Ocean site survey reveals anatomy of a hotspot track

Abstract

Seismological field work at a future International Ocean Network (ION) seafloor observatory has provided a unique three‐dimensional seismic image of Ninetyeast Ridge (Figure 1), a 5000‐km‐long hotspot track in the Indian Ocean. Preliminary results indicate that crust within the adjacent ocean basins is typically oceanic, with a mean crustal thickness of about 7 km. Approaching Ninetyeast Ridge, crust thickens to 25 km. Sedimentary cover varies considerably on the volcanic edifice and newly identified small volcanoes resisted erosion near the wave base before lithospheric cooling generated 2000 m of subsidence.