The shake in Gisborne
Posted 21 December 2007 // Te Ara
Last night’s earthquake 50 km south-east of Gisborne was a magnitude 6.8 shake at a depth of 40 km.
Extent of shaking, 1855 earthquake
You might like to compare that with some of New Zealand’s historic earthquakes – though the 1931 Hawke’s Bay quake (7.8 magnitude) is the best known and caused by far the greatest loss of life, the largest recorded was the Wairarapa and Wellington earthquake of 1855 – 8.2 on the magnitude scale. (OK, the Richter scale, if you like. Though that term seems to be out of fashion with the geologists these days.)
Even more informative, however, is the Modified Mercalli scale, which measures the intensity by the effects felt at different distances from the earthquake’s centre, from MM1 (Imperceptible) to MM12 (Completely devastating).
