Double 7.0+ magnitude earthquakes shake South Pacific island of Vanuatu

August 20, 2011 – VANUATU – A powerful magnitude 7.5  (7.1 downgrade USGS) earthquake struck off the Pacific island nation of Vanuatu, the U.S. Geological Survey reported Saturday. It said the quake, which struck at 3:55 a.m. local time on Sunday (12:55 p.m. EDT on Saturday), was centered 38 miles southwest of the town of Port-Vila and was quite shallow, at a depth of 25.2 miles. The Pacific Tsunami Warning Center said the major quake had not triggered a Pacific-wide tsunami but said: “Earthquakes of this size sometimes generate local tsunamis that can be destructive along coasts located within a hundred kilometers (80 miles) of the earthquake epicenter.” There was no immediate information of any damage or casualties, but when on land quakes of this magnitude can cause widespread and heavy damage. The quake was followed by a weaker aftershock of magnitude 5.9 some 20 minutes later. The Vanuatu archipelago is located on the so-called “Ring of Fire,” one of the most seismically active regions in the world. Port-Vila is the capital of Vanuatu and has an estimated population of 40,000 people. After a flurry of aftershocks, a second 7.0 earthquake stuck the same region at a depth of 2 km.  –Reuters              

See: String of moderate quakes shake globe