1. Computer lab continued - problem 2.13
Geology Geomath
Computer lab continued - problem 2.13
tom.h.wilson
Department of Geology and Geography
West Virginia University
Morgantown, WV
Tom Wilson, Department of Geology and Geography 1

2. Warm up exercise ?? General comments
Watch out for units: e.g., problems 5 and 7
9. A0 the age at the depth defined as 0. It does not have to be the age of the present-day depositional surface. In this problem A0 also represents the time it takes to fill up the lake.
The present-day depositional surface may be located at some arbitrary depth: in this case 11.5 meters.
Tom Wilson, Department of Geology and Geography

3. Warm up exercise ?? General comments 13.
In this expression N is the number of earthquakes of a given magnitude (m) and greater likely to occur in a given year.
To determine the probable length of time in years between events with magnitude m and greater you need to compute (1/N).
Consider the units.
Tom Wilson, Department of Geology and Geography

4. y=sin(5x)
Tom Wilson, Department of Geology and Geography

5. Problem 2. 13 deals with exponential decay formulation
Problem 2.13 deals with exponential decay formulation. This class of functions is used for dating a variety of geological materials and is very familiar to geologists
210Pb dating
22.3 year half life
Stalagmite from cave in France
Tom Wilson, Department of Geology and Geography

6. Visit http://curvebank.calstatela.edu/radiodecay/radiodecay.htm
Plot of carbon-14 decay rate against age of the sample in years.
Tom Wilson, Department of Geology and Geography

7. Visit http://curvebank.calstatela.edu/radiodecay/radiodecay.htm
Tom Wilson, Department of Geology and Geography

8. Some other geologic variables also have exponential dependence on depth, for example.
See Nittrouer et al., 2008
Tom Wilson, Department of Geology and Geography

9. Age – Depth relationships?
Atlantic Margin Seismic Sequences
Chapter 1, 2008, Nittrouer et al.
Tom Wilson, Department of Geology and Geography

10. Chapter 1, 2008, Nittrouer et al. page 33-34
Time-depth relationships can often be broken down into a series of linearly varying age-depth relationships
Again – this data from the Atlantic shelf margin does not suggest exponential age depth relationships
Chapter 1, 2008, Nittrouer et al. page 33-34
Tom Wilson, Department of Geology and Geography

11.
Tom Wilson, Department of Geology and Geography

12. Take the natural log - ln
Problem 2.13
Take the natural log - ln
Consider the inverse process: take e to the power of the natural log
Tom Wilson, Department of Geology and Geography

13. Problem 2.13 – to do list
Tom Wilson, Department of Geology and Geography

14. Due dates Problem 2.13 is due next Monday
Read through Chapter 3. Try to work through the discussion questions as you read.
Consider Problems 3.10 and 3.11
Tom Wilson, Department of Geology and Geography