1. Tectonics (Earthquakes and Volcanoes) Flashcards
What are the 4 structures of the Earth?
Crust, Mantle, Outer Core, Inner Core
What is crust, and describe the properties that make up the two different types.
The outer layer of the Earth.
There are two types:
Continental crust - thicker, older, less dense, made of granite.
Oceanic crust - thinner, newer, more dense, made of basalt.
What are Convection Currents
Heated plumes of magma which create crustal plate movement. Where convection currents diverge, plates move apart. Where convection currents converge,
plates move towards each other.
What is Earth’s crust broken into?
Plates
What is the name for a point where two tectonic plates meet?
A Plate Boundary
How many major plates are there?
7
How many minor plates are there?
8
Where do the majority of Earthquakes/Volcanoes lie?
On / near a plate boundary
What is a hotspot?
A hotspot in geography is a location on the Earth’s surface with high volcanic activity, typically away from plate boundaries. This is were the crust is very thin, i.e. Hawaii.
What is the Ring of Fire?
The largest concentration of volcanoes
is in the Pacific Ocean, known as the Ring of Fire.
What are the 4 types of plate boundaries?
Constructive (plates move apart)
Collison (plates meet together)
Destructive (oc goes under cc)
Conservative (plates rub against each other)
Earthquake
the violent shaking of earth’s crust.
Earthquake magnitude
the strength of an earthquake
Earthquake intensity
the violence of earth
movements produced by an earthquake
Mercalli Scale
scale used to measure earthquake
intensity
Richter Scale
scale used to measure earthquake
magnitude
Focus
the point at which the pressure is released inside the Earth. It is often many kilometres down
Epicentre
the point on the ground surface
immediately above the focus. This is where the greatest damage usually occurs.
Magma chamber
large underground pool of magma
Lava
magma, once it reaches the surface
Crater
bowl-shaped basin on the top of the volcano
Vent
central tube which magma travels through
Secondary Cones
eruptions from other vents may build up secondary cones on the flanks
Ash, steam, gas
material thrown out by the volcano.
Volcanic bombs
larger material thrown out by the force of
eruption.
Can scientists predict when and where an earthquake may occur?
Experts know where earthquakes are likely to happen, but it is difficult to predict when they will happen.
What can we use to predict when/where an Earthquake is going to happen?
seismometers, animal behaviour, radon
gas, dilatancy.
What can you do to prepare for an Earthquake?
improve building designs, evacuate, pack and carry go-bags
Responses
how countries and communities respond to tectonic hazards
and other disasters
Short Term Response to an extreme disaster
Search and rescue, helping the injured and providing key supplies.
Long-term response to an extreme disaster
Responses go on for months and years after a disaster. It involves rebuilding destroyed houses, schools, hospitals, etc. It also involves kick-starting the local economy
Social Impacts
direct impact on people
Economic Impacts
impact on economic activities such as businesses
Environmental Impacts
impact on the landscape including water and air pollution
Name a Volcanic Eruption in a HIC
Iceland, E15, 2010
Name an Earthquake / Tsunami in a HIC
Japan, 2011
Name an Earthquake in a LIC
Haiti, 2010
Name a Volcanic Eruption in a LIC
DRC, Mt.Nyiragongo, 2021
