Skills/Points from the Revision List (1) Flashcards
What is the structure of the earth and the properties of each of the layers?
Crust: Outer solid layer, divided into continental and oceanic crust; brittle and rigid.
Mantle: Semi-solid rock; moves tectonic plates with convection currents.
Outer Core: Liquid iron and nickel; creates Earth’s magnetic field
Inner Core: Solid iron and nickel; under high pressure, high temperature; contributes to Earth’s magnetic field.
Plate tectonics theory - what was Wegner’s theory and what was his evidence?
Alfred Wegener proposed the theory of continental drift, suggesting that continents were once part of a supercontinent called Pangaea and have since drifted apart to their current positions. His evidence was jigsaw fit, convection currents, fossil theory, palaeomagnetism
Know at least 2 (jigsaw fit, convection currents, fossil theory, palaeomagnetism).
Jigsaw Fit: Wegener observed the coastlines of South America and Africa fit together like pieces of a jigsaw puzzle, suggesting they were once connected.
Fossil Theory: The Mesosaurus only lived in the eastern coast of South America and the western coast of Africa. This suggests that they were once connected as the Mesosaurus wouldn’t be able to swim across the Atlantic Ocean.
Paleomagnetism: Rocks along the Mid-Atlantic have aligned magnetic patterns on either side. They act like magnets , recording Earth’s magnetic changes. Matching patterns on each side show the seafloor is spreading, supporting Wegener’s idea that continents move.
Convection Currents: Heat from the core rises up in the mantle as it is hotter. It creates a ridge push in between two tectonic plates and convection currents that rotate to move the plates and makes a slap pull at the end of them.
Can I explain why earthquakes and volcanoes are often found at plate boundaries?
On plate boundaries either crash into each other, slide past, or pull apart. This causes shaking (earthquakes) and magma to erupt out (volcanoes).
What are convection currents and why are they important?
How the mantle moves tectonic plates. Heat from the core rises up in the mantle as it is hotter. It creates a ridge push in between two tectonic plates and convection currents that rotate to move the plates and makes a slap pull at the end of them. They are important as they support Wegner’s theory
Can I explain what happens at convergent and divergent boundaries? (Earthquakes and volcano; formation and examples)
Convergent: Usually involves an oceanic plate and a continental plate. The more dense oceanic plate is forced beneath the less dense oceanic plate as they collide. This movement can cause earthquakes and volcanoes. eg. The Pacific Ring of Fire
Divergent: Usually involves two oceanic plates. Plates move apart from one another. When this happens the magma from the mantle rises up to make new crust. The movement of the plates over the mantle can cause underwater volcanoes and earthquakes. eg. The Mid-Atlantic Ridge
Can I explain the impacts from the Haiti Earthquake?
-approx. 220,000 people were killed and 300,000 were injured.
-around 300,000 houses were destroyed
-1.3 million Haitians were displaced and made homeless
Can I explain the response to the Haiti Earthquake?
-many countries sent search and rescue teams
-the government worked with others to organize help from different places
-the government, along with aid organizations, distributed food, water, and other essential supplies to those affected.
Can I explain the causes of a tsunami in an example location?
The cause of the Indian Ocean tsunami was due to the Indo-Australian plate subducting below the Eurasian plate. When the tension between them released , an earthquake (9.1 magnitude) occurs and water is displaced upwards at the epicentre. In deep water ,the waves are low and fast. As the waves approach shallow water they grow taller and slow down.
Can I explain the impact of a tsunami in an example location?
Indian ocean tsunami
-more than 220,000 people died
-more than 650,000 were seriously injured
-up to 2 million people were made homeless
-public buildings were wiped out in some areas
Know at least 4 countries that the Indian Ocean tsunami impacted
India, Indonesia, Malaysia, Maldives, Myanmar, Sri Lanka, Seychelles, Thailand and Somalia.
Can I explain how prediction, preparation and protection can reduce tectonic
hazards?
Prediction: Early detection of seismic activity through monitoring can give people warnings, allowing the, to evacuate.
Preparation: Practicing emergency plans, conducting drills, and raising public awareness can enhance preparedness for earthquakes, reducing casualties and damage.
Protection: Constructing earthquake-resistant buildings and infrastructure, implementing building codes, and investing in resilient materials can minimize the impact of earthquakes on communities.
What is nuclear power? How does it work?
Nuclear energy works by splitting of uranium atoms – a process called fission. This generates heat to produce steam, which is used by a turbine generator to generate electricity.
Can I explain the reasons why nuclear energy can be described as both sustainable and unsustainable?
Sustainable:
-it has saved 1.8 million lives a people didn’t risk their lives in coal mines and it doesn’t emit co2
-one ton of thorium is the same as 200 tons of uranium and 3500000 tons of coal. It is also hard to make weapons out of it
-even though nuclear waste is very toxic it is usually stored somewhere unlike the bi products of fossil fuels
Unsustainable:
-they can be used as weapons
-nuclear fuel contains poisonous chemicals such as plutonium
-if accidents happen it would be a major disaster
Can I explain what the impacts of the Chernobyl disaster were?
-radiation was found in food and drink
-pregnant people asked to abort due to defects
-animals gained mutations
-the area will not be habitable for 20,000 years
-Pripyat became a ghost town
