What alternatives are there to the plume hypothesis?

Slides:

Advertisements

Similar presentations

Chapter 9 Plate Tectonics.

Advertisements

Warm Up 11/26 The Hawaiian Islands were formed when the Pacific Plate moved over ____. a. a hot spot c. the Aleutian Plate b. a subduction zone d.

Do Plumes Exist? Gillian R. Foulger Durham University GEOL 4061 Frontiers of Earth Science.

Changing Earth Ch. 1 Review

Plate tectonics is the surface expression of mantle convection

Causes of Plate Motion.

The Changing Earth Chapter Eleven: Plate Tectonics 11.1 Pangaea 11.2 Sea Floor Spreading 11.3 Plate Boundaries.

Describe the differences and relation between the lithosphere and asthenosphere.

Silicate Earth Primitive mantle Present-day mantle Crust Oceanic crust Continental crust Reservoir Volume Mass Mass % (10 27 cm 3 )(10 27 g) Earth

03.05.a1 Ocean-Ocean Convergent Boundary One plate moves down = subduction Two oceanic plates move toward one another Trench and island arc.

Continental Drift Hypothesis – Wegner believed continents had once been joined, and over time they drifted apart Pangaea – the first super-continent Alfred.

EARTH’S INTERNAL STRUCTURE AND MAGMA FORMATION PROCESSES.

Cuernos Del Paine, Andes Mountains Gabriel Callaghan.

CHAPTER 2 Internal Structure of Earth and Plate Tectonics

Dynamic Earth Class February 2006.

WELCOME TO GG 101 PHYSICAL GEOLOGY My name is Patty Lee. We meet Monday, Wednesday and Friday from 10:30 to 11:20. SHOW UP!

Plate Tectonics and the cycling of Earth materials Plate tectonics drives the rock cycle: the movement of rocks (and the minerals that comprise them, and.

Ch. 4.2 The Theory of Plate Tectonics

Reporters: Alconera, P.P. Villacampa, E. Mangaway, Cris.

GLOBAL TOPOGRAPHY. CONTINENTAL & OCEANIC LITHOSPHERE.

What is a plume? By Julian Winter Alexandra Witze (2003)

Geology 12 Plate Boundaries There are three types of plate boundaries 1. Divergent (or constructive) plate boundary 2. Convergent (or destructive) plate.

Plate 8 th Grade Science With the marvelous Mr. Christine Tectonics.

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.

Class 1: Plate Tectonics Review Today’s topics:  Earth’s compositional layers  Plate tectonics: theory & actions.

10.3 Plate Tectonics By: Brendan, Sid, and Andy. Video 

IV. Modern Plate Tectonic Theory

The Theory of plate tectonics, Plate Movement, & Hot Spots

The Galapagos Hotspot: A plate vs plume controversy

What is the Theory of Plate Tectonics? – The theory of plate tectonics states that Earth’s lithosphere is broken into enormous slabs called plates. –

Theory of Plate Tectonics Lecture 4. Review Wegener - continental drift hypothesis Continental puzzle Fossil records Matching mountain ranges Ancient.

Possible Causes of Tectonic Plate Motion. Tectonic vs. Lithospheric Plates A tectonic plate is a piece of lithosphere that moves around on top of the.

Ch5 Sec5 The Theory of Plate Tectonics. Key Concepts What is the theory of plate tectonics? What are the three types of plate boundaries?

Handout Standard 2 Objective 3.a, b, c, and d Plate Tectonics 3.

VOLCANOES & IGNEOUS ACTIVITY CHAPTER 10. Section 10.1.

Plate Tectonics Earth Science Chapter 9. Continental Drift  scientific theory proposing the slow, steady movement of Earth’s continents  Alfred Wegener:

Forces Behind Change By: Mr. Martinez. Guiding Questions Natural events shape the earth. How does the movement of the earth’s plates cause land features?

Earth History GEOL 2110 Theory of Plate Tectonics Part 2: Elements of Plate Tectonics.

THE MECHANISMS OF PLATE MOTION

The Generation of Melting Anomalies by Plate Tectonic Processes Gillian R. Foulger University of Durham.

Convergent Plate Boundaries  plate motions provide the mechanisms by which mantle rocks melt to generate magma Plate Tectonics and Igneous Activity.

Please label the following layers..

Handout 1 Standard 2, Objective 3

Convection currents in the mantle result in the movement of lithospheric plates. The motion and interactions of the plates can create patterns in the.

Plate Tectonics.

8.E.5B.1 Analyze and interpret data to describe patterns in the location of volcanoes and earthquakes related to tectonic plate boundaries, interactions,

Plate Tectonics.

Plate Tectonics

Plate Tectonics Theory

Plate Boundary Notes.

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

Plate Tectonics.

9-3 Theory of Plate Tectonics

10.3 – Plate Tectonics and Igneous Activity

Unit 4: Earth Science How can Plates Move?.

CONTINENTAL DRIFT AND PLATE TECTONICS.

Hot Spots What They Are Their Characteristics How They Behave

Chapter 4, Lesson 3, Theory of Plate Tectonics

9.5 – Mechanisms of Plate Motion

Plate Tectonics.

How do plates move? MANTLE CONVECTION.

Mechanisms of Plate Motion

TESTING PLATE TECTONICS

Measuring Plate Motion

The Changing Earth Plate Tectonics.

VOLCANOES AND PLATE TECTONICS

Unit 4: Geophysics Part 1: Plate Tectonics.

5% of all known volcanoes in the world are not located close to a plate margin. These are known as intraplate volcanoes and occur as a result of mantle.

The Unifying Theory of Earth Science

Possible Causes of Tectonic Plate Motion

Presentation transcript:

What alternatives are there to the plume hypothesis? Helen Brown

Background! Great variability amongst “hot spots” Plume theory become progressively elaborate Question the hypothesis Investigate alternatives… should account for what is observed and be scientifically testable

Meteorite Impacts Catastrophic mechanism Recognition: shock related effects. Auto-obliterated? Pressure release or decompression melting Volume of melt comparable to LIP

Ridge Transform Intersections 3D finite element models Seamount formation Consider effect of lithospheric stress on all hotspots

Plate Tectonic Processes Volcanic anomalies are “by products” of plate tectonics Unifies convection and volcanism 2 key requirements: Intraplate Deformation Upper mantle is compositionally variable Location + amount of melt

Reheated Slabs Low velocity anomalies Do NOT resemble plumes Ancient slabs Velocity inversion Radioactive heat source Penetrative convection= NO need for plumes!

Lithospheric Delamination Explain continental volcanism 2 Conditions for delamination: Gravitationally unstable Viscosity lowered How cause magmatism: Astheno sucked into void Horizontal T gradients drive convection Dewatering

Edge Driven Convection (EDC) Instability between thick, stable lithosphere and thinner lithosphere. Fixed boundaries, mantle mobile. EDC driven by vertical T variation along the “edge”

Conclusions Common themes: Fertile mantle Lithospheric Extension Decompression melting Alternatives need further scientific investigation before they can truly challenge the long believed “Plume Hypothesis”