Japan’s March 11th magnitude 9 Tohoku Earthquake — which caused a tidal wave and the ensuing Fukushima Daiichi nuclear power plant disaster — was one of the most powerful ever recorded and just happened to be in an extremely dense seismic instrument zone. In the midst of all of this information comes the first study of how rocks and soil beneath the Earth’s surface are affected by a shift this large. Students at the Georgia Institute of Technology have taken data about the rocks and soil and translated it into usable information for builders and architects which they believe will help build better earthquake resistant buildings in the future. Read on to find out what they’ve learned.
In addition to being a helpful set of information for future buildings this data will also help seismologists predict what might happen to a city or town if an earthquake of this magnitude were to occur. “The degree of nonlinearity in the soil strength was among the largest ever observed,” said Zhigang Peng, an associate professor at Georgia Tech’s School of Earth and Atmospheric Sciences. “This is perhaps not too surprising because the ground shaking generated by this earthquake – acceleration as much as three times the Earth’s gravity – is also among the highest ever observed.” Peng and Chunquan Wu (pictured above) are perhaps some of the first scientists to explore this kind of data and use it to help create a useful plan for future construction.
The data came from sets of sensors on the Earth’s surface and matching sensors in the bedrock far below ground level. Peng and Wu were able to compare the sensor data from the surface and that from the bedrock in order to visualize how the ground moved during the quake and document changes in how it settled afterward. “Understanding how soil loses and regains its strength during and after large earthquakes is crucial for better understanding and predicting strong ground motions,” Peng said of their data study. “This, in turn, would help earthquake engineers to improve the design of buildings and foundations, and could ultimately help to protect people in future earthquakes.”
Via Science Daily