biostudies-literatureUnknown13(1)Qu RBecause of the steep subduction of a highly concave slab, researchers have characterized megathrusts under the Marianas as among the coldest and curviest plate coupling interfaces in various circum-Pacific subduction zones. Seismic tomography indicates that the heterogeneous underlying plate varies markedly in its subduction angle, velocity, and flexure along the strike and dip, while their effects on the thermal structure and intraslab earthquake occurrence remain enigmatic. By incorporating the 3-D MORVEL velocity and state-of-the-art slab geometry into thermomechanical modeling, we estimated the 3-D subduction thermal state and hydrothermal regime below the Marianas. We find that (1) the concave slab geometry and the complexity of the intraslab velocity variation in the Marianas are assScientific reports1948https://www.ebi.ac.uk/biostudies/studies/S-EPMC9894833biostudies-literatureSubduction thermal regime, petrological metamorphism and seismicity under the Mariana arc.PMC9894833Qu RZhang FZhu WJi YXie CZeng DfalseSubduction thermal regime, petrological metamorphism and seismicity under the Mariana arc.Because of the steep subduction of a highly concave slab, researchers have characterized megathrusts under the Marianas as among the coldest and curviest plate coupling interfaces in various circum-Pacific subduction zones. Seismic tomography indicates that the heterogeneous underlying plate varies markedly in its subduction angle, velocity, and flexure along the strike and dip, while their effects on the thermal structure and intraslab earthquake occurrence remain enigmatic. By incorporating the 3-D MORVEL velocity and state-of-the-art slab geometry into thermomechanical modeling, we estimated the 3-D subduction thermal state and hydrothermal regime below the Marianas. We find that (1) the concave slab geometry and the complexity of the intraslab velocity variation in the Marianas are ass2023-01-01T00:00:00Z2023 Feb2025-04-26T13:02:08.759Z2025-04-06T14:07:07.851ZS-EPMC98948333673255410.1038/s41598-023-29004-1