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Wang, R.
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Wang, R.
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- PublicationOpen AccessAftershock modeling based on uncertain stress calculations(2009)
; ; ; ; ; ; ; ;Hainzl, S.; GFZ German Research Centre for Geosciences, Potsdam, Germany ;Enescu, B.; GFZ German Research Centre for Geosciences, Potsdam, Germany ;Cocco, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Woessner, J.; Institute of Geophysics, ETH Zurich, Zurich, Switzerland ;Catalli, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Wang, R.; Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences,Potsdam, Germany ;Roth, F.; Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences,Potsdam, Germany; ; ; ; ; ; We discuss the impact of uncertainties in computed coseismic stress perturbations on the seismicity rate changes forecasted through a rate- and state-dependent frictional model. We aim to understand how the variability of Coulomb stress changes affects the correlation between predicted and observed changes in the rate of earthquake production. We use the aftershock activity following the 1992 M7.3 Landers (California) earthquake as a case study. To accomplish these tasks, we first analyze the variability of stress changes resulting from the use of different published slip distributions. We find that the standard deviation of the uncertainty is of the same size as the absolute stress change and that their ratio, the coefficient of variation (CV), is approximately constant in space. This uncertainty has a strong impact on the forecasted aftershock activity if a rate-and-state frictional model is considered. We use the early aftershocks to invert for friction parameters and the coefficient of variation by means of the maximum likelihood method. We show that, when the uncertainties are properly taken into account, the inversion yields stable results, which fit the spatiotemporal aftershock sequence. The analysis of the 1992 Landers sequence demonstrates that accounting for realistic uncertainties in stress changes strongly improves the correlation between modeled and observed seismicity rate changes. For this sequence, we measure a friction parameter Aσn ≈ 0.017 MPa and a coefficient of stress variation CV = 0.95.183 1072 - PublicationRestrictedThe European land and inland water CO2, CO, CH4 and N2O balance between 2001 and 2005(2012-08-24)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;Luyssaert, S.; CEA-CNRS-UVSQ, UMR8212 – Laboratoire des sciences du climat et de l’environnement (LSCE), Orme des Merisiers, 91191 Gif-sur-Yvette, France ;Abril, G.; Laboratoire EPOC, Environnements et Pal´eoenvironnements Oc´eaniques et Continentaux, UMR5805, CNRS, Universit´e de Bordeaux, Bordeaux, France ;Andres, R.; Oak Ridge National Laboratory, Environmental Sciences Division, Oak Ridge, TN 37831-6290, USA ;Bastviken, D.; Link¨oping University, The Department of Thematic Studies – Water and Environmental Studies, 586 62 Link¨oping, Sweden ;Bellassen, V.; CEA-CNRS-UVSQ, UMR8212 – Laboratoire des sciences du climat et de l’environnement (LSCE), Orme des Merisiers, 91191 Gif-sur-Yvette, France ;Bergamaschi, P.; European Commission, Joint Research Centre, Institute for Environment and Sustainability, Via E. Fermi 2749, 21027 Ispra (VA), Italy ;Bousquet, P.; CEA-CNRS-UVSQ, UMR8212 – Laboratoire des sciences du climat et de l’environnement (LSCE), Orme des Merisiers, 91191 Gif-sur-Yvette, France ;Chevallier, F.; CEA-CNRS-UVSQ, UMR8212 – Laboratoire des sciences du climat et de l’environnement (LSCE), Orme des Merisiers, 91191 Gif-sur-Yvette, France ;Ciais, P.; CEA-CNRS-UVSQ, UMR8212 – Laboratoire des sciences du climat et de l’environnement (LSCE), Orme des Merisiers, 91191 Gif-sur-Yvette, France ;Corazza, M.; European Commission, Joint Research Centre, Institute for Environment and Sustainability, Via E. Fermi 2749, 21027 Ispra (VA), Italy ;Dechow, R.; Johann Heinrich von Th¨unen-Institut, Institute for Agricultural Climate Research, Bundesallee 50, 38116 Braunschweig, Germany ;Erb, K.