A strong earthquake that hit New Zealand this week triggered tsunamis and landslides as well as killed at least two people and stranded thousands of others. What's making people talk about the disaster though is the seafloor that emerged out of the water as a result of the tremor.
Powerful Earthquake
The 7.8-magnitude earthquake after midnight on Monday, Nov. 14 was so strong it lifted the sea bed 2 meters (6.56 feet) and exposed seaweed-covered rocks and even marine animals above tide level.
Another 6.2-magnitude quake occurred at about 1:30 p.m., which was followed by more than 60 aftershocks with 4.5 magnitude or greater. Images shared on social media have revealed how the earthquake destroyed roads.
Coastal Uplift
Government-owned research institute GNS Science said that much of the northeastern region of the South Island elevated during the quake. The coast is estimated to have lifted up between 0.5 meters (1.64 feet) and 2 meters.
"The earthquake involved slip on at least four to six distinct faults, with the greatest slip occurring on the Kekerengu fault, which appears to have slipped about 10 meters along part of its length," USGS Earthquake Hazards Program associate coordinator Michael Blanpied said.
The phenomenon is what is known as coastal uplift. It occurs when land is raised above the sea because of tectonic forces. Coastal uplift can gradually happen over a geological timescale. It can also suddenly occur as a result of an earthquake.
Blanpied said that similar coastal uplifts have already been observed in the past, such as during the quakes that struck New Zealand in 1855 and 1931.
Raised Coastline Could Become Permanent Feature
GNS Science said that the newly raised coastline in Kaikoura could become a permanent feature. In many areas in New Zealand, there are historical and prehistoric examples of raised beaches that are still high above sea level. Many parts of the coast in New Zealand have also been repeatedly uplifted through time.
"Raised marine beaches and terraces along the Kaikoura Peninsula, Wairarapa coast, Cape Kidnappers, Mahia Peninsula, north of Gisborne and East Cape, are evidence of former beaches that were uplifted from the sea by earthquakes in prehistorical times," GNS Science said in a statement. "Many of these have been or are currently being studied to find out the size and age of past earthquakes."
Besides the seafloor that emerged out of the water, people have also been talking about the mysterious lights that turned the skies in New Zealand blue and green during the earthquake.
