Time-variable strain and stress rates induced by Holocene glacial isostatic adjustment in continental interiors

• Published in: Tectonophysics
• Main Authors: Craig, T, J, Calais, E, Fleitout, L, Bollinger, L, Scotti, O.
• Other Authors: Laboratoire de géologie de l'ENS (LGENS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL), LMI CARIBACT, URGéo, Université d’Etat d’Haïti, Faculté des Sciences (UEH, FDS), Géoazur (GEOAZUR 7329), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UniCA)-Université Côte d'Azur (UniCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD France-Sud ), DAM Île-de-France (DAM/DIF), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Bureau d'évaluation des risques sismiques pour la sûreté des installations (IRSN/PSE-ENV/SCAN/BERSSIN), Service de caractérisation des sites et des aléas naturels (IRSN/PSE-ENV/SCAN), Institut de Radioprotection et de Sûreté Nucléaire (IRSN)-Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Royal Society (under URF\R1\180088), Institut Universitaire de France, ANR-11-RSNR-0022,SINAPS@,Séisme et Installation Nucléaire -Améliorer et Pérenniser la Sûreté(2011)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2023
• Subjects: Postglacial deformation; Intraplate deformation; Continental seismicity; Strain-rates; [SDE]Environmental Sciences; Fennoscandian
• Online Access: https://irsn.hal.science/irsn-04331492; https://irsn.hal.science/irsn-04331492/document; https://irsn.hal.science/irsn-04331492/file/1-s2.0-S0040195123001130-main%20%281%29.pdf; https://doi.org/10.1016/j.tecto.2023.229815

International audience In continental interiors, tectonically-driven deformation rates are low, often to the point where they are undetectable with modern geodesy. However, a range of non-tectonic surface processes, particularly relating to hydrological, cryospheric, and sedimentological mass changes, can produce strain-rates which on geologically-short timescales are substantially greater than those produced by tectonics. Here, we illustrate the problem that such transient strain rates may pose in low-strain environments by considering the impact that the growth and decay of the Fennoscandian and Laurentian ice sheets over the Holocene had on Europe and North America respectively. Induced deformation extended far beyond the periphery of the ice sheets, with the potential to impact on seismicity rates thousands of kilometres south of the maximum ice extent. We consider how the modelled non-tectonic deformation would have interacted with several known active fault systems, including the European Cenozoic Rift System and the New Madrid fault system. In low strain continental interiors, seismic hazard assessment – crucial for the long-term planning of critical infrastructure, including nuclear waste disposal – is often dependent on sparse information from observational and historical seismicity, and from paleoseismological studies of surface fault systems. We recommend that for a more complete seismic hazard assessment, the impact of non-tectonic transients should be considered – both in the context of the role such transients may have played in recent seismicity, and the role they may play in seismicity to come. Whilst such consideration has previously been given to the direct impact on glacial loading in areas directly glaciated, we show that it should also be considered much more broadly.