Bathymetry and gravity profiles from the southwest Pacific have been used to locate and characterize the trace of a ridge-ridge-ridge triple junction created between ~84 and ~120 Ma. In areas free of subsequent volcanism, the triple junction trace is identified by a 1 km-deep bathymetric trough bordered by seafloor spreading fabric with distinctly different trends. Crustal thickness estimates obtained with gravity models indicate the triple junction trace is often characterized by anomalously thin crust, which may result from relatively low melt production at a triple junction. Crustal thickness estimates follow previously identified spreading rate-related trends.