SFB 574:  Volatiles and Fluids in Subduction Zones: Climate Feedback and the Causes of Natural Disasters

• Subject Area: Geosciences
• Term: from 2001 to 2012
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5484524

• Final Report Year: 2013

Final Report Abstract

The SFB 574 investigated the pathways, fluxes and turnover processes of fluids and volatiles, such as water, carbon, sulfur and halogens through subduction zones, because these control the severity and frequency of natural hazards (e.g. earthquakes and volcanic eruptions), the formation of resources (e.g. gas hydrates), and the regional to global climate via volcanic emissions and lithosphere-ocean-atmosphere elemental exchange fluxes. These objectives have been addressed through the combined work of 18 scientific subprojects and 1 junior research group established during the 11 year lifetime of SFB 574, which covered a wide range of disciplines and methods under the following themes: (A) Subduction zone processes and structure, (B) Fore-arc volatile turnover and fluid flow, and (C) Slab-arc-atmosphere transfer. The first regional focus was on the erosive subduction zone of Central America, which is transitional in the sense that upper plate crust changes from oceanic to continental northward. The second regional focus was then on the accretionary subduction zone of southern Chile with a continental upper-plate crust that thickens northward. Major results that are internationally associated with the SFB 574 are: 1. Recognition of mantle serpentinization as a major carrier of water into the subduction zone, facilitated by bend-faulting of the plate as it approaches the trench (observed offshore of Central America and Chile) and via multi-splay fracture zones off the Central and Southern segments of the Chilean Southern Volcanic Zone. The hydrogeological and thermodynamical conditions controlling the extent of serpentinization have been constrained by field measurements and by numerical modeling. Furthermore, it has been shown for both study areas that serpentinization of the upper mantle of the incoming plate can influence the entire range of subduction processes, from earthquake activity to magma production and also the chemical composition of the erupted lavas and ultimately the release of climate-influencing volatiles into the atmopshere. Serpentinization was one of the major unifying themes throughout the entire 11 years of the SFB. 2. Serpentinization of the forearc mantle and its role in defining the lower limit of the seismogenic zone and hence the size of rupture zones and earthquake magnitudes. 3. Improvement of our understanding of the hydrogeological system of the forearc at erosive and accretionary margins in relation to tectonic structures, the rates and depths of dewatering at the decollement and how this defines the onset of the seismogenic zone. 4. Stability of the continental slope as a function of the distribution of gas hydrates, the rates and pathways of cold-seep fluid emissions and the input of terrigenous sediment into the trench at erosional and accretionary margins. 5. The importance of the benthic filter in controlling methane fluxes into the ocean. 6. Combination of geophysical and geochemical evidence to demonstrate and measure 3-D flow within the mantle wedge, and development of complex numerical models to investigate the physical parameters of such flow conditions. 7. Evidence for external controls on volcanic degassing and eruption behaviour over a range of temporal scales from seismic stresses through Earth tides to glacial cycles. 8. Quantification of the mass budgets of volatile transfer through the investigated subduction zones through combination of empirical methods and fluid-thermodynamic modeling. 9. Compilation of empirical data for, and climate-modelling of, the effects of arc-volcanic volatile emissions on past, present and future atmosphere and climate conditions.

Publications

• (2003) Bending, faulting and mantle serpentinization at the Middle America Trench. Nature 425: 367-373
  Ranero CR, Phipps-Morgan J, McIntosh K, Reichert C
  
• (2004) Fluid expulsion related to mud extrusion off Costa Rica - a window to the subducting slab. Geology 32: 201-204
  Hensen C, Wallmann K, Schmidt M, Ranero CR, Suess E
  
• (2004) Serpentine and the Subduction Zone Water Cycle. Earth Planet Sci Lett 223: 17-34
  Rüpke LH, Phipps Morgan J, Hort M, Connolly J
  
• (2004) Trace element fractionation during fluid-induced eclogitization in a subducting slab: trace element and Lu-Hf/Sm-Nd isotope systematics. Earth Planet Sci Lett 227: 441-456
  John T, Scherer E, Haase K, Schenk V
  
• (2005) Heat flow and bending-related faulting at subduction trenches: Case studies offshore of Nicaragua and Central Chile. Earth Planet Sci Lett 236: 238-248
  Grevemeyer I, Kaul N, Diaz-Naveas JL, Villinger HW, Ranero CR, Reichert C
  
• (2005) In-situ benthic fluxes from an intermittently active mud volcano at the Costa Rica convergent margin. Earth Planet Sci Lett 235: 79-95
  Linke P, Wallmann K, Suess E, Hensen C, Rehder G
  
