Publication Date:
2017-06-06
Description:
The presented study is a part of the passive seismic
experiment PASSEQ 2006–2008, which took place around
the Trans-European Suture Zone (TESZ) from May 2006 to
June 2008. The data set of 4195 manually picked arrivals of
teleseismic P waves of 101 earthquakes (EQs) recorded in
the seismic stations deployed to the east of the TESZ was
inverted using the non-linear teleseismic tomography algorithm
TELINV. Two 3-D crustal models were used to estimate
the crustal travel time (TT) corrections. As a result,
we obtain a model of P-wave velocity variations in the upper
mantle beneath the TESZ and the East European Craton
(EEC). In the study area beneath the craton, we observe up
to 3% higher and beneath the TESZ about 2–3% lower seismic
velocities compared to the IASP91 velocity model. We
find the seismic lithosphere–asthenosphere boundary (LAB)
beneath the TESZ at a depth of about 180 km, while we observe
no seismic LAB beneath the EEC. The inversion results
obtained with the real and the synthetic data sets indicate a
ramp shape of the LAB in the northern TESZ, where we observe
values of seismic velocities close to those of the craton
down to about 150 km. The lithosphere thickness in the EEC
increases going from the TESZ to the NE from about 180 km
beneath Poland to 300 km or more beneath Lithuania. Moreover,
in western Lithuania we find an indication of an uppermantle
dome. In our results, the crustal units are not well
resolved. There are no clear indications of the features in the
upper mantle which could be related to the crustal units in the
study area. On the other hand, at a depth of 120–150 km we
indicate a trace of a boundary of proposed palaeosubduction
zone between the East Lithuanian Domain (EL) and theWest
Lithuanian Granulite Domain (WLG). Also, in our results,
we may have identified two anorogenic granitoid plutons.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
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