1. What are the elements that compose the Earth and give the percentage composition of each?
The earth as a whole consists of the following elements and percentages: * * Iron – 32% * Oxygen – 30% * Silicon – 15% * Magnesium – 14% * Sulfur – 3% * Nickel – 2% * Calcium – 2% * Aluminium – 1% * Sodium – 3 (percent by weight) * Potassium – 2.5 (percent by weight)

2. What is mineral? Describe the six physical and two chemical properties used to identify minerals.
Minerals are substances formed naturally in the Earth. They have a definite chemical composition and structure. Physical: The physical characteristics of minerals include traits that are use to identify and describe mineral species. * Cleavage is tendency of a crystalline mineral to break in certain directions yielding more or less smooth planar surfaces. These planes of lowest bond energy have minimum value of cohesion. An amorphous body of course has no cleavage. * Parting is obtained when the mineral is subjected to external force. The mineral breaks along planes of structural weakness. The weakness may result from pressure and twinning. Parting resembles cleavage. * Hardness. It is mineral's "scratchability". It is related to the attraction force between atoms. The degree of hardness is determined by observing comparatively the relative ease or difficulty with which one mineral is scratched by another, or by a finger nail, file or knife. * Diapheneity is the amount of light transmitted or absorbed by a solid. It is used strictly for hand specimens because most minerals that are opaque as hand specimen becomes transparent when very thin. * Luster. The appearance of a specimen in reflected light is a useful property that is often used in tables and flow charts to initially divide minerals into two groups. The basic distinction to be made is that of “metallic” versus “non-metallic”. * * The term crystal habit describes the favoured growth pattern of the crystals of a mineral species, whether individually or in aggregate. It may bear little relation to the form of a single, perfect crystal of the same mineral, which would be classified according to crystal system.
Chemical:
* Atoms, the building blocks of all matter. * Molecules, which are organized agglomerations of different types of atoms.

3. Describe the three main groups of rocks. Describe how each of these rocks are formed. Give at least three examples for each. * Igneous rock was form through the cooling and solidification of magma or lava. Igneous rock may form with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks.

Underground, they are form when magma deep within the Earth became trapped in small pockets. As these pockets of magma cool slowly, they become igneous rocks. Igneous rocks are also formed when volcanoes erupt. Igneous rocks are formed as the lava cools above ground. The upper 16 km of the Earth’s crust is composed of 95% igneous rock.

EXAMPLE:
Basalt, an example of an igneous rock.

Obsidian is volcanic glass without gas bubbles.

Granite is an igneous intrusive rock (crystallized at depth), with felsic composition and phaneritic, subeuhedral texture * Sedimentary Rocks Sedimentary rocks are called secondary, because they are often the result of the accumulation of small pieces broken off pre-existing rocks.

Type of rock that are formed by the deposition of material at the Earth's surface and within bodies of water. Mineral and other materials sitting in water for an extremely long time form sedimentary rock.

EXAMPLE:

Conglomerate is made up of rounded pebbles cemented together.

Breccia is made up of angular pebbles cemented together.

Sandstone is sand grains cemented together into solid stone.

* Metamorphic Rocks The metamorphic get their name from "meta" (change) and "morph" (form). Any rock can become a metamorphic rock. All that is required is for the rock to be move into an environment in which the minerals that make up the rock become unstable and out of equilibrium with the new environmental conditions.

It rises from the transformation of existing rock types, in a process called metamorphism, which means, "Change in form".[1] The original rock (protolith) is subjected to heat (temperatures greater than 150 to 200 °C) and pressure (1500 bars),[2] causing profound physical and/or chemical change.

EXAMPLE:

Quartzite, a form of metamorphic rock.

Slate is tougher than shale and it breaks into thin, flat layers. Slate is usually dark gray, but it can also be red colored. Slate has been used in some countries as roofing and more recently, it has been utilized as floor tiles.

Marble is metamorphosed limestone. In the process of being metamorphosed, the limestone is recrystallized, creating a change in color and texture and the destruction of included fossils.

4. Explain why some volcanoes production steep slopes while others erupt with voluminous lava flows producing gentle slopes.

Volcanoes production steep slope. The greatest slope angle that loose, unconsolidated particles can lie on without sliding down.
At the angle of repose, gravity (which drives the particles down slope) and friction (which prevents them from sliding down) are balanced. Giant Calderas form by collapse (see animation) in gigantic eruptions that spew volcanic rocks out hundreds or even a thousand miles in all directions. Sometimes the calderas are so filled with lava and volcanic ash that there is no recognizable depression at all. These can only be found by carefully locating the big fractures or "faults" in the ground that mark the edges of the caldera. One such caldera nearly fills Yellowstone National Park. In other cases, the edges of the caldera remain as large cliffs or ridges surrounding the central depression. However, the depression is so large that a person standing in the middle of it could hardly see the edges and would only recognize them if they were pointed out. These giant calderas can best be seen in images taken from space, like the one of the Valles Caldera in New Mexico (below,left).

Voluminous lava flows producing gentle slopes. There is no central crater at all. Instead, giant cracks open in the ground and expel vast quantities of lava that spread far and wide to form huge pools that can cover almost everything around. When these pools of lava cool and solidify, the surface remains mostly flat. Since the source cracks are usually buried, there is often nothing "volcano-like" to see--only a flat plain.

