Update October 2023
Scientists have recently reported the discovery of a massive body of water underneath the bed of the ocean in the Hikurangi Subduction Zone off the east coast of New Zealand. Seismologists indicate there is a 26% chance of a mega 9 earthquake in the next 50 years within the Alpine Fault region. The previously undiscovered reservoir is more than 3km below the Tasman Sea floor.
New Zealand needs to significantly beef-up financial reserve planning to deal with natural disasters. The Natural Disaster Fund has taken a beating since the Christchurch 7.1 magnitude earthquake on 4th September 2010 (epicentre 40km west of the city at a depth of 11km) and another 6.3 magnitude earthquake on 22nd February 2011 (epicentre 10km south west of the city at a depth of 5km).
Aftermath of Christchurch earthquake
An earthquake (title image) which struck the Tokyo -Yokohama region of Japan (the Great Kantō Earthquake) before noon on 1 September 1923 was so powerful it destroyed the central weather bureau’s seismological equipment. It was a 7.9 magnitude offshore quake and the epicentre was 60km south of Tokyo, 9.7km beneath the floor of Sagami Bay. An estimated 142,800 people died and most of the city’s buildings along with 290,000 homes were destroyed. The resultant damage was estimated at ¥5.5bn which was equivalent to 37% of Japan’s gross domestic product at that time.
Japan is bracing itself for another “big one” and seismologists predict there is a 70% chance of a massive earthquake hitting the Tokyo metropolitan area within thirty years and could cause direct damage costing ¥47tn (NZ$536bn). Disruption to manufacturing and commerce could cost an additional ¥48tn (NZ$547bn). An estimated 4.53 million people may be unable to return to their homes and an estimated 3 million people may be forced to evacuate. These estimates were provided by Japan’s Cabinet Office.
Scientific research indicates there is a 75% probability of a New Zealand Alpine Fault earthquake occurring within the next 50 years and there is a 4 out of 5 chance that it will be a magnitude 8+ event.