GEOLOGY 440/640 – Exercise 3

GISP ICE CORE PLOTS

1.Download GISP2 Stable isotope data into a spreadsheet
ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/gisp2/isotopes/gispd18o.txt

2.Massage the data – remove all rows in which data is incomplete

3. Make a plot of δ18O (y-axis) to Calendar Year Age ~115 ka (x-axis).

4. Arrange the y-axis so that more negative values are lower; arrange the x-axis
    so that 0 (Today) is on the right. Adjust your scales so that the plot fills the
     page.

5. On the complete plot, identify and subdivide the graph into: last glaciation
   (Wisconsinan), Holocene, late-glacial, Younger Dryas (use text for definitions).

6. Write a paragraph describing how the style of  δ18O variation varies between
    the Holocene and the last glaciation.

7. NEW PLOT Expand the part of the record from 9000 to 15OOO calendar years

8. What is the calendar age of the initial warming?

9. Pick calendar ages for the beginning and ending of the cooling that occurs
    after the initial warming.

10. Pick a calendar age for the start of the Holocene.

11. Convert the calendar years into radiocarbon years for the initial warming, final
     short cooling episode (Younger Dryas), and the Holocene.  Show the results
     14C yr B.P.