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Your search keyword '"Petersen, Florian"' showing total 3 results
Start Over Author "Petersen, Florian" Topic [sdu.stu.te]sciences of the universe [physics]/earth sciences/tectonics
3 results on '"Petersen, Florian"'

1. Basin inversion: reactivated rift structures in the central Ligurian Sea revealed using ocean bottom seismometers

Author

Thorwart, Martin, Dannowski, Anke, Grevemeyer, Ingo, Lange, Dietrich, Kopp, Heidrun, Petersen, Florian, Crawford, Wayne, Paul, Anne, The Alparray Working Group, Christian-Albrechts-Universität zu Kiel (CAU), Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut des Sciences de la Terre (ISTerre), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel-Université Grenoble Alpes (UGA), LOBSTER project that is part of the German Priority Programme SPP2017 4D-MB, ANR-15-CE31-0015,AlpArray-FR,Voir et comprendre les Alpes en 3D, de la croûte au manteau(2015), Institut de Physique du Globe de Paris (IPGP), and Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)

Subjects
010504 meteorology & atmospheric sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Stratigraphy, Inversion (geology), Soil Science, Induced seismicity, 010502 geochemistry & geophysics, 01 natural sciences, Mantle (geology), Geochemistry and Petrology, Thrust fault, 14. Life underwater, Compression (geology), ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Earth-Surface Processes, [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics, QE1-996.5, Rift, Continental crust, Paleontology, Crust, Geology, QE640-699, Geophysics, Seismology
Abstract

The northern margin of the Ligurian Basin shows notable seismicity at the Alpine front, including frequent magnitude 4 events. Seismicity decreases offshore towards the Basin centre and Corsica, revealing a diffuse distribution of low-magnitude earthquakes. We analyse data of the amphibious AlpArray seismic network with focus on the offshore component, the AlpArray ocean bottom seismometer (OBS) network, consisting of 24 broadband OBSs deployed for 8 months, to reveal the seismicity and depth distribution of micro-earthquakes beneath the Ligurian Sea. Two clusters occurred between ∼ 10 km to ∼ 16 km depth below the sea surface, within the lower crust and uppermost mantle. Thrust faulting focal mechanisms indicate compression and an inversion of the Ligurian Basin, which is an abandoned Oligocene–Miocene rift basin. The basin inversion is suggested to be related to the Africa–Europe plate convergence. The locations and focal mechanisms of seismicity suggest reactivation of pre-existing rift-related structures. Slightly different striking directions of presumed rift-related faults in the basin centre compared to faults further east and hence away from the rift basin may reflect the counter-clockwise rotation of the Corsica–Sardinia block. High mantle S-wave velocities and a low Vp/Vs ratio support the hypothesis of strengthening of crust and uppermost mantle during the Oligocene–Miocene rifting-related extension and thinning of continental crust.

Published
2021

2. Interseismic strain build-up on the submarine North Anatolian Fault offshore Istanbul

Author

Lange, Dietrich, Kopp, Heidrun, Royer, Jean-Yves, Henry, Pierre, Çakir, Ziyadin, Petersen, Florian, Sakic, Pierre, Ballu, Valerie, Bialas, Jörg, Özeren, Mehmet Sinan, Ergintav, Semih, Géli, Louis, GEOMAR - Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), Laboratoire Géosciences Océan (LGO), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Istanbul Technical University, GeoForschungsZentrum - Helmholtz-Zentrum Potsdam (GFZ), LIttoral ENvironnement et Sociétés - UMR 7266 (LIENSs), Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS), Eurasia Institute of Earth Sciences, Boğaziçi University [Istanbul], Institut Français de Recherche pour l'Exploitation de la Mer - Brest (IFREMER), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), ANR-16-CE03-0010,MAREGAMI2016,Caractérisation de la lacune sismique dans la région d'Istanbul(2016), Lange, Dietrich, Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), Université de Bretagne Sud (UBS)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Istanbul Technical University (ITÜ), LIttoral ENvironnement et Sociétés (LIENSs), La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS), Boǧaziçi üniversitesi = Boğaziçi University [Istanbul], BMBF (German Federal Ministry of Education and Research)Federal Ministry of Education & Research (BMBF) [03F0658I], bilateral ANR/TUBITAK collaborative research project MAREGAMI [ANR-16-CE03-0010-02], bilateral ANR/TUBITAK collaborative research project MAREGAMI (Tubitak Project) [116Y371], European UnionEuropean Union (EU), Brittany RegionRegion Bretagne, French government (CPER ODO), CNRS-INSU through the European Monitoring Seafloor Observatory programme (EMSO), Institut Français de Recherche pour l'Exploitation de la Mer - Brest (IFREMER Centre de Bretagne), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), and LIttoral ENvironnement et Sociétés - UMRi 7266 (LIENSs)

