PAPER 1/ NATURAL HAZARDS/ Past Climate Change Flashcards
(40 cards)
When did the Quaternary period start?
2.6 million years ago.
What period started 2.6 million years ago?
The Quaternary period started 2.6 million years ago.
What is a glacial period?
A period with cooler temperatures and ice advances, lasting thousands of years (about 100,000).
What is a period with cooler temperatures and ice advances?
A glacial period.
What is an interglacial period?
A period with warmer temperatures and ice retreats, lasting thousands of years (10,000 years on average).
What is a period with warmer temperatures and ice retreats, lasting thousands of years (10,000 years on average)?
An interglacial period.
Give an example of a glacial period.
An example of a glacial period is the Little Ice Age.
Give an example of an interglacial period.
An example of an interglacial period is the Medieval Warm Period.
What are all the pieces of evidence for climate change?
Ice and Sediment Cores, tree rings and pollen analysis are all pieces of evidence of climate change.
How are ice cores obtained?
Scientists drill into glaciers and pulling out cylindrical ice cores to analyse.
How can scientists tell temperature from ice cores?
If there are low levels of CO2 in the ice cores then there was a low temperature, whereas if there are high levels then, most likely the temperature was higher.
How far back can ice cores tell the temperature?
Ice cores can give evidence from at least 400,000 years.
How can scientists tell climatic conditions with sediment cores?
Scientists use organisms found in sediment cores, which are more accurate and hold records going back 5 million years.
How long ago can sediment cores hold information about the climate?
5 million years.
Ice cores can only collect data when?
Ice cores can only collect data during periods of snowfall. No snowfall means no data.
How often is a tree ring grown?
Tree rings are grown once per year if the tree is alive.
What do thicker tree rings indicate?
Thicker tree rings indicate warmer, wetter conditions.
What do thinner tree rings indicate?
Thinner tree rings indicate cooler, drier conditions.
What do tree rings measure?
Tree rings measure multiple aspects of climate - temperature and precipitation.
How long back can tree rings collect data?
Tree rings can measure data from up to 14,000 years ago.
What can make tree rings inaccurate?
Non-climate factors such as soil, fire and disease affects tree rings, making the size possibly less valid.
What does pollen analysis involve?
Pollen analysis involves examining preserved pollen from plants that has become trapped in sediment.
What are scientists able to do with this pollen trapped in sediment?
Scientists are able to identify and date the pollen to show which species were living at a given time, and as they know what conditions the plants that are living now they are able to deduce the climatic conditions of the time.
What is a disadvantage of weather stations?
They are not evenly distributed across the world, meaning that climate change is difficult to measure.