1. Internal dynamics of the Earth
CONTENTS
RESOURCES

2. CONTENTS INTERNAL DYNAMICS OF THE EARTH Tectonic plates Internal heat
Phenomena
Evidence
The interior of the Earth
Why the interior is so hot
Characteristics
Volcanic eruptions
Volcanic material
Types of eruptions
Reducing the damages
Reducing the damage
Warning systems
Earthquakes
Effects
Seismic waves
Mountain building
Relief features
Distribution of seismic and volcanic activity
Interaction of processes
Rocks
Igneous rocks
Metamorphic rocks
The rock cycle

3. RESOURCES Why the interior of the Earth is so hot
Characteristics of the interior of the Earth
Tectonic plates
Phenomena produced by internal
energy
Evidence of the heat from the interior of the Earth
Volcanic eruptions
Eruptions and volcanic material
Types of eruptions
Earthquakes
Effects of earthquakes
Seismic waves
Reducing the damage
Warning systems
Mountain building and relief features
Distribution of seismic and volcanic
activity
Links
The interior of the Earth
Interaction of internal and external processes
Igneous rocks
Metamorphic rocks
The rock cycle

4. Why the interior of the Earth is so hot
Earth today
4,000 million years ago
4,600 million years ago
metal materials
crust
mantle
nucleus
solid crust
ocean
liquid outer core
solid inner core
(6,000 ºC)
solid mantle
meteorite
Giant meteorites continually collided with
the Earth.
As the Earth heated up, it expanded in size. Metal materials sunk to the centre.

5. Temperature and pressure increase with depth.
Characteristics of the interior of the Earth
Temperature and pressure increase with depth.
At a depth of 50 km:
the temperature is 600 ºC
the pressure is 20,000 atmospheres
GEOTHERMAL
GRADIENT
Rate of increase
in temperature:
30 ºC per kilometre

6. Tectonic plates

7. Plates move in three ways.
Tectonic plates
Plates move in three ways.
At divergent boundaries, plates move apart.
At convergent boundaries, plates push together.
At transform boundaries, plates slide by each other.

8. Phenomena produced by internal energy
Volcanic
eruptions
Molten rock and gases are ejected through the Earth’s crust.
Continental drift
A slow horizontal movement of the continents.
Earthquakes
A violent trembling of the Earth’s crust which lasts a short time and varies in intensity.
Isostasy
Slow vertical movement of the Earth’s crust.

9. Evidence of heat from the interior of the Earth
Formation of the atmosphere
Hot rocks
Formation of a magnetic field
Hydrothermal phenomena

10. hot spots within the mantle
Volcanic eruptions
hotspot
hot spots within the mantle
crust
mantle
crust
mantle
outer core
inner core

11. Eruptions and volcanic material
vent
volcanic cone
PYROCLASTIC
MATERIALS
GASES
LAVA
magma chamber
pipe (conduit)
CLICK TO
SEE MORE

12. X Eruptions and volcanic material GASES PYROCLASTIC MATERIALS LAVA
carbon dioxde
water vapour
sulphur gases
carbon monoxide
vent
volcanic cone
PYROCLASTIC
MATERIALS
GASES
LAVA
magma chamber
pipe (conduit)
CLICK TO
SEE MORE X
[close]

13. X Eruptions and volcanic material PYROCLASTIC MATERIAL GASES
vent
volcanic cone
PYROCLASTIC
MATERIALS
GASES
LAVA
magma chamber
pipe (conduit)
CLICK TO
SEE MORE
PYROCLASTIC MATERIAL
ash
lapilli
volcanic bombs X
[close]

14. X Eruptions and volcanic material GASES PYROCLASTIC MATERIALS LAVA
HOME
CONTENTS
RESOURCES
Eruptions and volcanic material
vent
volcanic cone
PYROCLASTIC
MATERIALS
GASES
LAVA
magma chamber
pipe (conduit)
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SEE MORE
LAVA
At more than 1,000 ºC,
lava is very liquid and flows easily.
At less than 700 ºC,
lava is thick and flows slowly. X
[close]
Bubbles of gas escape gently.
Bubbles of gas splatter and cause explosions.

15. Types of eruptions HAWAIIAN STROMBOLIAN VULCANIAN CLICK ON THE GREEN
BUTTONS TO LEARN MORE.
HAWAIIAN
STROMBOLIAN
VULCANIAN

16. X Shield volcano Types of eruptions
CLICK ON THE GREEN
BUTTONS TO LEARN MORE.
magma temperature: very high (over 1,000 ºC)
very liquid lava
not very destructive nor explosive
Shield volcano
magma chamber
central vent
pipe (conduit) X
[close]
HAWAIIAN
STROMBOLIAN
VULCANIAN

17. X Stratovolcano (composite volcano) Types of eruptions
magma temperature: moderate ( ,000 ºC)
thick lava
explosive pyroclastic material
pipe (conduit)
Stratovolcano (composite volcano)
magma chamber
volcanic cone
central vent
CLICK ON THE GREEN
BUTTONS TO LEARN MORE. X
[close]
STROMBOLIAN
HAWAIIAN
STROMBOLIAN
VULCANIAN

