La tierra copia
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Transcript of La tierra copia
THE EARTH
The structure of the Earth
• Earth’s surface is divided into:
– Litosphere (solid and rocky part of Earth)
– Hydrosphere (water: oceans, rivers, lakes…)
– Atmosphere (air: layer of gases)– Biosphere (places where life exists)
Geology:
the study of the materials that make up the solid part of the Earth.
Geological ages
SnowballEarth750 - 635 millions
PROTEROZOIC
Paleozoic Age: Cambrian sea (525 millions)
PALEOZOIC AGE540-251 mill.
PANGEA
Trilobites
Formation of continents
MESOZOIC AGE251-65 millions.
Dinosaurs
CENOZOIC AGE(65-2 mill.)
Rise of mountains
Age of mammals
Quaternary Age(2 millions onwards)
Rise of human beings.
The inner structure of the Earth
The inner structure of the Earth
How many kms. Each layer?
Continental drift
• 2. EARTH’S STRUCTURE (pages 26,27)
• Planet Earth has three layers:• The core: inner part of the Earth, made up mainly by
iron. – Inner core, extremely hot and solid because of pressure.– Outer core: extremely hot liquid.
• The mantle, made up by a hot liquid/plastic called magma.
• Magma sometimes pushed up to the surface and creates volcanic eruptions (this magma is called lava).
• The crust: solid, outer part of Earth surface, where we live.– Continental crust (30-70 km. deep)– Oceanic crust (10 km. deep).
PANGEA(200 millions ago)
• Continental drift and tectonic plates.
Continents move slowly over the mantle, like wood on water.
200 millions ago, a supercontinent, called Pangea started to separate and create the current continents in the present. This is called continental drift(1).
• Tectonic plates: Our continents are part of tectonic plates, that move continually. There are eight major plates and some more smaller. These plates collide each other or move apart.
• The movement of this tectonic plates is responsible of eruptions and earthquakes in the boundaries of the plates.
[1] Continental drift: deriva continental. Tectonic plates: places tectónicas. Earthquake: terremoto. Boundaries: limits.
How continents move?
Internal forces of relief• 1.- Pressures • 1.a.- Folds
SYNCLINE(fold downwards)
ANTICLINE(fold upwards)
FOLDS
QUARCITE FOLDS in Sierra de Fuentes(Cáceres)
QUARCITEFOLDS IN SIERRA DE FUENTES(CÁCERES)
SYNCLINE OF CÁCERES
Cáceres
Internal forces of relief• 1.b.- Faults
Internal forces: faults
Faults: breaks in rock layers
Tiny fault in a rock. Quartz layer.
Fault: Ronda norte (Cáceres)
Fault plane (espejo de falla)
Falla de San Andrés
Internal forces of relief
• 2.- Earthquakes
FAULT
EarthquakeConsequencesCalifornia
Earthquakes on the ocean: tsunamis
Japan, 2012
Seismograph
Internal forces of relief• 2.-Volcanoes
Internal forces of relief: volcanoes
LAVA FLOWS
CRATER
VOLCANICBOMBS
CONE
VOLCANOESUNDER THE SEA
(India)
VOLCANOESERUPTIONSCAN CREATENEW ISLANDS
(ICELAND)
External agents of relief
• 1.- Water• 2.- Wind• 3.- Changes of temperature• 4.- Human action
External forces of relief
• Erosion• Transportation• Deposition
EXTERNAL AGENTS (WATER, AIR), CHEMISTRYERODES THEROCK (GRANITE)
BARRUECOS(MALPARTIDA DE CÁCERES)
TRANSPORTATIONAND DEPOSITION(SEDIMENTS)
Rivers transportsLots of sediments
Other external agents
The ice.
Glacier
Icetongue
Icetongue
Cirque
Near Jerte
Andes argentinos
V- and u- shaped valleys
Other agents: Human action.
Alcántara old quarry (vieja cantera de Alcántara).