Week Two - Week Two (Jan 22 & 24) January 22, 2008 Plate...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
22/01/2008 12:56:00 January 22, 2008 Plate Tectonics Earth’s Interior heat is derived from early accretion and radioactive decay Accretion o Left over from Earth’s formation ~ 4.6 Ga o Collisions o Gravitational stratification --- Friction Radio Active Decay o Release of energy during decay of radio active isotopes  o Half-life: time required for half of the atoms to decay o Some heat left over from short-lived isotopes that decayed early in  Earth’s history o Ongoing addition of heat from long-lived (primordial) isotopes with half- Heat Transfer o By conduction through solid portions (lithosphere, inner core): atomic  or molecular interactions o By convection through “fluid portions (mantle, outer core): transport of  molecules Slow Convection of the mantle ultimately drives plate tectonics Convection: a density-stratified fluid may experience vertical motion through  the addition of buoyancy near the base o Heated material will become buoyant and rise o Upon cooling (usually near surface) material will become negatively  buoyant and sink o Continuous flow organizes into convection cells
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Mantle convection o lithosphere o Solid with viscosity (resistance to flow) similar to cold steel
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/01/2008 for the course GEOL 3070 taught by Professor Marchitto during the Spring '08 term at Colorado.

Page1 / 8

Week Two - Week Two (Jan 22 & 24) January 22, 2008 Plate...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online