Transition Zone Discontinuities

Slides:

Advertisements

Similar presentations

Conclusions… Challenge: 1)Seismic waves are affected by variations in temperature, pressure, composition, mineralogy, structure (layering, scales and distribution.

Advertisements

Earth’s Interior and Geophysical Properties Chapter 17.

High Pressure Mineralogy Minerals Methods & Meaning High Pressure Mineralogy.

Inner Core Outer Core Lower Mantle Upper Mantle Crust Moho 6371Km 5000Km 2900 Km 0 Km 1050 Km asthenosphere Gutenburg Moho boundary is between 25 and.

Geology of the Lithosphere 2. Evidence for the Structure of the Crust & Upper Mantle What is the lithosphere and what is the structure of the lithosphere?

Lecture-3 1 Intro to Earth Dynamics. Lecture-3 2 Topics for Intro to Earth Dynamics F The gross radial structure of the Earth (chemical and mechanical.

Earth’s internal structure: a seismologist’s view.

Journey to the Center of the Earth

Structure and dynamics of earth’s lower mantle Edward J. Garnero and Allen K. McNamara Presented by: David de Vlieg Folkert van Straaten.

Basic Structure of the Earth

Earthquakes and Earth’s Interior

Department of Geology & Geophysics

Earth Structure.

By Mildred $100 Page 5Page 10Page 11Tectonics 1Tectonics 2 $200 $300 $400 $500 $100 $200 $300 $400 $500 $100 $200 $300 $400 $500 $100 $200 $300 $400.

Chemical and Clapeyron- induced buoyancy at the 660 km discontinuity D.J. Weidner & Y. Wang 1998.

Phase Transitions in the Earth’s Mantle

Probing Earth’s deep interior using mantle discontinuities Arwen Deuss University of Cambridge, UK also: Jennifer Andrews, Kit Chambers, Simon Redfern,

Surface waves Earthquakes generate both body waves (P, S) and surface waves Surface waves are generated along any free surface in the medium In the Earth,

Seismological observations Earth’s deep interior, and their geodynamical and mineral physical interpretation Arwen Deuss, Jennifer Andrews University of.

The Lithosphere There term lithosphere is in a variety of ways. The most general use is as: The lithosphere is the upper region of the crust and mantle.

Water in the Mantle ? Can be stored: 1)Hydrous minerals - only stable shallow 2) Dissolved in normally anhydrous minerals 3)A hydrous silica-rich fluid.

17.1 Notes: Earth’s Mantle & Crust Continental crust Thickness: Continental crust is thicker (30-40Km) Age: older (up to 4.4 billion yrs old) Composition:

Fluid, 90% iron solidified iron km ,00012,000 Mg(Fe) silicates phase changes basaltic-granitic crust chemical stratification and differentiation.

STRUCTURE OF THE EARTH. Differentiation of Earth Earth is divided into layers based on density and composition Solid Layers – Core (iron-nickel) – Mantle.

Earthquakes and the Interior  Earthquakes are definitely a geologic hazard for people living in earthquake regions, but the seismic waves generated by.

The Earth’s Structure A Journey to the Center of the Earth.

From RegentsEarth.com How to play “Earth Science Battleship” Divide the class into two teams, Red and Purple. Choose which team goes first. The main.

Constraints on the observation of mantle plumes using global seismology Arwen Deuss University of Cambridge, UK.

1/24/09 Updated 12/23/09 What about Hawaii? Don L. Anderson.

EXPLORING EARTH’S INTERIOR Chapter 14. Seismic rays are refracted away from the normal as they penetrate the earth, which causes them to bend, because.

Created byMildred (who else?) $100 Page 10 More pg.10 Page 11 More pg.11 My Fault $200 $300 $400 $500 $100 $200 $300 $400 $500 $100 $200 $300 $400 $500.

Constraints on transition zone discontinuities from surface wave overtone measurements Ueli Meier Jeannot Trampert Andrew Curtis.

The Formation and Structure of Planet Earth Lesson #2: The Maturing Earth Lesson Objective #2.

Earth’s Internal Processes

Hydration of Olivine and Earth’s Deep Water Cycle

The Core-Mantle Boundary Region Jeanloz & Williams, 1998 Lower mantle Outer core CMB Heat flow.

The Earth’s Interior.

Earth’s Layers. The Layers: Lower mantle Transition region.

Geology 5640/6640 Introduction to Seismology 11 Feb 2015 © A.R. Lowry 2015 Last time: Seismology as Investigative Tool Deep-Earth investigations use earthquakes.

