Lecture 2 - Climates at the time of the dinos

Question 1

Climate is the ____ and weather is ___

Answer 1

long term, day to day

Question 2

Fitness

Answer 2

liklihood of reaching sexual maturity and having offspring

Question 3

At the start of the Time of the DInos the coasts were ___ and the interiors were ___. The interiors also experienced stronger seasonal temperature swings

Answer 3

wet, dry

Question 4

Why are coasts more temperate than interiors?

Answer 4

The ocean has a regulating effect on temp

Question 5

How do we know that the interior was dry?

Answer 5

Salt deposits
The removal of water left salt deposits

Question 6

How do we know that the coasts were wet?

Answer 6

Coal formed in warm wet coastal swamps near the equator

Question 7

Coal forms when ____ falls into stagnant pools of water and does not_____

Answer 7

vegetation, breakdown

Question 8

Glacial tills near the south pile tell us that

Answer 8

the area was once glaciated

Question 9

What happened to extreme temos as pangea started to break up? why?

Answer 9

temps became less extreme because there were more coastal areas.

Question 10

As pangea started to break up climates became … warmer/colder

Answer 10

warmer. The global average was 4-9C warmer than present

Question 11

During the time of the DINOS there was no permanent ice so that meant that the gradient between the ___ and the poles was not as ___

Answer 11

equator, large. Distrubution of life was greater

Question 12

Is climate change a totally natural and normal phenomenon?

Answer 12

Yes

Question 13

Did humans observe climates uring the time of the DINOS?

Answer 13

No humans were not around

Question 14

Two causes of climate change

Answer 14

1. Changes in the amount of solar radiation reaching Earth (sun’s intensity. distance of the sun from earth)
2. Changes in the amount of GhG

Question 15

What are the four main climate archives?

Answer 15

Sediment
Ice
Coral
Tree rings

Question 16

Proxies

Answer 16

Cannot measure directly but give us insight which allows us to make connections

Question 17

Principle of Uniformitarianism

Answer 17

Earth is very old
Natural processes have been uniform through time
The study of modern geological processes is useful to our understanding of past geological events

Question 18

Sedimentary

Answer 18

Coastal area and evap= salt deposits
Swampy area and plants = coal
Cold area and ice = glacial tills

Question 19

Ice can trap ______ which tells us the

Answer 19

atmospheric gases in bubbles. conc of GHG
(limited by time 2.7 milllion years ago)

Question 20

Animals will preferentially build their shells out of the ____ isotype, but the ratio of light to heavy isotope varies with

Answer 20

light, temp

Question 21

Where did the GHG come from?

Answer 21

The breakup of pangea was caused by intense sea floor spreading. This meant there was extensive volcanism and a large amount of GHG were released
DInos were also gassy

Question 22

During the time of the dinos, sea levels were generally ___

Answer 22

high

Question 23

When sea levels are low there is ____. When sea levels are high there is ___

Answer 23

erosion, deposition

Question 24

White cliffs of Dover are an example of

Answer 24

massive deposit of marine organisms that indicate higher sea levels in the past

Question 25

What 2 factors cause sea levels to rise? Do they work together?

Answer 25

Tectonic activity
Climatic factors
Yes they work in tandom

Question 26

2 ways that tectonic activity can change the size of the basin

Answer 26

Collide or seperate continets
Change the size of mid ocean righes

Question 27

Describe how collision/seperation of cont impact sea leavel

Answer 27

Cont-cont collsion lower sea level
Splitting the continets apart make sea levels higher

Question 28

Fast preading ridges create ___ sea levels. SLow spreading crea ___

Answer 28

high (more water is being displaced), low

Question 29

Water is stored in ice sheets. No ice at the time of the dinos means

Answer 29

sea level was higher

Question 30

Warm water occupies more space that cool water

Answer 30

higher sea level at time of dinos

Question 31

Isostasy

Answer 31

A response/rebound as glaciers change.

Question 32

would isostatic rebound cause today

Answer 32

flooding

Question 33

Current estimates indicate that towards the end of the Time of Dinos, sea levels were ___m higher

Answer 33

125 m

Question 34

What are the 4 major factors leading to higher sea levels 100 to 80mya?

Answer 34

No major ice sheets
Thermal expansion of sea water
No colliding continents
Higher ocean ridge volume (more spreading, higher sea level)

Question 35

What is the impact of sea level on climate change?

Answer 35

Floodong of coastal areas has a moderating impact on temp

Question 36

Towards the end of the DINOs the globallu mild and warm climates deteriorated due to _____ on the sea floor and a drop in ____ which caused

Answer 36

decreased volcanism, sea level
Increased seasonality (less temperateO
Increased temp gradient b/w equator and poles