TY  - JOUR
A1  - Rößler, Dirk
A1  - Rumpker, Georg
A1  - Krüger, Frank
T1  - Ambiguous moment tensors and radiation patterns in anisotropic media with applications to the modeling of earthquake mechanisms in W-Bohemia
N2  - Anisotropic material properties are usually neglected during inversions for source parameters of earthquakes. In general anisotropic media, however, moment tensors for pure-shear sources can exhibit significant non-double-couple components. Such effects may be erroneously interpreted as an indication for volumetric changes at the source. Here we investigate effects of anisotropy on seismic moment tensors and radiation patterns for pure-shear and tensile-type sources. Anisotropy can significantly influence the interpretation of the source mechanisms. For example, the orientation of the slip within the fault plane may affect the total seismic moment. Also, moment tensors due to pure- shear and tensile faulting can have similar characteristics depending on the orientation of the elastic tensor. Furthermore, the tensile nature of an earthquake can be obscured by near-source anisotropic properties. As an application, we consider effects of inhomogeneous anisotropic properties on the seismic moment tensor and the radiation patterns of a selected type of micro-earthquakes observed in W-Bohemia. The combined effects of near-source and along- path anisotropy cause characteristic amplitude distortions of the P, S1 and S2 waves. However, the modeling suggests that neither homogeneous nor inhomogeneous anisotropic properties alone can explain the observed large non-double-couple components. The results also indicate that a correct analysis of the source mechanism, in principle, is achievable by application of anisotropic moment tensor inversion
Y1  - 2004
SN  - 0039-3169
ER  - 
TY  - JOUR
A1  - Mohsen, Amjad
A1  - Hofstetter, Rami
A1  - Bock, Günter
A1  - Kind, Rainer
A1  - Weber, Michael H.
A1  - Wylegalla, Kurt
A1  - Rumpker, Georg
T1  - A receiver function study across the Dead Sea Transform
N2  - We report on a receiver function study of the crust and upper mantle within DESERT, a multidisciplinary geophysical project to study the lithosphere across the Dead Sea Transform (DST). A temporary seismic network was operated on both sides of the DST between 2000 April and 2001 June. The depth of the Moho increases smoothly from about 30 to 34-38 km towards the east across the DST, with significant north-south variations east of the DST. These Moho depth estimates from receiver functions are consistent with results from steep-and wide-angle controlled-source techniques. Steep-angle reflections and receiver functions reveal an additional discontinuity in the lower crust, but only east of the DST. This leads to the conclusion that the internal crustal structure east and west of the DST is different. The P to S converted phases from both discontinuities at 410 and 660 km are delayed by 2 s with respect to the IASP91 global reference model. This would indicate that the transition zone is consistent with the global average, but the upper mantle above 410 km is 3-4 per cent slower than the standard earth model
Y1  - 2005
SN  - 0956-540X
ER  - 
TY  - JOUR
A1  - Mechie, James
A1  - Abu-Ayyash, Khalil
A1  - Ben-Avraham, Zvi
A1  - El-Kelani, R.
A1  - Mohsen, Amjad
A1  - Rumpker, Georg
A1  - Saul, J.
A1  - Weber, Michael H.
T1  - Crustal shear velocity structure across the Dead Sea Transform from two-dimensional modelling of DESERT project explosion seismic data
N2  - An analysis of the shear (S) waves recorded during the wide-angle reflection/refraction (WRR) experiment as part of the DESERT project crossing the Dead Sea Transform (DST) reveals average crustal S-wave velocities of 3.3-3.5 km s(-1) beneath the WRR profile. Together with average crustal P-wave velocities of 5.8-6.1 km s(-1) from an already published study this provides average crustal Poisson's ratios of 0.26-0.27 (V-p/V-s = 1.76-1.78) below the profile. The top two layers consisting predominantly of sedimentary rocks have S- wave velocities of 1.8-2.7kms(-1) and Poisson's ratios of 0.25-0.31 (V-p/V-s = 1.73-1.91). Beneath these two layers the seismic basement has average S- wave velocities of around 3.6 km s(-1) east of the DST and about 3.7 km s(-1) west of the DST and Poisson's ratios of 0.24-0.25 (V-p/V-s = 1.71-1.73). The lower crust has an average S-wave velocity of about 3.75 km s(-1) and an average Poisson's ratio of around 0.27 (V-p/V-s = 1.78). No Sn phase refracted through the uppermost mantle was observed. The results provide for the first time information from controlled source data on the crustal S-wave velocity structure for the region west of the DST in Israel and Palestine and agree with earlier results for the region east of the DST in the Jordanian highlands. A shear wave splitting study using SKS waves has found evidence for crustal anisotropy beneath the WRR profile while a receiver function study has found evidence for a lower crustal, high S-wave velocity layer east of the DST below the profile. Although no evidence was found in the S-wave data for either feature, the S-wave data are not incompatible with crustal anisotropy being present as the WRR profile only lies 30 degrees off the proposed symmetry axis of the anisotropy where the difference in the two S-wave velocities is still very small. In the case of the lower crustal, high S-wave velocity layer, if the velocity change at the top of this layer comprises a small first-order discontinuity underlain by a 2 km thick transition zone, instead of just a large first-order discontinuity, then both the receiver function data and the WRR data presented here can be satisfied. Finally, the S-wave velocities and Poisson's ratios which have been derived in this study are typical of continental crust and do not require extensional processes to explain them
Y1  - 2005
ER  - 
TY  - JOUR
A1  - Hetenyi, Gyorgy
A1  - Molinari, Irene
A1  - Clinton, John
A1  - Bokelmann, Gotz
A1  - Bondar, Istvan
A1  - Crawford, Wayne C.
