How was the Philippine Archipelago formed?

Lesson 13.6

HOW WAS THE
PHILIPPINE
ARCHIPELAGO
FORMED?

In 1912, Alfred Wegener proposed the past existence of a supercontinent called Pangaea (or Pangea).

According to Wegener, Pangaea had split apart into a northern half called “Laurasia” and a southern half called “Gondwanaland”.
Surrounded by a global ocean called “Panthalassa” and separated by a big body of water called “Tethys Sea”.

The slow drifting of continents has been occurring over the past 250 million years. In the 1960s, the theory of plate tectonics began to take credence because of the modification and refinement of the concept of continental drift.

Lesson 13.7

LANDFORMS
AND
BODIES OF WATER

LANDFORMS
Landforms are natural features that appear on the surface of the Earth. They are formed either by the movement of tectonic plates or the action of water or ice. The Earth’s surface is the result of both constructive processes.

Destructive Processes
-Weathering
-Erosion
Constructive Processes
-Plate Tectonic processes
(volcanic eruptions)
-Deposition

Major Landforms
•Mountains and Mountain Chains
A mountain is a large landform that stretches above the surrounding land in a limited area, usually in the form of a peak. A mountain is generally steeper than a hill. Mountains are formed through tectonic forces or volcanism.
A mountain range is a geographic area containing numerous geologically related mountains. A mountain system or system of mountain ranges sometimes is used to combine several geological features that are geographically (regionally) related. Mountain ranges are usually segmented by highlands or mountain passes and valleys.

•Volcanoes
A volcano is an opening, or rupture, in the surface or crust of the Earth or a planetary mass object, which allows hot lava, volcanic ash and gases to escape from the magma chamber below the surface.
Lava is a hot molten rock or magma that has erupted onto the Earth’s crust. Tephra refers to the airborne matter from a volcanic eruption.

•Hills
A hill is an elevated landform and is generally somewhat lower and less steep than a mountain. Hills are also smaller than mountains.

•Plains
Plains occur as lowlands and at the bottoms of valleys but also on plateaus or uplands at high elevations. Plains are formed because of sedimentation (process by which particles in suspension settle due to gravity) of the eroded soil from hills and mountains, or because of the flowing lava deposited by wind, water, and ice.

•Valleys
A valley is a low-lying area of land between two mountains or hills.

•Wetlands
A wetland is a land area that is saturated with water, either permanently or seasonally, such that it takes on the characteristics of a distinct ecosystem.
Primarily, the factor that distinguishes wetlands from other land forms or water bodies is the characteristic vegetation that is adapted to its unique soil conditions: Wetlands consist primarily of hydric soil, which supports aquatic plants. WATER FORMS
The hydrosphere is a part of the earth where water is found. It includes all the water underground, in lakes, rivers, oceans, streams, glaciers, as well as in the atmosphere. Water is vital to the existence of life.

•Oceans
An ocean is a body of saline water that composes much of a planet's hydrosphere. The ocean is the largest body of water an has an average salinity of 35 ppt.

•Seas
A sea is a large body of salt water that may be connected to an ocean.
The sea is the interconnected system of all the Earth's oceanic waters, including the five named "oceans", the Atlantic, Pacific, Indian, Southern and
Arctic Oceans.

What is the difference between ocean and sea?

?

Seas are smaller than oceans and are usually located where the land and ocean meet. Typically, seas are partially enclosed by land.

•Rivers
A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely at the end of its course, and does not reach another body of water.

•Lakes
A lake is a still body of freshwater completely surrounded by land.

Lesson 13.8

SHAPING
THE LANDSCAPE

Natural Forces
Same forces have been acting on and shaping the surface of the earth throughout its history. This concept is known as the principle of uniformitarianism. Volcanic eruptions, earthquakes, weathering, erosion, landslides, storms, and floods in the past have changed the landscape.

Man-made Forces
The changes described previously are brought about by natural causes. However, changes in our environment can also happen because of human or man-made forces. Sometimes, these forces benefit mankind, but sometimes, they do not.

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LISTENING =)