A swarm of powerful earthquakes struck in the ocean off New Zealand's northeastern coast Friday — with three of them measuring magnitude 7.0 and above — triggering some evacuations and tsunami warnings across the South Pacific.At this time, no tsunami threats have been reported for the California coast. The magnitude 8.1 tremor hit at 8:28 a.m. local time, only hours after a magnitude 7.4 struck near the Kermadec Islands at 6:41 a.m. and a magnitude 7.3 was centered off the east coast of the North Island at 2:27 a.m., according to the U.S. Geological Survey.Hawaii is under a tsunami watch, meaning the threat and potential effects are still being evaluated by the Pacific Tsunami Warning Center.A Tsunami threat warning has been issued for parts of Mexico and South America. The U.S. Tsunami Warning System also cautioned that the larger quake could cause tsunami waves of between 3 to 10 feet in Vanuatu and waves of up to 1 to 3 feet in several locations including Australia, Fiji, French Polynesia, New Caledonia and the Solomon Islands.This is a developing story, stay with KSBW 8 for the latest. -- The SF Gate contributed to this story.