Thousands of people on New Zealand’s North Island were sent into a panic after a powerful 7.1 magnitude earthquake struck the north coast at 4:37 am local time. The quake’s epicenter was located 169 km northeast of Gisborne with a depth of 55 km. There were several reports of homes and buildings having cracks on their walls as well as damages to their water supply, but no casualties or serious injuries.
The earthquake also caused waves as high as 31 cm to form, prompting the government to issue a tsunami warning forcing people to evacuate to higher ground. The warning would later be lifted, but those living close to the coasts were advised that they might experience unusually strong currents and fluctuating sea levels that could last for several hours.
Tsunami Threat CANCELLED but strong & unusual currents are expected for several hours. Stay off beaches & shore areas. DO NOT go sightseeing
— Auckland CDEM (@AucklandCDEM) September 1, 2016
The residents of Gisborne, who had been told earlier to evacuate to higher ground, have since returned to their homes. Gisborne mayor Meng Foon posted a video on his Facebook account of his home’s ceiling shaking as the earthquake took place.
Morning commutes were also disrupted as the Britomart train station in Auckland had to be shut down as a safety precaution following the quake. As many as 4,000 people from as far away as the West Coast and Christchurch reported feeling the 7.1 magnitude earthquake. However, despite the tremors, the fire department reported that there were no damages.
— Stuff.co.nz News (@NZStuff) September 2, 2016
This is the biggest earthquake to hit New Zealand’s North Island in the last 20 years. The last time that the region had experienced an earthquake of this magnitude was way back in 1995 when an intensity 7.2 quake occurred in a similar spot. While earthquakes in the area are not an uncommon occurrence given that it is located in one of New Zealand’s most seismically active areas, having one that measured 7.1 on the Richter scale was a bit surprising, according to John Ristau, a seismologist working for the GNS.
“It’s one of the more seismically active areas in New Zealand, but to have a 7.1 quake is unusual.”
A magnitude 6.8 earthquake was recorded around the same area a couple of years ago in November of 2014. The only difference between this quake and the one that occurred earlier in the day is that the latter took place near an interface boundary or fault line, and not on it.
“What you have in New Zealand is you have the North Island sitting on the Australian tectonic plate and off the East Coast you have the Pacific plate that’s pushing beneath the North Island. That generally causes a lot of earthquakes along the East Coast. What we call it is a plate interface boundary,” said Ristau.
The seismologist also urged citizens to be vigilant as dozens of aftershocks continued to rattle the area. He also suspected that the region might continue to experience aftershocks in the next few days, but added that they would update people as things progressed.
— Simon Smith (@WordSmithNZ) September 1, 2016
Scientists are also looking into the possibility that the seismic event might have been two earthquakes, according to news site stuff.co.nz. According to scientists, the complexity made it far too difficult to estimate the quake’s depth and to identify whether or not there was a tsunami risk involved.
New Zealand is situated in what is known as the Pacific Ring of Fire, a boundary of Australian and Pacific plates that experiences an average of at least 15,000 tremors a year.
In February 2011, a magnitude 6.3 earthquake struck the southern city of Christchurch, which left 185 people dead and causing an estimated $3 billion worth of damage.
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