EQ1

Question 1

When did ice sheets begin melting after the last glacial maximum?

Answer 1

About 18,000 years ago

Question 2

What caused rapid deglaciation around 15,000 years ago?

Answer 2

Temperatures similar to today

Question 3

What major event happened around 12,500–11,500 years ago?

Answer 3

Glacial conditions returned: temps dropped 6–7°C

Question 4

What is believed to have caused the return of glacial conditions 12,500 yrs ago?

Answer 4

Drainage of Lake Agassiz disrupted the Thermohaline Circulation

Question 5

When was the Little Ice Age and how cold did it get?

Answer 5

1350–1900: 1–2°C colder, coldest around 1550–1750

Question 6

Name 2 effects of the Little Ice Age

Answer 6

Rivers froze in the UK/Europe/NY & Arctic sea ice spread south

Question 7

Why didn’t the Little Ice Age become a full stadial?

Answer 7

Industrial Revolution’s GHG emissions caused warming.

Question 8

What do ice cores from Greenland and Antarctica reveal about past climates?

Answer 8

They show 800,000 years of climate data; CO₂ levels were low in glacial and high in interglacial periods

Question 9

What era are we currently in, and what came before it?

Answer 9

We’re in the Quaternary era (began ~2 million years ago); preceded by the Tertiary, which ended with global cooling

Question 10

What are the main epochs in the Quaternary period?

Answer 10

•Pleistocene: Ended ~12,000 years ago, had glacial & interglacial periods

•Holocene: Began ~12,000 years ago, warmer interglacial

•Anthropocene?: Proposed modern epoch due to human impact (not officially accepted in 2024)

Question 11

What is an epoch and what evidence do they leave?

Answer 11

An epoch is a geological time period. Glacial epochs (like the Pleistocene) leave landforms, though they can be reshaped over time

Question 12

What is the Milankovitch theory?

Answer 12

It explains natural climate change due to changes in Earth’s orbit and tilt, affecting the amount of solar energy the Earth receives

Question 13

What are the 3 main cycles in the Milankovitch theory?

Answer 13

1. Eccentricity (100,000 years): shape of Earth’s orbit changes from circular to elliptical
2. Axial tilt/Obliquity (41,000 years): angle of Earth’s tilt changes

3.Precession (26,000 years): Earth’s axis wobbles, like a spinning top

Question 14

What is positive feedback in glaciation?

Answer 14

A change that makes cooling stronger

•Example: More ice → more sunlight reflected → cooler → more ice

Question 15

What is negative feedback in glaciation?

Answer 15

A change that reduces cooling.

•Example: Warmer temps → more evaporation → more snow → snow reflects sunlight → cools Earth slightly

Question 16

What is solar forcing and how does it affect climate?

Answer 16

Changes in energy from the sun due to sunspots (11-year cycle).

•Example: Fewer sunspots from 1645–1715 linked to the Little Ice Age (1°C cooler)

Question 17

How can volcanic activity cause short-term climate change?

Answer 17

Large eruptions release ash that blocks sunlight, cooling the Earth.

•Example: 1815 Tambora eruption cooled the Earth by 0.5°C for 3 years

Question 18

What is an ice sheet?

Answer 18

A huge layer of ice covering land for a long time (size: 10–100,000 sq km)

Question 19

What is an ice cap?

Answer 19

A smaller version of an ice sheet, found in flat, high polar/sub-polar areas (3–10,000 sq km)

Question 20

What is an ice field?

Answer 20

Ice covering mountainous regions, made of several connected glaciers (10–10,000 sq km)

Question 21

What is a valley glacier

Answer 21

A glacier that flows within the walls of a valley (3–1,500 sq km)

Question 22

What is a piedmont glacier?

Answer 22

A glacier that spreads out in a fan shape after leaving a steep valley (3–1,000 sq km)

Question 23

What is a cirque glacier?

Answer 23

A small glacier in a bowl-shaped hollow called a cirque (0.5–8 sq km)

Question 24

What is an ice shelf?

Answer 24

A floating sheet of ice attached to land (10–10,000 sq km)

Question 25

What’s the difference between land-based and marine-based glaciers?

Answer 25

•Land-based: Sit on land (e.g., Mer de Glace, Alps – 12km long, 300m thick, shrinking 30m/year due to climate change) •Marine-based: Rest below sea level (e.g., parts of West Antarctic Ice Sheet)

Question 26

What is a warm-based glacier?

Answer 26

Found at high altitudes (not polar); pressure causes basal ice to melt, allowing movement •Example: Athabasca Glacier, Canada.

Question 27

What is a cold-based glacier?

Answer 27

Found in polar regions; base stays frozen, little melting or debris movement •Example: West Antarctic Ice Sheet

Question 28

What is a polythermal glacier?

Answer 28

Has both warm and cold parts — cold at the edges, warmer in the middle •Example: Glaciers in Svalbard, Norway

Question 29

What is a surging glacier?

Answer 29

Glacier that suddenly flows much faster — up to 100m/day •Example: Some in Greenland lose 30m/day due to surging and calving

Question 30

How much of the Earth is covered by glacial ice, and what does it store?

Answer 30

• Covers 10% of Earth’s land surface • Holds 75% of all freshwater • Makes up 1.8% of all water on Earth

Question 31

Where is most of the world’s glacial ice found?

Answer 31

•85% in Antarctica (West & East Ice Sheets) •Also found in: Iceland, Canada, USA, Himalayas, Andes, Alps, Tanzania, Argentina

Question 32

Why do some places have glaciers while others don’t?

Answer 32

High altitudes are colder (temperature drops ~1°C per 100m), and sun’s energy is weaker due to lower angles

Question 33

What local factors affect glacier growth or shrinkage?

Answer 33

Aspect and relief — North/East-facing slopes (in the Northern Hemisphere) are more shaded and hold snow better, helping glaciers form or grow