some sort of things related to earth science

1. Mineral
Naturally formed inorganic substance with a particular chemical
composition and a regularly repeating internal structure. Either in their
perfect crystalline form or otherwise, minerals are the constituents of
rocks. In more general usage, a mineral is any substance economically
valuable for mining (including coal and oil, despite their organic origins).

2. Classification of Minerals
 Magmatic – These includes the feldspars, quartz, pyroxenes,
amphiboles, micas, and olivines that crystallize from silica-rich rock melts
within the crust or from extruded lavas.
 Sedimentary – the most commonly occurring sedimentary minerals are
either pure concentrates or mixtures of sand , clay minerals, and
carbonates (chiefly calcite, aragonite, and dolomite).
 Metamorphic - these minerals include andalusite, cordierite, garnet,
tremolite, lawsonite, pumpellyite, glaucophane, wollastonite, chlorite,
micas, hornblende, staurolite, kyanite, and diopside.

3. Rocks
Are solid pieces of the Earth or any other inorganic body in the
Solar System. They are composed of minerals or materials of organic
origin.
Types of Rocks
 Igneous Rock
 Sedimentary Rock
 Metamorphic Rocks

4. Igneous Rocks
formed by the cooling and solidification of magma, the molten rock
material that originates in the lower part of the Earth’s crust, or mantle,
where it reaches temperatures as high as 1,000°C.
Common Igneous Rocks
volcanic(porous or glassy)
obsidian scoria pumice

5. volcanic(fine-graned)
rhyolite andesite basalt
plutonic(coarse-graned)
granite diorite gabbro

6. Sedimentary Rock
are formed by the comprehension of particles deposited by water,
wind, or ice. They may be created by the erosion of older rocks, the
deposition of organic materials, or they may be formed from chemical.
Common Sedimentary Rocks
Clastic
sandstone shale conglomerate

7. Chemical
fine-grained limestone agate (microcrystalline quartz)
Organic
coal limestone

8. Metamorphic Rocks
are formed through the action of high pressure or heat on existing
igneous or sedimentary rocks, causing changes to the composition,
structure, and texture of the rocks.
Common Metamorphic Rocks
quartzite marble gneiss (& garnet crystals)

9. Rock Studies
The study of the Earth’s crust and its composition fall under
a number of interrelated sciences, each with its own specialist.
Among these are:
 Geologists - who identify and survey rock formations and
determine when and how they were formed.
 Petrologists – who identify and classify the rocks themselves,.
 Mineralogists – who study the mineral contents of the rocks.
 Palaeontologists – study the fossil remains of plants and
animals found in rocks.

10. The Earth’s Interior
Our planet is the third planet from the sun. it is almost spherical,
flattened slightly at the poles, and is composed of five concentric layers:
inner core, outer core, mantle, crust, and atmosphere. About 70% of the
surface (including the north and south polar icecaps) is covered with
water.
Mean distance from the Sun: 149,500,000 km
Equatorial diameter: 12,755 km
Circumference: 40,070 km
Rotation period: 23 hr 56 min 4.1 sec
Year: 365 days 5 hr 48 min 46 sec. Earths average speed around the
sun is 30 kps/18.5 mps; the plane of its orbit is inclined to its equatorial
plane at an angle of 23.5°, the reason of unchanging seasons

11. Atmosphere: nitrogen 78.09%; oxygen 20.95%; argon 0.93%; carbon
dioxide 0.03%; and less than 0.0001% neon, helium, krypton,
hydrogen, xenon, ozone
Surface: land surface 150,000,000sq km (greatest height above sea
level 8,872m Mount Everest); water surface 361,000,000sq
km/139,400,000sq mi (greatest depth 11,034m/36,201ft Mariana Trench
in Pacific). The interior is thought to be an inner core about
2,600km/1,600ml in diameter, of solid iron and nickel; an outer core
about 2,250km/1400mi thick, of molten iron and nickel; and mantle of
mostly solid rock about 2,900km/1,800mi thick.
Satellite: Moon
Age: 4.6 billion years. The earth was formed with the rest of the Solar
System by consolidation of interstellar dust. Life begun 3.5-4 billion
years ago.

12. Divisions in the Earth's
Interior
(Adapted from, Beatty, 1990.)

13. The Earth’s Crust
The crust is a rocky outer layer of earth, consisting of two
distinct parts, the oceanic crust and continental crust.
 Oceanic crust – This part is on average about 10km thick and
consists mostly of basaltic rock overlain by muddy sediments.
 Continental crust – it is largely of granitic composition and is
more complex in its structure. Because it is continually recycled
back into the mantle by the process of subduction.
The Core
The core is the innermost part of the earth. It is divided into
an outer core, which begins at the depth of 2,900km, and the inner
core, which begins at a depth of 4,980km. both parts are thought
to consist of iron nickel alloy. The outer core is liquid and the inner
core is solid.

