1. Describe the properties of each of these parts of the Earth’s interior: lithosphere, mantle, and core. What are they made of? How hot are they? What are a few of their physical properties?
2. Suppose that Earth’s interior contains a large amount of lead. Based on your prior knowledge, how dense is lead? Would the lead be more likely to be found in the crust, mantle, or core?
Earth Science Essay Example
3. When you put your hand near a pan above a pan filled with boiling water, does your hand warm up because of convection or conduction? If you touch the pan, does your hand warm up because of convection or conduction? Based on your answers, which type of heat transfer moves heat more easily and efficiently?
4. The oceanic crust is thinner and denser than continental crust. All crust sits atop the mantle. What might our planet be like if this were not true. 5. If sediments fall onto the seafloor over time, what can sediment thickness tell scientists about the age of the seafloor in different regions? 6. How might convection cells in the mantle affect the movement of plates of lithosphere on the planet’s surface? 7. How can the locations where ancient fossils are found be used as evidence for continental drift?
8. Why is continental drift referred to as a hypothesis (or idea) and not a theory?
9. Why was Wegener’s continental drift idea rejected by the scientific community and why is it accepted
Answer 1. The lithosphere is cold, brittle, and made of rock. There are two types: oceanic and continental. The mantle is hot and the material is always convecting. The core is dense, hot, and metallic. The liquid outer core is where the magnetic field originates.
2. Lead is very dense. Since dense material are pulled more by gravity, the lead would have been pulled into the core.
3. Above the pan, your hand is heated as warm air rises by convection. On the pan, your hand is heated because warm material travels toward it, by conduction. Conduction is far more efficient at heat transfer, which is why we heat water by conduction and not convection!
4. If all crusts locate below the mantle, our planet Earth might be a huge ball of magma because mantle make up of magma will become the outermost layer of the Earth. It means that there no crust any more.
5. If sediments fall onto the seafloor over time, sediments thickness can tell scientists about the age of seafloor at different regions by the layers of the rock. The deeper, the older of the rock is.
6. Convection cells are also found in the mantle. Mantle material is heated by the core and so it rises upwards. When it reaches the surface of the Earth, it moves horizontally. As the material moves away from the core’s heat, it cools. Eventually the mantle material at the top of the convection cell becomes cool and dense enough that it sinks back down into the deeper mantle. When it reaches the bottom of the mantle, it travels horizontally just above the core. Then it reaches the location where warm mantle material is rising, and the mantle convection cell is complete.
7. Fossils of the same species from the same time period have been found on widely separated continents. Some of these fossils have seeds that could not have blown across the ocean or they are of reptiles that only swam in fresh water. The simplest explanation is that the lands the fossils sit on were joined at the time the organisms lived and have since drifted apart.
8. Continental drift is referred to as a hypothesis (or idea) and not a theory because during Wegener’s life time he could not explain clearly on how the solid Earth can move and had not enough evidence to show. That was the reason why scientists and other people did not believe in him. So continental drift is just only idea of Alfred Wegener not hypothesis.
9. Wegener’s continental drift idea rejected by the scientific community because: – He was not geologist, he was meteorologist. – He had not enough evidence used to proof his idea. – He could not explain clearly on how the solid Earth could move.