TY - JOUR
T1 - The Tornquist Zone, a north east inclining lithospheric transition at the south western margin of the Baltic Shield
T2 - Revealed through a nonlinear teleseismic tomographic inversion
AU - Voss, P.
AU - Mosegaard, K.
AU - Gregersen, S.
AU - Pedersen, L.B.
AU - Roberts, R.G.
AU - Shomali, H.
AU - Berthelsen, A.
AU - Thybo, H.
AU - Pedersen, T.
AU - Kind, R.
AU - Bock, G.
AU - Gossler, J.
AU - Wylegala, K.
AU - Rabbel, W.
AU - Woelbern, I.
AU - Budweg, M.
AU - Busche, H.
AU - Korn, M.
AU - Hock, S.
AU - Guterch, A.
AU - Grad, M.
AU - Wilde-Piorko, M.
AU - Zuchniak, M.
AU - Plomerova, M.
AU - Ansorge, J.
AU - Kissling, E.
AU - Arlitt, R.
AU - Waldhauser, F.
AU - Ziegler, P.
AU - Achauer, U.
AU - Pedersen, H.
AU - Cotte, N.
AU - Paulssen, H.
AU - Engdahl, E.R.
N1 - Funding Information:
The present work has been carried out within the framework of the international TOR Working Group with the following members, besides the three main authors: L. B. Pedersen, R. G. Roberts, H. Shomali, A. Berthelsen, H. Thybo, T. Pedersen, R. Kind, G. Bock, J. Gossler, K. Wylegala, W. Rabbel, I. Woelbern, M. Budweg, H. Busche, M. Korn, S. Hock, A. Guterch, M. Grad, M. Wilde-Piorko, M. Zuchniak, J. Plomerova, J. Ansorge, E. Kissling, R. Arlitt, F.Waldhauser, P. Ziegler, U. Achauer, H. Pedersen, N. Cotte, H. Paulssen and E. R. Engdahl. The TOR project has been supported in Germany by the GeoForschungsZentrum Potsdam through personnel and seismographs from the German seismograph pool, and by the Deutsche Forschungsgemeinschaft, in Switzerland by the Swiss National Science Foundation under contract no. 21-43444.95, in Denmark by the Danish Natural Science Research Council, grant no. 9401105, and in Sweden by the Swedish Natural Science Research Council, contract no. G-AA/GU 04990-336. The field work of the Polish groups was partly supported by the Institute of Geophysics, Polish Academy of Sciences. The research of the Czech group was partly supported by a grant of the Czech Academy of Sciences. We thank S. Sandoval and an anonymous reviewer for thoughtful and constructive reviews. H. M. Benz is thanked for constructive comments to this study and for hosting the first author. Figures were produced using GMT ( Wessel and Smith, 1991 ). This is a EUROPROBE publication.
PY - 2006/4/5
Y1 - 2006/4/5
N2 - From July 1996 to August 1997 the TOR project operated 130 seismographs in North Germany, Denmark and South Sweden, with the aim of collecting signals from local, regional and teleseismic earthquakes. This data set is particularly interesting since the seismic antenna crosses the most significant geological boundary in Europe, the Tornquist Zone, which in the northern part is the border between the Baltic Shield and the younger European lithosphere. Previous studies have shown significant physical changes in the crust and upper mantle across this transition zone, including two independent teleseismic tomographic studies of the TOR data set. But these two studies disagree on the orientation of the slope of the transition. Both studies used an iterative linearized inversion method. We will in this work Preprint submitted to Elsevier Science 27 July 2005 present an inversion based on Bayesian statistics, where the solution space is examined in order to study a very large number of tomographic solutions and to examine the solution uniqueness and uncertainty. The method is applied to measurements of 3345 relative teleseismic P-phase travel times from 48 teleseismic earthquakes with good azimuthal coverage with respect to the great circle arc of the TOR array. We find the lithospheric transition to be a north east inclination of around 30°to 45° off vertical.
AB - From July 1996 to August 1997 the TOR project operated 130 seismographs in North Germany, Denmark and South Sweden, with the aim of collecting signals from local, regional and teleseismic earthquakes. This data set is particularly interesting since the seismic antenna crosses the most significant geological boundary in Europe, the Tornquist Zone, which in the northern part is the border between the Baltic Shield and the younger European lithosphere. Previous studies have shown significant physical changes in the crust and upper mantle across this transition zone, including two independent teleseismic tomographic studies of the TOR data set. But these two studies disagree on the orientation of the slope of the transition. Both studies used an iterative linearized inversion method. We will in this work Preprint submitted to Elsevier Science 27 July 2005 present an inversion based on Bayesian statistics, where the solution space is examined in order to study a very large number of tomographic solutions and to examine the solution uniqueness and uncertainty. The method is applied to measurements of 3345 relative teleseismic P-phase travel times from 48 teleseismic earthquakes with good azimuthal coverage with respect to the great circle arc of the TOR array. We find the lithospheric transition to be a north east inclination of around 30°to 45° off vertical.
KW - Markov chain Monte Carlo inversion
KW - Teleseismic tomography
KW - Tornquist Zone
UR - http://www.scopus.com/inward/record.url?scp=33645893173&partnerID=8YFLogxK
U2 - 10.1016/j.tecto.2005.11.016
DO - 10.1016/j.tecto.2005.11.016
M3 - Article
VL - 416
SP - 151
EP - 166
JO - Tectonophysics
JF - Tectonophysics
SN - 0040-1951
IS - 1-4
ER -