• (2006) Estimates of methane output from mud extrusions at the erosive convergent margin off Costa Rica. Marine Geology 225: 129-144
  Mau S, Sahling H, Rehder G, Suess E, Linke P, Soeding E
  
• (2006), Volcanic hazards in Nicaragua: Past, present, and future. In: WI Rose, GJS Bluth, et al. (eds) Volcanic hazards in Central America. Geol Soc Am Spec Publ 412: 141-165
  Freundt A, Kutterolf S, Schmincke H-U, Hansteen TH, Wehrmann H, Perez W, Strauch W, Navarro M
  
• (2007) Fumarolic gases at Mombacho volcano (Nicaragua): presence of magmatic gas species and implications for volcanic surveillance. Bull Volcanol 69: 785-795
  Garofalo K, Tassi F, Vaselli O, Delgado-Huertas A, Tedesco D, Frische M, Hansteen TH, Poreda RJ, Strauch W
  
• (2007) Passive and active seismological study of bending-related faulting and mantle serpentinization at the Middle America trench. Earth Planet Sci Lett 258: 528-542
  Grevemeyer I, Ranero CR, Flüh ER, Kläschen D, Bialas J
  
• (2008) Arc-Parallel Flow in the Mantle Wedge Beneath Costa Rica and Nicaragua. Nature
  Hoernle K, Abt DL, Fischer KM, Nichols H, Hauff F, Abers G, van den Bogaard P, Heydolph K, Alvarado G, Protti JM, Strauch W
  
• (2008) Lifetime and cyclicity of fluid venting at forearc mound structures determined by tephrostratigraphy and radiometric dating of authigenic carbonates. Geology 36: 707-710
  Kutterolf S, Liebetrau V, Mörz T, Freundt A, Hammerich T, Garbe-Schönberg D
  
• (2008) Subduction cycling of volatiles and trace elements through the Central American volcanic arc: evidence from melt inclusions. Contrib Mineral Petrol 155: 433-456
  Sadofsky S, Portnyagin M, Hoernle K, van den Bogaard P
  
• (2008) The hydrogeological system of erosional convergent margins and its influence on tectonics and interplate seismogenesis. Geochem Geophys Geosys 9(3): Q03S04
  Ranero CR, Grevemeyer I, Sahling H, Barckhausen U, Hensen C, Wallmann K, Weinrebe W, Vannucchi P, von Huene R, McIntosh K
  
• (2008). Impact of bending related faulting on the seismic properties of the incoming oceanic plate offshore of Nicaragua. J Geophys Res 113: B05410
  Ivandic M, Grevemeyer I, Berhorst A, Flueh E R, McIntosh K
  
• (2010) Nitrogen recycling in subducted oceanic lithosphere: The record in high- and ultra-high pressure metabasaltic rocks. Geochim Cosmochim Acta 74: 1636-1652
  Halama R, Bebout G, John T, Schenk V
  
• (2011) A stable (Li, O) and radiogenic (Sr, Nd) isotope perspective on metasomatic processes in a subducting slab. Chemical Geology 281: 151-166
  Halama R, John T, Herms P, Hauff F, Schenk V
  
• (2011) Active tectonics of the South Chilean marine fore arc (35°S - 40°S). Tectonics 30: TC3006
  Geersen J, Behrmann JH, Völker D, Krastel S, Ranero CR, Diaz-Naveas J, Weinrebe W
  
• (2011) Arc parallel shear deformation and escape flow in the mantle wedge of the Central America subduction zone: Evidence from P-wave anisotropy. Geochemistry, Geophysics, Geosystems 12: Q05S31
  Rabbel W, Koulatov I, Dinc AN, Jakovlev A
  
• (2011) Comparative mass balance of volcanic edifices at the Southern Volcanic Zone of the Andes between 33°S and 46°S. J Volcanol Geotherm Res 205: 114-129
  Völker D, Kutterolf S, Wehrmann H
  
• (2011) Elasmobranch egg capsules associated with modern and ancient cold seeps: A nursery for marine deep-water predators. Marine Ecology Progress Series 437: 175-181
  Treude T, Kiel S, Linke P, Peckmann J, Goedert JL
  
• (2011) Magnetotelluric image of the fluid cycle in the Costa Rican subduction zone. Nature Geoscience 4: 108-111
  Worzewski T, Jegen M, Kopp H, Brasse H, Taylor Castillo W
  