Rocks and the Earth’s Interior

Earthquakes A manifestation of rock deformation

EXPLORING EARTH’S INTERIOR

Earth’s Interior “Seeing into the Earth”

The Earth’s Crust.

FALCON FOCUS ON YOUR OWN… Search for the 6 differences between the two pictures.

Chapter 2 Earth’s Interior

What is the earth like inside?

Earth’s Layers Three main layers Crust, Mantle, and Core

Chapter 2, Lesson 3, Earth’s Interior

Earth Science 7 The Layers of the Earth.

Earth’s Materials and Processes-Part 8 Investigating Earth’s Interior

Earth Layers and Types of Crust

Phase velocity Medium parameters (scale lengths of layering, intrinsic P and/or S velocities, rigidity, etc.). Geometric “fit” of a particular.

Earth Layers Powerpoint for day 1 of Earth Model activity. 5 slide powerpoint meant to be shown at beginning (and maybe end) of class. Should last 5-10.

Length scale of heterogeneity

CIDER/ITP Short Course

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.

We have been talking about minerals primarily in the earth’s crust

Earths Interior and Layered Structure

Geophysics/Tectonics

Chapter 2, Lesson 3, Earth’s Interior

Describe how the “hotspot” differs from the global

Unit: Water and the Atmosphere

Earthquakes! Created by Mildred (who else?).

A Journey to the Center of the Earth

We have been talking about minerals primarily in the earth’s crust

Essential Question: How are the Earth’s layers divided?

Chapter 2, Lesson 3, Earth’s Interior

Introduction to Earth Structure

Earth’s Interior.

Presentation transcript:

Transition Zone Discontinuities Why focus here? 1. Deeper than “normal” melt sources 2. Very sensitive to changes in temperature and chemistry “Normal” = Ridge, which has a melt source confined within upper mantle and should not affect TZ discontinuities.  This is a bit of a spoiler for the students for the ridge temperature results in the activity. Can decide you want to keep this in and have them confirm, or take it out and let them investigate. In this sense, TZ discontinuities are used to test temperature beneath ocean islands. (Hotspots? Maybe hot, maybe not.)

Transition Zone Phase Transitions 410 520 660 Olivine (α) Wadsleyite (β) Perovskite Ringwoodite (γ) Wendy Mao posted some nice PowerPoint slides for these phase transitions. They follow this slide.

Olivine (Mg,Fe)2SiO4 From Wendy Mao 0-14 GPa (0 - 410 km)

Olivine (Mg,Fe)2SiO4 Wadsleyite 0-14 GPa (0 - 410 km) 14-19 GPa + 8% density From Wendy Mao 0-14 GPa (0 - 410 km) 14-19 GPa (410 - 520 km)

Wadsleyite Ringwoodite 1 – 140,000 atm (0 - 410 km) 14-19 GPa + 2% density From Wendy Mao 1 – 140,000 atm (0 - 410 km) 14-19 GPa (410 - 520 km) 19-24 GPa (520 - 660 km)

+ ‘Perovskite’ (Mg,Fe)SiO3 Ringwoodite (Mg,Fe)2SiO4 24-127 GPa (660 - 2740 km) + + 12% density From Wendy Mao Ferropericlase (Mg,Fe)O 19-24 GPa (520 - 660 km)

‘Perovskite’ ‘Post-Perovskite’ 24-127 GPa (660 - 2740 km) ‘Perovskite’ (Mg,Fe)SiO3 + 2% density From Wendy Mao 24-127 GPa (660 - 2740 km) 127 GPa-136 GPa (2740 - 2890 km) Discovered in 2004

Transition Zone Topography Left = Standard onion slice picture, Right highlights variations in discontinuity depth (and strength) and the presence of additional discontinuities that may not be global features  Indicates heterogeneity within the Earth, probably for both temperature and composition.

Clapeyron Slope Describes changes in phase transition with temperature and pressure “Normal” TZ Thickness Colder Warmer

Mineralogy: Not Just Olivine “Garnet” Component “Olivine Component”

Mineralogy: Not Just Olivine From http://www.mantleplumes.org/

Detecting Discontinuities Triplications Receiver Functions ScS Reverberations SS Precursors Seismic methods used to detect discontinuities. Scale is approximate. Star = Earthquake, Squares = Stations (Indicates general geographic region where each method can be detected). Color change of seismic raypath indicates change in wave type (ex. P-wave converts to S beneath the station for Receiver Functions)