625-101 The Global Environment, 2006 Lecture Summary
The Earth in Time and Space Week 1 (27 Feb) L1 When the Earth froze over MS * About 600 million years ago, the Earth nearly froze over like a giant "snowball". Understanding how we know this, why it occurred and why it then thawed highlights many of the important things we need to learn.
    L2 Our Rocky Neighbours AG Ch 25 Our world is one of the rocky planets that make up the inner part of our Solar System. Some geological processes are common to all of these planets and give us clues as to how and when they formed.
    L3 Gas Giants and Ice Worlds AG Ch 25 The outer Solar System is a very different place dominated by giant planets made of gas, surrounded by satellites made mostly of ice.
  Week 2 (6 Mar) L4 How the Solar System began AG Ch 25 Smaller bodies like meteorites, asteroids and comets give important clues to how the planets formed and evolved in the early history of the Solar System.
    L5 How old is old? AG Ch 8 The relationships between different rock sequences, what they are made of and the fossils they contain enable us to determine how old one rock is relative to another. This is the basis for the Geological Time Scale.
    L6 Measuring Deep Time AG Ch 8 The abundance of naturally occuring radioactive isotopes can be used to directly determine the age of many rocks and minerals, and also the age of the Earth.
Evolution of Planet Earth Week 3 (13 Mar) L7 New rocks from old MS Ch 8 The continents are made largely by recycling even older rocks by erosion and metamorphism in an endless process we refer to as the "rock cycle".
    L8 Rocks through time MS Ch 8 The age distribution of rocks at the Earth's surface suggests the continents form in very different ways to the rocks that floor the oceans.
    L9 Ancient environments MS Ch 4,8 Sedimentary rocks tell us of ancient environments very different to the modern world, but with some surprising similarities.
The Weather Machine Week 4 (20 Mar) L10 The Atmosphere and Circulation TL Ch 9 The atmosphere has a complicated structure, a number of different layers, varying temperatures and seasons, and many important constituents that make up the gas we call "air".
    L11 Weather Systems TL Ch 9 Sequences of high and low atmospheric pressure lead to changes in wind, temperature, and the formation of clouds and rain. These processes control our day-to-day weather.
    L12 Antarctica TL Ch 14 Antarctica is the coldest and dryest place on Earth, is almost entirely covered by ice, and is influenced by extreme weather.
  Week 5 (27 Mar) L13 Severe Weather TL * Extreme events like hurricanes and tornadoes are infrequent but costly, damaging property and often resulting in numerous deaths.
    L14 The Greenhouse Effect and Ozone TL Ch 9 The greenhouse effect is crucial to life on earth and maintaining our current climate. Ozone is also important, but in a different way.
    L15 Future Climate Change TL * What is global warming? How will our weather and climate change in the short term?
Life on Earth Week 6 (3 Apr) L16 The next Ice Age? MS Ch 14 30 years ago, the concern was about how we could prevent the coming ice Age. To understand why this was, we need to look back at the history and causes of the last Ice Age, 18,000 years ago.
  L17 The coming of people MS Human evolution has been intimately tied to the environmental extremes of the ice ages highlighting the extraordinary ability of our species to adapt to changing environments.
L18 Living Earth MS * Life on Earth started at least 3.5 billion years ago, but it was not until the aftermath of the "Snowball Earth" event 600 million years ago that life as we know it really got going.
  Week 7 (10 Apr) L19 Is there life out there? MS * The evolution of life on Earth and the composition of the atmosphere is intimately coupled in ways that help us to understand how we might seek evidence for extraterrestrial life.
    L20 Our icehouse world SG * In the last 100 million years our planet has gone from a "greenhouse"- world where dinosaurs "ruled the roost" to an "icehouse"-world where mammals dominate.
      GOOD FRIDAY      
      ANZAC DAY      
The Earth's Interior Week 8 (24 Apr) L21 The shape of the Earth MS Ch 23 The shape of the Earth reflects the dynamic process that have created the Earth's lithosphere and its interaction with the hydrosphere.
    L22 "Catscanning" the Earth MS Ch 18 Using earthquake waves as the probes we can "see" structure inside the Earth in ways analogous to medical catscanning.
  Week 9 (1 May) L23 Hot Earth MS Ch 18 Natural radioactivity keeps the solid Earth hot and provides the ultimate source of energy driving dynamic processes such as volcanoes and earthquakes.
    L24 Dangerous Earth MS Ch 18 Living on a dynamic planet entails many natural hazards, the most catastrophic being a 15th century Chinese earthquake with as many as 800,000 casualties.
    L25 Rich Earth MS Ch 13,24 Knowledge of the geological history and structure of the continents informs our understanding of the distribution of energy, metal and groundwater resources.
Plate Tectonics
Week 10 (8 May) L26 Dynamic Earth AG Ch 17 The theory of Plate Tectonics explains how a realtively thin outer shell of the earth, the lithosphere, is divided into different rigid plates that are in constant motion relative to each other.
    L27 Putting the Pieces Together AG Ch 17 The theory of Continental Drift, a forerunner of plate tectonics, proposed that all continents were once joined to each other in a supercontinent, that subsequently broke apart.
    L28 The Big Breakup AG Ch 19 Divergent Plate Boundaries occur where two plates move apart. In continents plate divergence forms Rift Valleys that may eventually widen to form new ocean basins. Palaeomagnetism can show how the two sides have moved apart through time
  Week 11 (15 May) L29 The Spreading Sea-Floor AG Ch 17 & 19 In the oceans plates diverge by the process of Sea-Floor Spreading which forms the mid-ocean spreading ridges which are the sites of creation of new oceanic crust. Magnetic 'stripes' on the ocean floor reveal the pattern and age of spreading.
    L30 Fire Beneath the Waves AG Ch 19 & 22 The Oceanic Crust is built up by a continuing process of volcanic activity along the mid-ocean ridge system giving it a very uniform composiiotn and structure. Another kind of volcanic activity is also observed at Hotspots above rising 'plumes' of hot material in the Earth's Mantle.
    L31 Transforming Boundaries AG Ch 20 Transform Plate Boundaries are places where two plates move sideways past each other. They mostly occur in the oceanic crust where they form offsets between segments of oceanic ridge. They also occur as major faults in the continental crust.
  Week 12 (22 May) L32 Coming Together AG Ch 21 Convergent Plate Boundaries in the oceans are the sites of major earthquakes and volcanoes above a descending oceanic plate that is consumed in the mantle in a process called subduction.
    L33 The Big Crunch AG Ch 21 Plate Convergence in the Continental crust involves complex deformation and mountain building. The greatest mountains are produced in where two continental plates collide.
* no direct reference in Hamblin & Christiansen   L34 Revision All   Revision
AG * no direct reference in Hamblin & Christiansen
TL Mike Sandiford
Andrew Gleadow
Todd Lane