• (2011) Mantle wedge hydration in Nicaragua from local earthquake tomography. Geophys J Int 186: 99-112
  Dinc AN, Rabbel W, Flüh ER, Taylor W
  
• (2011) Submarine slope failures along the convergent continental margin of the Middle America Trench. G-cubed 12: Q05S32
  Harders R, Ranero C, Weinrebe W, Behrmann J
  
• (2011) The influence of eruption season on the global aerosol evolution and radiative impact of tropical volcanic eruptions. Atmos Chem Phys 11: 12351-12367
  Toohey M, Krüger K, Niemeier U, Timmreck C
  
• (2011) Volcanic CO2 output at the Central American subduction zone inferred from melt inclusions in olivine crystals from mafic tephras. G-cubed 12: Q06003
  Wehrmann H, Hoernle K, Portnyagin M, Wiedenbeck M, Heydoph K
  
• (2012) Evidence for channelized external fluid flow and element transfer in subducting slabs (Raspas Complex, Ecuador). Chem Geol 310-311: 79-96
  Herms P, John T, Bakker RJ, Schenk V
  
• (2012) Formation of carbonate concretions in surface sediments of two mud mounds offshore Costa Rica: A stable isotope study. Int J Earth Sci
  Mavromatis V, Botz R, Schmidt M, Liebetrau V, Hensen C
  
• (2012) Moho topography and subducting oceanic slab of the Chilean continental margin in the maximum slip segment of the 1960 Mw 9.5 Valdivia (Chile) earthquake from P-receiver functions. Tectonophysics 530-531: 180-192
  Dzierma Y, Thorwart M, Rabbel W
  
• (2012) On the likelihood of future eruptions in the Chilean Southern Volcanic Zone: interpreting the past century's eruption record based on statistical analyses. Andean Geology 39: 380-393
  Dzierma Y, Wehrmann H
  
• (2012) Quantification of methane emission from bacterial mat sites at Quepos Slide offshore Costa Rica. Int J Earth Sci
  Karaca D, Schleicher T, Hensen C, Linke P, Wallmann K
  
• (2012) Radiative forcing and climate impact resulting from the SO2 injections based on a 200,000 year record of Plinian eruptions along the Central American Volcanic Arc. Int J Earth Sci
  Metzner D, Kutterolf S, Toohey M, Niemeier U, Timmreck C, Freundt A, Krüger K
  
• (2012) Seismic evidence of tectonic control on the depth of water influx into incoming oceanic plates at subduction trenches. Geochem Geophys Geosyst 13: Q05013
  Lefeldt M, Ranero CR, Grevemeyer I
  
• (2012) Seismic velocity structure of the slab and continental plate in the region of the 1960 Valdivia (Chile) slip maximum - insights into fluid release and plate coupling. Earth Planet Sci Lett 331-332: 164-176
  Dzierma Y, Rabbel W, Thorwart M, Koulakov I, Wehrmann H, Hoernle K, Comte D
  
• (2012) Tracing the effects of highpressure metasomatic fluids and seawater alteration in blueschist-facies overprinted eclogites: Implications for subduction channel processes. Chem Geol 292-293: 69-87
  van der Straaten F, Halama R, John T, Schenk V, Hauff F, Andersen N
  
• (2013) A Detection of Milankovitch Frequencies in Global Volcanic Activity. Geology 41: 227-230
  Kutterolf S, Jegen M, Mitrovica JX, Kwasnitschka T, Freundt A, Huybers P
  
• (2013) Across-arc geochemical variations in the Southern Volcanic Zone, Chile (34.5°- 38.0°S): Constraints on mantle wedge and source input compositions. Geochim Cosmoschim Acta
  Jacques G, Hoernle K, Gill J, Hauff F, Wehrmann H, Garbe-Schönberg D, van den Bogaard P, Bindeman I, Lara L
  
• (2013) Combined bromine and chlorine release from large explosive volcanic eruptions: A threat to stratospheric ozone? Geology
  Kutterolf S, Hansteen TH, Appel K, Freundt A, Krüger K, Perez W, Wehrmann H
  
• (2013) Comparison of seismic activity for Llaima and Villarrica volcanoes prior to and after the Maule 2010 earthquake. Int J Earth Sci
  Mora-Stock C, Thorwart M, Wunderlich T, Bredemeyer S, Rabbel W
  
• (2013) Submarine weathering of silicate minerals and the extent of pore water freshening at active continental margins. Geochim Cosmochim Acta 100: 200-216
  Scholz F, Hensen C, Schmidt M, Geersen J