Sunday, 4 March 2012

Management and preparation for the 2011 Japan earthquake

By Josh Paxton

Were there any early warning systems for the earthquake?
  • Yes. There was a national system installed on 2007 to warn people of earthquakes and this system gathers information from over 1000 seismographs from around japan. After an earth quake is detected the system automatically sends out a warning after on 8.6 seconds of first detecting the earthquake.
  • It sends warning messages via a number of different ways such as through automatic messages on TV, through the mobile phone network and radio.

Were there any early warning systems for the tsunami?

  • Yes. There is a chain of tsunami buoys around the pacific that detect tsunami’.
  • But it takes longer to detect tsunami’s, around 8 minutes, so many places only had around 15 minutes of warning before it hit. 

Were there defences against a tsunami?

  • Yes. At least 40% of japans 22,000 miles coast line is lined with concrete sea walls, break waters and other structures that are meant to reduce the impact of high waves and an tsunami. 
  • But many of these seawalls and structures were inadequate and were effected by japan sinking one meter after the earthquake. 
  • The Kamaishi Tsunami Protection Breakwater, 1,950 m (6,400 ft) long and 63 m (207 ft.) in depth, was completed in March 2009 after three decades of construction, at a cost of $1.5 billion. It was the world’s deepest breakwater. But this did not help against the tsunami and over 1300 people have been killed or are missing. 

Were the buildings protected against the threat of an earthquake?

  • Yes. After the Kobe earthquake in 1995 became a world leader in engineering against earthquakes for new structures and the retrofitting of old buildings to protect them against earthquakes. 
  • Strong Japanese building codes specify rules for short, medium and tall buildings. 
  • New buildings shorter than three stories are required to have reinforced walls and foundation slabs of a certain thickness. 
  • Mid-rise buildings such as hospitals and laboratories in Japan often rest on huge rubber or fluid-filled shock absorbers. 
  • Many large building have large weights on the top of them which will move to counter any movement of the building. 
  • Buildings were also built with large rubber shock absorbers into their foundations and cross bracing of buildings to help prevent brake up during shaking. 

Was there education to prevent loss of life?

  • Yes. Local authorities issue advice to people on how to prepare for an earthquake by securing homes, appliances and heavy furniture and getting together earthquake kits. 
  • Schools, offices and factories have frequent earthquake drills. 
  • The government and offices observe disaster prevention day, 1st September.

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