Lecture 2 - Climates at the time of the dinos Flashcards
Climate is the ____ and weather is ___
long term, day to day
Fitness
liklihood of reaching sexual maturity and having offspring
At the start of the Time of the DInos the coasts were ___ and the interiors were ___. The interiors also experienced stronger seasonal temperature swings
wet, dry
Why are coasts more temperate than interiors?
The ocean has a regulating effect on temp
How do we know that the interior was dry?
Salt deposits
The removal of water left salt deposits
How do we know that the coasts were wet?
Coal formed in warm wet coastal swamps near the equator
Coal forms when ____ falls into stagnant pools of water and does not_____
vegetation, breakdown
Glacial tills near the south pile tell us that
the area was once glaciated
What happened to extreme temos as pangea started to break up? why?
temps became less extreme because there were more coastal areas.
As pangea started to break up climates became … warmer/colder
warmer. The global average was 4-9C warmer than present
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 ___
equator, large. Distrubution of life was greater
Is climate change a totally natural and normal phenomenon?
Yes
Did humans observe climates uring the time of the DINOS?
No humans were not around
Two causes of climate change
- Changes in the amount of solar radiation reaching Earth (sun’s intensity. distance of the sun from earth)
- Changes in the amount of GhG
What are the four main climate archives?
Sediment
Ice
Coral
Tree rings
Proxies
Cannot measure directly but give us insight which allows us to make connections
Principle of Uniformitarianism
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
Sedimentary
Coastal area and evap= salt deposits
Swampy area and plants = coal
Cold area and ice = glacial tills
Ice can trap ______ which tells us the
atmospheric gases in bubbles. conc of GHG
(limited by time 2.7 milllion years ago)
Animals will preferentially build their shells out of the ____ isotype, but the ratio of light to heavy isotope varies with
light, temp
Where did the GHG come from?
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
During the time of the dinos, sea levels were generally ___
high
When sea levels are low there is ____. When sea levels are high there is ___
erosion, deposition
White cliffs of Dover are an example of
massive deposit of marine organisms that indicate higher sea levels in the past
