@article{HenschDahmRitteretal.2019, author = {Hensch, Martin and Dahm, Torsten and Ritter, Joachim and Heimann, Sebastian and Schmidt, Bernd and Stange, Stefan and Lehmann, Klaus}, title = {Deep low-frequency earthquakes reveal ongoing magmatic recharge beneath Laacher See Volcano (Eifel, Germany)}, series = {Geophysical journal international}, volume = {216}, journal = {Geophysical journal international}, number = {3}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0956-540X}, doi = {10.1093/gji/ggy532}, pages = {2025 -- 2036}, year = {2019}, abstract = {The occurrence of deep low-frequency (DLF) microearthquakes beneath volcanoes is commonly attributed to mass transport in the volcanic plumbing system and used to infer feeding channels from and into magma reservoirs. The key question is how magmas migrate from depth to the shallow crust and whether magma reservoirs are currently being recharged. For the first time since the improvement of the local seismic networks in the East Eifel region (Rhineland-Palatinate, Germany), we detect and locate recurrent DLF earthquakes in the lower crust and upper mantle beneath the Laacher See Volcano (LSV), using a joint data set of permanent sensors and a temporary deployment. So far, eight DLF earthquake sequences were observed in four distinct clusters between 10 and 40 km depth. These clusters of weak events (M-L< 2) align along an approximately 80. southeast dipping line south of the LSV. Moment tensor solutions of these events have large shear components, and the irregular dispersion and long coda of body waves indicate interaction processes between shear cracks and fluids. We find a rotation of P-axes orientation for shallow tectonic earthquakes compared to DLF events, indicating that the stress field in the depth interval of DLF events might favour a vertical migration of magma or magmatic fluids. The caldera of the LSV was formed by the last major eruption of the East Eifel Volcanic Field only 12.9 kyr ago, fed by a shallow magma chamber at 5-8 km depth and erupting a total magma volume of 6.7 km(3). The observed DLF earthquake activity and continuous volcanic gas emissions around the LSV indicate an active magmatic system, possibly connected with an upper mantle melt zone.}, language = {en} } @misc{HetenyiMolinariClintonetal.2018, author = {Hetenyi, Gyorgy and Molinari, Irene and Clinton, John and Bokelmann, Gotz and Bondar, Istvan and Crawford, Wayne C. and Dessa, Jean-Xavier and Doubre, Cecile and Friederich, Wolfgang and Fuchs, Florian and Giardini, Domenico and Graczer, Zoltan and Handy, Mark R. and Herak, Marijan and Jia, Yan and Kissling, Edi and Kopp, Heidrun and Korn, Michael and Margheriti, Lucia and Meier, Thomas and Mucciarelli, Marco and Paul, Anne and Pesaresi, Damiano and Piromallo, Claudia and Plenefisch, Thomas and Plomerova, Jaroslava and Ritter, Joachim and Rumpker, Georg and Sipka, Vesna and Spallarossa, Daniele and Thomas, Christine and Tilmann, Frederik and Wassermann, Joachim and Weber, Michael and Weber, Zoltan and Wesztergom, Viktor and Zivcic, Mladen and Abreu, Rafael and Allegretti, Ivo and Apoloner, Maria-Theresia and Aubert, Coralie and Besancon, Simon and de Berc, Maxime Bes and Brunel, Didier and Capello, Marco and Carman, Martina and Cavaliere, Adriano and Cheze, Jerome and Chiarabba, Claudio and Cougoulat, Glenn and Cristiano, Luigia and Czifra, Tibor and Danesi, Stefania and Daniel, Romuald and Dannowski, Anke and Dasovic, Iva and Deschamps, Anne and Egdorf, Sven and Fiket, Tomislav and Fischer, Kasper and Funke, Sigward and Govoni, Aladino and Groschl, Gidera and Heimers, Stefan and Heit, Ben and Herak, Davorka and Huber, Johann and Jaric, Dejan and Jedlicka, Petr and Jund, Helene and Klingen, Stefan and Klotz, Bernhard and Kolinsky, Petr and Kotek, Josef and Kuhne, Lothar and Kuk, Kreso and Lange, Dietrich and Loos, Jurgen and Lovati, Sara and Malengros, Deny and Maron, Christophe and Martin, Xavier and Massa, Marco and Mazzarini, Francesco and Metral, Laurent and Moretti, Milena and Munzarova, Helena and Nardi, Anna and Pahor, Jurij and Pequegnat, Catherine and Petersen, Florian and Piccinini, Davide and Pondrelli, Silvia and Prevolnik, Snjezan and Racine, Roman and Regnier, Marc and Reiss, Miriam and Salimbeni, Simone and Santulin, Marco and Scherer, Werner and Schippkus, Sven and Schulte-Kortnack, Detlef and Solarino, Stefano and Spieker, Kathrin and Stipcevic, Josip and Strollo, Angelo and Sule, Balint and Szanyi, Gyongyver and Szucs, Eszter and Thorwart, Martin and Ueding, Stefan and Vallocchia, Massimiliano and Vecsey, Ludek and Voigt, Rene and Weidle, Christian and Weyland, Gauthier and Wiemer, Stefan and Wolf, Felix and Wolyniec, David and Zieke, Thomas}, title = {The AlpArray seismic network}, series = {Surveys in Geophysics}, volume = {39}, journal = {Surveys in Geophysics}, number = {5}, publisher = {Springer}, address = {Dordrecht}, organization = {ETHZ SED Elect Lab AlpArray Seismic Network Team AlpArray OBS Cruise Crew AlpArray Working Grp}, issn = {0169-3298}, doi = {10.1007/s10712-018-9472-4}, pages = {1009 -- 1033}, year = {2018}, abstract = {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.}, language = {en} }