Subjects
[SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics, Geophysics, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Science, Natural hazards, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, lcsh:Q, lcsh:Science, earthquakes, subduction-zone, marmara sea region, Article, Seismology
Abstract

Using offshore geodetic observations, we show that a segment of the North Anatolian Fault in the central Sea of Marmara is locked and therefore accumulating strain. The strain accumulation along this fault segment was previously extrapolated from onshore observations or inferred from the absence of seismicity, but both methods could not distinguish between fully locked or fully creeping fault behavior. A network of acoustic transponders measured crustal deformation with mm-precision on the seafloor for 2.5 years and did not detect any significant fault displacement. Absence of deformation together with sparse seismicity monitored by ocean bottom seismometers indicates complete fault locking to at least 3 km depth and presumably into the crystalline basement. The slip-deficit of at least 4 m since the last known rupture in 1766 is equivalent to an earthquake of magnitude 7.1 to 7.4 in the Sea of Marmara offshore metropolitan Istanbul., The state of the Main Marmara Fault (fault segment of the North Anatolian Fault) is widely discussed, towards whether it is creeping or locked. The authors here present seafloor geodetic measurements which indicate a complete locking of the fault in the central part of the Sea of Marmara. This provides significant information for the assessment of both seismic and potential tsunami hazard to Istanbul.

Published
2019

3. No significant steady state surface creep along the North Anatolian Fault offshore Istanbul: Results of 6 months of seafloor acoustic ranging

Author

Sakic, Pierre, Piété, Helen, Ballu, Valerie, Royer, Jean-Yves, Kopp, Heidrunn, Lange, Dietrich, Petersen, Florian, Özeren, M. Sinan, Ergintav, Semih, Geli, Louis, Henry, Pierre, Deschamps, Anne, LIttoral ENvironnement et Sociétés - UMRi 7266 (LIENSs), Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS), Université de Brest (UBO), Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), Istanbul Technical University (ITÜ), Kandilli Observatory and Earthquake Research Institute (KOERI), Boǧaziçi üniversitesi = Boğaziçi University [Istanbul], Unité de recherche Géosciences Marines (Ifremer) (GM), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), LIttoral ENvironnement et Sociétés - UMR 7266 (LIENSs), GEOMAR - Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), Istanbul Teknik Universitesi, Boğaziçi University [Istanbul], Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), LIttoral ENvironnement et Sociétés (LIENSs), La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS), Géosciences Marines (GM), and Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
acoustic ranging, acoustic, [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics, North Anatolian Fault, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Seafloor geodesy, seismic hazard, Marmara, seafloor geodesy, earthquakes, Marmara Sea
Abstract

International audience; The submarine Istanbul-Silivri fault segment, within 15 km of Istanbul, is the only portion of the North Anatolian Fault that has not ruptured in the last 250 years. We report first results of a seafloor acoustic ranging experiment to quantify current horizontal deformation along this segment and assess whether the segment is creeping aseismically or accumulating stress to be released in a future event. Ten transponders were installed to monitor length variations along 15 baselines. A joint least squares inversion for across-fault baseline changes, accounting for sound speed drift at each transponder, precludes fault displacement rates larger than a few millimeters per year during the 6 month observation period. Forward modeling shows that the data better fit a locked state or a very moderate surface creep—less than 6 mm/yr compared to a far-field slip rate of over 20 mm/yr—suggesting that the fault segment is currently accumulating stress.

Published
2016

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