Tectonic

Geophysical

caused by internal earth processes

Hydro-meteorological

caused by atmospheric, hydro-logical or oceanographic processes

Tectonic Hazards

Earthquakes, volcanoes + other geophysical events that happen somewhere a risk is caused (near ppl)

Inner core

solid

Outer core

liquid

Mantle

molten

Crust

solid

Oceanic plate

dense, compact, basalt

Continental plate

not dense, thick , granite

Acid Lava

Thick viscous lava which flows short distances

Basic Lava

Thin , runny lava which can flow long distances

Composite Volcano

Steep sided cone with layers of ash and lava

Compressional Margin

This is where two plates move together

Core

The centre of the earth

Mantle

The molten rock that surrounds the earth's core

Crust

The thin layer of the earth's surface

Crater

The mouth of the volcano

Earthquake

A shaking of the earth's crust

Epicentre

The point within the earth's crust where the earthquake occurred

Focus

The point on the earth's surface directly above the epicentre

Fold Mountains

Mountains formed by the earth's movements

Geosynclines

A depression between two plates

Lava

The name given to liquid magma when it reaches the surface of the earth

Richter Scale

This measures the strength of the earthquake

Shield Volcano

A gentle sided volcano with a wide base made up of basic lava that flows fast on a constructive plate boundary eg. Mount Kea

Subduction Zone

Where a oceanic plate sinks and slides under continental plate leads to earthquakes eg. Indian Ocean 2004 Tsunami

Tectonic Plate

A huge section of the earth's crust

Tensional Margin

Where two plates move apart

Tsunami

Huge tidal waves that are caused by submarine earthquakes

Vent

The opening through which the lava flows in a volcano

Volcano

A cone shaped mountain created by lava and ash being erupted from the earth

Destructive/convergent

1. Oceanic and continental crust move towards each other

2. Oceanic crust subducts (pushed under) as it is more dense

3. Oceanic melts into mantle, gets stuck, tension released= earthquakes

constructive/divergent

1: plates pulled apart

2: magma rises + forms new crust

4: sea floor spreading occurs

Transform/conservative

1: plates slide past each other

2: no volcanoes- bad earthquakes

Collision/ destructive

1: 2 continental plates move towards each other

2: push up to create fold mountains

How far does the East Africa rift extend?

3000 km + 0.5 cm per year

What volcanoes are on the East African rift?

Mount Kilimanjaro, Mount Kenya, Mount M

Strato volcano

steep, destructive plate boundary, thick lava, ash, andesite, eg. Soufriere often caldera

Caldera

crater in volcano caused by blowing top off

Intra-plate earthquake

occurs in middle of plateeg. Gujarat India 2001

Inter-plate earthquake

at plate boundary

Hotspots

place in mantle that is hotter than rest causes volcano as land moves over it (not on plate boundary) eg. Hawaiian islands

Alfred Wegener

theorised pangea and ridiculed

Convection currents theory

1)rock heated by core

2)hot rock rises to crust

3)rock cools + sink to core

4)warms up +repeats

Wilson cycle

1) Constructive plate pulls apart

2) new oceanic crust rises (dense)

3) sea floor spreads

4) oceanic crust will eventually subduct the continental crust + close sea floor

Sea floor spread

constructive pulls apart, magma rises + solidifies, widens sea floor

Ridge push

magma rises as plates move apart then cools to form new plate material cools (becomes denser) and slides down away from ridge causing other plates to move

Slab pull

denser plate slips back into mantle due to gravity and pulls rest of plate with it

Locked fault

plates get stuck

Benioff zone

where subduction zones are that often have earthquakes up to 670km eg. Peru Chile trench

Biggest earthquake?

9.1 Magnitude Indonesia 2012