GLACIOUESTATIC SEA LEVEL CHANGES

 

1. Very important for coastal landforms.

 

2. They result from advancing and retreating glaciers and the

  polar ice caps. A climatic problem ???

 

3. There is a change in volume of seawater and ice (polar caps)

 

4. Last Glacial Maximum was approximately 16,000 to 18,000 years B.P. Sea level has been rising ever since.......... Sea level is still slowly rising in most places.......

5.   During glacial episodes as much as 50 million cubic kilometers (12 million cubic miles) of sea water were removed from the oceans and transformed into glacial ice, sea level dropped 350 to 400 feet.

6.   During the last Glacial Maximum, sea level was approximately 120 meters lower than today. San Francisco Bay was mostly dry..... much of Monterey Bay Continental Shelf was exposed......

7. If all the ice in Greenland and Antarctica melted in one week, sea level would rise approximately 70 meters worldwide.

 

 

SOME EVIDENCE OF CLIMATE INSTABILITY AND SEA LEVEL CHANGES

 

1. Milankovitch Cycles

 

2. Glacial Deposits on Continents / Continental Shelves

 

3. Pluvial Lakes

 

4. Relic river sediments

 

5. Tidal Gauge Data

 

6. Wave Cut Terraces near shorelines

 

7. Carbon Dioxide and Oxygen Isotopes preserved in Glacial Ice and Planktonic oozes.

 

8. Elevated 2 meter notch at Palawan Island , Philippines

 

9. Seismic Reflection Profiling Continental Shelves...... onlapping and offlapping sediments

10. Estuarine stratigraphy