A natural and controlled source seismic profile through the Eastern Alps: TRANSALP

Institut für Geowissenschaften, Universität Potsdam, POB 601553, 14415 Potsdam, Germany
Earth and Planetary Science Letters (Impact Factor: 4.73). 08/2004; 225(1):115-129. DOI: 10.1016/j.epsl.2004.05.040


The combined passive and active seismic TRANSALP experiment produced an unprecedented high-resolution crustal image of the Eastern Alps between Munich and Venice. The European and Adriatic Mohos (EM and AM, respectively) are clearly imaged with different seismic techniques: near-vertical incidence reflections and receiver functions (RFs). The European Moho dips gently southward from 35 km beneath the northern foreland to a maximum depth of 55 km beneath the central part of the Eastern Alps, whereas the Adriatic Moho is imaged primarily by receiver functions at a relatively constant depth of about 40 km. In both data sets, we have also detected first-order Alpine shear zones, such as the Helvetic detachment, Inntal fault and Sub-Tauern ramp in the north. Apart from the Valsugana thrust, receiver functions in the southern part of the Eastern Alps have also observed a north dipping interface, which may penetrate the entire Adriatic crust [Adriatic Crust Interface (ACI)]. Deep crustal seismicity may be related to the ACI. We interpret the ACI as the currently active retroshear zone in the doubly vergent Alpine collisional belt.

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    • "It is imaged by the K-model as well, and furthermore, Dando (2010) delineated this slab by teleseismic tomography based on data from the CBP-project (Dando et al., 2011; Houseman et al., 2010). Additional support for the existence of high velocity mantle above the 410 km mantle discontinuity is supplied by receiver functions, which have piercing points in the area of the " deep slab " (Kummerow et al., 2004). The L-model does not extend as deep and far enough to the east to resolve this high velocity body. "
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    • "Beneath the ''Transalp'' seismic profile in the Eastern Alps, the European Moho is imaged by both reflection seismic and receiver functions to dip gently southward, from a depth of 35 km beneath the northern foreland to a maximum depth of 55 km beneath the central part of the Eastern Alps. In contrast, the Adriatic Moho is imaged by the receiver function method to be at a relatively constant depth of about 40 km (Kummerow et al. 2004). A south-directed subduction of European lithosphere was also reconstructed for the entire Eastern Alps (Brückl et al. 2010), contrary to the northward subduction of the Adriatic plate beneath the European plate since late Oligocene to Miocene time as has been suggested (Schmid et al. 2004) based on mantle tomography (Lippitsch et al. 2003). "
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    • "In Fig. 9, the velocity maps at 24 and 30 s still exhibit low velocities associated with the Alps and northern-central Apennines. The low velocities beneath the central Alps are probably related to the thick crust in this region, where the crust has been estimated to be about 50 km (Waldhauser et al. 2002; Kummerow et al. 2004; Li et al. 2007; Tesauro et al. 2008). The low-velocity anomalies "
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