The document discusses various types of landforms created by tectonic activity and erosion processes on Earth. It describes how tectonic plates interact and cause geological events like earthquakes and volcanoes that shape the surface of the planet. Specifically, it details how plate collisions can form mountains and volcanoes, while plate divergences produce ocean ridges. It also explains different erosional forces like rivers, wind, glaciers, and karst that carve and transport earthen materials, forming diverse topographic features over long periods of time.
3. The Earth is divided into layers :
1. The core
2. The mantle
3. The crust
3
2
1
4. The core, over 6 000 km deep, is
made of iron and nickel. Earth’s
core temperature is estimated at
around 5 000 ºC.
The outer core, is liquid, but the
inner core remains solid because
of the high pressure.
6 000 km
5. The mantle, over 3 000 km deep, is
divided into two layers:
a) the lower mantle ou
asthenosphere, viscous;
b) the higher mantle, solid.
3 000 km
6. The higher mantle and the crust, a
thin solid layer (5 km deep), form
the lithosphere.
30 km
5 km
Crust
Lithosphere
Higher mantle
8. The lithosphere is broken into
tectonic plates, which ride on the
asthenosphere.
9. Tectonic plates move because of
asthenosphere movements.
Tectonic movements cause the
collision or divergence of tectonic
plates.
10. Plate boundaries are commonly
associated with geological events
such as earthquakes and the
creation of topographic features
such as mountains or volcanoes
11. Continents move at a speed of 10
cm per year because of plates
tectonics.
Continental drift is the movement
of the Earth's continents.
12. Cambrian 500 m. a.
Arthropodes (e.g. trilobites) prosper in the
oceans.
Trilobite
13. Ordovician 470 m. a.
The water temperature close to the surface is
40 ºC. One day is equivalent to 21 hours.
14. Silurien 430 m. a.
Land plants evolve from algae.
15. Dévonien 370 m. a.
First amphibians evolved from fish.
16. Carboniferous 300 m. a.
Earth is covered by forests, which produced
large quantities of coal in Europe.
First reptiles developed in response to an
drier climate.
17. Trias 220 m. a.
Pangaea was the supercontinent that existed
250 million years ago, before the component
continents were separated into their current
configuration.
18. Jurassic 150 m. a.
A warmer and wetter climate allows the
developement of large rainforests. Ice caps
don’t exist.
It was a golden age for dinosaurs.
19. Cretaceous 65 m. a.
Asteroid
A massive asteroid impact of 10 km caused
the a mass extinction of animal and plant
species.
20. Éocène 50 m. a.
Mammals expand after the extinction of the
dinosaurs. Australia separated from
Anctartica. The Himalaya is a result of the
continental collision between the indo-
Asutralian plate and the Eurasian Plate.
21. +50 m. a.
+250 m. a.
In several million years,
Africa will collide with
Europe.
Finally, every continent
will form a new
pangaea.
24. The collision of tectonic
plates can produce two kinds
of lithosphere deformation
depending on the material
composition:
• Faults (fractures)
• Folds (curved
deformation)
Fault
Fold
25. The oceanic ridges are submarine
mountain ranges that result from the
divergence of tectonic plates.
Oceanic
ridge
America Europe
26. Vaults and folds exist from the
microscopi scale at hundreds of
kilometers.
The large vaults and folds result
in orogenics movements, which
are the origin of most of large
kinds of relief.
.
27. A mountain is a natural elevation of the Earth surface.
A peak is the pointed top of a mountain.
28. Altitude and steepness are used as criteria for
defining a mountain.
If altitude is considered, the highest mountain is the
Everest. But if steepnees is considered, the highest
mountain is Mauna Kea (Hawai).
Everest 10 200 m Mauna Kea
8 844 m
29. If the altitude of an elevation is not significant, it
is a hill,
If its steepness is not significant, it is a plateau, a
large flat area of land at high altitude.
Hill Plateau
30. The biggest landform in the world is the
Tibetan Plateau, called “the roof of the
world”.
It is four times the size of France and
has an average elevation of 4 500 m.
31. A mountain range is a long
and narrow succesion of
mountains.
A massif is a compact group
of mountains.
Massif
32. A fault might cause an earthquake, a sudden
movement of the Earth’s surface.
An Earthquake’s point at ground level is called
epicenter.
33. A seismograph is a device which
measures and records the magnitude
(strengh) of an earthquake.
