Date:  Wednesday, February 15, 1995
Time:  4:15 PM   Refreshments at 4:00
Location:  ERL 126



ICE AGES AND THE EARTH'S ORBIT


Richard A. Muller
Professor of Physics
University of California and Lawrence Berkeley Laboratory


Abstract


For many decades it has been widely accepted that the 100 kyr cycle of the
ice ages is caused by changes in the eccentricity of the Earth's orbit. 
However we can prove this theory wrong by use of a high-resolution spectral
analysis of oxygen isotopes in sea-floor cores.  We present an alternative
theory: that the climate is related to changes in the Earth's orbital
inclination,  and to varying extraterrestrial accretion as the orbit moves
in and out of the Sun's Zodiacal ring.  The new theory provides an
excellent match to the data, and can be further tested by searching for
iridium in Greenland ice.