Physical evidence for climate change Flashcards
1
Q
What do sediments deposited on the sea floor record?
A
The chemical composition of sewater when they were deposited
2
Q
What do sediments deposited on the sea floor contain?
A
Oxygen isotopes
3
Q
What happens during periods of cold climate?
A
water molecules containing O-16 are more easily evaporated, so the ocean becomes richer in O-18
4
Q
What do sediments with high levels of O-18 indicate?
A
A period of cold climate
5
Q
What is seal level affected by?
A
Things like the volume of water stored as ice
6
Q
What happens to sea level as the climate warms?
A
Ice caps melt and sea level rises
7
Q
What shows that sea level is higher than it used to be?
A
Some valleys formed above sea level are now submerged, e.g. Poole Harbour in Dorset and Lough Swilly in Ireland