-H.; Alpen-Adria Universitaet Klagenfurt-Vienna-Graz, Institute of Social Ecology Vienna (SEC), Schottenfeldgasse 29, 1070 Vienna, Austria ;Etiope, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Fortems-Cheiney, A.; CEA-CNRS-UVSQ, UMR8212 – Laboratoire des sciences du climat et de l’environnement (LSCE), Orme des Merisiers, 91191 Gif-sur-Yvette, France ;Grassi, G.; European Commission, Joint Research Centre, Institute for Environment and Sustainability, Via E. Fermi 2749, 21027 Ispra (VA), Italy ;Hartmann, J.; Institute for Biogeochemistry and Marine Chemistry, KlimaCampus, University of Hamburg, Bundesstrasse 55, 20146 Hamburg, Germany ;Jung, M.; Max-Planck Institute for Biogeochemistry, Biogeochemical Processes, P.O. Box 100164, 07701 Jena, Germany ;J. Lathiére, J.; CEA-CNRS-UVSQ, UMR8212 – Laboratoire des sciences du climat et de l’environnement (LSCE), Orme des Merisiers, 91191 Gif-sur-Yvette, France ;Lohila, A.; Finnish Meteorological Institute, Climate Change Research, P.O. Box 503, 00101 Helsinki, Finland ;Mayorga, E.; University of Washington, Applied Physics Laboratory, Box 355640, Seattle, WA 98105-6698, USA ;Moosdorf, N.; Institute for Biogeochemistry and Marine Chemistry, KlimaCampus, University of Hamburg, Bundesstrasse 55, 20146 Hamburg, Germany ;Njakou, D. S.; University of Antwerp, Researchgroup Plant and Vegetation Ecology, Universiteitsplein 1, 2610 Wilrijk, Belgium ;Otto, J.; CEA-CNRS-UVSQ, UMR8212 – Laboratoire des sciences du climat et de l’environnement (LSCE), Orme des Merisiers, 91191 Gif-sur-Yvette, France ;Papale, D.; University of Tuscia, Department for innovation in biological, agro-food and forest systems (DIBAF), Via S. Camillo de Lellis, snc- 01100 Viterbo, Italy ;Peters, W.; Wageningen University, Meteorology and Air Quality, Droevendaalsesteenweg 4, 6700 PB, Wageningen, The Netherlands ;Peylin, P.; CEA-CNRS-UVSQ, UMR8212 – Laboratoire des sciences du climat et de l’environnement (LSCE), Orme des Merisiers, 91191 Gif-sur-Yvette, France ;Raymond, P.; Yale University, School of Forestry and Environmental Studies, 195 Prospect Street, New Haven, CT 06511, USA ;Rödenbeck, C.; Max Planck Institute for biogeochemistry, Biogeochemical Systems Department, P.O. Box 100164, 07701 Jena, Germany ;Saarnio, S.; University of Eastern Finland, Department of Biology and Finnish Environment Institute, the Joensuu Office, PL 111, 80101 Joensuu, Finland ;Schulze, E.-D.; Max-Planck Institute for Biogeochemistry, Biogeochemical Processes, P.O. Box 100164, 07701 Jena, Germany ;Szopa, S.; CEA-CNRS-UVSQ, UMR8212 – Laboratoire des sciences du climat et de l’environnement (LSCE), Orme des Merisiers, 91191 Gif-sur-Yvette, France ;Thompson, R.; CEA-CNRS-UVSQ, UMR8212 – Laboratoire des sciences du climat et de l’environnement (LSCE), Orme des Merisiers, 91191 Gif-sur-Yvette, France ;Verkerk, P. J.; European Forest Institute, Sustainability and Climate Change Programme, Torikatu 34, 80100 Joensuu, Finland ;Vuichard, N.; CEA-CNRS-UVSQ, UMR8212 – Laboratoire des sciences du climat et de l’environnement (LSCE), Orme des Merisiers, 91191 Gif-sur-Yvette, France ;Wang, R.; Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China ;Wattenbach, M.; Helmholtz Centre Potsdam GFZ German Research Centre For Geosciences, Deutsches GeoForschungsZentrum GFZ, Telegrafenberg, 14473 Potsdam, Germany ;Zaehle, S.; Max Planck Institute for biogeochemistry, Biogeochemical Systems Department, P.O. Box 100164, 07701 Jena, Germany; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; Globally, terrestrial ecosystems have absorbed about 30% of anthropogenic greenhouse gas emissions over the period 2000–2007 and inter-hemispheric gradients indicate that a significant fraction of terrestrial carbon sequestration must be north of the Equator. We present a compilation of the CO2, CO, CH4 and N2O balances of Europe following a dual constraint approach in which (1) a landbased balance derived mainly from ecosystem carbon inventories and (2) a land-based balance derived from flux measurements are compared to (3) the atmospheric data-based balance derived from inversions constrained by measurements of atmospheric GHG (greenhouse gas) concentrations. Good agreement between the GHG balances based on fluxes (1294±545 Tg C in CO2-eq yr−1), inventories (1299±200 Tg C in CO2-eq yr−1) and inversions (1210±405 Tg C in CO2-eq yr−1) increases our confidence that the processes underlying the European GHG budget are well understood and reasonably sampled. However, the uncertainty remains large and largely lacks formal estimates. Given that European net land to atmosphere exchanges are determined by a few dominant fluxes, the uncertainty of these key components needs to be formally estimated before efforts could be made to reduce the overall uncertainty. The net land-to-atmosphere flux is a net source for CO2, CO, CH4 and N2O, because the anthropogenic emissions by far exceed the biogenic sink strength. The dual-constraint approach confirmed that the European biogenic sink removes as much as 205±72 Tg C yr−1 from fossil fuel burning from the atmosphere. However, This C is being sequestered in both terrestrial and inland aquatic ecosystems. If the C-cost for ecosystem management is taken into account, the net uptake of ecosystems is estimated to decrease by 45% but still indicates substantial C-sequestration. However, when the balance is extended from CO2 towards the main GHGs, C-uptake by terrestrial and aquatic ecosystems is offset by emissions of non-CO2 GHGs. As such, the European ecosystems are unlikely to contribute to mitigating the effects of climate change.1996 24 - PublicationRestrictedSimultaneous magma and gas eruptions at three volcanoes in southern Italy: An earthquake trigger?(2009-03)
