GLACIERS

GLACIERS

1. Inter glacial = warm period glacial = cold period

   • Last ice age was pleistocene era
   • This inter glacial (current) period is called the holocene
   • Current geological time period is the Quaternary (started 2.6 million years ago)
     • The last glacial maximum
       • Anglian
       • Wolstonian
       • Devensian (picture below)
   • Cold period = 80,000 to 100,000 years
   • Warm periods = 10,000 to 15,000 years

2. What affects the distribution of cold environments?

   • Local
     • Altitude (every 100m up 0.6C is lost?
     • Latitude (e.g. north is colder)
     • Ocean currents (the way heat is distributed across the planet)
     • Continentality (the amount of radiation land/ sea absorbed)
   • Global
     • Milankovitch Cycles (eliptical orbit every 100,000 years causes less radiation from sun)
     • Sunspots (lack of)
     • Asteroid collision (tephra and dirt causes blackout)
     • Volcanic activity (super volcano e.g. Yellowstone would block out sun's rays)

3. Types of Ice

   • Ice sheet - a mass of glacier ice that covers surrounding terrain for over 50,000 km squared
     • Antarctica
   • Valley glacier - streams of flowing ice contained withing steep valley walls
     • The Alps
   • Ice cap - a mass of ice less than 50,000 km squared covering highland areas
     • Arctic
   • Snow patches - a pattern of snow which lays on the ground for longer than the season
     • Scotland

4. Positive feedback = speed up global warming negative feedback = slow down global warming

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