Assertion: ocean's ph | /r/HasProperty | stable
Facets:
value: at 8.2 due
type: TEMPORAL
value: relatively
type: DEGREE
value: for the last 750,000 years
type: TEMPORAL
Source sentences:
text: For the last 750,000 years the pH of the surface ocean has been relatively stable and slightly alkaline at 8.2 due to the carbonate buffer system.