TongaKermadecBogen

The TongaKermadecBogen is a major tectonic feature in the southwest Pacific Ocean, comprising the Tonga Trench, the Kermadec Trench, and the associated volcanic arc that links them. It marks the boundary where the Pacific Plate subducts beneath the Australian Plate, producing intense seismicity and magmatism. The system extends from the Lau Basin region near Tonga northward to the Kermadec Islands north of New Zealand.

The trenches reach great depths and host some of the deepest oceanic trenches. The volcanic arc includes the island realm of Tonga and the Kermadec Islands, and contains many submarine volcanoes and hydrothermal vent systems. The back-arc region, including the Lau Basin, reflects slab rollback and complex mantle flow.

The TongaKermadecBogen is central to studies of subduction dynamics, arc volcanism, and regional geohazards. Its high seismicity includes large thrust earthquakes that can trigger tsunamis, affecting Pacific nations and offshore infrastructure. It remains a focus for marine geology and plate tectonics research.