year 9 science yearly 2023 with verified questions and answers

What is continental drift? The theory that continents move slowly over time Who came up with the theory of continental drift? Alfred Wegener What evidence supports Wegener's theory? Jigsaw fit of continents (particularly between the east coast of South America and west Africa). Identical fossils (the same plant and animal fossils found on distant land masses). Identical geology (exactly the same type and age of rocks on distant land masses). Glacial features (ice sheets have moved across the landscape to areas that now are too close to the equator for ice to form). How old is the Earth? 4.6 billion years old What are fossils? Remnants of past life What can fossils be of? Whole organisms (mammoth in ice). Part of an organism (bones or shells). Preserved evidence of animal activity (footprints, nest, faecal matter). How are fossils formed? When plants and animals die they are quickly buried by clay, sand and other sediments. More layers of sediment accumulate above the animal's remains forming a fossil. Name the structures of the Earth Crust, upper mantle, lower mantle, outer core, inner core What is plate tectonics? The theory that the crust of the Earth is divided into large slabs (tectonic plates) which float on the mantle What are convection currents? Magma in the mantle moves. Hot parts rise, cool parts sink, which creates circular currents. These currents cause tectonic plates to move. What is ridge push? Gravitational force which pulls down on mid-ocean ridges, pushing oceanic plates away from the diverging boundary. What is the point where 2 plates meet? Plate boundary What are the types of plate boundaries? Divergent, convergent and transform Describe divergent boundaries Plates move away from each other. The lava and magma rises from the mantle, hardening into rock and making new crust. Rift valleys or mid-ocean trenches form. Describe convergent boundaries Plates come together and collide. When involving oceanic crust subduction zone occurs. Forms into a mountain range or deep sea trench. Describe a transform boundary Plates slide past each other. Creates friction from the plates rubbing. Energy is released causing earthquakes. What are earthquakes caused by? Friction between tectonic plates What do earthquakes release? Energy in the form of seismic waves What's the focus? Where the earthquakes starts, where plates meet What's the epicenter? The point on Earth's surface directly above the focus What are body waves? P and S waves Describe P waves Primary wave. Moves fastest. Recorded first. Longitudinal/compression wave. Up and down motion. Travels through liquid and solid. Describe S waves Secondary wave. Moves slower. Recorded second. Transverse wave. Side-to-side motion. Only travels through solid. What is the Richter scale? Scale that measures the magnitude of an earthquake What are seismometers/seismographs? Device used to detect seismic waves What is a seismogram? What seismometers record How do scientists monitor volcanoes? They use seismometres (measure earthquakes occurring near an eruption), tiltmeters (monitors change in landscape) and measure temperature (volcanoes become hotter when magma rises). What is seismic imaging technology? It bounces sound waves off underground rock structures. This reveals possible crude-oil and natural gases. What is a tiltmeter? Measures small changes from the vertical level on the ground. Name the spheres of earth Lithosphere, hydrosphere, atmosphere, biosphere Describe the lithosphere Earth's core, mantle and crust, continents, rocks, sand, dust, mountains, metals, asphalt, bricks. Describe the hydrosphere Water, oceans, lakes, rivers, groundwater, glaciers, polar ice caps, rain, snow Describe the atmosphere Air, oxygen, nitrogen, water vapour, ozone, wind Describe the biosphere Life, plants, humans, animals, microbs How do earthquakes impact the spheres? Lithosphere - ruptures the sediments on the surface, damages buildings. Hydrosphere - earthquakes underwater can cause tsunamis Atmosphere - earthquakes release methane gas that contributes to the greenhouse effect Biosphere - buildings that fall due to earthquakes can harm and kill life How do volcanoes impact the spheres? Lithosphere - the lithosphere is made up of structures which are vulnerable during eruptions Hydrosphere - volcanic eruptions can cause water to become warmer, making it more acidic Atmosphere - volcanoes release many toxic gases into the air, contributing to climate change and the greenhouse effect Biosphere - lava burns plants, cutting out a food source for animals. Humans struggle to breath through the ash. Name the steps of the water cycle Evaporation, condensation, precipitation, runoff Name steps of the carbon cycle Photosynthesis, consumption, respiration, dead organisms, fossils and fossil fuels, combustion, Name the steps of the nitrogen cycle. Nitrogen in the air, nitrate salts, bacteria, nitrogen separating bacteria What natural resources are from the ATMOSPHERE and what are they used for? Air and wind. Used for breathing and creating energy What natural resources are from the BIOSPHERE and what are they used for? Wood, wool. Used to make clothes, buildings, houses. What natural resources are from the LITHOSPHERE and what are they used for? Rocks, sand, fossil fuels. Used to create energy and in building. What natural resources are from the HYDROSPHERE and what are they used for? Water. Used for drinking, h