1.   Such extreme heating could result from undersea volcanic activity or from heat generated by the falling of a giant meteor, they speculate.

2.   As the undersea activity increased, Tokyo and local authorities readied evacuation and assistance plans.

3.   The agency said there was no danger of tsunami, waves caused by underseas disturbances such as undersea volcanic activity or earthquakes.

4.   The agency said there was no fear of tsunami, huge waves caused by undersea disturbances such as undersea volcanic activity or earthquakes from the two tremors.

5.   The agency said there was no fear of tsunami, huge waves caused by undersea disturbances such as undersea volcanic activity or earthquakes.

6.   Weather agency officials said there was no concern of tsunami, the waves caused by undersea seismic activity, from either tremor.