Sismologie, risques
Structure de la croûte et ressources minérale
darbyshire.fiona_ann [at] uqam.ca
Mots- clés: seismology, tectonophysics, subcontinental lithosphere, broadband seismographs, teleseismic data, surface waves, anisotropy, Canadian Shield
200 km depth slice through the P-wave relative arrival-time tomography model of Villemaire et al (2012), showing upper-mantle structure of eastern Canada and the northeast US. GF: Grenville Front, AF: Appalachian Front. White triangles are seismograph stations, brown diamonds are kimberlites and red circles show other magmatic centres.
Of particular interest: a high-velocity body in the north that may be linked to possible fossil Archean subduction remnants, a patchy low-velocity corridor in the south, attributed to modification of the North American lithosphere by the passage of the Great Meteor hotspot.
My primary interest is the structure of the crust and upper mantle beneath continental cratons and their margins. I use waveform data from teleseismic earthquakes, recorded at regional broadband seismograph arrays, to investigate variations in wavespeed in the subcontinental lithosphere in order to understand the history of formation, current dynamics, and interactions with mantle processes.
Over the past 6 years, I have installed 15 new broadband seismographs across central and southern Québec, Nunavik and Labrador, which transmit data in real time to the national data archives at the Geological Survey of Canada. In addition, I am actively involved with aspects of the EarthScope programme; the Transportable Array deployment in southeastern Canada plus two FlexArray projects, SPREE (Superior Province Rifting EarthScope Experiment) and QM-III (Québec-Maine Across Three Sutures) which target specific regions of particular tectonic interest. I have also been working on upper-mantle structure beneath Hudson Bay over several years, through collaboration with the HuBLE (Hudson Bay Lithospheric Experiment) project.
The techniques employed in my research use several parts of the teleseismic waveforms recorded at the seismograph stations: P-wave receiver functions for crustal structure, P-wave arrival times for mantle tomography, SKS phases for splitting analysis of anisotropy, and surface-wave tomography for upper mantle structure and stratification of seismic anisotropy.
Altoe, I., Eeken, T., Goes, S., Foster, A., Darbyshire, F., 2020. Thermo-compositional structure of the north-eastern Canadian Shield from Rayleigh wave dispersion analysis as a record of its tectonic history. Earth and Planetary Science Letters 547, 116465.
Dubé, J.M., Darbyshire, F.A., Liddell, M.V., Stephenson, R., Oakey, G., 2020. Seismic anisotropy of the Canadian High Arctic: Evidence from shear-wave splitting. Tectonophysics 789, 228524.
Foster, A., Darbyshire, F., Schaeffer, A., 2020. Anisotropic structure of the central North American Craton surrounding the Mid-Continent Rift: Evidence from Rayleigh waves. Precambrian Research 342, 105662.
Gosselin, J.M., Audet, P., Schaeffer, A.J., Darbyshire, F.A., Estéve, C., 2020. Azimuthal anisotropy in Bayesian surface-wave tomography: application to northern Cascadia and Haida Gwaii, British Columbia. Geophysical Journal International, ggaa561.
Bollmann, T.A., van der Lee, S., Frederiksen, A.W., Wolin, E., Revenaugh, J., Wiens, D.A., Darbyshire, F.A., Stein, S., Wysession, M.E., Jurdy, D., 2019. P‐wave Teleseismic Traveltime Tomography of the North American Midcontinent. Journal of Geophysical Research: Solid Earth 124(2), 1725-1742.
Darbyshire, F.A., Dahl-Jensen, T., Larsen, T.B., Voss, P.H. and Joyal, G., 2018. Crust and uppermost-mantle structure of Greenland and the Northwest Atlantic from Rayleigh wave group velocity tomography. Geophysical Journal International 212 (3), 1546-1569.
Liddell, M.V., Bastow, I., Rawlinson, N., Darbyshire, F., Gilligan, A., Watson, E., 2018. Precambrian Plate Tectonics in Northern Hudson Bay: Evidence from P and S‐wave Seismic Tomography and Analysis of Source Side Effects in Relative Arrival‐Time Datasets. Journal of Geophysical Research: Solid Earth 123 (7), 5690-5709. DOI: 10.1029/2018JB015473
Zaporozan, T., Frederiksen, A.W., Bryksin, A. and Darbyshire, F., 2018. Surface-wave images of western Canada: lithospheric variations across the Cordillera–craton boundary. Canadian Journal of Earth Sciences 55 (8), 887-896.
Darbyshire, F.A., Bastow, I.D., Petrescu, L., Gilligan, A., Thompson, D.A., 2017. A tale of two orogens: Crustal processes in the Proterozoic Trans-Hudson and Grenville Orogens, eastern Canada. Tectonics 36 (8), 1633-1659.
Levin, V., Servali, A., Van Tongeren, J., Menke, W., Darbyshire, F., 2017. Crust-mantle boundary in eastern North America, from the (oldest) craton to the (youngest) rift. Special Paper of the Geological Society of America 526, 107-131.
