How is convergence accomodated in this complicated area?
The Solomon and Vanuatu Islands are subduction-related features caused by the subduction of the Indo-Australian Plate beneath the greater Pacific Plate. It is a seismically active area of frequent large earthquakes. This animation addresses both the subduction earthquakes, as well as a strike-slip component between the island chains. Basically the earthquakes are caused by the northeasterly movement of the Indo-Australian Plate as it dives beneath the Pacific Plate, but there are variations along the plate boundary
The Solomon and Vanuatu Islands occupy the center of a region that is marked by a complicated arrangement of tectonic micro plates crushed between the greater Pacific and Indo-Australian Plates. It is a seismically active area of frequent large earthquakes. The Australian continent is moving northeast at a rate of ~6 cm/year with variation along the boundaries up to 13 cm/year. In the region of the Solomon and Vanuatu islands, the earthquakes are caused by the northeasterly movement of the Indo-Australian Plate as it dives beneath the Pacific Plate.
Three areas in cross section to reveal a change from
- Steeply dipping subduction along the New Hebrides trench
- Strike slip motion along the Solomon Islands
- Shallow subduction zone to the west.