New Hebrides trench: subduction rate from associated lithospheric bulge

Abstract

We present new data on the lithospheric bulge in the vicinity of the Loyalty and New Hebrides Islands, and attempt to interpret the difference of the topographic profile of the outer wall of the New Hebrides trench from a theoretical profile. The free edge of the lithospheric plate appears to correspond to a line of maximum seismic strain release. The uplift rate and consequently the subduction rate have been calculated from studies of the dynamic aspect of the bulge and from 230Th/234U ages of raised coral terraces.