Support materials only that illustrate some possible contexts for exploring Science as a Human Endeavour concepts in relation to Science Understanding content.
Development of plate tectonic theory
Alfred Wegener, a meteorologist, first proposed a theory of continental drift in 1912 and followed this with publication of an expanded theory in 1915. His theory provoked much debate in scientific circles, because although there was some evidence of continental movement, there was no clear mechanism to drive plate movement. It took more than 50 years and the collection of a large body of evidence for broad acceptance of what we now refer to as plate tectonics theory (ACSES037). Patterns in the distribution of rock types and fossil fragments occurring across various continents were provided as early evidence for the theory, and scientists working with palaeomagnetism found further evidence that the continents had different configurations in the past by comparing the magnetic fields recorded by rocks of similar age across different continents. Marine geology conducted in the late 1950s and early 1960s also provided evidence for sea floor spreading along plate boundaries (ACSES038). By the late 1960s the explanatory and predictive power of the theory of plate tectonics became more broadly accepted, with numerous scientists presenting papers elaborating the concepts involved (ACSES037).
Measuring plate movement
Heat energy stored and generated in Earth’s interior creates convection currents on a massive, continental scale that result in the movement of very large sections of Earth’s rigid crust and uppermost mantle. Development of satellite measurement techniques, particularly global positioning system (GPS) technologies, enables accurate measurement of plate movement (ACSES039). Plate movement is tracked directly by means of GPS data; repeated measurements of carefully selected points on Earth’s surface are taken and plate movement is inferred through determination of how the distance between them changes. Measurement of plate movements enables scientists to predict the direction and rate of plate movement and to develop better understandings of processes such as mountain building and mantle convection (ACSES042).
Geothermal heat from Earth’s interior provides a low carbon emission energy source, and can be accessed via hot rock, hot sedimentary aquifer and direct heat technologies. Geothermal systems involve a heat source, permeable rock and a fluid to transport heat to the surface; of these the permeable rock and fluid reservoirs can be artificially created. Proponents of geothermal power generation point to its high baseload capacity, low carbon dioxide emissions, low environmental impacts and potential to provide increased energy security (ACSES043). In areas of Europe, heat from geothermal sources has been brought to the surface using both simple conductive and convective processes to heat homes and large greenhouses for horticulture (ACSES041). However in countries that are less geologically active, such as Australia, sourcing geothermal energy requires significant infrastructure and investment and it remains a challenge to make geothermal energy production economically viable.