TY - JOUR
T1 - Uniqueness of modeling results from teleseismic P-Wave tomography in Project Tor
AU - Gregersen, S.
AU - Voss, P.
AU - Nielsen, L.V.
AU - Achauer, U.
AU - Busche, H.
AU - Rabbel, W.
AU - Shomali, Z.H.
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 7 authors: L.B. Pedersen, R.G. Roberts, A. Berthelsen, H. Thybo, K. Mosegaard, T. Pedersen, R. Kind, G. Bock, J. Gossler, K. Wylegala, I. Woelbern, M. Budweg, 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, H. Pedersen, N. Cotte, H. Paulssen and E.R. Engdahl. Many scientists have supported the project as members of the original Tor planning group or through the field work with advice. The following scientists are thanked for their participation: D. Gee, R. Gorbatschev, A. Tryggvason, N. Juhojuntti, H. Wagner, N. Balling, B.H. Jacobsen, P.H. Nielsen, W. Hanka, P. and E. Bankwitz, M. Weber, H.-P. Harjes, A. Biegling, J. Skamletz, E. Perchuc, W. Spakman, J. Zednik, T. Hyvonen, S.-E. Hjelt, L.N. Solodilov. The Tor project has been supported in Germany by the GeoForschungsZentrum Potsdam and 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.
PY - 2010/1/15
Y1 - 2010/1/15
N2 - Within Project Tor, which is about Teleseismic Tomography across the Tornquist Zone in Germany-Denmark-Sweden, we have confirmed very significant deep lithosphere differences. And modeling is substantiated via completely independent methods. In 1996-1997 our 130 seismographs constituted the largest seismic antenna ever in Europe. The Tor area was chosen along a well studied crustal profile of an earlier project, and the modeling efforts were concentrated on the deep lithosphere and asthenosphere differences to depths around 300 km. The Tor data have been subjected to P-wave travel time tomography, surface wave and receiver function analysis as well as anisotropy and scattering measurements. An important goal of the project was to make several independent inversions of the tomography data, and compare the results in an attempt to evaluate uniqueness, resolution and accuracy of these inversions. The comparisons of this paper involve more diversity in methods than any previous comparison. The geological outcome is a substantiation of earlier statements that: "The transition is interpreted to be sharp and steep in two places. It goes all through the lithosphere at the northern rim of the Tornquist Zone near the border between Sweden and Denmark, and here the lithosphere difference is large to depths more than 200 km. The other lithosphere difference, of smaller scale, is found near the southern edge of the Ringkøbing-Fyn High near the border between Denmark and Germany. Also this transition is sharp and steep, and goes all through the lithosphere to depths around 120 km. These two sharp transitions divide the Tor region into 3 different lithosphere structures distinguishable in P-wave travel time tomography, surface wave dispersion, P- and S-wave anisotropy and partly in P-wave scattering". The mentioned broad-scale features are judged to be unambiguously determined, with well-described resolution and accuracy. Unfortunately a detail like the slope of the subcrustal lithosphere transition right under the Tornquist Zone cannot be constrained even if this is where the resolution is best, and the curiosity largest.
AB - Within Project Tor, which is about Teleseismic Tomography across the Tornquist Zone in Germany-Denmark-Sweden, we have confirmed very significant deep lithosphere differences. And modeling is substantiated via completely independent methods. In 1996-1997 our 130 seismographs constituted the largest seismic antenna ever in Europe. The Tor area was chosen along a well studied crustal profile of an earlier project, and the modeling efforts were concentrated on the deep lithosphere and asthenosphere differences to depths around 300 km. The Tor data have been subjected to P-wave travel time tomography, surface wave and receiver function analysis as well as anisotropy and scattering measurements. An important goal of the project was to make several independent inversions of the tomography data, and compare the results in an attempt to evaluate uniqueness, resolution and accuracy of these inversions. The comparisons of this paper involve more diversity in methods than any previous comparison. The geological outcome is a substantiation of earlier statements that: "The transition is interpreted to be sharp and steep in two places. It goes all through the lithosphere at the northern rim of the Tornquist Zone near the border between Sweden and Denmark, and here the lithosphere difference is large to depths more than 200 km. The other lithosphere difference, of smaller scale, is found near the southern edge of the Ringkøbing-Fyn High near the border between Denmark and Germany. Also this transition is sharp and steep, and goes all through the lithosphere to depths around 120 km. These two sharp transitions divide the Tor region into 3 different lithosphere structures distinguishable in P-wave travel time tomography, surface wave dispersion, P- and S-wave anisotropy and partly in P-wave scattering". The mentioned broad-scale features are judged to be unambiguously determined, with well-described resolution and accuracy. Unfortunately a detail like the slope of the subcrustal lithosphere transition right under the Tornquist Zone cannot be constrained even if this is where the resolution is best, and the curiosity largest.
KW - Comparison of modeling
KW - Germany-Denmark-Sweden
KW - Lithosphere transition
KW - Model accuracy
KW - Model resolution
KW - Model uniqueness
KW - P-wave tomography
KW - Project Tor
KW - Subcrustal lithosphere
KW - Teleseismic tomography
KW - Tornquist Zone
UR - http://www.scopus.com/inward/record.url?scp=72149112730&partnerID=8YFLogxK
U2 - 10.1016/j.tecto.2009.01.020
DO - 10.1016/j.tecto.2009.01.020
M3 - Article
VL - 481
SP - 99
EP - 107
JO - Tectonophysics
JF - Tectonophysics
SN - 0040-1951
IS - 1-4
ER -