At 9.26 this morning a devastating earthquake struck New Zealand, trapping Central Otago residents in the region. All roads in and out of the area have been blocked and emergency relief and supplies are not expected to arrive for another seven days. Panic buying has set in and police have shut down petrol stations and closed supermarkets. Only a handful of the seriously injured can be airlifted for medical treatment. Risks include severe rockfall, tsunamis and opening of cracks. Tsunamis are possible on Lake Dunstan and Lake Roxburgh, not as a direct result of an earth- quake, but when a landslide or rockfall enters the lake. People should avoid the water and move to higher ground, particularly people residing in Cromwell. Today more than 1.2 million people have taken part in New Zealand’s largest earthquake drill, ShakeOut. Over 4200 of them were in Central Otago. Schools and businesses held exercises and those taking part ducked for cover then evacuated their premises. The most probable natural disasters in Central Otago are an earthquake, fire or flood. In the
event of a large earthquake, up to a magnitude eight on the Richter scale, the Clyde dam, which has been built to high specifications, is not expected to burst. However, if an earthquake over magnitude eight struck and the dam did burst it would be Alexandra residents, not Clyde, who would be initially flooded by the rushing water. The water would hit the Clock and Bridge hills then surge back to Clyde. Central Otago District Coun- cil emergency management officer Hamish Keith, who helped in Christchurch after both the September 2010 and February 22 earthquakes, said in the event the dam burst Alexandra residents should try to get above the historic flood line on Station St. As Central Otago was considered one of the most isolated regions in New Zealand it has been estimated in the event of a devastating earthquake or other natural disaster it could take a week, or longer, for aid from Civil Defence to arrive. In most other areas of New Zealand relief was expected to take three days to arrive. As the region’s emergency management officer Mr Keith could be considered the most prepared resident in the area and he admits it was not often he did not have a full tank of gas. In an emergency police have the authority to shut down petrol stations, so reserves can be set aside for emergency services, and supermarkets, so food supplies can be rationed if needed. The Alpine Fault, the fault which causes the greatest concern for the area, runs for about 600km up the spine of the South Island and is one of the world’s major geological features. It has ruptured four times in the past 900 years, each time producing an earthquake of about magnitude eight. There is a high probability, estimated at 30 per cent, of it rupturing again in the next 50 years. Central Otago has several local faultlines including the Dunstan Fault and the Cairnmuir Fault.