People live in a constant state of readiness in a country that suffers a fifth of the world's most powerful earthquakes

If any country is able to cope with an earthquake of this scale, it is Japan.

It is too early to gauge the full extent of the devastation wreaked on the country's north-east coast by the earthquake and the huge tsunami that followed. But even as waves continue to breach the coast, it is already apparent that Japan's state of readiness has spared it from a far worse fate.

As a country that accounts for a fifth of the world's most powerful earthquakes, Japan is in a constant state of readiness for the arrival of the "big one".

Every schoolchild knows what to do the moment the earth begins to shake: slip a padded cover on to their heads and duck beneath the nearest desk. People who are at home when disaster strikes know, almost instinctively, to open the front door in case it is necessary to make a quick exit to open ground.

Those who find themselves stranded on the upper floors of office or apartment buildings – as so many have done in Tokyo – know that their quake-resistant surroundings will sway violently, but probably stay upright.

Modern buildings – and Japan's addiction to concrete means most tall buildings are very modern – are built with deep foundations, the most advanced supported by shock absorbers that allow the structure to move with the earth, rather than against it.

Even so, had the earthquake not been so far off the coast of Japan, the damage to the country could have been even more severe, said Kanoa Koyanagi, a geophysicist at the Pacific Tsunami Warning Centre in Hawaii.

"Very fortunately it was a good distance offshore. If that happened right under the city it would be a major problem. Anything above a magnitude eight under even a modern metropolitan city is going to be a major problem," Koyanagi said.

While confusion reigned on Friday evening as thousands of people in Tokyo made their way to ad hoc evacuation centres and designated muster areas, or began a long walk home, the atmosphere was one of concern rather than panic.

Despite the declaration of a state of emergency at one nuclear plant, the threat of a radiation leak is one that, so far, Japan appears to have avoided. Eleven nuclear reactors shut down automatically when the quake struck, although emergency teams were still struggling to restore the cooling system at the Fukushima No 1 power plant.

Japan's famed bullet trains slow to an automatic halt in the event of a large earthquake. In the Shinkansen system's four-plus decades of whisking millions of people across Japan at high speed, it has yet to suffer a fatality.

The level of individual preparedness is mixed, but many households keep a basic earthquake survival kit of bottled water, dry rations, a first-aid kit and torches equipped with radios that broadcast regular updates.

Television channels immediately switch from normal programming to live coverage of the aftermath of a large quake. The names of the affected areas are flashed on the screen, along with details of the quake's intensity in each area. A map of Japan showing coastal areas subject to tsunami warnings is a constant presence in the corner of the screen.

The most impressive coverage of Friday's earthquake came from Japan's public broadcaster, NHK, which can draw on bureaus nationwide for on-the-spot updates.

The poor handling of the aftermath of the Kobe earthquake in 1995, in which 6,400 people died, not only prompted a rethink of building regulations but also of Japan's ability to launch a search and rescue effort.

While fires raged in Kobe after the city was rocked at 5.46am on 17 January, Japan's government was slow to accept help from US military forces based in the country and from overseas.

In Kobe more than 80% of the victims were crushed to death. But on Friday early reports suggested that the majority of deaths and injuries were caused by a huge tsunami that put the entire region on alert. For all its preparedness for earthquakes, there was next to nothing it could do to resist the power of the ocean.