The magnitude is a logarithmic scale,
so an increase of 1 step corresponds
to a 32 times increase in the amount
of energy released.
Magnitude Description Effects Frequency
2 Micro Not felt 8 000 per day
4 Light Shaking of indoor items 6 000 per year
6 Strong Major damage to poorly constructed 120 per year
buildings
8 Great Serious damage. 1 per year
34. A submarine earthquake might cause a tsunami, a
lseries of waves caused by the displacement of a large
volume of water.
The sudden elevation of a fault cause the displacement
of a large volume of water to sea surface.
35. This wave cause a raised line of
water not very high (1 m), but
very long (200 km) and
extremely fast (800 km/h).
This makes tsunamis dificult to
detect over deep water.
200 km
36. As the tsunami approaches the
coast, its wavelength and velocity
diminish, but its height grows
enormously: the wave might be
over 30 m.
37. The 2004 Indian Ocean
Tsunami killed over 200 000
people.
30 m
1,80 m
38. A tsunami can change the coast landscape.
Before After
39. A volcano is an opening in the Earth’s crust, which allows
magma, ash and gases to scape from below the surface.
40. Magma is molten rock that is found beneath the surface
of the Earth.
If the magma reaches the surface, it erupts as lava or
tephra.
Lapilli Volcanic bomb
Lava is hot liquid rock which comes Pyroclasts or tephra are solid
out of the earth through a volcano fragments which are blasted into
the air (ashes, lapilli, volcanic
bombs…)
41. Volcanic cones are structures built by the accumulation
and solidification of lava flows.
42. A lava dome is a circular mound-shaped structure from
the slow eruption of very viscous lava from a volcano.
43. Volcanic fissures are fissures through which lava
erupts, usually without any explosive activity.
Volcanic fissures produce often lava fountains.
52. A fumarole is an opening in Earth’s crust which emits
steam and gases.
53. A geyser is a spring characterized by intermittent
discharge of water ejected turbulently and accompanied
by steam.
54. A nuée ardente is a fast-moving
currents of hot gas which travels
away from the volcano at speeds
generally as great as 700 km/h.
The gas can reach temperatures of
about 1 000 °C.
In Martinique, a nuée ardente
killed 30 000 people.
55. A lahar is a type of debris flow composed of pyroclastic
material, rocky debris, and water. The material flows
down from a volcano, typically along a river valley.
Snow is suddenly melted by lava, the
flood can flow 100 km/h, causing
catastrophic destruction in their path.
56. Lahars can be deadly because of their energy
and speed.
The lahars from the Nevado del Ruiz
eruption in Colombia in 1985 caused
the Armero tragedy, which killed an
estimated 23,000 when the city of
Armero was buried.
57. A caldera is a cauldron-like volcanic feature usually
formed by the collapse of land following a extremely
violent volcanic eruption.
A collapse is triggered by An islet (a dome) is often
the emptying of the magma formed in the center of the
chamber beneath the caldera..
volcano
59. The eruption of a caldera in Toba,
70 000 years ago, was the Earth’s
largest eruption.
This event resulted in a global
cooling of atound 15 ºC and 10
years volcanic winter.
61. Volcanos often form landscapes of remarkable beauty.
Champagne Pool (United Kingdom)
Giants Causeway (New Zealand)
Morning Glory Pool (United States)
65. Coastal erosion
River erosion
Erosion is the process of
weathering and transport of solids
in the natural environment.
Wind erosion
Kars erosion
Ice erosion
71. A beach is a landform along the shoreline of an
ocean, sea or lake
The color of sand depends on the composition: the
white sands contain coral and shell fragments; the
black sands have a volcanic origin.
Beachrock
Pebbles
Black sands
White sands
72. A sandbar is a linear landform extending into a body of
water, typically composed of sand or small pebbles.
73. Lagoon
A spit is a type of sandbar that
connects to land and extends into
the sea.
A lagoon is a body of sea water
separated from the sea by a bar.
A tombolo is a landform in which
an island is attached to the
mainland by a sandbar.
Spit Tombolo
74. A cliff is a vertical landform due
to the processes of erosion.
Cliffs are common on coasts and
in mountainous areas,
A natural arch is a landform with
an opening underneath. It may
become in a needle.
78. River erosion is the weathering
and transport of solids by rivers
79. A river is a natural watercourse flowing toward an
ocean, a lake, a sea, or another river.
A tributary or affluent is a river which flows into a main
river.
