Seismologically, Japan is one of the most active countries in the world: almost ten per cent of all active volcanoes are located there, and ten per cent of all major earthquakes ranging in the magnitude of 7 on the Richter scale (nowadays referred to a moment magnitude scale, MMS) occur in the archipelago. Earthquakes happen daily, but most of them are just minor tremors that people would not even notice.

earthquakes-cover.jpg
The two most recent massive quakes were the Great Hanshin Earthquake (or Kobe Earthquake) on 17 January 1995, with a magnitude of 6.8, resulting in some 6,400 casualties. The Great East Japan Earthquake on 11 March 2011, with a magnitude of 9.03, caused a major tsunami and resulted in 15,880 deaths. The last major earthquake that struck Tokyo occurred on 1 September 1923, the Great Kantō Earthquake with a magnitude of 7.9 and estimated casualties of over 140,000, mostly due to fires that raged through the city in the aftermath, but also due to ensuing ethnic massacres against the Korean and Chinese minorities.

The Japan Meteorological Agency (JMA) uses a seismic intensity scale measured in units of shindo (震度) that describes the degree of shaking at a point on the Earth’s surface, just like the Mercalli intensity scale.

Since the 1980s the building codes have been revised, implementing tighter safety regulations on new structures. While many Japanese cities are equipped with sophisticated quake sensors and architects to employ innovative methods like airbags levitating buildings, dampers, base isolators, shear trusses, and other seismic retrofitting, earthquakes remain notoriously difficult to predict. Aftershocks may cause further damage by weakening affected structures. Many casualties are in fact caused by fires, falling debris, and traffic accidents.

Earthquake Safety Procedures

  1. Extinguish any fires, turn off electrical appliances and gas pipes.
  2. Open any exit doors, as they might get blocked by debris or jammed shut.
  3. Do not rush outside the building, as you might get hit by falling debris, glass or masonry.
  4. Stay away from windows to avoid splintering glass. If possible, draw your curtains to keep splintering glass out.
  5. It is NOT advised to duck and cover under objects, such as furniture or cars, as they will be crushed, slightly curl up in a fetal position next to more massive objects, such as sofas or beds to create a void around you.
  6. If you are outside while the quake strikes, head for the nearest park or open space. Earthquake evacuation zones are indicated in all residential areas (usually parks or schoolyards).
  7. If you are at home, go to the nearest open space after the tremors have died down, bring your valuables and personal documents. Protect yourself with a cushion or a bicycle helmet, etc. against falling debris and do not forget to wear shoes to protect your feet from shards and other sharp objects.

Earthquake Preparation Kit


Make sure you have at all times a kit with the items listed below, ready for an emergency and within reach, near your front door or close to your bed. Also, store water and most importantly, a torch next to your bed.
  • Plastic water bottles, exchange them every few months
  • Electric torch, also prepare spare batteries and bulbs
  • Food, canned, pre-processed and packed (such as crackers or other non-perishable food)
  • Portable, battery-operated radio, along with extra batteries
  • Candles and matches
  • Large rubbish bags made of plastic
  • Toilet paper and other hygiene supplies, such as soap, etc.
  • Thick gloves and spare clothes
  • First aid kit
  • The medication you might regularly need, also glasses or spare contact lenses
  • Money, small bills and coins you might need to buy things at convenience stores
  • Pens, pencils, and notepads

Links:


Cover photo: Kobe Earthquake Memorial Park (Japan Reference - JREF)