Topic 1B - Hazardous Earth (Tectonics) Flashcards
State the structure of the Earth, starting from the inner core. [4]
Inner Core [1]
Outer Core [1]
Mantle [1]
Crust [1]
What is the 2 types of crust and what is each crust made up of? [4]
Continental [1] Granitic [1]
Oceanic [1] Basaltic [1]
What are the 2 areas of the upper mantle? [2]
Lithosphere [1]
Asthenosphere [1]
Why does the core not melt? [2]
The core is made of iron and nickel [1] and is under enormous pressure, meaning it cannot melt [1]
Explain how convection current function under the crust. [4]
Heated rock rises towards the crust [1]
As it cools, it is forced sideways by the asthenosphere [1]
The rock then cools and sinks [1]
The outer core then reheats the rock and repeats the process [1]
Explain how convergent plate boundaries function in order to create different landforms [4]
Oceanic plate subducts the less dense continental plate [1]
The continental plate is melted in the asthenosphere [1]
Temp and pressure increases, causing release of impurities [1]
Magma from asthenosphere rises to form composite volcanoes. [1]
Explain how divergent plate boundary’s function [4]
Convection currents cause plates to diverge [1]
Rising heat causes asthenosphere to melt, forming magma [1]
The magma rises and cools to form a new lithosphere. [1]
This will form a shield volcano due to rising magma. [1]
Explain how earthquake occur at conservative plate boundaries [4]
Convection currents cause plates to slide past [1]
The 2 plates are jammed and cannot slide. [1]
As they are jammed, pressure builds along the boundary. [1]
When the 2 plates jolt, the pressure is released, causing an earthquake. [1]
Give 3 characteristics of a composite volcano [3]
Tall, steep sided shape [1]
Viscous (thick and sticky) lava [1]
Can produce lava bombs and cause lahars to form [1]
Give 3 characteristics of a shield volcano [3]
Gentle slopes and a wide base [1]
Erupts less viscous lava [1]
Gentle but more frequent eruptions [1]
Describe how hotspots are formed [3]
A plume of heated rock rises through the mantle [1]
It then causes the asthenosphere + lithosphere to melt [1]
Magma rises through the crust and erupts [1]
Define primary and secondary impacts [2]
Primary - Immediate damage from the natural disaster [1]
Secondary - Knock-on effects from the natural disaster [1]
Define the terms focus and epicentre [2]
Focus - Point of rupture of the earthquake underground [1]
Epicentre - Point of rupture above the focus [1]
Identify 2 factors which determine the damage caused by an earthquake [3]
Density of human population [1]
Ability of the country to prepare/recover for earthquake [1]
Magnitude of an earthquake [1]
Give the measurement and unit in which an earthquake is measured in [2]
State the increase in the earthquake if the magnitude increased from 6 to 7. [1]
Magnitude [1]
Mw/ Richter scale [1]
x10 increase [1]
