The Tonga Plate is a small southwest Pacific
tectonic plate
Plate tectonics (from the la, label=Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of large te ...
or microplate. It is centered at approximately 19° S. latitude and 173° E. longitude. The plate is an elongated plate oriented NNE - SSW and is a northward continuation of the Kermadec linear zone north of New Zealand. The plate is bounded on the east and north by the
Pacific Plate
The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At , it is the largest tectonic plate.
The plate first came into existence 190 million years ago, at the triple junction between the Farallon, Phoenix, and Iza ...
, on the northwest by the
Niuafo’ou Microplate, on the west and south by the
Indo-Australian Plate
The Indo-Australian Plate is a major tectonic plate that includes the continent of Australia and the surrounding ocean and extends northwest to include the Indian subcontinent and the adjacent waters. It was formed by the fusion of the Indian an ...
. The Tonga plate is subducting the Pacific plate along the
Tonga Trench. This subduction turns into a
transform fault
A transform fault or transform boundary, is a fault along a plate boundary where the motion is predominantly horizontal. It ends abruptly where it connects to another plate boundary, either another transform, a spreading ridge, or a subductio ...
boundary north of Tonga. An active rift or spreading center separates the Tonga Plate from the Australian Plate and the Niuafo’ou microplate to the west. The Tonga Plate is seismically very active and is rotating clockwise.
These were the plates that moved when the
2009 tsunami
The 2009 Samoa earthquake and tsunami took place on 29 September 2009 in the southern Pacific Ocean adjacent to the Kermadec-Tonga subduction zone. The submarine earthquake occurred in an Extensional tectonics, extensional environment and had a ...
hit Samoa.
See also
*
References
*Bird, P., An updated digital model of plate boundaries, Geochem. Geophys. Geosyst., 4(3), 1027, , 2003.
Tectonic plates
Natural history of Oceania
Geology of the Pacific Ocean
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