MSC 111 Lecture 4: MSC 1111 Chapter 4: Earth Structure and Plate Tectonics I

• School: University of Miami
• Department: Marine Science
• Course: MSC 111
• Professor: Peterson Larry

Document Summary

Dark volcanic rock- heavier elements and higher concentrations of metals) Rock is shiny because magma cools instantly due to the cold seafloor temperatures (instant mineralization) More dense than the crust (4. 5 g/cm3) and hotter (1500-3000 degrees celsius) Due to radioactivity and pressure from the crust and metals. Rich in magnesium and iron silicates (peridotite) Fluid (cid:373)otio(cid:374)s i(cid:374) the i(cid:374)(cid:374)e(cid:396) (cid:272)o(cid:396)e ge(cid:374)e(cid:396)ate ea(cid:396)th"s (cid:373)ag(cid:374)eti(cid:272) field that p(cid:396)ote(cid:272)t us f(cid:396)o(cid:373) solar winds that would blow away our atmosphere and render earth uninhabitable. Geochemistry is deduced from limited samples of mantle material. Theoretical and lab hints at a deeper system. Physical evidence is gathered through seismic waves. Wave behavior of different kinds of waves characterize the core. P-waves: horizontal motion, particles move in the direction of the wave. S-waves: vertical motion of the particles, perpendicular to direction of wave. P-waves travel faster than s-waves and therefore recorded first. Wave velocity increases as density of the medium through which it travels increases (all waves)