A powerful 6.6 magnitude earthquake struck Wednesday off the coast of Vanuatu in the South Pacific, but U.S. geologists said it was too deep to cause a tsunami. The U.S. Geological Survey said the quake struck at 1603 GMT about 37 kilometers (23 miles) west of Sola, Vanuatu. The National Tsunami Warning Center in Palmer, Alaska said that the New Year's Day temblor, with a depth of 195 kilometers, was "located too deep within the earth" to generate a sizeable tidal wave.