EDITORIAL: Get ready now for next big quake

Seismologists warn that a major earthquake could strike any part of Japan any time. We need to think beyond conventional earthquake predictions and thoroughly re-examine our preparedness around the nation.

The frequent jolts we are still getting are related to the magnitude-9 Great East Japan Earthquake of March 11. So far, we have had five magnitude-7 and as many as 75 magnitude-6 aftershocks. There is no indication of their stopping any time soon. On the contrary, experts predict we are in for a long haul.

A magnitude-8 temblor could occur anywhere north, south or east of the epicentral zone that extends 500 kilometers north and south and 200 km east and west. Should the quake have an offshore focus, it could trigger another huge tsunami.

But there are also other jolts we should be guarding against. The March quake caused the Tohoku region to shift up to 5 meters east. This is said to have resulted in a drastic redistribution of seismic energy beneath the Japanese archipelago. And this explains the escalation of seismic activity around the nation after the March 11 event.

The latter is believed to have induced a string of quakes in Niigata, Nagano and Shizuoka prefectures. There is heightened seismic activity now in 16 zones along eastern Japan, from Tokyo Bay to Kyushu.

We need to watch out not only for the next mega-quake, but also for inland temblors, including one occurring directly under Tokyo or its environs. An inland quake could knock down buildings and cause tremendous damage, even if its magnitude is no more than 6 or 7.

Our most urgent task is to earthquake-proof unstable structures. Although 73 percent of public elementary and junior high schools are earthquake-proof, as many as 7,500 school buildings have been found to be in danger of collapse in a temblor with an intensity of upper 6 on the Japanese scale of 7. They must be reinforced at once. And that goes for older homes, too.

At home, tall or heavy pieces of furniture should be anchored securely so they won't topple over us while we are sleeping at night.

The extent of earthquake damage can vary greatly depending on when it occurs--daytime or night, weekday or holiday. The March quake struck on a weekday afternoon, which made it easier for people to flee in an organized manner. But what if this had happened in the middle of the night?

Lately, we have been experiencing frequent tremors at all hours and in all locations. Every time it happens, we would be wise to mentally prepare ourselves for what to do in the event of the Big One.

We could be on the street or in an underground shopping mall, or at home cooking a meal. What hazardous objects are around us that could put us in harm's way?

And when the Big One strikes, how do we protect ourselves? If we are outdoors, where should we go?

We should use our imagination and determine what we will need to ensure our survival. We must prepare ourselves step by step, starting with anything that might help to keep us safe.

--The Asahi Shimbun, April 27