Vertical tectonic motions in the Lesser Antilles: linking short- and long-term observations
Elenora van Rijsingen, Eric Calais, Romain Jolivet, Jean-Bernard de Chabalier, Richard Robertson, Graham Ryan and Steeve Symithe
In this work we show, using modern geodetic data, a general subsidence of the Lesser Antilles island arc at 1-2 mm/yr, consistent with geologically-observed subsidence since 125 thousand years. Using elastic dislocation models, we show that a (partially) locked subduction interface would produce uplift of the island arc, opposite to the observations, hence supporting a poorly-coupled subduction. We propose that the regional, long-term subsidence is likely controlled by slab dynamic processes. Such processes could also play a role in tuning the aseismic character of the subduction megathrust, which appears to be a long-term feature.
van Rijsingen, E.M., Calais, E., Jolivet, R., de Chabalier, J.-B., Robertson, R., Ryan, G.A., Symithe, S. Vertical tectonic motions in the Lesser Antilles: linking short- and long-term observations. Preprint available via https://doi.org/10.31223/X5360D.
Inferring interseismic coupling along the Lesser Antilles subduction zone: a Bayesian approach
Elenora van Rijsingen, Eric Calais, Romain Jolivet, Jean-Bernard de Chabalier, Jorge Jara, Steeve Symithe, Richard Robertson and Graham Ryan
The Lesser Antilles subduction zone forms the boundary between the North- and South American plates that sink underneath the overlying Caribbean plate. We invert GPS measurements on the Lesser Antilles islands using a Bayesian approach to determine how much strain is currently being acculumated along the subduction interface, that is, how coupled the interface is. A high coupling means that large 'megathrust' earthquakes are likely, while a low coupling means that they are less likely to occur. We find a low to very low coupled interface, which implies that very large megathrust earthquakes are unlikely and/or must be very rare in the Lesser Antilles.
van Rijsingen, E.M., Calais, E., Jolivet, R., de Chabalier, J.-B., Jara, J., Symithe, S., Robertson, R., Ryan, G.A.. Inferring Interseismic Coupling along the Lesser Antilles Arc: a Bayesian Approach (2021). Journal of Geophysical Research: Solid Earth. https://doi.org/10.1029/2020JB020677
The diversity of slip modes along the Chaman fault illuminated by InSAR*
Manon Dalaison, Romain Jolivet, Elenora van Rijsingen and Sylvain Michel
The Chaman fault marks the western border of the ~100 km wide transform plate boundary between the Eurasian and Indian tectonic plates in Pakistan and Afghanistan. This fault system links the Makran subduction and accretionary wedge system to the Southwest with the Himalayas to the Northeast.Although global pate models predict 20-35 mm/yr of left-lateral movement, very few large earthquakes were recorded or described in historical catalog in the region. We use Interferometric Synthetic Aperture Radar (InSAR) to quantify the partitioning of deformation between major transform faults in the region, as well as the spatial distribution of aseismic slip along the Chaman and neighboring faults.
Dalaison, M., Jolivet, R., van Rijsingen, E.M., Michel, S. The interplay between seismic and aseismic slip along the Chaman fault illuminated by InSAR (submitted to JGR Solid Earth).
Investigating tsunamigenic earthquakes and subduction zone characteristics*
Iris van Zelst, Silvia Brizzi, Elenora van Rijsingen, Francesca Funiciello
and Ylona van Dinther
Tsunamigenic earthquakes pose a large hazard in subduction zones, but it is currently unclear in which tectonic setting they preferentially occur. We use a bivariate and multivariate statistics to investigate global correlations between tsunamigenic earthquakes and subduction zone characteristics. We find that tsunamigenic earthquakes may be more prone to occur in tectonic settings where plates subduct relatively fast beneath a sediment-starved, erosional margin.
van Zelst, I., Brizzi, S., van Rijsingen, E., Funiciello, F., van Dinther, Y. Investigating global correlations between tsunami, earthquake and subduction zone characteristics (in preparation for resubmission to Tectonophyscis). Preprint available via https://doi.org/10.31223/osf.io/dm2t4.
Analogue modelling of subduction megathrust earthquakes and subducting topography
Elenora van Rijsingen, Francesca Funiciello, Fabio Corbi and Serge Lallemand
The largest and most destructive earthquakes on Earth occur along the plate contact in subduction zones, the region where an oceanic plate dives below another plate. Here we use analogue models that include a 3-D-printed seafloor, to investigate the effect of a smooth vs a rough seafloor on the occurence of large subduction earthquakes. We observe that the rough seafloor geometry generally hinders the occurrence of large earthquakes, by segmenting the plate interface, making it more difficult for ruptures to propagate.
van Rijsingen, E., Funiciello, F., Corbi, F., Lallemand, S. (2019). Rough subducting seafloor reduces interseismic coupling and mega-earthquake occurrence: Insights from analogue models. Geophysical Research Letters. https://doi.org/10.1029/2018GL081272.
A global quantitative comparison between seafloor roughness and megathrust earthquakes
Elenora van Rijsingen, Serge Lallemand, Michel Peyret, Diane Arcay, Arnauld Heuret, Francesca Funiciello and Fabio Corbi
The Earth's seafloor consists of a landscape full with seamounts and ridges, which can be described as seafloor roughness. To better understand how such roughness influences earthquakes when it enters subduction zones, we perform a global quantitative comparison with large megathrust earthquakes. We use power spectral analysis on bathymetry data to quantify the roughness of the seafloor facing subduction zones, which we use as a proxy for the subduction interface. We find that the seafloor in front of large earthquakes is generally smoother than in areas where no large earthquakes have occurred.
van Rijsingen, E., Lallemand, S., Peyret, M., Arcay, D., Heuret, A., Corbi, F., Funiciello, F. (2018). How subduction interface roughness influences the occurrence of large interplate earthquakes. Geo-chemistry, Geophysics, Geosystems. https://doi.org/10.1029/2018GC007618.
Lallemand, S., Peyret, M., van Rijsingen, E., Arcay,D., Heuret, A. (2018). Roughness characteristics of oceanic seafloor prior to subduction in relation to the seismogenic potential of subduction zones. Geochemistry, Geophysics, Geosystems. https://doi.org/10.1029/2018GC007434.