Sunda subduction drives ongoing India-Asia convergence

• Published in: Tectonophysics Vol. 849; p. 229727
• Main Authors: Bose, Santanu, Schellart, Wouter P., Strak, Vincent, Duarte, João C., Chen, Zhihao
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 20.02.2023
• Subjects: Driving force of plate motion; Geodynamics; India-Eurasia collision; Indian indentation; Subduction; India-Eurasia collision; Geodynamics; Indian indentation; Driving force of plate motion; Subduction
• ISSN: 0040-1951; 1879-3266
• DOI: 10.1016/j.tecto.2023.229727

The Himalaya and the Tibetan plateau, the highest mountain range on Earth, have been growing continuously for the last 55 Myr since India collided with Eurasia. The forces driving this protracted mountain building process are still not fully understood. Although subduction zones are considered the main driving force for plate tectonics, mantle flow and plate boundary migration, their role in driving the Indian indentation and the northward movement of the collisional plate boundary is yet to be tested with geodynamic models. Here, we use four-dimensional geodynamic physical models to show that active subduction of the Indo-Australian plate along the Sunda subduction zone is probably the main driver of the India-Asia convergence, Indian indentation, and the consequent growth of the Himalaya-Tibet mountains, and also the present-day eastward crustal displacement of southeast Asia. Our experiments show that at least 880 km of northward indentation of India would not have ensued in the absence of the lateral subduction zones. Our experiments with lateral subduction zones show that subduction of the Indian continental lithosphere is maximum close to the eastern and western syntaxes, which ranges between 450 and 500 km. Based on our model results we propose that the protracted growth of collisional mountains on Earth, like the Himalaya, is highly dependent on nearby active subduction zones. •Buoyancy-driven 4D geodynamic models investigate the role of the slab pull force on continental subduction and indentation.•Active subduction at the Sunda trench is the principal driver of ongoing India-Asia convergence and Indian indentation.•Our models predict that lateral subduction zones lead to mountain growth like the Himalaya over tens of millions of years.