Earth's Wobbly Inner Core Illuminated by Nuclear Explosions - Eos

Shock waves from Cold War era nuclear tests gave seismologists a glimpse of the inner core. Its wobbly rotation could explain phenomena such as the periodic change in the length of a day.

Earths inner core is a ball of solid metal as hot as the surface of the Sun, rotating in a molten tempest of iron and nickelHades, if ever there were one. The sphere is ever growing as the surroundin… [+6015 chars]

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