3rd 5

Question 1

The quantenary glacial-interglacial period

Answer 1

The last 2.7Ma characterised by glacial - interglacial cycle

The period contains the highest variability throughout the cenozoic force by the milankovitch cycles

Question 2

Glacial period characteristics

Answer 2

• ice ages paced by changes in the earths orbit
• large parts of Eurasia and North America ice covered
• sea level = 130m lower
• global temperature ~6 degrees lower. They were cooler because greater ice albedo and greater land albedo (less vegetation)
• lower atmospheric GHGs

Question 3

Conditions favorable for ice sheets

Answer 3

• accumulation rates exceed ablation

- temperature

Question 4

Temperature and I’ve mass balance

Answer 4

Limited by cold air not being able to hold water. High latitudes = winter temperatures always cold.

Winter is NOT the critical season. It’s summer melting which controls ice sheet growth. No matter how much snow falls during winter, it can easily melt if the following summer is warm and ablation is rapid

Question 5

Terminating ice ages

Answer 5

Ice sheets melt when summer Insolation is high =’axial tilt is high

The change in solar radiation due to milankovitch forcing is