18. X Dome volcano Types of eruptions
CLICK ON THE GREEN
BUTTONS TO LEARN MORE.
magma temperature: low (less than 700 ºC)
violent, destructive explosions
generally gases and ash are expelled
magma chamber
Dome volcano
volcanic pipe of solidified lava X
[close]
VULCANIAN
HAWAIIAN
STROMBOLIAN
VULCANIAN

19. Earthquakes Earthquakes are caused by a sudden release of energy from
epicentre
seismic waves
hypocentre (focus)
Earthquakes are caused by a sudden release of energy from
the Earth’s crust.

20. Effects of earthquakes
Richter Scale
9.6
Chile (1960)
hypocentre (focus)
epicentre
landslides
damage to buildings
tsunami
seismic waves

21. Seismic waves Studying seismic waves seismograph seismogram
WHAT OTHER INFORMATION
CAN SCIENTISTS LEARN
FROM SEISMIC WAVES?
seismic waves

22. Seismic waves
tectonic (lithospheric) plates
Answer:
They can learn information about the internal structure of the Earth.
crust (granite and basalt)
lithosphere
mantle (perioditite)
liquid outer core
core (iron)
solid inner core
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23. Reducing the damage from earthquakes and volcanoes
Risk map
Prediction
low high
Prediction
Emissions of water vapour and other gases are observed.
Buildings are designed to withstand seismic movement.
Preparedness

24. Warning systems satellite Hawaii buoy
An early warning buoy system receives information about waves, wind and seismic movement.

25. Two plates push together.
Mountain building and relief features
The crust thickens.
outer core
mantle
rift valley
Two plates
move apart.
rising current
Himalayas
Two plates push together.
RELIEF FEATURES
OF THE EARTH
HOW RELIEF
IS FORMED

26. Two plates push together.
HOME
CONTENTS
RESOURCES
Mountain building and relief features
Two plates push together.
RELIEF FEATURES
OF THE EARTH
rift
The crust thickens.
Eurasia
Ebro massif
Two plates
move apart.
Pyrenees
mantle
Iberian plate
Iberian plate
rising current
Betic ranges
Alboran plate
Alboran plate
outer core
60 million years ago
100 million years ago
20 million years ago
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27. Mountain building and relief features
CLICK ON THE RED DOTS TO LEARN MORE
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28. X Mountain building and relief features Continental shelves:
areas near the coastline, under the sea, made up of continental crust X
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TO LEARN MORE
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29. X Mountain building and relief features
Oceanic (mid-oceanic) ridges: chains of submarine mountains with intense volcanic activity X
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TO LEARN MORE
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30. X Mountain building and relief features
Great plains: large extensions of flat land X
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TO LEARN MORE
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31. X Mountain building and relief features Mountain ranges:
chains of mountains X
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TO LEARN MORE
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32. X Mountain building and relief features Ocean trenches:
the deepest areas
of the ocean X
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TO LEARN MORE
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33. X Mountain building and relief features Submarine volcanoes
can create volcanic archipelagos. X
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TO LEARN MORE
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34. X Mountain building and relief features
Abyssal plains: the largest plains on the planet X
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TO LEARN MORE
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35. Distribution of seismic and volcanic activity
high seismic activity
moderate seismic activity
low seismic activity
volcanic activity

36. Interaction of internal and external processes
Agents erode and reduce the weight of the lithosphere.
Isostatic movement
uplift
The weight of deposited sediment produces subsidence.
subsidence (sinking)

37. Igneous rocks Common igneous rocks GRANITE PEGAMATITE SYENITE GABBRO
VOLCANIC SCORIA
PUMICE
OBSIDIAN
BASALT
Plutonic or intrusive igneous rocks
Volcanic or extrusive igneous rocks

38. Metamorphic rocks Common metamorphic rocks Clay minerals or slate
Clay minerals, slate, or schist
Sandstone with quartz
Limestone
SLATE
SCHIST
GNEISS
QUARTZITE
MARBLE
increase in temperature and pressure
intense increase in temperature and pressure
very intense increase in temperature and pressure
intense increase in temperature and pressure
intense
increase in temperature and pressure
Original rock and metamorphism
Metamorphic rock

39. The rock cycle MAGMA SEDIMENTS melting metamorphism SEDIMENTARY ROCK
IGNEOUS ROCK
METAMORPHIC ROCK
melting
metamorphism
weathering and erosion
weathering
and erosion
compaction and cementation
cooling

40. Links Rockhounds How do rocks undergo change?
How do rocks undergo change?
The interior of the Earth
Rocks and the rock cycle
The Earth: A living planet
How earthquakes happen
Observe animations of processes that occur along plate boundaries.
Interactives: Volcanoes
Plate tectonics
Animated guide: volcanoes
Earthquakes
The rock cycle diagram