NES1210_DynamicEarth_L1_TTW22

Module Introduction

  • Dynamic Earth (NES1210)

    • Instructor: Dr. Mark T. Ireland

    • Contact: mark.Ireland@newcastle.ac.uk

    • Date: January 2025

    • Base: Newcastle University

    • Learning platform: Canvas for module details and readings.

Course Overview

  • Course Structure: Semester 2 led by Dr. Cees van der Land.

  • Timetable Highlights:

    • Week 22: Earth and Planetary Structure and Formation

    • Week 23: Geological Time

    • Week 24: Plate Tectonics - Evidence and Fundamentals

    • Week 25: Plate Tectonics - Driving Forces & Hazards

    • Week 26: Deformation of the Earth

    • Week 27: Introduction to Mineralogy

    • Week 28: Sedimentary Systems and Cycles

    • Week 29: Sediment Transport and Deposition

    • Week 30: Depositional Environments

    • Week 35: Igneous Rocks and Minerals

    • Week 36: Metamorphic Rocks and Minerals

Interactive Learning

  • Interactive Polls

    • Purpose: Enhance engagement in lectures.

    • Features: Feeling of active learning, critical thinking encouraged, anonymous participation, and feedback mechanisms.

Earth Structure - Core to Crust

  • Introduction: The Earth consists of three main layers - Crust, Mantle, and Core.

  • Seismic Wave Analysis: Used to understand Earth's internal structure.

Layer Details:

Crust

  • Thickness: Ranges from 5 km (oceanic) to 80 km (continental).

  • Types:

    • Oceanic Crust: Thin (5-10 km), primarily basalt.

    • Continental Crust: Thicker (up to 80 km), heterogeneous.

  • Main Components: Oxygen and Silicon (Si).

  • Moho Discontinuity: Base of the crust defined by this seismic boundary.

Mantle

  • Layers:

    • Transition from Lithosphere (upper) to Asthenosphere (below).

    • Lower mantle characterized by D” layer close to core-mantle boundary.

  • Volcanic activity transports mantle fragments to surface.

Core

  • Inner Core: Solid, radius of 1,216 km; 80% iron, with nickel and sulfur.

  • Outer Core: Liquid, density between 12.6-13.0 g/cm³.

  • Main composition: Iron and nickel with additional elements.

Heat Distribution in Earth

  • Earth as a heat engine driving tectonic activity.

  • Heat Sources:

    • Primordial: From accretion, compression, core formation.

    • Radioactive Decay: From isotopes (K, U, Th).

Heat Flow Mechanisms

  • Key Processes: Conduction, Convection, Radiation.

  • Fourier’s Law: Governs conductive heat transfer.

Geophysics Overview

  • Explains Earth's workings, composition, and changes over time.

  • Studies rocks at the surface to gain insights about deeper layers.

  • Importance of geophysics: natural resource identification, hazard protection, environmental impact mitigation.

Seismological Methods

  • Use of seismic waves from earthquakes to understand Earth's inner structure.

  • Types of Waves:

    • P waves: Longitudinal.

    • S waves: Compression.

Seismic Tomography

  • Technique to profile Earth's interior leveraging seismic wave travel times.

  • Helps derive 3D images, analogous to medical imaging.

Concluding Topics

  • Further Learning: Reading assignments on seismic tomography and mantle studies.

  • Next Lecture: Focus on Earth and other planetary formations in the solar system.