Assertion: magnetic field | /r/CapableOf | flip over last billion years
Facets:
value: according to the geologic record
type: OTHER
value: many times
type: TEMPORAL
Source sentences:
text: Earth's magnetic field has flipped many times over the last billion years, according to the geologic record.
text: Earth's magnetic field has flipped many times over the last billion years, according to the geologic record.