The lithosphere‐asthenosphere boundary and mid‐lithospheric discontinuities are primary
attributes of the upper mantle. The Pannonian region is an extensional sedimentary
basin enclosed by collisional orogens. Here, we estimate the negative phase depth
of S‐to‐P receiver functions to image the lithospheric thickness and other discontinuities
with high resolution, based on the recent dense seismological broadband networks.
The lithosphere‐asthenosphere boundary is relatively shallow (<90 km) in the Pannonian
Basin system, and deeper (∼90–140 km) in the surrounding orogens, where average surface
heat flow values are higher (120 mW/m2) and lower (50–70 mW/m2),
respectively. The 1D and 2D common conversion point migration with 3D velocity model
provide comparable but different resolution images beneath the wider region of the
Pannonian Basin. We obtained deeper values in the Western (∼120 km) and Southern‐Carpathians
orogens (∼135 km). Furthermore, we provide new information on the lithospheric thickness
and its seismic properties in the eastern part of the study region (e.g., Apuseni
Mountains (∼95 km), Eastern‐Carpathians (∼120 km), Moesian Platform (∼90 km) and Transylvanian
Basin (∼85 km). The shallower negative phase depth can be interpreted as the lithosphere‐asthenosphere
boundary beneath the Pannonian Basin system in agreement with its high heat flow values.
In contrast, the deeper negative phase depth estimates in the colder surroundings
can be interpreted as intra‐ or mid‐lithospheric discontinuities, when compared with
local seismic tomography models. In this region, the correlation with heat flow implies
that the observed negative phase depth is of thermo‐chemical or rheological nature.
