GEOLOGY

Detailed explanation-1: -The main earthquake was 7.2 Ms and the epicentre was near Masterton and 12 km deep. The quake lasted for over a minute and was preceded by a foreshock three hours earlier at 8.15 pm. Many buildings were damaged in Masterton.

Detailed explanation-2: -The biggest known earthquake in New Zealand was the 1855 magnitude 8.2 in the Wairarapa; around 5, 000 km2 of land was shifted vertically during the earthquake. The largest earthquake recorded in the world in the last 100 years was the 1960 magnitude 9.5 earthquake in Chile.

Detailed explanation-3: -The 1855 earthquake is the most severe earthquake to have occurred in New Zealand since systematic European colonisation began in 1840. The shock was felt across almost the whole country, and was highly destructive in Wellington (MM 10), and severely damaging in Whanganui and Kaikōura.

Detailed explanation-4: -The 1855 Wairarapa earthquake occurred on 23 January at about 9.17 p.m., affecting much of the Cook Strait area of New Zealand, including Marlborough in the South Island and Wellington and the Wairarapa in the North Island. In Wellington, close to the epicentre, shaking lasted for at least 50 seconds.

Detailed explanation-5: -The Wairarapa Fault is an active seismic fault in the southern part of the North Island of New Zealand. It is a dextral (right lateral) strike-slip fault with a component of uplift to the northwest as expressed by the Rimutaka Range.