Crustal Structure of the British Isles and its Epeirogenic Consequences

Davis, M. W. and White, N. J. and Priestley, K. F. and Baptie, B. J. and Tilmann, F. (2012) Crustal Structure of the British Isles and its Epeirogenic Consequences. Geophysical Journal International, 190 (2). pp. 705-725. DOI 10.1111/j.1365-246X.2012.05485.x

[img] PDF (This is a RoMEO green journal)
j.1365-246X.2012.05485.x.pdf
Restricted to Registered users only

Download (15MB)

Abstract

Crustal receiver functions have been calculated for a network of 51 three-component broadband seismometers distributed across the British Isles and NW Europe. Over 3200 receiver functions were assembled for 1055 events. For each station, preliminary estimates of crustal thickness and Vp/Vs ratio were obtained from H−κ plots. Stacked receiver functions were then inverted to determine shear wave velocity as a function of depth. Each result was checked by guided forward modelling and by Monte Carlo error analysis. In this way, the robustness of our final calculated velocity profiles was carefully tested. A set of depth migrated profiles was also constructed using an average of 50 events for each station over a range of backazimuths. These profiles agree well with legacy wide-angle crustal models. Our results show that crustal thickness varies between 24 and 36 km across the British Isles. Thicker crust is found beneath north Wales and beneath central Scotland. Thinner crust occurs beneath northwest Scotland and northwest Ireland. By combining our database with the results of controlled source, wide-angle experiments and with depth-converted reflection profiles, we have produced a detailed crustal thickness map for a region encompassing the British Isles. Our synthesis of crustal thickness and structure has important implications for the tectonic and magmatic histories of this region. Complex Moho structure with lower crustal P-wave velocities of >7 km s−1 occurs beneath regions of Cenozoic magmatism, which may be consistent with magmatic underplating. Thin crust beneath northern Britain suggests that present-day long wavelength topography is maintained by regional dynamic support, originating beneath the lithospheric plate.

Item Type: Article
Uncontrolled Keywords: 2012AREP; IA63;
Subjects: 02 - Geodynamics, Geophysics and Tectonics
Divisions: 02 - Geodynamics, Geophysics and Tectonics
Journal or Publication Title: Geophysical Journal International
Volume: 190
Page Range: pp. 705-725
Identification Number: 10.1111/j.1365-246X.2012.05485.x
Depositing User: Sarah Humbert
Date Deposited: 27 Mar 2012 13:31
Last Modified: 23 Jul 2013 10:03
URI: http://eprints.esc.cam.ac.uk/id/eprint/2432

Actions (login required)

View Item View Item

About cookies