Physics of Earth's Evolution However the Earth came to its presently differentiated form, it must have obeyed our known physics: Conservation of energy.

Slides:



Advertisements
Similar presentations
Energy in the Geosphere
Advertisements

The Earth’s Interior Glencoe Ch Pages
Plate tectonics is the surface expression of mantle convection
Plate Tectonics & Convection
FORMATION OF CRUST AND ATMOSPHERE Planets of solar system probably formed from remnants of supernovas, i.e., disc-shaped clouds of hot gases (solar nebula).
Lecture Outlines Physical Geology, 14/e Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Plummer, Carlson &
Chapter 17 Earth’s interior. Earth’s interior structure Earth is composed of three shells; –Crust –Mantle –Core.
The atmosphere includes layers of gases that surround the earth. The lithosphere is the surface of the earth that forms continents and the ocean floor.
Earth: Inside and Out. Key Ideas How is the Earth’s interior structured? How has the appearance of the Earth changed over time? What geologic Features.
Pg. 25.  After Earth formed, radioactive elements decayed and heat was released  Caused melting of interior  Denser elements sank to core (iron and.
THE HEAT LOSS OF THE EARTH Claude Jaupart Jean-Claude Mareschal Stéphane Labrosse Institut de Physique du Globe de Paris.
Chapter 17 Earth’s Interior and Geophysical Properties
GEOMAGNETISM: a dynamo at the centre of the Earth Lecture 1 How the dynamo is powered Lecture 2 How the dynamo works Lecture 3 Interpreting the observations.
Power Requirements for Earth’s Magnetic Field Bruce Buffett University of Chicago.
Science Starter Turn to the next blank page in your ISN and cut and paste the handout that is located on the front desk. You will need colored pencils.
Heat Transfer.  Earth’s molten outer core is nearly as hot as the surface of the sun.  Heat is transferred from the core to the surface of the Earth.
Basic Structure of the Earth
Structure of the Earth. Gravity reshapes the proto-Earth into a sphere. The interior of the Earth separates into a core and mantle. Forming the planets.
Layers of the Earth.
Natural Disasters Earth’s Internal Structure Introduction to Plate Tectonics Earth’s Energy Sources and Systems.
Section 1: Earth: A Unique Planet
Earth on the Move Earth Structure & Plate Tectonics Notes.
Heat flow, thermal regime, energy budget of the Earth Definitions Measuring heat flow Kelvin and the age of the Earth Radioactivity Continental heat flow.
Dr. Jeff Amato Geological Sciences Rocks Igneous Rocks.
Earth’s Internal Heat.
Class 1: Plate Tectonics Review Today’s topics:  Earth’s compositional layers  Plate tectonics: theory & actions.
Energy, heat and temperature Olivia Jensen – 13/10/11... for 666 Module 2.
Thermal Histories of Convective Earth Models & Constrains on Radiogenic Heat Production in The Earth By: G. Davis, JGR, 1980 Presenting: Colleen, Caroline,
Earth’s Interior Zones. You have one minute to list everything you know about the Earth.
Composition of the Earth. The Size of the Earth The Earth is almost spherical with a radius of nearly km. Variations in the value of acceleration.
The Early Earth “Mr. Montgomery’s Early Earth PowerPoint redefines PowerPoint excellency” - PPTA.
Section 1: Earth: A Unique Planet
Earth’s Interior Structure
Structure of the Earth Objective: describe the structure of the Earth.
Journey to the Center of Earth Layers of the Earth Crust Mantle Outer Core Inner Core.
Do you know ? ….. Lampang and Phrae Provinces used to be the Sea? -Why is it so? -What cause that effect on the Earth ? -What is the evidence that the.
Inside the Earth Planet Earth All objects on or near Earth are pulled toward Earth’s center by gravity. Earth formed as gravity pulled small particles.
The Structure of the Earth Internal Structure and Heat.
Chapter 12: Earth’s Interior
Daily Review #1 What happens in radioactive decay? Define half-life.
Lesson 2: Earth’s Interior. Clues to Earth’s Interior – What’s below Earth’s surface? – Temperature and Pressure Increase with Depth – Using Earthquake.
THE EARTH’S LAYERS Continued. TO REVIEW!! The crust is less than 1% of Earth by mass. The mantle (inner and outer) represents about 68% of Earth by mass.
 Gravitational Contraction ◦ Gravity pulled Earth’s center together causing friction that released heat energy. ◦ This thermal energy is left over.
Layers of the Earth The Layers of the Earth are the Inner Core, Outer Core, Mantle and Crust.
Earth’s Layers G 103. General Information -Iron,Oxyge, Silicon, & Magnesium - Deepest drill 12 km -Radius of Earth 6371 km - How do we know about the.
Earth’s Structure. What is the earth made from? If it was possible to dig to the centre of the Earth, what would you find? You would dig through three.
Bb How and when did the Earth and Solar System Form?
EARTH’S INTERNAL STRUCTURE And processes. What Was Early Earth Like?  Describe what Earth was like right as the Solar System was forming?  Why did earth.
Mantle Geophysics and Tectonophysics
Mantle convective heat flux into continental lithosphere
Introduction to Planet Earth
Structure of the Earth.
Convection Currents.
Chapter 2 Earth as a System 2.1 Earth: A Unique Planet
Chapter 2 Earth: A Unique Planet
Earth’s Interior Structure
Chapter 2 -1 Earth: A unique planet
LITHOSPHERE VOCABULARY
Convection Currents.
Unit 1: Introduction to Earth Science part 3
Bell Ringer 1. What physical layer of the Earth makes up all of the crust and the very upper portion of the mantle? 2. The core can be broken up into.
Driving Force of Plate Movement
Introduction to Planet Earth
Science Starter Turn to the next blank page in your ISN and cut and paste the handout that is located on the front desk. You will need colored pencils.
Structure of the Earth.
Layers of the Earth: Flashcards
Earth’s Internal Heat.
Layers of the Earth.
Introduction to Earth Structure
Presentation transcript:

Physics of Earth's Evolution However the Earth came to its presently differentiated form, it must have obeyed our known physics: Conservation of energy and momentum The laws of thermodynamics The laws governing electromagnetism EPSC 666 November 4, Olivia

Energetics About 4.6 billion years ago, the primordial Earth condensed from a cloud of planetesimals with a composition not unlike that of the chondritic meteorites we find that have fallen to Earth. The gravitational potential energy available in this collapse could have brought the mass of Earth to a temperature exceeding 30000K –- a plasma primordial Earth?

Early Earth Early Earth surely didn't exist in a gravity- bound plasma state; internal temperature was probably pretty much as it is today – perhaps a little cooler, perhaps a little hotter. 26 Al  26 Mg (t ½ ~ 700k years;  1000K) The “Big Splat” (deep magma ocean) U, Th, K (long-lived; current sources)

Heat budget Losses: 1.Measured global cooling rate: ~30TW → 44TW* and probably higher during the ancient past. 2. Geomagnetic field loss (external): ~1 → 4TW Sources: 1. Radioactive decay: crust (6 → 9TW), upper mantle (12 → 21TW), lower mantle (3 → 14TW) 2. Entropy increase in mantle: (~3TW) 3. From core into mantle: ( > 8.6TW + ~1 → 2TW) 4. Remnant primordial gravitational energy: (~9 → 14TW) * In 2008, average rate of human energy consumption – all forms: 15 → 16TW New Theory of the Earth, Anderson, D.L, 2007, Cambridge

Earth model and T Mao, H-K and Hemley, R,

Modes of cooling Inner core: conduction cooling, freezing surface (an interior source 40 K?) Outer core: very vigorous convection D'' layer (lowermost mantle): conduction Lower mantle ( > 660km depth): vigorous convection Upper mantle ( < 660km): convection Lithosphere ( upper 0 – 200km): conduction

Convection Convection continues to differentiate, to reorganize the Earth's mantle. Requirements for convection: Locally, the temperature gradient, dT(z)/dz, must exceed the adiabatic gradient: dT(z)/dz > g α P T / C P The observed “vigour” of mantle convection suggests that the adiabatic gradient must be “substantially” exceeded: The Rayleigh number, Ra, the ratio of bouyant to viscous forces: Ra ~ 10 6

Temperature Mao, H-K and Hemley, R,

PREM Dziewonski and Anderson (1981)