EARTH'S INTERIOR, CONTINENTAL DRIFT, AND PLATE TECTONICS

SCIENCE Q1 - L1

Earth’s outer shell crust is divided to several plates that glides over mantle

Plate Tectonics

Combination of the ___ and ___ of the ____ about 100 km thick

Crust, Uppermost Section = Lithosphere

Types of Lithospheric Plates

Continental and Oceanic lithosphere

Solid part of the earth that is broken to plate tectonics and holds it

Lithosphere

Found under land masses

Continental

Found in the ocean floor

Oceanic

Thinner, about 7-10 km

Oceanic

Thicker, about 25-70 km

Continental

Old rocks

Continental

Younger

Oceanic

Continental is made up of rocks called___

Granite

Oceanic is mainly made up of rocks called___

Basalt

Denser (3.0 g/cm3)

Oceanic

Less denser (2.7 g/cm3)

Continental

Why is Oceanic crust younger than Continental crust?

There are small volcanoes underwater, usually at mid-ocean ridges.

From these volcanoes, magma comes up from deep inside the earth (mantle).

When magma cools, it turns into new rock, forming new seafloor / sea bed.

As more magma of the sea bed to the sides comes out, the older parts are pushed or carried away.

Eventually, the old sea floor sinks back into the earth in places called trenches.

Earth’s Primary Plates

1. Pacific Plate

   2. North American Plate

   3. South American Plate

   4. Eurasian Plate

   5. African Plate

   6. Antarctic Plate

   7. Australian plate

Earth’s Secondary Plates

1. Juan de Fuca

2. Cocos Plate

3. Nazca Plate

4. Carribean Plate

5. Arabian Plate

6. Indian Plate

7. Scotian Plate

8. Philippine Plate

Considerations / Why they found out about plates

1. Earthquake Epicenters (which lies sa boundaries)

2. Volcanoes (volcanic islands underwater)

3. Mountain ranges

Continental Drift Theory is made by?

Alfred Wegener, who proposed that continents were once joined and drifted apart.

What is Continental Drift Theory?

Earth's continents were once joined together in a single supercontinent called PANGAEA, which later broke apart and drifted to their present positions

What are the evidences?

Fossils found in particular continent

The rocks

Types of Boundaries

Divergent, Convergent, Transform/Fault

2 oceanic plates move away from eachother

Divergent

What forms in OC-OC Divergent?

Oceanic Ridges

Mid-Atlantic Ridges

New Land Forms

What forms in CO-CO Divergent?

Rift Valleys

Volcanoes

2 plates move or come together. Compression stress

Convergent

What forms in OC-OC Convergent?

Volcanic Islands underwater

What forms in CO-CO Convergent?

Mountain Ranges

What forms in CO-OC Convergent?

Volcanic Islands

Deep sea trenches

Volcanic Arc

Types of Transform Fault

Normal Fault, Reverse Fault, Strike-slip fault

__ and ___ leads to faults

Earthquakes and tsunamis

State the 5 Earth’s Interior and its definitions

CRUST

Oceanic - crust below the ocean 20 ٧٢ Continental-crust made of land

MANTLE - Liquid layer magma (melted rock)

ASTHENOSPHERE - part of mantle with convection currents

OUTER CORE - Liquid layer made up of iron & nickel

INNER CORE - solid layer made up of iron & nickel

Why inner and outer core does not mix?

The inner core is denser and solid, while outer core is less dense and liquid

There are discontinuities or borders which is the:

Mohorovicic - crust & mantle (between)

Gutenberg - mantle & outer core Lehmann - outer core & inner core

Types of spheres and its description

ATMOSPHERE (air) layer of gases

BIOSPHERE (living things)

where life forms

HYDROSPHERE (water)

liquid part of the earth

LITHOSPHERE (land)

solid part of the earth (rocks & minerals)

Why do tectonic plates move?

Convection Currents. These are formed by rising of hot magma near the core towards the surface, while cooler magma a near the crust sinks, setting up current that causes the plates to move

Forms when 2 plates move or come together - compression stress

Convergent

Spreading centers, plates move apart - tension stress

Divergent

What is a Volcanic Arc?

More dense oceanic crust goes under the less dense continental crust

As plates move under continental plate, the rock melts & rises, creating volcanoes.

Trenches are created

What is Subduction Zone?

Area where oceanic crust goes under Continental crust

One plate goes to another plate

What are Faults?

A large fracture (a break) in earth's crust

Plate Tectonics have different ___

Directions

Strike-slip is a type of ___

Transform fault

Philippines is made by ___ of ___

Convergent of plates

What is formed in Transform Fault?

Nothing, just kiskisan between plates

Group of Mountain Ranges

Mountain Belt

Northern Part of Pangaea

Laurasia

Southern Part of Pangaea

Gondwanaland