Using Isotopes Worksheet
1. The bottom axis of the graph indicates the number of years before present. What is the time frame represented on this graph? ~ 450,000 years ago
2. What does the red dotted line represent? Current sea level
3. How did sea level 400,000 years ago compare to sea level today? It was ~20 m lower.
4. How did sea level 150,000 years ago compare to sea level today? It was ~ 150 m lower.
5. At roughly what time was sea level at its highest during this time frame? ~125,000 years ago
6. At roughly what time was sea level the lowest during this time frame? ~425,000 years ago
7. What happened to sea level between 400,000 and 350,000 years ago? It dropped drastically - ~100 meters
8. How do you think that might have affected marine life at that time? Answers may vary and most likely will focus on habitat loss and extinction.