Department of Earth Science |Northeastern Illinois University

ESCI 121

Section 06
Fall 2009

Daily Objectives #3  (September 8, 2009)                                                                                                         Dr. Sanders

By the end of today's class, you should be able to do the following:


Review the list of characteristics that can be used to describe rocks.
w Explain the definition/meaning of the term density.
w Find the densities of the rock samples provided, using the triple-beam balances and other lab supplies.
w In groups, measure the density of two rock samples using a balance to find mass, and the water-displacement method to find volume.  If your measurement is within plus or minus 10% of the actual measurement, your group will earn two points for the day (1 point per rock).  

New this time:

Sketch a diagram illustrating the internal structure of the earth as defined by the density of its layers.

w Examine maps that show landforms to see different strategies for illustrating topography (raised-relief, topographic, color-coded).

Using maps in the classroom, the world map you printed, and the 14 sites you plotted, make a list giving the topography and geographic setting of each site.  (Keep the list handy for future use!)

w Participate in a Jigsaw exercise to investigate Earth's large scale patterns. 


▫ Break into Expert Groups, based on what you studied for the homework assignment:

     1) Volcanoes                       4) Depth of focus of earthquakes
     2) Hotspot volcanoes         5) Thickness of Earth's crust
     3) Earthquakes                  

▫ Record the names of your colleagues in your Expert Group. 
▫ Examine the maps that each person in your Expert Group brought today for their homework assignment.  Does each map show exactly the same thing?  Compare maps; note any similarities and differences. 

▫ Using your world map from last class, the ocean floor map at the left side of the room, and the world map at the back of the room, locate and plot on the Expert Group maps our 14 study sites from last class.

▫ For each of the 14 study sites, determine the characteristics of that site based on your group's area of expertise.  (For example, if your group's area of expertise is "Hot spot volcanoes", then for each of the 14 sites, tell whether hot spot volcanoes occur at that location, or not.  Record your observations for each site on the Expert Group Summary Sheet provided.  Before you leave this group, everyone in the group should have a complete set of all the same information!

w Next steps: Next, we will "scramble" the jigsaw pieces and share information with others who are experts in different areas.  We will try to assess patterns we uncover.  Then we will investigate these patterns and what they might mean.  To do this, it would be very helpful if you have in front of you a world map showing tectonic plate boundaries.  The textbook you are using may have this; please examine it and find out if it does; if it does, please bring it to class next time!

Department of Earth Science | Northeastern Illinois University

Copyright 2009 Laura L. Sanders.  Last updated September 7, 2009.