Liddell, M.V., Bastow, I., Darbyshire, F., Gilligan, A. and Pugh, S., 2017. The formation of Laurentia: Evidence from shear wave splitting. Earth and Planetary Science Letters 479, 170-178.
Petrescu, L., Darbyshire, F., Bastow, I., Totten, E., Gilligan, A., 2017. Seismic anisotropy of Precambrian lithosphere: Insights from Rayleigh wave tomography of the eastern Superior Craton. Journal of Geophysical Research: Solid Earth 122 (5), 3754-3775.
Boyce, A., Bastow, I.D., Darbyshire, F.A., Ellwood, A.G., Gilligan, A., Levin, V., Menke, W., 2016. Subduction beneath Laurentia modified the eastern North American cratonic edge: Evidence from P wave and S wave tomography. Journal of Geophysical Research: Solid Earth 121 (7), 5013-5030.
Gilligan, A., Bastow, I.D., Darbyshire, F.A., 2016. Seismological structure of the 1.8 Ga Trans-Hudson Orogen of North America. Geochemistry, Geophysics, Geosystems 17, 2421-2433.
Gilligan, A., Bastow, I.D., Watson, E., Darbyshire, F.A., Levin, V., Menke, W., Lane, V., Hawthorn, D., Boyce, A., Liddell, M.V., Petrescu, L., 2016. Lithospheric deformation in the Canadian appalachians: Evidence from shear wave splitting. Geophysical Journal International 206 (2), 1273-1280.
Menke, W., Skryzalin, P., Levin, V., Harper, T., Darbyshire, F., Dong, T., 2016. The Northern Appalachian Anomaly: A modern asthenospheric upwelling. Geophysical Research Letters 43 (19), 10,173-10,179.
Petrescu, L., Bastow, I.D., Darbyshire, F.A., Gilligan, A., Bodin, T., Menke, W., Levin, V., 2016. Three billion years of crustal evolution in eastern Canada: Constraints from receiver functions. Journal of Geophysical Research B: Solid Earth 121 (2), 788-811.
Zhang, H., van der Lee, S., Wolin, E., Bollmann, T.A., Revenaugh, J., Wiens, D.A., Frederiksen, A.W., Darbyshire, F.A., Aleqabi, G.I., Wysession, M.E., Stein, S., Jurdy, D.M., 2016. Distinct crustal structure of the North American Midcontinent Rift from P wave receiver functions. Journal of Geophysical Research: Solid Earth 121 (11), 8136-8153.
Bastow, I.D., Eaton, D.W., Kendall, J.-M., Helffrich, G., Snyder, D.B., Thompson, D.A., Wookey, J., Darbyshire, F.A., Pawlak, A.E., 2015. The Hudson Bay Lithospheric Experiment (HuBLE): Insights into Precambrian plate tectonics and the development of mantle keels. Geological Society Special Publication 389 (1), 41-67.
Darbyshire, F. A., Bastow, I. D., Forte, A. M., Hobbs, T. E., Calvel, A., Gonzalez‐Monteza, A., & Schow, 2015. Variability and origin of seismic anisotropy across eastern Canada: evidence from shear‐wave splitting measurements. Journal of Geophysical Research: Solid Earth.
Porritt, R.W., Miller, M.S., Darbyshire, F.A., 2015. Lithospheric architecture beneath Hudson Bay. Geochemistry, Geophysics, Geosystems 16 (7), 2262-2275.
Wolin, E., van der Lee, S., Bollmann, T.A., Wiens, D.A., Revenaugh, J., Darbyshire, F.A., Frederiksen, A.W., Stein, S., Wysession, M.E., 2015. Seasonal and diurnal variations in long-period noise at SPREE stations: The influence of soil characteristics on shallow stations’ performance. Bulletin of the Seismological Society of America 105 (5), 2433-2452.
Darbyshire, F.A., Eaton, D.W., Bastow, I.D. 2013, Seismic imaging of the lithosphere beneath Hudson Bay: Episodic growth of the Laurentian mantle keel, Earth and Planetary Science Letters, vol. 373, pp. 179-193.
Frederiksen, A.W., Bollmann, T., Darbyshire, F., Van Der Lee, S. 2013, Modification of continental lithosphere by tectonic processes: A tomographic image of central North America, Journal of Geophysical Research, vol. 118, no. 3, pp. 1051-1066.
Villemaire, M., Darbyshire, F.A., Bastow, I.D. 2012. P-wave tomography of eastern North America: Evidence for mantle evolution from Archean to Phanerozoic, and modification during subsequent hot spot tectonism, Journal of Geophysical Research : Solid Earth, 117 (12).
Villemaire, M., Darbyshire, F.A., Bastow, I.D., 2012. Evolution of the mantle from Archean to Phanerozoic and its modification during subsequent hotspot tectonism : seismic evidence from eastern North America. Journal of Geophysical Research, 117, doi:10.1029/2012JB009639
Pawlak, A., Eaton, D.W., Darbyshire, F., Lebedev, S., Bastow, I.D. 2012. Crustal anisotropy beneath Hudson Bay from ambient noise tomography: Evidence for post-orogenic lower-crustal flow? Journal of Geophysical Research B: Solid Earth, 117.
