Why does Tonga have so many earthquakes?
Tonga-Kermadec subduction zone, along the southwestern part of the circum-Pacific “Ring of Fire”, produces tsunami-generating earthquakes and volcanoes, including the explosive eruption of Hunga Tonga-Hunga Ha’apai in 2022. The region has surprisingly complex tectonics that generate volcanoes and a variety of earthquakes ranging from deep subduction quakes to shallow great earthquakes that produce tsunamis.
This animation breaks out the history of how the New Hebrides back-arc region developed. Watch the New Hebrides Part 1 first to get a broader overview of the earthquakes, volcanoes and tsunami hazards across the region.
The New Hebrides region is much more than a simple boundary where the Australia Plate dives beneath the Pacific Plate. The two plates converge to form the New Hebrides subduction zone along the southwestern part of the circum-Pacific “Ring of Fire” but the back arc region is far more complex!
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