Kathy Day/La Jolla Light
People watch the coast off La Jolla on March 11 after a tsunami advisory was issued for California's coast.
After a strong earthquake struck off Japan's coast early Thursday, the Pacific Tsunami Warning Center said an oceanwide tsunami was not expected.
The 7.1-magnitude quake was reported about 25 miles under the water off the coast of Miyagi prefecture. It was originally reported as a 7.4 magnitude but later downgraded. A tsunami warning was issued for Japan's coast already ravaged by last months 9.0-magnitude earthquake.
The Pacific Tsunami Warning Center sent out a bulletin moments after the quake struck advising that historical data suggests no threat exists for San Diego and the rest of the West Coast of the United States .
A strong earthquake has occurred, but a tsunami IS NOT expected along the California, Oregon, Washington, British Columbia, or Alaska coast. NO tsunami warning, watch or advisory is in effect for these areas. Based on the earthquake magnitude, location and historic tsunami records, a damaging tsunami IS NOT expected along the California, Oregon, Washington, British Columbia, and Alaska coasts. At coastal locations which have experienced strong ground shaking, local tsunamis are possible due to underwater landslides.
KHNL in Hawaii is reporting no tsunami advisory to the Hawaiian islands.
Hundreds of aftershocks have shaken the northeast region of Japan since the March 11 quake just four weeks ago.
Paul Caruso, a geophysicist at the U.S. Geological Survey in Golden, Colo., said Thursday's quake struck at about the same location and depth as the March 11 quake. It's the strongest of the more than 1,000 aftershocks that have been felt since, except for a 7.9 aftershock that day.