Chapter 12

Question 1

What do marine sediments and oxygen isotope analyses tell us about the global climate?

Answer 1

Since 16O is easier to evaporate, it is more likely to end up in precipitation (rain and snow) on the continent.

Question 2

What does pollen tell us about the global climate?

Answer 2

Changes in pollen type and abundance can indicate a change in climate

Question 3

Describe what we learn from tree growth rings.

Answer 3

• Narrow rings indicate drought
• Wide rings indicate good growing conditions
• Used to determine info on yearly precipitation (wet vs dry-no numbers)

Question 4

What do we learn from ice cores?

Answer 4

• Isotope analysis-indicate cold and mild years

* Bubbles trapped in ice-indicate composition of atmosphere

Question 5

What is polar amplification?

Answer 5

•SHRINKING ICE SHEETS

–Polar amplification threatens Antarctica and Greenland ice sheets

Question 6

Describe the Medieval Warm Period and the Little Ice Age. When did they occur? How do we know they occurred?

Answer 6

• Period where temperature was warmer than today
• Cold period lasting from about 1400 to 1900
• Viking settlements changed

Question 7

How does plate tectonics relate to climate change?

Answer 7

Plate Tectonics
–Continents change latitude and orientation over geologic time
–Utah was once South of Equator

Question 8

What is a sunspot? How often do they form?

Answer 8

•Dark blotch or storm on the sun•Flare up every 11 years

Question 9

How are sunspot activity, the Maunder minimum and the Little Ice Age related?

Answer 9

The Maunder Minimum was a time when there was very few sun spots. It occurred during the coldest part of the Little Ice Age. The lack of sun spots was the cause of the Little Ice Age.

Question 10

Milankovitch cycles are used to explain what

Answer 10

climate change

Question 11

Describe earth precession

Answer 11

the wobbling of Earth’s axis, like a spinning top that is winding down.

Question 12

How long does the Earth take to complete 1 of these wobbles? Precession

Answer 12

23,000 years

Question 13

The Earth is titled on its axis. What is the angle of tilt today?

Answer 13

22.1-24.5

Question 14

How long does it take to cycle through one complete rotation (22.1 to 24.5 back to 22.1)?

Answer 14

41,000 years

Question 15

If the tilt is higher, what happens to the winter temperatures?

Answer 15

•High tilt-colder winters and warmer summers•Low tilt-more mild climate

Question 16

What is the difference between high eccentricity and low eccentricity. How long does the cycle take?

Answer 16

–The Earth’s distance from the Sun changes greatly over the course of 1 year
–Much greater solar radiation when close to the sun and much less when far from the sun
•Cycle-~100,000years

Question 17

How do volcanic eruptions affect the global climate?

Answer 17

• Sulfur absorbs incoming solar radiation
• Ash blocks out the sun
• Lowers global temperatures for a couple of years

Question 18

What is the relationship between the Greenhouse Effect and Global warming?

Answer 18

•Global Warming–Increase in global average temperatures due to enhanced greenhouse effect
–Releasing CO2and CH4into atmosphere causes temperatures to rise

Question 19

Q: So which will evaporate first? 16O or 18O?

Answer 19

16O will evaporate first because it is lighter.

Question 20

If there is an ice age, the snow doesn’t melt every year and glaciers grow. Will there be lots of 16O or 18O in the glacial ice?

Answer 20

There will be lots of 16O in the glacial ice.

Question 21

If there is an ice age, more of the 16O ends up in the glaciers, what does that do to the concentration of 18O in the ocean?

Answer 21

The concentration of 18O increases in the ocean (more in the ocean).

Question 22

So, will the oxygen in the shells of marine organisms that live during an ice age have more 16O or 18O?

Answer 22

Marine organisms living during an ice age will have more 18O than organisms living during a warm period.

Question 23

Sunspots flare up every how many years?

Answer 23

11 years

Question 24

What was the time period for the Maunder Minimum?

Answer 24

1650-1700

Question 25

How does this relate to temperature during the little ice age? Maunder Minimum

Answer 25

The Maunder Minimum occurred during the coldest part of the Little Ice Age.

Question 26

Eccentricity is what and happens how often?

Answer 26

Changes in shape of Earth’s orbit: 100,000 years

Question 27

What is Obliquity.

Answer 27

Changes in Axial Tilt
22.1°-24.5°
41,000 year cycle

Question 28

What is Precession

Answer 28

Changes the orientation of Earth’s axis

Every 23,000 years