1. As an indicator of shifts in the Earth's climate, the isotope record has two advantages. 作为地球气候变化的指标，同位素记录有两个优势。
2. Thus, more of the heavy isotope is left behind in the ocean and absorbed by marine organisms. 因此，更多的重氧同位素留在了海洋里，并被海洋有机物吸收。
3. Almost all the oxygen in water is oxygen 16, but a few molecules out of every thousand incorporate the heavier isotope 18. 水中几乎所有的氧都是氧16，但每一千个分子中就有几个含有较重的同位素18。
4. It is a global record: there is remarkably little variation in isotope ratios in sedimentary specimens taken from different continental locations. 这是一个全球性的记录：在取自不同大陆位置的沉积标本中，同位素比率的变化非常小。
5. The oxygen isotope ratio of the ocean changes as a great deal of water is withdrawn from it by evaporation and is precipitated as snow to form glacial ice. 随着大量的水通过蒸发被抽离，并以雪的形式沉淀形成冰川冰，海洋中氧同位素的比率就发生了变化。
