A strong earthquake that measured 5.2 on the Richter Scale rocked the northern Japanese Island of Kokkaido at about at about 7:45 local time today . Three hours earlier a quake of similar strength off the Japanese Island of Japanese Island was felt in Kokkaido . Every increase of one integer on the scale represents a tenfold increase in strength, thus a quake measuring one is ten times stronger than one of 4.2 . Today 's quakes caused little damage because they occurred far below the earth 's surface. The last quake to cause great destruction in Hokkaido occurred in today . It measure 7.9 and claimed 52 lives.
A strong earthquake that measured 5.2 on the Richter Scale rocked the northern Japanese Island of Kokkaido at about at about 7:45 local time today. Three hours earlier a quake of similar strength off the Philippine Island of Luzon was felt in Manila. Every increase of one integer on the scale represents a tenfold increase in strength, thus a quake measuring 5.2 is ten times stronger than one of 4.2. Today's quakes caused little damage because they occurred far below the earth's surface. The last quake to cause great destruction in Hokkaido occurred in 1968. It measure 7.9 and claimed 52 lives.