Magnitude 6.0 Earthquake on South Island, New Zealand.

The GeoNet project, which monitors quakes in New Zealand, recorded a Magnitude 6.0 Earthquake at a depth of 5 km in the Southern Alps to the northwest of Christchurch, slightly before 6.50 am local time on Tuesday 6 January 2015 (slightly before 5.50 pm on Monday 5 January, GMT). This was a large event, and potentially dangerous, though there are no reports of any damage or casualties. The area has been hit by several aftershocks since the initial event.

 The approximate location of the 6 January 2015 Southern Alps Earthquake.  Google Maps.

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 such as the ones felt in Christchurch recently. 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, fueling the volcanoes of New Zealand.

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.

See also...

Magnitude 4.6 Earthquake near Christchurch, New Zealand.                                        A Magnitude 6.6 Earthquake at a depth of 8 km hit New Zealand's South Island, 10 km southwest of Christchurch, slightly after 11.35 pm local time (slightly after 10.35 am GMT)...

Magnitude 4.7 Earthquake under Cook Straight, New Zealand.                                               New Zealand's GeoNet Project, which monitors geohazards in the country, recorded a Magnitude 4.7 Earthquake at a...

Eruption on White Island.                                          White Island, or Te Puia o Whakaari, an island volcano in New Zealand's Bay of Plenty, began to erupt  suddenly at about 10.20 am local time on Monday 20 August 2013, producing a...

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