Goodscience 7 and 8 Part 4 PDF

 What do you already know about Earth and the rock cycle? What is in our solar system? (Hint: don't just list the planets!) Geological hazards...

 What do you already know about Earth and the rock cycle? What is in our solar system? (Hint: don't just list the planets!) Geological hazards are sometimes called natural disasters; how many can you identify? How do landscapes change over time? 72 GOOD SCIENCE NSW STAGE 4 a Alphabet: Think of a word a What if... the outer core of a Five questions: Write five about geology (Hint: rocks, Earth was solid instead of questions that have the fossils, Earth ) for each letter liquid? answer 'fossils'. of the alphabet. 0 !. -- - ! The oldest rock in Earth's crust is a metamorphic rock known as the Acasta Gneiss. It is approximately 3.96 billion years old. The rock was originally granite, formed when molten rock solidified about 4.2 billion years ago. About 3.9 billion years ago, this rock was pushed down several kilometres underneath the surface. The heat and pressure changed (metamorphosed) the original rock into the gneiss. Movement of Earth's crust later brought the rock back up to the surface. 73 EARTH AND SPACE 5.1 When Earth formed approximately 4.5 billion years ago it was a ball of molten (melted) rock. As it gradually cooled, EARTH'S this molten rock separated into three main layers: the core, the mantle and the crust. STRUCTURE The most dense metallic elements moved to the centre to form Earth's core. Elements of medium density formed the At the end of this lesson I will be able to: mantle around the core, and the least dense elements moved describe Earth's structure to the surface to form its crust. in terms of the core, mantle, crust and lithosphere. Figure 5.1 Earth's main layers are the crust, the mantle and the core. Crust 0-100 km thick core Earth's central layer, which has a liquid outer core and a solid inner core crust Earth's thin outer layer Mantle (upper mantle density the amount of matter in a certain and lower mantle) volume lithosphere Outer core Earth's rigid outer zone (crust and upper mantle), made up of tectonic plates mantle Earth's middle layer, made up Inner core of an upper mantle and a lower mantle seismic wave a wave of energy caused by an earthquake or explosion LITERACY LINK 0 Create a mind map using the key terms and at least two additional terms of your choice. 0 Earth's core is solid on the inside, liquid on the outside NUMERACY LINK 0 Earth's centre is the core, made up of a liquid outer core and a solid inner core. Scientists used information from seismic waves generated A section of the continental crust by earthquakes to determine this. The core is made up of a mixture of is 34 km thick. metals, mostly nickel and iron. Because it is so hot, the outer core is Convert 34 km to metres. made of liquid metal. The pressure in the inner core is so immense that the atoms are forced together to form a solid. What is Earth's core made up of? 74 GOOD SCIENCE NSW STAGE 4  CHAPTER 5: EARTH AND THE ROCK CYCLE 8 The mantle sits between Earth's core INVESTIGATION 5,1 and the crust Modelling Earth's structure Earth's thickest layer is the mantle. It lies between the core and the crust. Even though the mantle is made of solid rock, the very high temperatures and pressure enable the rock to flow very slowly over time. This process is similar to what you might see when you put a blob of silly putty on the edge of a desk. The processes in the mantle cause a lot of the change and movement on Earth's surface. The mantle can be thought of as two parts: the upper mantle and the lower mantle. Are most rocks in the mantle solid or liquid? 8 The crust is Earth's thin outer layer The crust is Earth's hard outer layer, and its thinnest layer. If Earth were an apple, the crust would be thinner than the apple's skin. The crust is made of a variety of rocks. There are two different types of crust: continental crust and oceanic crust. a Identify Earth's three main layers. The continental crust forms the continents and the shallow seas b Describe each layer in five around the continents. It covers about 40% of Earth's surface. It is words or less. 10-100 km thick. 2 Identify Earth's thickest and The oceanic crust is formed in Earth's ocean basins. It covers about thinnest layers. 60% of Earth's surface, and is 5-7 km thick. 3 Identify the two types of crust. What is Earth's crust made of'? 4 Explain why the mantle i!l able to move. 0 Earth's lithosphere is the rocky outer zone 5 If you started digging directly through Earth in Sydney, you would emerge in the Atlantic The lithosphere is Earth's rigid, rocky outer zone. It includes Ocean near the Azores Islands. the crust and the upper mantle. The lithosphere is made List, in order, the layers of Earth up of tectonic plates that 'float' and move around on a that you would travel through. zone called the asthenosphere. There are 15 major 6 Distinguish between tectonic plates and some smaller ones. the lithosphere and the asthenosphere. The asthenosphere is a thin zone of the mantle that sits just beneath the lithosphere. Rocks here are almost at their melting point (about l300°C), so they.. n 7 Turn back to the See-Know­ flow more than they do in other parts of the Wonder image on page 73. mantle. This allows the tectonic Redraw it and label Earth's plates of the lithosphere to move layers. (Hint: The image shows the upper and lower mantle.) and act on each other, which can cause earthquakes and volcanoes at Earth's surface. make up the lithosphere? , "' j ;i;; ":::; ;;;: ;;:: I/ j,