and effective way invert diverse types of surface-based and/or crosshole geophysical data. cross-gradients function has been introduced as means construct models in which spatial changes two distinct physical-property are parallel antiparallel. Inversion methods that use such constraints also provide estimates nonlinear nonunique field-scale relationships between model parameters. Here, we...

The Kristineberg mining area in the western part of Paleoproterozoic Skellefte Ore District, northern Sweden, is well known for its base-metal and recent gold discoveries. A pilot 3D geologic model has been constructed on a crustal scale, covering an [Formula: see text] to depths text]. Constrained inverse forward gravity modeling have performed confirm refine previous along seismic profiles using mainly 2.5D techniques. was geared generating isodensity surfaces that enclose regions within...

Geological storage of CO2 is one means mitigating the effects continued burning fossil fuels for power generation. An important component in concept monitoring distribution at depth. Seismic methods can play a significant role this monitoring, particular cross-well are interest due to their high resolution. For these purposes, series seismic surveys were acquired within framework CO2SINK project Ketzin, Germany, various stages an injection test. We study here potential applying waveform...

In local earthquake (LE) tomography for P‐ and S‐wave velocities (or Vp/Vs ratios), constraints punishing deviations from a given ratio are often used. synthetic model test we demonstrate that though such inhibit unreasonable variations, they bias the resulting ratios. As an alternative approach, structural based on cross‐product of gradients can be used to constrain joint inversion. We show models as low in artifacts if damping was used, but ratios less biased, which is important...

A recent seismic refraction study across southern Norway has revealed that the up to 2469 m high Southern Scandes Mountains are not isostatically compensated by a thick crust. Rather, Moho depths close average for continental crust with elevations of similar 1 km. Evidence from new data indicate beneath highest topography around 38-40 These measurements 2 km deeper than early estimates interpolated coarsely spaced profiles, but 3 shallower Receiver Function area. depth variation mountains...

At 155 km, the Pärvie fault is world's longest known endglacial (EGF). It located in northernmost Sweden a region where several kilometre-scale EGFs have been identified. Based on studies of Quaternary deposits, landslides and liquefaction structures, these faults are inferred to ruptured as large earthquakes when latest ice sheet disappeared from region, some 9500 yr ago. The still exhibit relatively high seismic activity, here we present new earthquake data northern general particular....

Abstract The Reykjanes Peninsula (RP) hosts several volcanic lineaments that have been periodically active over the last 4000 years. Since 2021, following a ca. 800‐year quiescence, eight eruptions occurred on RP, with more expected in future. To better understand origins of this renewed volcanism and help forecast future eruptions, we examine (i) if ongoing is fed from single or multiple magma storage zone(s) smaller reservoirs and; (ii) where are located (i.e. mantle lower upper crustal...

Abstract The 2014–2015 Holuhraun eruption on Iceland was located within the Askja fissure swarm but accompanied by caldera subsidence in Bárðarbunga central volcano 45 km to southwest. Geophysical monitoring of identified a seismic that migrated from site over course two weeks. In order better understand this lateral connection between and Holuhraun, we present mineral textures compositions, mineral‐melt‐equilibrium calculations, whole rock trace element data, oxygen isotope ratios for...

We have found that the extensively used finite difference scheme time3d produces time fields which are 'asymmetric' in sense traveltimes computed to right of source faster than left. All schemes will, as they approximations wave equation, some extent fail obey reciprocity perfectly. show, however, errors may be significant—and unnecessarily large. An asymmetry point initialization has been identified, and after correction with an improved reciprocity.

A 3D reflection seismic survey was performed in 2005 at the Ketzin carbon dioxide [Formula: see text] pilot geological-storage site (the project) near Berlin, Germany, to image geological structure of depths about text]. Because acquisition geometry, frequency limitations source, and artefacts data processing, detailed structures shallower than were unclear. To obtain structural images shallow subsurface, we applied traveltime tomography top anticline, where faulting is present....

A complex sequence of earthquakes struck the western part South Iceland Seismic Zone (SISZ) on 29 May 2008. The initiated with a M w 6.3 (NEIC) earthquake in SISZ. Aftershocks from delineate two parallel N–S trending structures 4 km apart, addition to activity along an E‐W zone further westward. Continuous GPS measurements can best be explained by right‐lateral strike‐slip motion faults, little slip occurring other illuminated activity. We estimate total moment release 6.2, 6.1 first rupture...

Abstract Understanding how monogenetic volcanic systems work requires full comprehension of the local and regional stresses that govern magma migration inside them why/how they seem to change from one eruption another. During 2011–2012 El Hierro (Canary Islands) characteristics unrest, including a continuous in location seismicity, made future vent unpredictable, so short term hazard assessment was highly imprecise. A 3D P-wave velocity model is obtained using arrival times earthquakes...

A major obstacle in tomographic inversion is near‐surface velocity variations. Such shallow variations need to be known and correctly accounted for obtain images of deeper structures with high resolution quality. Bedrock cover many areas consists unconsolidated sediments glacial till. To handle the problems associated this cover, we present a method that solves 3D structure receiver static corrections simultaneously. We test on first‐arrival picks from deep seismic reflection data acquired...

The Skellefte district forms part of the Svecofennian ca. 1.90 to 1.80 Ga, supracrustal sequence and associated intrusive rocks in northern Sweden. western district, which is most important metallogenic province Sweden today, hosts major volcanic-hosted massive sulfide (VHMS) deposits (e.g., 23 million metric tons (Mt) Kristineberg Cu-Zn-Pb-Ag-Au deposit). In order obtain a better understanding VHMS ore potential at depth, new seismic reflection data were acquired along two parallel...