1960 Tsunami a timely reminder for Whitianga
Fifty eight years ago in May 1960 a strong sequence of earthquakes that lasted until June 6 rocked Chile, killed thousands, and caused inundation around the Pacific Rim, including at Whitianga and the eastern coast of New Zealand.
The strongest quake dubbed the Great Chilean earthquake (Gran terremoto de Chile) occurred on May 22nd at 19:11 GMT (May 23 NZ), lasted for 10 minutes and was the most powerful earthquake that had ever been recorded.
Localised tsunamis with waves up to 25 metres (85 ft) battered the Chilean coast and raced across the Pacific devastating Hilo, Hawaii.
Waves as high as 10.7 metres were recorded 10,000 miles away from the epicentre (near Lumaco, about 570 kms south of Santiago), and as far away as Japan, the Phillipines and New Zealand.
On 23 May 1960 (NZ time), a tsunami from the magnitude 9.5 Great Chilean Earthquake (May 22 Chile) caused damage in New Zealand coastal areas.
Whitianga was strongly effected by the tsunami which caused flooding along the harbour and portions of Buffalo Beach.
Writing in a book about Coromandel history, Eugene and Valerie Grayland, when recounting the story of the HMS Buffalo in 1969 said,"Until sixty years ago the ribs of the ship could be seen at low water, but later the wreckage settled further into the seabed and disappeared, to reappear dramatically in May 1960 when a seismic wave caused by earthquakes in Chile created strange effects round New Zealand coasts. Whitianga residents ran out over the sands that were left dry after the sea receded in this freakish fashion and searched for relics in the remains of the wreck. The sea later covered the wreck again."
Eyewitness accounts of the effects of the 1960 Chile tsunami in Whitianga were sourced from the New Zealand Nautical Almanac.
H W Pascoe and Bruce Smith provided some insight in to the character of the tsunami inundation at Whitianga overnight from May 23 to May 24, 1960 (NZ time).
Bruce Smith stated that he first observed the tsunami effects around 9:30 pm on May 23. "The sea came up Monk Street to where the Power Station was and up to the Dairy Company front office steps. There was inundation ‘into the old aerodrome hangar along the northern end of Buffalo Beach, where it wet crates of corrugated iron stored on the floor damaging them."
Pascoe’s account also gave some indication of the current speed when he stated that a vessel he was handling was "doing 12 knots and going backwards" due to an incoming surge. He added that they continued to move backwards for "20 minutes until the tide turned and swept us out through the entrance to safety." He also noted that "about 2 am on Tuesday morning in Whitinga seemed to be the worst time." Mr Pascoe also described the weather as "very fine" with "practically no wind or swell outside in the Bay."
Whitianga has experienced three tsunamis since European settlement - in 1808, 1877 and 1960.
The unique shape of the town's inner bays enhances the risk of damage during a tsunami.
Mercury Bay’s shape would cause waves to bounce around the bay and potentially swamp parts of Buffalo Beach, and enter the harbour near the marina.
Just before noon on 25 May, a radio message from Hawaii said that a tsunami from a major aftershock of the Chile earthquake might hit New Zealand within about an hour and a half. It sparked a major tsunami evacuation.
Warned by nationwide radio broadcasts ("A wave is reported approaching at 400 miles an hour") and telephone messages, port facilities along the east coast were cleared, schools in low-lying coastal areas were closed and children were taken to safe areas.
Almost the entire populations of Whitianga, Mercury Bay, Waihī Beach, Whakatāne, Ōhope, Ōpōtiki and Kaikōura headed for high ground.
It was the largest evacuation in New Zealand’s history. The warnings, however, had an unintended side effect – many people went to the coast to watch the tsunami arrive.
Luckily, it proved to be very minor, and hard to separate from the fluctuations continuing from the main tsunami. Had it been larger, however, many onlookers could have drowned, as tsunami waves travel much faster than people can run.