; ; ; ; ; ;Walter, T. R.; Department 2: Physics of the Earth, Helmholtz Centre Potsdam, GFZ German Research Centre for Geoscience, Telegrafenberg, 14473 Potsdam, Germany ;Wang, R.; Department 2: Physics of the Earth, Helmholtz Centre Potsdam, GFZ German Research Centre for Geoscience, Telegrafenberg, 14473 Potsdam, Germany ;Acocella, V.; Dipartimento Scienze Geologiche, Università Roma Tre, Largo S.L. Murialdo 1, 00146 Rome, Italy ;Neri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Zschau, J.; Department 2: Physics of the Earth, Helmholtz Centre Potsdam, GFZ German Research Centre for Geoscience, Telegrafenberg, 14473 Potsdam, Germany; ; ; ; In September 2002, a series of tectonic earthquakes occurred north of Sicily, Italy, followed by three events of volcanic unrest within 150 km. On 28 October 2002, Mount Etna erupted; on 3 November 2002, submarine degassing occurred near Panarea Island; and on 28 December 2002, Stromboli Island erupted. All of these events were considered unusual: the Mount Etna northeast-rift eruption was the largest in 55 yr; the Panarea degassing was one of the strongest ever detected there; and the Stromboli eruption, which produced a landslide and tsunami, was the largest effusive eruption in 17 yr. Here we investigate the synchronous occurrence of these clustered events, and develop a possible explanatory model. We compute short-term earthquake-induced dynamic strain changes and compare them to long-term tectonic effects. Results suggest that the earthquake-induced strain changes exceeded annual tectonic strains by at least an order of magnitude. This agitation occurred in seconds, and may have induced fluid and gas pressure migration within the already active hydrothermal and magmatic systems.187 25 - PublicationOpen AccessPerformance assessment of finite-fault inversion codes in the Marmara configuration”- “Near-Real time estimation of most relevant earthquake source parameters(2015-04-30)
; ; ; ; ; ;Cirella, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Piatanesi, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Diao, F. ;Wang, R. ;Aochi, H.; ; ; ;102 477 - PublicationOpen AccessPoroelastic model in a vertically sealed gas storage: a case study from cyclic injection/production in a carbonate aquifer(2021)
; ; ; ; ; ; ; ; ; ; ; ; ;Natural gas can be temporarily stored in a variety of underground facilities, such as depleted gas and oil fields, natural aquifers and caverns in salt rocks. Being extensively monitored during operations, these systems provide a favourable opportunity to investigate how pressure varies in time and space and possibly induces/triggers earthquakes on nearby faults. Elaborate and detailed numerical modelling techniques are often applied to study gas reservoirs. Here we show the possibilities and discuss the limitations of a flexible and easily formulated tool that can be straightforwardly applied to simulate temporal pore-pressure variations and study the relation with recorded microseismic events. We use the software POEL (POroELastic diffusion and deformation) which computes the poroelastic response to fluid injection/extraction in a horizontally layered poroelastic structure. We further develop its application to address the pres- ence of vertical impermeable faults bounding the reservoir and of multiple injection/extraction sources. Exploiting available information on the reservoir geometry and physical parameters, and records of injection/extraction rates for a gas reservoir in southern Europe, we perform an extensive parametric study considering different model configurations. Comparing modelled spatiotemporal pore-pressure variations with in situ measurements, we show that the inclusion of vertical impermeable faults provides an improvement in reproducing the observations and results in pore-pressure accumulation near the faults and in a variation of the temporal pore- pressure diffusion pattern. To study the relation between gas storage activity and recorded local microseismicity, we applied different seismicity models based on the estimated pore- pressure distribution. This analysis helps to understand the spatial distribution of seismicity and its temporal modulation. The results show that the observed microseismicity could be partly linked to the storage activity, but the contribution of tectonic background seismicity cannot be excluded.191 81