EESA06H3 Chapter Notes - Chapter 4: Paleomagnetism, Viscosity, Project Mohole
Document Summary
How gravity measurements can indicate where certain regions of the crust & upper mantle are being held up or down out of their natural position of equilibrium. Geoscientists are not able to sample rocks very far below the surface. Rock samples from mines & wells are useful but. Mines = 3 km into the earth. Intrusion & erosion of diamond-bearing kimberlite pipes. So, deep parts of earth are mostly studied inderectly via geophysics. The application of physical laws & principles to the study of the earth. Includes study of seismic waves, magnetic field, gravity & heat. Info can be obtained from large earthquakes & nuclear bomb explosion (both generate seismic waves) The bending of seismic waves as they pass from 1 material to another. Lens analogy: wave crosses form one rock layer to another and then changes direction = refraction = occurs only is velocity of seismic waves is diff in each layer.
