Along‐Arc Heterogeneity in Local Seismicity across the Lesser Antilles Subduction Zone from a Dense Ocean‐Bottom Seismometer Network
Year: 2019
Type: article
Abstract: The Lesser Antilles arc is only one of two subduction zones where slow‐spreading Atlantic lithosphere is consumed. Slow‐spreading may result in the Atlantic lithosphere being more pervasively and heterogeneously hydrated than fast‐spreading Pacific lithosphere, thus affecting the flux of fluids into the deep mantle. Understanding the distribution of seismicity can help unravel the effect of fluids on geodynamic and seismogenic processes. However, a detailed view of local seismicity across the whole Lesser Antilles subduction zone is lacking. Using a temporary ocean‐bottom seismic network we invert for hypocenters and 1D velocity model. A systematic search yields a 27 km thick crust, reflecting average arc and back‐arc structures. We find abundant intraslab seismicity beneath Martinique and Dominica, which may relate to the subducted Marathon and/or Mercurius Fracture Zones. Pervasive seismicity in the cold mantle wedge corner and thrust seismicity deep on the subducting plate interface suggest an unusually wide megathrust seismogenic zone reaching ∼65 km depth. Our results provide an excellent framework for future understanding of regional seismic hazard in eastern Caribbean and the volatile cycling beneath the Lesser Antilles arc.
Source: Seismological Research Letters
DOI: 10.1785/0220190147
Authors: Lidong Bie, Andreas Rietbrock, Stephen Hicks, Robert Allen, Jon Blundy, Valerie Clouard, Jenny Collier, Jon Davidson, Thomas Garth, Saskia Goes, Nick Harmon, Tim Henstock, Jeroen van Hunen, Mike Kendall, Frank Krüger, Lloyd Lynch, Colin Macpherson, Richard Robertson, Kate Rychert, Stephen Tait, Jamie Wilkinson, Marjorie Wilson
Institutions: Karlsruhe Institute of Technology, University of Liverpool, Imperial College London, University of Bristol, Institut de physique du globe de Paris, Université Paris Diderot, Durham University, University of Oxford, National Oceanography Centre, University of Southampton, University of Potsdam, University of the West Indies, Natural History Museum, University of Leeds
Language: English
Subfield: Geophysics
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: green
Funders: University of Southampton, Imperial College London, University of Oxford, University of Leeds, University of Bristol, Durham University, Universität Potsdam, Université Paris Diderot, Institut de Physique du Globe de Paris, University of California, San Diego, Natural Environment Research Council
Awards: How does crust form at arcs? - a Multidisciplinary Study of the Lesser Antilles Volcanic Arc, Volatile Recycling at the Lesser Antilles Arc: Processes and Consequences, Volatile Recycling at the Lesser Antilles Arc: Processes and Consequences, Volatile Recycling at the Lesser Antilles Arc: Processes and Consequences
OpenAlex ID: W2986555100