5. Show the diagram of the rock cycle. Explain the cycle.

The Rock Cycle is a group of changes. Igneous rock can change into sedimentary rock or into metamorphic rock. Sedimentary rock can change into metamorphic rock or into igneous rock. Metamorphic rock can change into igneous or sedimentary rock.
Igneous rock forms when magma cools and makes crystals. Magma is a hot liquid made of melted minerals. The minerals can form crystals when they cool. Igneous rock can form underground, where the magma cools slowly.
When it pours out on Earth's surface, magma is called lava.
On Earth's surface, wind and water can break rock into pieces. They can also carry rock pieces to another place. Usually, the rock pieces, called sediments, drop from the wind or water to make a layer. The layer can be buried under other layers of sediments. After a long time the sediments can be cemented together to make sedimentary rock. In this way, igneous rock can become sedimentary rock.
All rock can be heated. Inside Earth there is heat from pressure. There is heat from friction. There is also heat from radioactive decay (the process that gives us nuclear power plants that make electricity).
So, what does the heat do to the rock? It bakes the rock.
Baked rock does not melt, but it does change. It forms crystals. If it has crystals already, it forms larger crystals. Because this rock changes, it is called metamorphic. Remember that a caterpillar changes to become a butterfly. That change is called metamorphosis. Metamorphosis can occur in rock when they are heated to 300 to 700 degrees Celsius.
When Earth's tectonic plates move around, they produce heat. When they collide, they build mountains and metamorphose (met-ah-MORE-foes) the rock.
The rock cycle continues. Mountains made of metamorphic rocks can be broken up and washed away by streams. New sediments from these mountains can make new sedimentary rock.
The rock cycle never stops.

6. Show the hydrologic cycle. Explain the cycle.
The hydrologic cycle begins with the evaporation of water from the surface of the ocean. As moist air is lifted, it cools and water vapor condenses to form clouds. Moisture istransported around the globe until it returns to the surface as precipitation. Once the water reaches the ground, one of two processes may occur; 1) some of the water may evaporate back into the atmosphere or 2) the water may penetrate the surface and become groundwater. Groundwater either seeps its way to into the oceans, rivers, and streams, or is released back into the atmosphere through transpiration. The balance of water that remains on the earth's surface is runoff, which empties into lakes, rivers and streams and is carried back to the oceans, where the cycle begins again.

7. What is seismic wave? Describe the different type of seismic waves.
A seismic wave s an elastic wave generated by an impulse such as an earthquake or an explosion. Seismic waves may travel either along or near the earth's surface (Rayleigh and Love waves) or through the earth's interior (P and S waves). Seismic waves are waves of energy that travel through the Earth's layers, and are a result of an earthquake, explosion, or a volcano that imparts low-frequency acoustic energy.

* Primary or P waves are push and pull waves. They are also called longitudinal waves. These waves resemble sound waves, since both are compression-dilatation or compression rarefaction waves. * Secondary, S or Shear Waves are also called transverse wave. In these waves the particles vibrate at right angles to the direction in which they travel (the direction of propagation). S waves pas only through solids. * L or Surface Waves reach the earth's surface after P and S waves. Surface wave travels with a lower velocity than the other two around the surface of the earth. Surface wave is very destructive. * Raileigh waves are characterised by the motion of particles in elliptical orbits in the plane of propagation. * In the second kind of waves i.e. love waves, the motion of particles is horizontal and at 90° angle of the direction of their movement.

8. What are the earth’s internal layers. Describe each. * The mantle is much hotter and has the ability to flow. * The Outer and Inner Cores are hotter still with pressures so great that you would be squeezed into a ball smaller than a marble if you were able to go to the center of the Earth

9. Describe the differences and relationships between Asthenosphere and lithosphere. How they affect the earth’s surface features?
The lithosphere is the outermost shell of the earth, made up of the upper crust and the upper mantle while the asthenosphere is underneath the lithosphere. It is the point at which the mantle becomes liquid. Whereas, it is hypothesized that asthenosphere is created as lithosphere is created because it will be dragged about by the various plate motions.

10. Describe and explain why earthquake occur and the scales used to measure their magnitude and intensity.
Earthquakes are usually caused when rock underground suddenly breaks along a fault. This sudden release of energy causes the seismic waves that make the ground shake. When two blocks of rock or two plates are rubbing against each other, they stick a little. They don't just slide smoothly; the rocks catch on each other. The rocks are still pushing against each other, but not moving. After a while, the rocks break because of all the pressure that's built up. When the rocks break, the earthquake occurs. During the earthquake and afterward, the plates or blocks of rock start moving, and they continue to move until they get stuck again. The spot underground where the rock breaks is called the focus of the earthquake. The place right above the focus (on top of the ground) is called the epicenter of the earthquake.
An earthquake is measured by its Magnitude and Intensity. The Magnitude indicates the amount of energy released at the source (or epicentre) and is measured by the open-ended Richter Scale. The intensity of an earthquake at a particular locality indicates the violence of earth motion produced there by the earthquake. It is determined from reported effects of the tremor on human beings, furniture, buildings, geological structure, etc. Many places, including Hong Kong, have adopted the Modified Mercalli Scale (MMS) which classifies earthquake effects into twelve grades.