According to new studies conducted by Kevin Chao – a postdoctoral researcher at the Massachusetts Institute of Technology’s Department of Earth, Atmospheric and Planetary Sciences, an earthquake can change or damage the elastic properties of the Earth’s crust. If the earthquake is strong enough, it could damage the elastic and stress endurance capabilities for over 6,000 kilometers for a period stretching three weeks.
The researchers said that the Earth is very dynamic and interconnected system, and one large earthquake can have a cascading effect and start a sequence of events thousands of kilometers away.
Kevin Chao said that a quake in another region creates surface waves, which when passing through another fault region, causes imbalance between the frictional properties which keep the surfaces joined. The elasticity that affords the crust the ability to withstand the strain and the stress state that cause it to fail.
All these properties change when a wave passes, and they rearrange and change. A fault line with high stress is ready to fail. It accumulates more stress, and an earthquake becomes inevitable in the future.
The 2012 earthquake off the coast of North Sumatra in the Indian Ocean was of a magnitude of 8.6, and it was followed by two earthquakes in Japan with a magnitude greater than 5.5.
Scientists studied data from strain meter readings, GPS equipment, and information on seismic activity that included all small earthquakes following a major earthquake.
Scientist found that the two quakes of magnitude greater than 5.5 were a part of a collection of activities in the days after the Indian Ocean quake.
The Indian Ocean quake created a surface wave that passed through the northeast of Japan triggering seismic activity in the region. The region was already stressed by a previous episode of an earthquake in 2011. Additional stress though temporary of the passing wave was enough to trigger another series of quakes.
Details of the research have been published in the journal Science Advances.