Structure of the crust and upper mantle beneath the Bransfield Strait (Antarctica) using P receiver functions

The Bransfield Strait is a tectonically active back-arc rift basin located between the South Shetland archipelago (SSI) and Antarctic Peninsula (AP). We use teleseismic P-wave receiver functions from twelve seismic stations in order to improve current understanding of crustal upper mantle structure region. calculate thickness average Vp/Vs ratio crust, Mantle Transition Zone (MTZ) their spatial variability along study area. Our analysis reveals homogeneous AP, averaging 33.5 ± 1.2 km. VP/VS increases east west, with an 1.78 0.04 typical continental crust. In SSI results are highly heterogeneous. minimum observed Deception Island (~15 km), near axis, while crust thickens towards edges ~30 High ratios (>1.95) correlate shallow Moho may be linked presence melts accordance volcanism detected underplating layer Phoenix slab beneath SSI. There evidence low velocity zone (LVZ) wedge under also suggesting there widespread partial melting mantle. infer that dips steeply, as we observe thickened MTZ AP.