TOKYO -- An earthquake in central Japan Thursday killed two women, injured 53 people and damaged more than 7,500 homes but could have been much worse if not for strict building codes and the depth of the epicenter, authorities said.
The earthquake, measuring 6.6 on the open-ended Richter scale at its epicenter off the coast, struck at 11:08 a.m. and shook the Tokyo area for 10 minutes, halting most train traffic and cutting off electricity and phone lines in the central business district, officials said.
The quake hit hardest in Chiba Prefecture, a state bordering Tokyo on the southeast, where it registered 5 on the Richter scale.
A 32-year-old woman was killed when a stone lantern fell on her in Mobara City, 30 miles southeast of Tokyo, Chiba Prefecture police said.
In nearby Ichihara City, a stone wall collapsed, killing another woman, police said.
The public-funded NHK television reported 53 people were injured, most by the collapse of concrete walls that surround many Japanese homes. NKH said the earthquake damaged 7,533 houses.
An estimated 650,000 people were affected when the quake halted train traffic, including the high-speed bullet trains, a Tokyo television station reported. Several windows broke at the New Tokyo International Airport in Narita where traffic was temporarily halted.
Geologists said the epicenter was 6 miles off the coast of Chiba and 44 miles below the seabed.
If it had hit closer to the ocean floor, the quake could have caused greater vibration, lifted the seabed up and possibly created a huge sea wave, said Yoshimitsu Okada, the director of the National Research Center for Disaster Prevention in Tsukuba City.
A tsunami, or sea wave, warning issued for the heavily populated east coast of Japan was canceled about an hour after the quake.
'In many other countries 6.6 would have caused much damage,' said Seiya Ueda, a professor of geophysics at Tokyo University. 'With this shaking perhaps houses might have collapsed in South America.'
'The modern buildings in Tokyo are critically controlled by law to withstand much shaking,' he said. 'Houses are built earthquake-consciously.'
The magnitude of the temblor in Tokyo was 4 on the Richter scale.
According to the Richter scale, a magnitude of 4 can cause moderate damage, 5 considerable damage and 6 severe damage.
At least eight people were injured in Tokyo, including two carpenters who fell from a house they were building, the National Police Agency said.
Geologists have been forecasting a large earthquake for the area southwest of Tokyo for years because it sits on a volcanic belt above two converging plates of the earth's surface.
The Great Kanto earthquake of Sept. 1, 1923, killed 140,000 people in the Tokyo area was projected at 7.3 on the Richter scale.
The strongest earthquake on record, projected at 8.6 on the Richter scale, was monitored in Ecuador in 1906. But the highest recorded death toll resulted from a quake in 1556, projected at 8.2 on the Richter scale, in Shensi Province, China. Official estimates put the number of deaths between 650,000 and 750,000.