The GeoNet project, which monitors quakes in New Zealand, recorded a Magnitude 5.4 Earthquake at a depth of 64 km, about beneath the South Taranaki Bight, between North and South islands, New Zealand, at about 11.45 pm New Zealand Daylight Time (about 10.45 am GMT) on Saturday 25 January 2020. There are no reports of any damage or casualties associated with this event, but it was felt by over 26 500 people from Christchurch up to Auckland, according to GeoNet.
The approximate location of the 25 January 2020 South Taranaki Bight Earthquake. USGS.
New Zealand is located on the boundary beneath the Australian and Pacific Plates. Beneath the islands the Pacific Plate is being subducted beneath the Australian Plate. This causes a great deal of friction which causes Earthquakes where the boundary between the two plates is close to the surface; this is to the east of North Island, but onshore on South Island, where it can lead to strong Earthquakes. Technically such quakes also occur where the plate margin is deeper, but these are felt less strongly as the rocks between the boundary and the surface absorb much of the energy, making strong tremors much less frequent on North Island. As the Pacific Plate sinks deeper into the Earth it is partially melted by the friction and the heat of the planet's interior. Some of the melted material then rises through the overlying Australian Plate, fuelling the volcanoes of New Zealand.
The subduction zone beneath New Zealand, and how if fuels Earthquakes and volcanoes. Te Ara.
Witness reports of Earthquakes can help scientists to understand these events, and the underlying geologic processes that cause them. If you felt either of these quakes then you can report it to the GeoNet here.
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