Tectonic Hazards Flashcards
What are the two types of crusts?
Continental and Oceanic crust
Which is the thicker crust
Continental crust (30-50km)
Which is the thinner crust
Oceanic crust (7km)
Which crust is less dense
Continental crust ⭐️
Is oceanic more or less dense
More dense (fatty)
What is the Continental crust made of
Granite
Which crust is made of basalt
Oceanic 🌊
What does the crust+rigid upper mantle make?
The lithosphere
Which part of the mantle is rigid
The upper mantle
The lower mantle is semi-
Semi-molten
What is the lower mantle the zone of
Zone of convection currents
What is made of MOLTEN iron and nickel
The outer core 🔥
What is the inner core make of
SOLID iron and nickel 🪨
Why is the inner core the densest layer of the Earth
Because of the immense pressure 💨
What is the thinnest layer of the earth
The crust 🍕
What is broken up into tectonic plates
The lithosphere
How many plates are there
13
What do the plates float on
The semi-molten lower mantle
How can the plates move independently
Convection currents
What are convection currents
Flows of the lower mantle 🩸
Name the 4 plate margins
Constructive, Destructive, collision, conservative
Which plate margin causes earthquakes and volcanoes 🌋
Constructive
What happens at a constructive plate margin ⬅️
the two plates move apart ⬅️➡️ and magma rises to fill the gap and creates a new crust
What happens at a conservative plate margin
Two plates slide past each other 🛝
What does a conservative (transform) plate margin cause 🛝?
Earthquakes 🌍
What happens at a destructive plate margin
Two plates move towards each other, ➡️💥⬅️the edge of one plate gets destroyed as it plunges beneath the other plate (subduction) ⬇️
What do destructive plate margins cause
Earthquakes and volcanoes 🌋🌍
What does a collision margin cause ➡️🗻⬅️
Earthquakes and volcanoes 🌋🌍
What happens at a collision margin
Two plates move towards each other and are forced upward to create fold mountains ➡️🗻⬅️
What is the focus of an earthquake
The point underground from where the plates slip and where the seismic waves radiate from
What is the epicentre of an earthquake
The point on the Earth’s surface directly above the focus- strongest shaking💪 🫨
What are seismic waves
Energy waves that cause the ground to shake
What do primary waves do
Stretch and compress the ground
What do seismic waves do
Shake the ground from side to side
What is the Richter scale
It assesses the amount of energy released by the earthquake, and the intensity of shaking
What is the magnitude of an earthquake
It measures the energy released at the source of the earthquake
Magma chamber of a volcano
A reservoir of molten rock within the crust below a volcano. An eruption becomes more likely when it rises
Primary hazard
Direct consequence of earthquake
Secondary hazard
indirect consequence of earthquake
