A major earthquake registering 7.2 on the Richter scale shook the Solomon Islands in the South Pacific today, the U.S. Geological Survey says. The preliminary reading of 7.2 is slightly stronger than the 7.1 magnitude earthquake that hit the San Francisco Bay area Oct. 17. The earthquake struck the islands at 8:05 a.m. today, or 5:05 p.m. EDT Friday, said USGS spokesman Don Finley. It was the largest earthquake in the Solomons since a 7.4 quake on Nov. 5, 1978. There were no immediate reports of injury or damage. Major earthquakes in the Solomons usually don't cause much damage or many casualties because the area is sparsely populated and not extensively developed. The Pacific Tsunami Warning Center in Honolulu said no Pacific-wide tsunami _ popularly called a tidal wave _ was generated by the quake, but some areas might see small changes in sea levels. Saturday's earthquake was the strongest in the world in five months, Finley said. An 8.3 quake hit the Macquarie Islands south of Australia on May 23. The survey's earthquake monitors in Golden, Colo., said early seismograph readings placed the epicenter of Saturday's earthquake about 200 miles southeast of Honiaria, which is on Guadacanal Island and is the capital of the Solomons. That places the earthquake just east of San Cristobal, the easternmost island in the Solomons chain and about 1,300 miles northeast of Brisbane, Australia. The Richter scale is a measure of ground motion as recorded on seismographs. Every increase of one number means a tenfold increase in magnitude. Thus a reading of 7.5 reflects an earthquake 10 times stronger than one of 6.5. An earthquake of 3.5 on the Richter scale can cause slight damage in the local area, 4 moderate damage, 5 considerable damage, 6 severe damage. A 7 reading is a ``major'' earthquake, capable of widespread heavy damage; 8 is a ``great'' quake, capable of tremendous damage.
An earthquake of magnitude 7.2 shook the Solomon Islands today (28 October) the USGS reported. It was the largest there since 7.4 quake in 1978. There were no immediate reports or injury or damage, but quakes in that area usually don't cause much because it is sparsely populated and not developed. No Pacific-wide tsunami was generated by the quake. Earlier in the year, an 8.3 quake hit the Macquarie Islands south of Australia. A 7 magnitude earthquake is considered major and is capable of heavy damage. A magnitude 8 quake is a "great" quake capable of tremendous damage.