Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
15 Cards in this Set
- Front
- Back
|
How has the climate fluctuated over the British Isles? |
Glacial Allerod Loch Pre Boreal Boreal Atlantic Sub Boreal Sub Atlantic |
|
|
What was the Devensian glacial period?
|
Very cold glacial phase and the end of the more recent glacial phase. |
|
|
What was the Allerod Period? |
Increasing warmth about 12,000 years ago |
|
|
What was the Atlantic period?
|
The climate was optimum warm and wet (7500BP) |
|
|
What is evidence for climate change?
|
Pollen Analysis Dendrochronology Other less major types Ice Core Analysis |
|
|
What is Pollen Analysis? |
When pollen is preserved in oxygen free environments it doesn't decay. The older the pollen the deeper it is in things such as bogs. Then the pollen can get dated by Radiocarbon Dating |
|
|
What are the advantages of this?
|
Pollen is specific to a species Only need a small sample of sediment Allows post-glacial period to be divided into phases |
|
|
What are the Disadvantages of this?
|
Different plants produce different amounts of pollen, skewing results Exotic pollen blown elsewhere Only indirect evidence Pollen grains can be incorrectly identified |
|
|
What is Dendrochronology?
|
The study of tree stumps which can tell you precipitation levels of a year |
|
|
How? |
The wider the ring, the more precipitation there was that year |
|
|
What are the disadvantages? |
Trees respond primarily to moisture rather than temp Small sample size as few trees are over 4000 years old |
|
|
Example of where this has been used?
|
Bristlecone pines- Methuselah |
|
|
What is Methuselah? |
11,000 ft up in White Mountains of California, and has grown very slowly due to harsh climate Shows when Santorini eruption may have been |
|
|
What are the Other Types of evidence? |
Organic remains of beetles that cant decay Historical human evidence Ice cores drilled from Greenland ice cap to see how CO2 there was Relict landscapes |
|
|
Ice Core Analysis?
|
Analysis of oxygen isotopes and sheets of sea creatures |
