Seismic waves from earthquakes reveal changes in the Earth's outer core - Phys.org

In May 1997, a large earthquake shook the Kermadec Islands region in the South Pacific Ocean. A little over 20 years later, in September 2018, a second big earthquake hit the same location, its waves of seismic energy emanating from the same region.

In May 1997, a large earthquake shook the Kermadec Islands region in the South Pacific Ocean. A little over 20 years later, in September 2018, a second big earthquake hit the same location, its waves… [+5637 chars]

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