80. Nile
Amazon
The longest rivers in the world are the Nile (6 718 km),
and the Amazon (6 500 km).
However, the Amazon is by far the largest river
because it has the largest flooded basin in the world,
(350 000 km2). It is approximately one-fifth of the
world's total river flow.
82. A lake is a body of water of
considerable size that is
surrounded by land.
It is larger and deeper than a pond.
83. Niagara Falls (52 m)
A waterfall is a place where
flowing water rapidly drops in
elevation as it flows over a
steep region or a cliff.
84. A canyon or gorge is a deep valley
between cliffs often carved by a river.
The Grand Canyon in Arizona is 446 km
long, up to 29 km wide and attains a
depth of 1 830 m.
85. A meander is a curve of a river.
It is formed when the moving water
in a river erodes the outer banks
and widens its valley.
86. The mouth is the place where a river flows
into the sea.
An estuary is the wide part of a river at the
place where it joins the sea.
A delta is a low land formed at the mouth of
a river, often shaped like a triangle.
Delta
Estuaire
87. A ria is a drowned river valley that results
of sea level changes.
98. Wind erosion is the weathering
and transport of solids by rivers.
99. Wind erosion is very important in deserts because
of the lack of vegetation.
100. A desert pavement or reg is a desert surface that is
covered with pebbles. An erg (also sand sea) is a large
area of desert covered with sand.
Erg
Reg
101. A dune is a hill of sand built by aeolian processes
in the ergs.
A barchan dune is an arc-shaped sand ridge.
Wind
direction
Barchans
102. Riples are structures with a
sinusoidal profile.
Yardangs are rocky structures
carved from bedrock by the wind
abrasion.
Yardangs
Ripples
110. Karst erosion is a landscape
shaped by the dissolution of
limestone.
111. A doline or sinkhole is a natural depression or hole in
the Earth’s surface.
If the depression is very large and flat, it is called a polje.
Doline
Polje
112. A limestone pavement is a natural karst landform
consisting of a flat, incised surface of exposed limestone.
113. A stalactite is a structure that hangs from the ceiling of
limestone caves.
A stalagmite is a structure that rises from the floor of
the cave due to the dripping of calcium carbonate.
Stalactites
Stalagmites
124. Ice erosion is the weathering
and transport of solids by
glaciers.
125. A glacier is a large persistent body of ice.
Nowadays glaciers cover a small area of the Earth. However,
20,000 years ago, glacier covered large regions.
126. During glaciation, water was
taken from the oceans to
form the ice, thus global sea
level dropped by about 110
meters
127. Nowadays there are two types of glaciers:
1) the indlandsis or ice sheet, masses of glacier
ice that are greater than 50 000 km2 (Antarctica
and Greenland);
2) the alpine glaciers, formed on the crests of
mountains.
Indlandsis Alpine glacier
128. The indlandsis must be
distinguished from the sea ice,
formed from seawater that
freezes.
Sea ice cyclically freezes and
melts due to the seasons.
129. An iceberg is a large piece of
ice from freshwater that has
broken off from a glacier and is
floating in open water.
130. Alpine glaciers form on the crests and
slopes of mountains.
An alpine glacier that fills a valley is
sometimes called a valley glacier.
131. A cirque is a concave landform
found among mountains as a
result of alpine glaciers. .
132. A moraine is an accumulation
of glacial debris.
134. The meeting of three or more arêtes creates pointed
pyramidal peaks, called horns.
135. A U-shaped valley has steep, straight sides, and a flat
bottom. It is formed when a glacier travels across and
down a slope, carving the valley by the action of
scouring. When the ice recedes, the valley remains.
136. A glacial lake is a
lake with origins in a
melted glacier.
137. In Finland, the Ice Age resulted in
a vast quantity of lakes.
In fact, more than 10 percent of
Finland is covered by water.
138. A fjord is a drowned glacier valley
with steep sides that results of sea
level changes.
139. Coasts having the most pronounced
fjords include the northwest coast of
Europe, the west coast of North
America, the west coast of New
Zealand, and the west coast of South
America and to south-western
Tasmania.
141. A topographic map is a type of map
characterized by large-scale detail and
quantitative representation of relief,
142. Profil topographique
A contour line (also isohypse)
is a curve that joins points of
equal elevation (height).
Contour lines are represented
using numbers (100 m, 200 m,
etc.) or colors (green for
depressions, white for
mountains, etc.).
A topographic profile is a
vertical view of a topographic
map.
Carte cartographique
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