A MASSIVE EARTHQUAKE MEASURING 7.8 ON THE RICHTER SCALE WAS RECORDED IN THE SOUTH PACIFIC, OFF THE COAST OF TONGA, ON THURSDAY MORNING NEW ZEALAND TIME (1527 GMT WEDNESDAY), DPA REPORTED. THE PACIFIC TSUNAMI WARNING CENTRE (PTWC) ISSUED A TSUNAMI ALERT FOR FIJI AND NEW ZEALAND AFTER TIDE GAUGES IN PAGO PAGO, SAMOA, AND NIUE SHOWED A SMALL RISE IN SEA LEVELS, BUT THIS WAS SUBSEQUENTLY WITHDRAWN. PEOPLE RAN INTO THE STREETS OF TONGA'S CAPITAL NUKUALOFA AS BUILDINGS SHOOK DURING THE QUAKE WHICH LASTED ABOUT FOUR MINUTES, A POLICE OFFICER TOLD RADIO NEW ZEALAND. EARLY REPORTS SAID THERE HAD BEEN SOME MINOR DAMAGE BUT NO REPORTS OF INJURY. SOME PEOPLE FLED THEIR HOMES IN GISBORNE, ON THE EAST COAST OF NEW ZEALAND'S NORTH ISLAND, WHERE CIVIL DEFENCE WORKERS WENT ON STANDBY AFTER A TSUNAMI WAS REPORTED LIKELY TO HIT AT 6:20 AM LOCAL TIME. BUT THE WARNING WAS LIFTED SHORTLY BEFORE THEN, AT 6 AM, AND RADIO NEW ZEALAND REPEATEDLY BROADCAST ANNOUNCEMENTS THAT THE SCARE WAS OVER. THE QUAKE WAS ORIGINALLY ESTIMATED TO BE OF 8.1 MAGNITUDE, A SIZE NEW ZEALAND'S INSTITUTE OF GEOLOGICAL AND NUCLEAR SCIENCES (GNS) SAID THE WORLD EXPERIENCED ONLY ONCE A YEAR ON AVERAGE. IT WAS SUBSEQUENTLY DOWNGRADED TO 7.8, MAKING IT ONE OF ABOUT 18 QUAKES RANGING FROM 7 - 7.9 RECORDED ANNUALLY. GNS SAID THE QUAKE WAS CENTRED 170 KILOMETRES NORTH-EAST OF NUKUALOFA, AT A DEPTH OF 38 KILOMETRES BENEATH THE SURFACE. IT WAS FELT IN AUCKLAND 3,700 KILOMETRES AWAY. PAULA CHIPMAN, A US TOURIST FROM SEATTLE VACATIONING IN TONGA, SAID SHE FELT THE GROUND SHAKE BUT THAT NO WARNINGS WERE ISSUED IN THE HOTEL SHE WAS STAYING. "THERE'S STUFF ON THE FLOOR, STUFF UPSTAIRS THAT HAS COME OUT OF THE ROOMS...(BUT) EVERYTHING LOOKS PRETTY MUCH INTACT," SHE TOLD CNN. CHIPMAN ALSO SAID POWER WAS OUT IN THE HOTEL. A TSUNAMI IN THE INDIAN OCEAN ON DECEMBER 26, 2004, KILLED MORE THAN 220,000 PEOPLE IN THE REGION. AN EARLY WARNING SYSTEM DEVELOPED AFTER THE DISASTER, WHICH INCLUDES NEW SEISMIC SENSORS IN THE PACIFIC AND INDIAN OCEANS, IS STILL IN THE PROCESS OF BEING IMPLEMENTED TO HELP ALERT PEOPLE TO THE POSSIBILITY OF A TSUNAMI DEVELOPING. AUTHORITIES EXPECTED THE SYSTEM TO BE FULLY IMPLEMENTED BY 2008. NO TSUNAMI WARNINGS OR WATCHES WERE ISSUED FOR THE US AS A RESULT OF THE EARTHQUAKE, THE WEST COAST AND ALASKA TSUNAMI WARNING CENTRE SAID.