West-east transition from underplating to steep subduction in the India-Tibet collision zone revealed by receiver-function profiles

- Closely-spaced receiver-function profiles image India-Tibet collision at 90-92°E.
- Indian lower crust is presently thicker in the west than in the east.
- Indian plate transitions from underplating to steep subduction at about 91.5°E.
- Plate convergence taken up alternately by underthrusting and subduction/delamination.