Oahu lifeguards were prepared yesterday for strong or unusual ocean currents generated by an earthquake off New Zealand.

The magnitude-7.6 quake struck 95 miles west-northwest of Invercargill on New Zealand's South Island at 11:23 p.m. Tuesday, Hawaii time.

The quake, initially estimated at 7.8, generated a tsunami in the region with 8-inch waves, according to the Pacific Tsunami Warning Center in Ewa Beach.

About 20 minutes after the quake, the center issued an advisory for the islands that was canceled an hour later, but the center warned that “;some coastal areas in Hawaii could experience small non-destructive sea level changes and strong or unusual currents”; for a few hours starting at 11:07 a.m. yesterday.

As of noon yesterday, Lt. J.R. Sloan of the city's Ocean Safety and Lifeguard Services said “;there was nothing out of the ordinary,”; but lifeguards, in cooperation with the Coast Guard and Fire Department, were prepared to react if tidal changes occurred.

Lifeguards watched Waimea Bay, Pokai Bay and Hanauma Bay because the bays' topography creates stronger currents, Sloan said.

Sloan said this earthquake was less significant than the magnitude-8.1 temblor that struck Japan in 2006, which resulted in a visible change in sea level at Hawaii beaches and the closing of Hanauma Bay for two to three days.

Tuesday's quake caused roadway and structural damage in New Zealand, but no injuries were reported. Smaller quakes of 5.1 and 5.3 in magnitude shook the same spot early yesterday afternoon.