Earth’s inner core is changing shape

By analysing how seismic waves from earthquakes travelled through the planet, scientists have found that Earth’s inner core is changing shape. They noted that the waveforms of some seismic signals changed between 2004 and 2008, and attributed the phenomenon to the inner core — normally thought to be solid and unyielding - bulging in some areas. Changes in the dynamics of the core could affect the Earth’s magnetic field and the length of our 24-hour day.