Coaching Centre
Chapter 5: Plate Tectonics Notes
The evidence for plate tectonics, the forces that move plates, how earthquakes and volcanoes happen and are measured, what happens at each kind of plate boundary, Australia's journey north, and the technology used to monitor and warn of geological hazards.
Sections
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5A The evidence for plate tectonics Mastered
How the theory of plate tectonics grew from Wegener's continental drift and Hess's sea-floor spreading, the fossil, rock and glacier evidence for Gondwana, magnetic stripes and sea-floor ages, and how a rejected idea became accepted science.
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5B What moves the plates Mastered
Why plates rest on solid but slowly flowing mantle rock rather than liquid magma, how density decides which plate sinks, and the roles of mantle convection, ridge push and slab pull (gravity) in moving tectonic plates.
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5C Earthquakes Mastered
How stress builds and is released at faults, the focus and epicentre, P, S and surface waves, how seismologists locate an earthquake with three stations, and how magnitude and intensity are measured, with recent examples from Australia and the world.
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5D Volcanoes Mastered
Where magma comes from, how silica and gas control whether an eruption is gentle or explosive, shield and composite volcanoes, hotspots such as Hawaiʻi, and the hazards and benefits of volcanoes, with recent eruptions including Hunga Tonga–Hunga Haʻapai.
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5E Plate boundaries Mastered
What happens at convergent (ocean–continent, ocean–ocean and continent–continent), divergent and transform plate boundaries, the landforms and earthquakes each produces, and how to identify a boundary from evidence such as earthquake depths and mountain heights.
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5F Australia on the move Mastered
How GPS measures the Australian Plate moving about 7 cm a year north-north-east, why Australia's map coordinates had to be updated, Australia's journey from Gondwana and its future collision with Asia, Australia's young and active volcanoes, and First Nations knowledge of eruptions and rising seas.
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5G Monitoring and predicting hazards Mastered
How scientists monitor earthquakes, volcanoes and tsunamis with seismometers, GPS, satellites, gas sensors and DART buoys, why earthquakes can be forecast but not predicted, how tsunami warnings work in Australia, and how engineering reduces the impact of earthquakes.
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5H Plate tectonics review Mastered
A summary of the whole Plate Tectonics chapter, key words, and a mixed test covering the evidence for plate tectonics, what moves plates, earthquakes, volcanoes, plate boundaries, Australia's movement and monitoring hazards.