Why is low oxygen 18 oxygen 16 in ice cores or snow indicative of higher temperatures?

Because water molecules with heavy 18O isotopes in them condense more easily than normal water molecules, air becomes progressively depleted in 18O as it travels to high latitudes and becomes colder and drier. In turn, the snow that forms most glacial ice is also depleted in 18O.

Why does the ratio of oxygen 18 to oxygen 16 in the oceans increase during an ice age?

During an ice age there is more Oxygen-18 in ocean water. This occurs because Oxygen-16 is lighter and is more easily evaporated from the oceans. The 18O/16O ratio would be larger during glacial periods because ocean water would be enriched in 18O, while more 16O would be trapped in the ice caps.

What is the importance of oxygen 18?

Oxygen-18 in the water or gaseous form serves as a source for short-lived positron-emitting isotope fluorine-18, which allows tracking the processes of cerebral blood flow, glucose metabolism in the central nervous and cardiovascular systems, evaluating the impact of drugs on neuroreceptors.

How is oxygen 18 formed?

Oxygen is composed of 8 protons, and in its most common form with 8 neutrons, giving it an atomic weight of 16 (16O) — this is know as a “light” oxygen. It is called “light” because a small fraction of oxygen atoms have 2 extra neutrons and a resulting atomic weight of 18 (18O), which is then known as “heavy” oxygen.

At what depth in the ice core is the Ice Age closest to 100000 years?

1430 m
At what depth in the ice core is the ice age closest to 100,000 years? You got it! The ice age is 100.38 kyr at 1430 m.

Why is O-18 considered heavy?

Since it is lighter than 18O, 16O evaporates first, so in warm, tropical areas, the ocean is high in 18O. Additionally, as water vapor condenses to form rain, water droplets rich in 18O precipitate first because it is heavier than 16O.