September 7, 2004
The Asahi Shimbun

The temblors are the strongest felt near the Tonankai quake epicenter since 1944.

At least 42 people were injured, four seriously, in two strong offshore quakes that rattled the Kii Peninsula-where the deadly Tonankai Earthquake struck in 1944-on Sunday night. No deaths were reported, police said Monday.

Twelve people were injured in Osaka Prefecture and 10 in Mie Prefecture. Seven were hurt in Aichi Prefecture, five in Nara Prefecture, three in Kyoto Prefecture, and one each in Shiga, Gifu, Shizuoka, Wakayama and Hyogo prefectures.

Thousands were evacuated because of tsunami warnings.

The first earthquake hit at 7:07 p.m., with the second, stronger temblor jarring the region at 11:57 p.m. Both registered a lower 5, meaning personal movement was difficult, on the Japanese intensity scale of 7.

In Aichi Prefecture, a 70-year-old woman in the town of Nishio fell and fractured her left leg after the quake woke her up. In Okazaki, two people were burned when a electric hot-water pot toppled from a sideboard.

In Mie Prefecture, two people broke bones after falling.

On the open-ended Richter scale, the first quake had a magnitude of 6.9, and the second nearly 7.4. In the first temblor, the lower 5 intensity was felt in Shimo-Kitayama, Nara Prefecture, and in Shingu, Wakayama Prefecture. The second quake was a lower 5 at Matsusaka and Karasu in Mie Prefecture. Both quakes were felt as far away as Kyushu in the south and the Kanto region to the northeast.

The focuses of both quakes were 40 kilometers deep, while the epicenters were about 20 to 30 kilometers south of the area of the predicted extremely strong Tonankai quake. Experts expect the Tonankai quake to have a magnitude of about 8.

The Great Hanshin Earthquake in January 1995 that killed more than 6,000 people in Kobe measured a magnitude 7.3 on the Richter scale. In 1944, the Tonankai 7.9-magnitude quake left more than 1,200 people dead or missing.

Officials of the Japan Meteorological Agency's seismic observation section said they will watch future movements carefully for signs of a powerful quake.

Sunday's quakes are ``firsts'' in two ways, agency officials said.

One, they are the strongest quakes to be felt near the epicenter of the Tonankai Earthquake since 1944. Two, it is the first time in Japan that earthquakes with magnitudes of about 7 were recorded in quick succession. A difference remains from the previous big one, however.

``The mechanism that caused the two earthquakes on Sunday is different from the one that caused the 1944 Tonankai Earthquake,'' said agency official Masahiro Yamamoto.

Sunday's earthquakes took place near the long undersea Nankai trough that runs from the area off the coast of the Tokai region to an area offshore of Shikoku. Along the trough, extremely powerful earthquakes of the size of the 1944 Tonankai Earthquake have occurred once every 100 to 150 years.

The earthquakes were caused by sliding movements in the two crustal plates-the Philippine Sea plate and the Eurasia plate. However, Sunday's two quakes happened when a part of the Philippine Sea plate split.(IHT/Asahi: September 7,2004)

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