国际英语新闻：Strong earthquake strikes off American Samoa, prompts tsunami warning

WASHINGTON, Sept. 29 (Xinhua) -- A strong earthquake struck off the U.S. Pacific island of American Samoa Tuesday, and tsunami alerts were issued for a vast swath of the Pacific Ocean.

    The U.S. Geological Survey (USGS) said the tremor was measured at 7.9 on the Richter Scale and its epicenter was located 190 km southwest of the Samoa coast, with a depth of 33 km.

    The quake occurred at 10:48 a.m. Pacific Time (1748 GMT).

    It was not known if a tsunami was generated but an earthquake of such magnitude is capable of causing a tsunami.

    The Hawaii-based Pacific Tsunami Warning Center issued a tsunami warning for a vast areas of the Pacific Ocean, including American Samoa, Fiji, New Zealand, Tonga, Samoa Niue Island, the Wallis and Futuna Islands, the Tokelau atolls, the Cook Islands, Tuvalu, Kiribati, the Kermadec Islands, the Baker and Howland Islands, Jarvis Island, French Polynesia and the Palmyra Islands.

    A tsunami watch was issued for Vanuatu, Nauru, the Marshall Islands, the Solomon Islands, New Caledonia, Kosrae Island, Papua New Guinea, Hawaii, Pohnpei in Micronesia, the Wake Islands, Pitcairn and the Midway Islands.

    But authorities don't expect a tsunami could hit the U.S. west coast including California, Oregon, Washington and Alaska.

    The National Oceanic and Atmospheric Administration's West Coast and Alaska Tsunamia Warning Center didn't issue any warning.

    Since the tsunami disaster which hit Southeast Asia in 2004, the West Coast has been concerned about the danger of tsunami from the Pacific Ocean.