at least for the 70 percent of the earth that is ocean, as far back as 

 700 thousand years. 



To be able to study these global changes on a continuous time scale 

 of hundreds of thousands of years is exciting for two reasons. First, it pro- 

 vides excellent material for descriptive modeling. Second, it may reveal 

 for the first time the actual time series of events during the transition be- 

 tween what are thought to be the two stable states of global climate : the 

 ice age and the temperate age. Knowledge of the time constants of such 

 transitions is vital to descriptive modeling of global oceans and climate. 

 It would also help to assess in natural perspective the observed deteriora- 

 tion of the earth environment presently attributed to the influence of hu- 

 man technology. 



Of the natural fluctuations in the global environment none is more 

 profound or more significant to human ecology than climatic change, yet 

 its mechanism is unknown. To gain an understanding of this mechanism 

 the pattern of climatic change through time must be examined in detail. 



The impact of climatic fluctuations is supported by historical records 

 from Medieval Europe and Iceland, where during the 13th and 14th cen- 

 turies, for example, deteriorating climate conditions were marked by 

 great extensions of North Atlantic sea ice, a completely frozen Baltic, and 

 crop failures in southern Europe. 



An important factor governing climate and one that can be more ac- 

 curately understood through the study of deep-sea sediments is the effect 



of oceanic current systems on local climate. The effect of the Gulf Stream 39 



on the present climate of Western Europe is now well known. It is known 

 that the position of the Gulf Stream changes through time, sometimes be- 

 ing displaced north of its present position, sometimes to the south. It is 

 not known if these fluctuations are in harmony with the major global 

 cycles or if the Gulf Stream's fluctuations have a different frequency. Shift- 

 ing current patterns also affect regions of ocean surface productivity. 

 Knowledge of the historical changes in productivity will allow a clearer 

 understanding of presently changing patterns. 



Climatic fluctuations constitute the background against which the 

 present behavior of the ocean and oceanic climate must be judged and 

 against which all long-range forecasting must be seen. As man's concern 

 for the deteriorating environment increases, he is inclined to blame tech- 

 nology for most changes. In order to assess the truth of these accusations, 

 long-period as well as short-period fluctuations of natural origin must be 

 accurately known. It is true that man already has modified local climate 

 around urban areas. There has been much discussion about the possible 

 detrimental effects on climate of the supersonic jet aircraft. If the mech- 

 anisms by which natural climatic changes occur are not understood, how 

 can one forecast the effects of technology on climate? 



Program Objectives 



The objective is to examine changes in current patterns and water 

 mass properties in the Atlantic and Pacific Oceans during the Quater- 

 nary. The areas of investigation have been selected because of an ex- 

 isting superior knowledge base and because of the adequacy of available 



