Geographical History Flashcards
Glaciers, ice ages and time periods
Which epoch are we currently in?
The Quaternary epoch (specifically Holocene)
When did the Quaternary epoch begin?
2.6 million years ago, as the pleistocene epoch; start of current ice age
When did the Holocene epoch begin?
11.7k years ago; contains the whole history of the development of civilisation
What are signifiers of an ice age?
Repeated periods of cold and warm (glacial advances and retreats/interglacials)
When was the last cold period, and how cold was it?
~26, 500 years ago; -18 Celcius
What are Milankovitch cycles?
Cyclic fluctuations in the Earth’s orbit which affect amount of radiation from sun to Earth
What are the three Milankovitch cycles?
Orbital eccentricity, axial tilt/obliquity, precession
What is orbital eccentricity, and how long does the cycle last?
Orbit of the Earth goes from round to oval and back again; 400k years
What is axial tilt, and how long does the cycle last?
The axis of the spinning Earth moving closer to the Sun and further away again; 41k years
What is precession, and how long does the cycle last?
The axis of the spinning Earth is not fixed, but itself spins around in a circle; 24k years
What are the cold snaps called?
Oldest, older, and younger Dryas
When was the oldest Dryas?
~17,000 BP
When was the older Dryas?
~14,000 BP
When was the younger Dryas?
~12,000 BP; start of Holocene
When the Little Ice Age?
1350-1950AD
When is the next glacial period predicted to be?
3500AD
When was the Old Stone Age, and what was it called?
7,000BC; Palaeolithic
When was the Middle Stone Age, and what was it called?
6,000BC; Mesolithic
When was the New Stone Age, and what was it called?
3,500BC; Neolithic
What was the name of the trainsitionary period between Neolithic to Iron Age?
Chalcolithic
When was the start of the Iron Age?
700BC
When was the Industrial Revolution?
1760AD
What tools were typical of the Mesolithic period?
Composite tools
What was significant about the Mesolithic period geographically?
Britain separated from the continent, occurring in three distinct melting events, the last of which was called the Flandrian Transgression; in 5600BC, landslide in Norway set off a tsunami across the sea
What was significant about the Neolithic life-style wise, and what materials were used?
Initiated agriculture and domestication, stopping the hunter-gatherer lifestyle; used stone, bone, wood still
What materials were used in the Chalcolithic period?
Stone and Cu
What materials started to be made in the Iron Age?
Bronze (Cu + Sn) and steel (Fe + C)
