Earth’s Core Rotates Faster than Surface, Study Confirms
The giant orb of iron and nickel that anchors Earth’s center is spinning faster than the planet’s surface, according to a new study that confirms scientists’ expectations.
The finding is based on analyses of earthquake pairs that occur at roughly the same spot on Earth but at different times. On seismic recoding instruments, the earthquake signatures from waveform doublets, as they are called, look nearly identical.
When earthquakes strike, their seismic waves can travel through the planet and surface all over the globe.
The researchers analyzed 18 sets of waveform doublets — some separated in time by up to 35 years — from earthquakes occurring off the coast of South America but which were recorded at seismic stations near Alaska.
livscience.com