2.1 Earthquakes And Volcanos Flashcards
How are stratovolcanos formed
The are formed but a destructive plate boundary when the oceanic crust goes underneath a continental the crust gets destroyed producing more magma this creates pressure therefore allowing the magma to escape forming a volcano this process is called subduction
How are shield volcanos formed and characteristics
the lava comes out from the crust because of tectonic plates are moving apart making a vent once the lava spews out it instantly cools because its at the bottom of the ocean making the shape it is
Characteristics
- Fluid/thin/runny lava;
- Low (height to width ratio);
- Gentle slopes;
- Gentle eruption;
- Frequent eruptions
Main features of volcanos
Crater- a dip in earth crust
Main vent- an opening in the earths crust where magma comes out
Magma chamber, a large pool of magma under a volcano
Magma- extremely hot fluid under the crust
Types of magma
Andersitc magma
Basalistic Manama
Granitic magma
Hazards of volcanos
Pyroclastic flow, extremely hot and fast will kill you
Acid rain sulphur dioxide
Lava, extremely hot, can cause fires
Ash, same texture as sand, super heavy can cause choking
Lava bomb, lateral blast
Why do people still live near a volcano
Why do people still live near a volcano
they have always lived there
Government will support them
Reckless, naiveness, (this happens more in LEDC because of lack of education)
Employment, volcanic ash is good for soil
Types of plate boundaries
Destructive/convergent plate boundary- when two continental plates and oceanic plates collide and go underneath
Constructive plate boundary- when two tectonic plates move away from each other
Collision plate boundary- when when two continental plates move towards each other.
Conservative plate boundary- when two plates slide past each other
What is an earth quake and how is it formed
Earthquake- a sudden shaking of the ground, quakes
Can form on the constructive, destructive, conservative plate boundary
Forms by the plates sliding against each other in a sideway motion, may cause friction or get stuck
Features of earthquakes
focuses, the origin of the earthquake and its below the surface, seismic energy
Epicentres, the part above the focus on the surface wherer the shocks are much stronger than the
How do you measure earthquakes
Magnitude- the measurements of the earthquake
Richter scale- measure the magnitude of the earthquake 4 or higher is dangerous highest ever recorded is 9.5
Hazards of earthquakes (primary)
Primary hazards- Buildings and road collapsing Electrical cables damaged and sewers dagmaged People killed Landslides tsunamis
Can you predict a volcano or a earthquake
You can predict a volcano but not a earthquake
How to reduce impacts of earthquakes and volcanos
aid from other countries
Buildings can be built to withstand an earthquake
Individual planning, survival kit
Evacuation planning, education
Observing/monitor (volcano)
Strengthen roofs of houses
Building strategies to survive earthquakes
squat building not tall, wide base
Less windows, less glass that shatters
Foundations, deep and strong
Using metal bars
Flexible building materials
Why do people still live in areas with chances of earthquakes
they have always lived there
Government will support them
Reckless, naiveness, (this happens more in LEDC because of lack of education)
Employment
To expensive to move