Bastow, I.D., Thompson, D., Wookey, J., Kendall, J.-M., Helffrich, G., Snyder, D., Eaton, D. & Darbyshire, F.A.,2011. Precambrian plate tectonics: Seismic evidence from Hudson Bay, Canada, Geology, 39, 91-94.
Stein, S., van der Lee, S., Jurdy, D., Stein, C., Wiens, D., Wysession, M., Revenaugh, J., Frederiksen, A., Darbyshire, F., Bollman, T., Lodewyk, J., Wollin, E., Merino, M. & Tekverk, K., 2011. Learning from failure: the SPREE Mid-Continent Rift Experiment, GSA Today, 21(9), 5-7.
Darbyshire, F.A., Eaton, D.W., 2010. The lithospheric root beneath Hudson Bay, Canada from Rayleigh-wave dispersion: No clear seismological distinction between Archean and Proterozoic mantle, Lithos, 120(1-2), 144-159.
Eaton, D.W., Darbyshire, F., 2010. Lithospheric architecture and tectonic evolution of the Hudson Bay region, Tectonophysics, 480(1-4), 1-22.
Darbyshire, F. A., Lebedev, S., 2009. Rayleigh wave phase-velocity heterogeneity and multi-layered azimuthal anisotropy of the Superior Craton, Ontario, Geophysical Journal International, 176 (1), 215-234. GEOTOP publication n° 2008-0028.
Eaton, D.W., Darbyshire, F., Evans, R., Grutter, H., Jones, A., Yuan, X., 2009. The elusive lithosphere-asthenosphere boundary beneath cratons, Lithos special issue, 109 (1-2), 1-22.
Darbyshire, F.A., Eaton, D.W., Frederiksen, A.W., Ertolahti, L., 2007. New insights into the lithosphere beneath the Superior Province from Rayleigh wave dispersion and receiver function analysis, Geophys. J. Int., 169(3), 1043-1068, doi:10.1111/j.1365-246X.2006.03259.x.
Frederiksen, A.W., Miong, S.-K., Darbyshire, F., Eaton, D., Rondenay, S., Sol, S., 2007. Variations in Lithospheric Thickness Across the Superior Province, Ontario, Canada: Evidence from Tomography and Shear-Wave Splitting, J. Geophys. Res., 112, doi:10.1029/2006JB004861.
Darbyshire, F.A., Asudeh, I., 2006. Generic instrument responses for the POLARIS and FedNor seismograph network in Canada, Geol. Surv. Canada, Open File 5185, 23pp.
Darbyshire, F.A., 2005. Upper mantle structure of Arctic Canada from Rayleigh wave dispersion,Tectonophysics, 405, 1-23.
Darbyshire, F.A., Larsen, T.B., Mosegaard, K., Dahl-Jensen, T., Gudmundsson, Ó., Bach, T., Gregersen, S., Pedersen, H.A., Hanka, W., 2004. A first detailed look at the Greenland lithosphere and upper mantle, using Rayleigh wave tomography, Geophys. J. Int., 158, 267-286.
Darbyshire, F.A., 2003. Crustal structure across the Canadian High Arctic region from teleseismic receiver function analysis, Geophys. J. Int., 152, 372-391.
Snyder, D., Asudeh, I., Darbyshire, F., Drysdale, J., 2002. Field-based feasibility study of teleseismic surveys at high northern latitudes, Northwest Territories and Nunavut, Geol. Surv. Canada, Current Research C03, 10 pp.
Weir, N.R.W., White, R.S., Brandsdóttir, B., Einarsson, P., Shimamura, H., Shiobara, H., RISE fieldwork team,2001. Crustal structure of the northern Reykjanes Ridge and Reykjanes Peninsula, southwest Iceland, J. Geophys. Res.,106, 6347-6368.
Darbyshire, F.A., White, R.S., Priestley, K.F., 2000. Structure of the crust and uppermost mantle of Iceland from a combined seismic and gravity study, Earth Planet. Sci. Lett.,181, 409-428.
Darbyshire, F.A., Priestley, K.F., White, R.S., Stefánsson, R., Jakobsdóttir, S., Gudmundsson, G.,2000. Crustal structure of central and northern Iceland from analysis of teleseismic receiver functions, Geophys. J. Int., 143, 163-184.
Sujet de recherche : Subduction zone slow slip and megathrust earthquake interaction (Costa Rica and Cascadia subduction zones)
Sujet de recherche : Lithospheric structure of the eastern North American Maritimes from surface wave analysis
Sujet de recherche : Evolution, modification and destruction of cratonic lithosphere: Evidence from surface wave tomography.
Sujet de recherche : Shear wave splitting and seismic anisotropy of Greenland.