It is the 3rd earthquake today in the region
The Kermadec Islands are a subtropical island arc in the South Pacific Ocean 800-1,000 km northeast of New Zealand's North Island, and a similar distance southwest of Tonga.
A tsunami is possible after that magnitude 8 earthquake. This is according to the United States tsunami warning system.
There also has been 5 magnitude earthquake 7 km south southwest of Krania, Elassona Greece