Glacier Goo fun sites
https://www.cresis.ku.edu/education/iibLessons/iib018.pdf
https://www.cresis.ku.edu/education/wiki/index.php/Glacier_Goo_-_Middle_School
http://www2.umaine.edu/USITASE/teachers/pdf/glaciergoo2.pdf
http://depts.washington.edu/rocknout/Lesson%20Plans/Glaciers_On_The_Move.pdf
this uses different colors