Milankovitch cycles
How long do they last?
90,000-100,000 years
What are the three types?
Eccentricity, axial tilt and precession.
Milankovitch theory?
The 3 cycles combine to affect the amount of solar heat that's incident on the earths surface and subsequently influence climatic patterns
The milankovitch cycle describes
The changes in the earths movement upon the climate. Natural global warming and cooling is considered to be initiated by milankovitch cycles.
What are milankovitch cycles?
The cyclical movement of the earths orbit around the sun
The orbital and axial variations influence
The initiation of long term natural cycles, like ice ages and warm periods known as glacial and inter glacial periods.
Eccentricity
The shape of the earths orbit: circular or elliptical. When the earth cycle is elliptical we spend less time close to the sun in a year, which cools the earth. Circular = less variation in energy that earth encounters
Tilt ( the obliquity cycle )
The tilt of the earths axis toward and away from the sun. The greater the tilt, the more solar energy the poles recieve, tilt is larger = more variation between summer and winter = chance to melt ice age ( warm summer ) and chance to go back into ice age ( cold winter ). Smaller tilt = less variation between summer and winter
Precession
The wobble of the earths axis toward and away from the sun. Northern hemisphere towards sun = cool summer, furthest from the sun = warm winter , the southern hemisphere will have a cold winter and warm summer