Japan May Be “Sinking” Due To Earthquake Damage

The recent 9.0 scale earthquake in North-east Japan may have caused the soil in Japan to sink by as much as four feet.

AsianScientist (Apr. 18, 2011) – The recent 9.0 scale earthquake in North-east Japan may have done more than cause a tsunami and a nuclear crisis at the level of 1986’s Chernobyl accident.

It may also have caused the soil in Japan to sink – by as much as four feet in certain areas.

According to a new analysis by Oregon State University’s Geotechnical Extreme Events Reconnaissance (GEER) advance team, the amount of sinking, known scientifically as “soil liquefaction”, extended over hundreds of miles.

The findings were daunting to experienced engineers who are accustomed to seeing disaster sites, including the recent earthquakes in Chile and New Zealand. These results also raise questions about whether existing building codes and engineering technologies are adequate in other vulnerable locations in the world.

Video of the liquefaction in Japan:

The researchers found that entire structures were tilted and sinking into the sediments, even while they remained intact. The shifts in soil destroyed water, sewer and gas pipelines, crippling the utilities and infrastructure these communities need to function.

Places as far away as Tokyo Bay was found to have liquefaction-induced ground failures. Impacts and deformation were erratic, often varying significantly from one street to the next. Port facilities along the coast faced major liquefaction damage.

Thankfully, strong Japanese construction standards helped prevent many buildings from collapse – even as they tilted and sank into the ground. Small armies of utility crews are already at work in Japan on fixing the damage, which has been estimated to cost as much as $300 billion.

Soil liquefaction
Liquefaction caused nearly three feet of settlement at this water purification plant that serves 19,000 people, breaking pipes and flooding underground structures. (Source: Scott Ashford/Oregon State University)

The researchers hope that the lessons learnt from the Japanese earthquake may encourage future construction to use techniques known to reduce liquefaction, such as better compaction to make soils dense, or the use of reinforcing stone columns.

The full report can be found at: Geotechnical Quick Report on the Kanto Plain Region during the March 11, 2011, Off Pacific Coast of Tohoku Earthquake, Japan.

Related Articles:
Japan’s Nuclear Crisis: Are There Serious Health Implications?.
APEC Secretariat Offers Condolences And Solidarity To Japan.

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Source: Oregon State University.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

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