Washington, May 19 : An earthquake measuring 7.7 on the Richter scale jolted southeast of the Loyalty Islands on Friday, triggering the possibility of "hazardous tsunami waves", according to authorities. In its latest update, the US Geological Survey (USGS) said the quake struck at 2.57 a.m., reports Xinhua news agency. The epicentre, with a depth of 37.7 km, was determined to be at 23.229 degrees south latitude and 170.694 degrees east longitude, the USGS added. Meanwhile, the US Tsunami Warning System reported that hazardous tsunami waves from this earthquake are possible within 1,000 km of the epicentre along the coasts of Vanuatu, New Caledonia and Fiji. The Loyalty Islands is one of three administrative subdivisions of New Caledonia encompassing the Loyalty Island archipelago in the Pacific, which are located northeast of the New Caledonian mainland of Grande Terre. /IANS