A magnitude-7.8 earthquake off New Zealand last night briefly triggered a tsunami advisory for Hawaii.

The Pacific Tsunami Warning Center in Ewa Beach canceled the advisory at 12:52 a.m. this morning.
The advisory had warned that while there was no data to suggest a destructive tsunami threat to the Islands, some coastal areas could see small sea level changes and strong or unusual currents lasting for several hours.
The tsunami center says such effects still might occur, beginning shortly after 11 a.m. today.
Oahu lifeguards are urging beachgoers to use caution today because of the possibility of unusual rip currents and strong tidal surges through early this afternoon.
At Hanauma Bay, there were between 500 and 1,000 snorkelers in the water at midday, and city water safety officials reported “absolutely no unusual changes” in the bay waters due to 7.8 quake.
Water safety officials said they didn’t have to ask anyone to leave the water but continue to monitor the situation and are prepared to evacuate the water and adjacent beach if necessary.
The earthquake generated a small tsunami along New Zealand’s coasts, but no injuries or major damage were reported. The Pacific Tsunami Warning Center said the waves were less than 8 inches.
The Joint Australian Tsunami Warning Centre also issued a tsunami alert for eastern Australia that was still in effect today.
The quake’s epicenter was 100 miles west of Invercargill, off the west coast of New Zealand’s South Island at a depth of 21 miles, the U.S. Geological Survey said.
The quake was felt widely across South Island. Police in the town of Tuatapere said they had reports of minor cracks in buildings and stock falling from supermarket shelves.
However, no reports of serious damage or injuries were received, police said.
Scientists with New Zealand’s Institute of Geological and Nuclear Sciences were working with their U.S. counterparts today to reconcile their readings with those taken overseas.
The quake was reported locally at 6.6-magnitude before reports from the U.S. listed it at 7.8-magnitude and as high as 8.2.
“We’ve had big differences in the measurements of the quake, ranging from 6.6 by GNS Science, to 8.2 by a tsunami warning center in Hawaii. We’re issuing a precautionary message,” Vince Cholewa, an emergency management spokesman in Wellington, told the domestic news agency NZPA.
Scientists in New Zealand reported aftershocks, the first of 6.1 magnitude occurring 19 minutes after the main temblor.
New Zealand sits above an area of the Earth’s crust where the Pacific and Australian tectonic plates collide and records more than 14,000 earthquakes a year, though only about 150 are felt by residents. Fewer than 10 temblors a year do any damage.