Evrything Flashcards
What is the crust crust?
This is the thinnest layer of the earth
• It contains rocks and minerals.
Under the oceans, the crust is
mainly basalt but under the continants it is granite
What is the mantle?
This is the thickest layer of the
Earth
• It moves in slow, big circles
caused by Convection Currents
What is the. Outer core?
Semi liquid iron
What is the epicentre of an earthquake?
The point on the Earth surface directly above the focus of the earthquake
What is the focus?
The point in the earths crust were the earthquake happens
What is the Richter scale?
It measures the magnitude of an earthquake by measuring the tremors using a seismo graph. The scale is 1 to 10
What is the mercalli scale?
This measures the total destruction or impact caused by an earthquake. It doesn’t measure the strength. It uses descriptive damage phrases to illustrate the tremors. This scale goes from 1 to 12.
Define primary effect
Something that happens in the short term by the earthquake
What is the secondary effect?
It is something happening in a long-term as a result of a primary effect
Define volcanoes
They are openings or cracks in the lithosphere where magma from inside the Earth can escape into the surface
Define active volcanoes
Liable to erupt example mount Aetna
Define extinct volcano
A volcano which has not erupted for many thousands or millions of years
Define dormant volcano
A volcano which has not erupted for many years
Define super volcano
Volcano 1000 times bigger than a regular volcano has the potential to produce an eruption with major effects on the global climate plus Ecos
What is the subduction zone?
where one plate is forced downwards below another plate and
grinds past it causing huge amounts of friction and heat.
What is the oceanic crust?
plate that is made up of more dense rock. It sinks easily due to its
density and is constantly created at boundaries. It is ‘young/new
rock’ and forms our ocean bed.
What is the destructive plate boundary?
where two plates are moving towards each other, one of which is
continental crust and one is made of oceanic crust
What is the continental crust
this is a plate that is made up of less dense rock. Because it is less
dense it doesn’t sink. It is exceptionally old and makes up our land
surfaces
What is a boundary?
where two very large crustal plates meet on the earth’s surface.
Earthquakes and volcanoes happen here.
What are fold mountains
are large mountain ranges formed by the collision and ‘folding’
of two continental plates as they plates continually push into one another.
What is an oceanoc trench
a particularly deep point of the ocean bed where the oceanic and
continental crust have dragged each other downwards.
Two plates move __________ each other as a result of __________
___________.
• The ________________ plate is more dense than the _______________ plate,
as a result the oceanic plate sinks below.
• Huge amounts of ____________ occurs at the subduction zone. Plates get
jammed together and suddenly they are released, causing an __________.
• The friction causes ____________ of the oceanic plate in the mantle. The
extra molten rock rises upwards.
• The molten rock is very _________ (like treacle) and often gets _________ in
the volcano underground.
• Eventually the pressure rises and a ____________ eruption takes place.
Towards,convectioncurrents,comtinental,oceanic,pressure,earthquake,melting,rhick,stuck,violent
Which layer is the thickest
Mantle
Which layer of the earth is hottest
Inner core
Which layer of the earth is broken up in tectonics
Crust
Is the inner core of the earth liquid
False
Which theory did Alfred Wegenerr have
Jigsaw fit
Volcanoes only happen at divergent playe boundaries
False
What will happen at a divergent (constructive) plate boundaries
Shield volcanoes
Earthquakes
What will happen at a conse vative (transfo m) plate bounda y?
Earthwuakes
What will happen at a convergent collision bounda y?
Fold mountains
Earthquakes
We use different scales to measure ea thquakes. Which scale only measures magnitude?
Richter scale
Which plate bounda y is the island of Montse rat on?
Convergant destructive
Which of these desc ibes a pyroclastic flow?
fast-moving cu rents of hot gas and rock
Which of these desc ibes a lahar?
violent type of mudflow or deb is flow
Tsunamis are a seconda y hazard. What t iggered the 2004 Indian Ocean tsunami?
Umderwater earthquake
Which of these is a good method of seismic proofing?
Cross bracing
