Temperature Profiles in Permafrost


Summary

Students create a STELLA model of heat flow in the outer km of Earth's crust and then perform experiments to change the air temperature variable in an attempt to replicate the findings of Lachenbruch and Marshall (1986). These workers used inflections in the geothermal gradient of Alaskan permafrost to search for evidence of recent climatic change.

Learning Goals

The Heat Flow in Permafrost exercise has several purposes:
  • To teach the students about the basics of heat transfer and the geothermal gradient
  • To introduce oscillatory behavior
  • To introduce the STELLA concept of "bi-flows"
  • To introduce the STELLA "ghost" function in designing and building model structures

Context for Use

This activity was developed for a class introducing dynamical systems modeling to upper level undergraduate students.

Description and Teaching Materials

Heat_Flow_in_Permafrost_Exercises.pdf (Acrobat (PDF) 20kB Jun7 05)
heat_flow.v5.STM ( 59kB Jun7 05)
Heat_Flow2.f90 ( 4kB Jun7 05)

Teaching Notes and Tips

Instructor Notes (Acrobat (PDF) 66kB Apr10 06)

Assessment

Heat_Flow_in_Permafrost_Lab_Answer_Key.pdf (Acrobat (PDF) 239kB Jun7 05)
assignment_assessment__3.pdf (Acrobat (PDF) 5kB Jun7 05)

References and Resources

The following are readings for this exercise:

Turcotte, D.L., and Schubert, G., 2000, Geodynamics, 2nd ed., Cambridge, U.K.: Cambridge University Press, p. 132-143, 150-152.

Lachenbruch, A.H., and Marshall, B.V., 1986, Changing climate: geothermal evidence from permafrost in the Alaskan Arctic, Science, v. 234, p. 689-696.