A1  - Dessa, Jean-Xavier
A1  - Doubre, Cecile
A1  - Friederich, Wolfgang
A1  - Fuchs, Florian
A1  - Giardini, Domenico
A1  - Graczer, Zoltan
A1  - Handy, Mark R.
A1  - Herak, Marijan
A1  - Jia, Yan
A1  - Kissling, Edi
A1  - Kopp, Heidrun
A1  - Korn, Michael
A1  - Margheriti, Lucia
A1  - Meier, Thomas
A1  - Mucciarelli, Marco
A1  - Paul, Anne
A1  - Pesaresi, Damiano
A1  - Piromallo, Claudia
A1  - Plenefisch, Thomas
A1  - Plomerova, Jaroslava
A1  - Ritter, Joachim
A1  - Rumpker, Georg
A1  - Sipka, Vesna
A1  - Spallarossa, Daniele
A1  - Thomas, Christine
A1  - Tilmann, Frederik
A1  - Wassermann, Joachim
A1  - Weber, Michael
A1  - Weber, Zoltan
A1  - Wesztergom, Viktor
A1  - Zivcic, Mladen
A1  - Abreu, Rafael
A1  - Allegretti, Ivo
A1  - Apoloner, Maria-Theresia
A1  - Aubert, Coralie
A1  - Besancon, Simon
A1  - de Berc, Maxime Bes
A1  - Brunel, Didier
A1  - Capello, Marco
A1  - Carman, Martina
A1  - Cavaliere, Adriano
A1  - Cheze, Jerome
A1  - Chiarabba, Claudio
A1  - Cougoulat, Glenn
A1  - Cristiano, Luigia
A1  - Czifra, Tibor
A1  - Danesi, Stefania
A1  - Daniel, Romuald
A1  - Dannowski, Anke
A1  - Dasovic, Iva
A1  - Deschamps, Anne
A1  - Egdorf, Sven
A1  - Fiket, Tomislav
A1  - Fischer, Kasper
A1  - Funke, Sigward
A1  - Govoni, Aladino
A1  - Groschl, Gidera
A1  - Heimers, Stefan
A1  - Heit, Ben
A1  - Herak, Davorka
A1  - Huber, Johann
A1  - Jaric, Dejan
A1  - Jedlicka, Petr
A1  - Jund, Helene
A1  - Klingen, Stefan
A1  - Klotz, Bernhard
A1  - Kolinsky, Petr
A1  - Kotek, Josef
A1  - Kuhne, Lothar
A1  - Kuk, Kreso
A1  - Lange, Dietrich
A1  - Loos, Jurgen
A1  - Lovati, Sara
A1  - Malengros, Deny
A1  - Maron, Christophe
A1  - Martin, Xavier
A1  - Massa, Marco
A1  - Mazzarini, Francesco
A1  - Metral, Laurent
A1  - Moretti, Milena
A1  - Munzarova, Helena
A1  - Nardi, Anna
A1  - Pahor, Jurij
A1  - Pequegnat, Catherine
A1  - Petersen, Florian
A1  - Piccinini, Davide
A1  - Pondrelli, Silvia
A1  - Prevolnik, Snjezan
A1  - Racine, Roman
A1  - Regnier, Marc
A1  - Reiss, Miriam
A1  - Salimbeni, Simone
A1  - Santulin, Marco
A1  - Scherer, Werner
A1  - Schippkus, Sven
A1  - Schulte-Kortnack, Detlef
A1  - Solarino, Stefano
A1  - Spieker, Kathrin
A1  - Stipcevic, Josip
A1  - Strollo, Angelo
A1  - Sule, Balint
A1  - Szanyi, Gyongyver
A1  - Szucs, Eszter
A1  - Thorwart, Martin
A1  - Ueding, Stefan
A1  - Vallocchia, Massimiliano
A1  - Vecsey, Ludek
A1  - Voigt, Rene
A1  - Weidle, Christian
A1  - Weyland, Gauthier
A1  - Wiemer, Stefan
A1  - Wolf, Felix
A1  - Wolyniec, David
A1  - Zieke, Thomas
T1  - The AlpArray seismic network
BT  - a large-scale european experiment to image the alpine orogen
JF  - Surveys in Geophysics
N2  - The AlpArray programme is a multinational, European consortium to advance our understanding of orogenesis and its relationship to mantle dynamics, plate reorganizations, surface processes and seismic hazard in the Alps-Apennines-Carpathians-Dinarides orogenic system. The AlpArray Seismic Network has been deployed with contributions from 36 institutions from 11 countries to map physical properties of the lithosphere and asthenosphere in 3D and thus to obtain new, high-resolution geophysical images of structures from the surface down to the base of the mantle transition zone. With over 600 broadband stations operated for 2 years, this seismic experiment is one of the largest simultaneously operated seismological networks in the academic domain, employing hexagonal coverage with station spacing at less than 52 km. This dense and regularly spaced experiment is made possible by the coordinated coeval deployment of temporary stations from numerous national pools, including ocean-bottom seismometers, which were funded by different national agencies. They combine with permanent networks, which also required the cooperation of many different operators. Together these stations ultimately fill coverage gaps. Following a short overview of previous large-scale seismological experiments in the Alpine region, we here present the goals, construction, deployment, characteristics and data management of the AlpArray Seismic Network, which will provide data that is expected to be unprecedented in quality to image the complex Alpine mountains at depth.
KW  - Seismology
KW  - Alps
KW  - Seismic network
KW  - Geodynamics
KW  - Seismic imaging
KW  - Mountain building
Y1  - 2018
U6  - https://doi.org/10.1007/s10712-018-9472-4
SN  - 0169-3298
SN  - 1573-0956
VL  - 39
IS  - 5
SP  - 1009
EP  - 1033
PB  - Springer
CY  - Dordrecht
ER  -