claim: But the new research shows that the amount of oxygen in those shells doesn’t actually remain constant over time.
evidences.evidence_id: Europa (moon):155
evidences.article: Europa (moon)
evidences.evidence: Observations with the Goddard High Resolution Spectrograph of the Hubble Space Telescope, first described in 1995, revealed that Europa has a thin atmosphere composed mostly of molecular oxygen (O2), and some water vapor.
evidences.votes: NOT_ENOUGH_INFO NOT_ENOUGH_INFO
evidences.evidence_id: Oxygen:151
evidences.article: Oxygen
evidences.evidence: Paleoclimatologists measure the ratio of oxygen-18 and oxygen-16 in the shells and skeletons of marine organisms to determine the climate millions of years ago (see oxygen isotope ratio cycle).
evidences.votes: NOT_ENOUGH_INFO NOT_ENOUGH_INFO
evidences.evidence_id: Oxygen:155
evidences.article: Oxygen
evidences.evidence: Paleoclimatologists also directly measure this ratio in the water molecules of ice core samples as old as hundreds of thousands of years.
evidences.votes: NOT_ENOUGH_INFO NOT_ENOUGH_INFO
evidences.evidence_id: Radiocarbon dating:124
evidences.article: Radiocarbon dating
evidences.evidence: The effect also applies to marine organisms such as shells, and marine mammals such as whales and seals, which have radiocarbon ages that appear to be hundreds of years old.
evidences.votes: NOT_ENOUGH_INFO NOT_ENOUGH_INFO
evidences.evidence_id: Radiocarbon dating:135
evidences.article: Radiocarbon dating
evidences.evidence: The effect varies greatly and there is no general offset that can be applied; additional research is usually needed to determine the size of the offset, for example by comparing the radiocarbon age of deposited freshwater shells with associated organic material.
evidences.votes: NOT_ENOUGH_INFO NOT_ENOUGH_INFO