NZ quakes, tsunami warnings
Swell conditions normal in New Zealand. Credit: Benedict Adam/CCBY2.0
New Zealanders woke this morning to a series of earthquakes. The largest of them, an 8.1 magnitude quake centred near the Kermadec Islands, triggered a rush of tsunami warnings for both the east and west coasts in the country’s north.
The 8.1 quake occurred at a depth of 20km, relatively shallow for earthquakes, and conditions created could have caused a large tsunami. Fortunately, ocean conditions stayed calm.
“There are a number of complex criteria that have to come together to determine whether there will be significant tsunami, such as the speed of propagation, and whether material was displaced on the ocean floor,” said Tim Stern, a geophysicist at Victoria University, Wellington.