The witnessed enlargement seems to be caused by new iron crystals forming faster on the east side of the core versus the west.
Another conundrum occurs when considering if misguided cooling in the inner core might change Earth's magnetic field, something that’s currently activated by movements of liquid iron inside the outer core, which is in turn generated from lost heat from the inner core. “If the inner core is losing more heat in the east than the west, then the outer core will move more in the east too,†Frost added