Restless Earth Flashcards
Define Caldera?
A large ridge forming at the dge of a supervolcano where the original cone has either collapsed or been destroyed in a large eruption
What is a conservative plate margin?
A plate margin where the tectonic plates are sliding past each other
What is a constructive plate margin?
A plate margin where the tectonic plates are moving apart
What is a destructive plate margin?
A plate margin where the tectonic plates collide
What is continental crust?
The part of the Earth’s crust that makes the continents
What are convection currents?
Circulating movements of the magma in the mantle caused by the heat of the core
Define Epicentre?
The point on the ground directly above the focus (centre) of the earthquake
Define Focus?
The point of origin of an earthquake
Define Magnitude?
The size of an earthquake
What is oceanic crust?
The part of the Earth’s crust which is below the oceans
What is an ocean trench?
A deep depression on the ocean floor formed at the subduction zones of destructive plate margins
What are tectonic plates?
The latge pieces of broken crust that cover the earth
What is a plate margin?
The boundary between two tectonic plates
Define prediction?
Forecasting future changes
What are primary effects?
The impacts of a natural disaster that happen immediately or soon afetr the event
Define response?
The way in which people react to a situation eg. an earthquake
What are secondary effects?
The after effects of a disaster eg. disease spreads or loss of the economy
What is subduction?
The transformation into magma of a denser tectonic plate as it dives under a less dense plate
What is a Supervolcano?
A volcano capable of erupting on a much larger scale than a normal volcano
What are tectonic hazards?
Threats posed by earthquakes, volcanoes etc
Define Tsunami?
Huge waves caused by earthquakes under the sea
What type of volcano is this?
Composite
What type of plate margin is this?
Constructive
Name the process that makes the Earth’s tectonic plates move?
Convection cells
What is the temperature inside the Earth’s core?
5,500 °C
List two characteristics of an Oceanic Crust
5-10 km thick
Dense
Destroyed at destructive plate margins
Forms constantly at constructive plate margins
Geologically young compared to continental crust
List two characteristics of a Continental Crust
25-100km thick
Less dense
Cannot be destroyed. New crust is not formed
It is geologically old 3-4 billion years old
Which two plates does Iceland lie on?
North American and Eurasian
What do you call the fault line that runs along the West coast of the USA?
The San Andres Fault
Name the layers in the Earth’s structure?
Draw a destructive plate boundary?
In what year did Eyjafjallajokull (Iceland) erupt?
2010
Name a fold mountain range?
Himalayas
Alps
Atlas
Andes
Describe the sequence of fold mountain formation?
What type of volcano is this?
Shield volcano
List two characteristics of a composite volcano?
Made up of alternating layers of lava and ash (other volcanoes just consist of lava)
Found at destructive boundaries
Often has pyroclastic flows. A pyroclastic flow is a mixture of hot steam, ash, rock and dust
A pyroclastic flow can roll down the sides of a volcano at very high speeds and with temperatures of over 400°C
List two characteristics of a shield volcano?
Shield volcanoes are usually found at constructive or tensional boundaries
They are low, with gently sloping sides
They are formed by eruptions of thin, runny lava
Eruptions tend to be frequent but relatively gentle
When did Montserrat start erupting?
1995
Name a supervocano
Yellowstone
How do we measure the size of a volcanic eruption?
What is Old Faithful and where is it found?
A Geyser
Yellowstone National Park
Do earthquakes happen on all four plate boundaries?
Yes
What two ways can we measure the size of the earthquake?
Richter Scale- Measured from 1-9
Mercalli Scale- Measured from I-XII
When was the Haiti earthquake?
2010
How powerful was the Haiti earthquake?
7.0 Richter Scale
What is the capital of Haiti?
Port-au-Prince
How many people died in the Haiti earthquake?
220,000
List two immediate responses to the Haiti earthquake?
The USA sent 10,000 troops
The UN sent troops and police and they set up a “Food Aid Cluster” to feed 2 million people
The USA sent $100 million in aid
235,000 people were relocated to other safer areas of the island
Can we predict volcanic eruptions and earthquakes?
Volcanoes Yes
Earthquakes NO!!
