Isopach

Isopach maps use contour lines to demonstrate differences in thickness of a certain entity. This mainly pertains to geologist to measure different thicknesses in surface rock. Being able to understand the thickness of a surface is important in land surveying and for finding oil as well as other natural resources in the Earth. As demonstrated in this map below Isopach can also be used for measuring earth deposit in the air and can be useful in the field of volcanology.





http://www.geo.utexas.edu/faculty/barker/kempter/rbtephra.gif