Subduction

Subduction is a tectonic process in which one lithospheric plate moves beneath another and sinks into the mantle at a convergent plate boundary. This process is associated with deep ocean trenches, volcanic arcs, and some of the world’s largest earthquakes.

In geodesy, subduction zones are monitored using space-geodetic techniques such as GNSS, InSAR, and VLBI to measure plate convergence rates, crustal deformation, and strain accumulation with millimeter precision. Geodetic observations are essential for understanding seismic hazard, earthquake cycles, postseismic deformation, and long-term lithospheric dynamics in subduction regions.