14.  Inner core: 1.7% of the Earth's mass; depth of 5,150-6,370 kilometers (3,219 -
3,981 miles)
 Outer core: 30.8% of Earth's mass; depth of 2,890-5,150 kilometers (1,806 -
3,219 miles)
 D": 3% of Earth's mass; depth of 2,700-2,890 kilometers (1,688 - 1,806 miles)
 Lower mantle: 49.2% of Earth's mass; depth of 650-2,890 kilometers (406 -1,806
miles)
 Transition region: 7.5% of Earth's mass; depth of 400-650 kilometers (250-406
miles)
 Upper mantle: 10.3% of Earth's mass; depth of 10-400 kilometers (6 - 250 miles)
 Oceanic crust: 0.099% of Earth's mass; depth of 0-10 kilometers (0 - 6 miles)
 Continental crust: 0.374% of Earth's mass; depth of 0-50 kilometers (0 - 31
miles).

16. Earthquake
An abrupt motion that propagates through the earth and along its surfaces is
called earthquake. Earthquakes are caused by the sudden released in rocks of
strain accumulated over time as a result of tectonics. The study of earthquakes is
called seismology. The force of earthquakes (magnitude) is measured on the
Richter scale, and their effect (intensity) on the Mercalli scale. The point at which
an earthquake originates is the seismic focus or hypocenter; the point on the
earth’s surface directly above this is the epicenter.
Earthquakes happen as large blocks of the Earth’s crust move suddenly past
one another because of the force of plate tectonic. These blocks of the Earth’s
crust meet at cracks called faults. Sometimes those pieces do not slide smoothly
past one another. There can be friction along the fault – jagged edges that snag the
blocks of rock. This makes it difficult for them to move past each other. Sometimes
they get stuck together temporarily. When the pieces of rock overcome the snags,
energy is released. The release of energy causes shaking at the ground surface.
The location inside the Earth where an earthquake begins is called the
focus. The point at the Earth’s surface directly above the focus is called the
epicenter. The strongest shaking happens at the epicenter.

17. Description of the 12 levels of the Modified Mercalli intensity scale:
 I. Not felt except by a very few under especially favorable conditions.
 II. Felt only by a few persons at rest, especially on upper floors of buildings.
 III. Felt quite noticeably by persons indoors, especially on upper floors of buildings. Many
people do not recognize it as an earthquake. Standing motor cars may rock slightly.
Vibrations similar to the passing of a truck. Duration estimated.
 IV. Felt indoors by many, outdoors by few during the day. At night, some awakened.
Dishes, windows, doors disturbed; walls make cracking sound. Sensation like heavy
truck striking building. Standing motor cars rocked noticeably.
 V. Felt by nearly everyone; many awakened. Some dishes, windows broken. Unstable
objects overturned. Pendulum clocks may stop.
 VI. Felt by all, many frightened. Some heavy furniture moved; a few instances of fallen
plaster. Damage slight.

18.  VII. Damage negligible in buildings of good design and construction; slight to
moderate in well-built ordinary structures; considerable damage in poorly built or badly
designed structures; some chimneys broken.
 VIII. Damage slight in specially designed structures; considerable damage in ordinary
substantial buildings with partial collapse. Damage great in poorly built structures. Fall
of chimneys, factory stacks, columns, monuments, walls. Heavy furniture overturned.
 IX. Damage considerable in specially designed structures; well-designed frame
structures thrown out of plumb. Damage great in substantial buildings, with partial
collapse. Buildings shifted off foundations.
 X. Some well-built wooden structures destroyed; most masonry and frame structures
destroyed with foundations. Rails bent.
 XI. Few, if any (masonry) structures remain standing. Bridges destroyed. Rails bent
greatly.
 XII. Damage total. Lines of sight and level are distorted. Objects thrown into the air.

19. Some of the Major Earthquakes Since 1980
Date Location Magnitude
(Richter scale)
Estimated
number of
deaths
10 October
1980
Northern Algeria 7.2 4,800
19,21
September
1985
Mexico City, Mexico 8.1 5,000
7 December
1988
Armenia 6.8 25,000
20-21 June
1990
Northwestern Iran 7.7 50,000
16 July 1990 Luzon, Philippines 7.7 1,660
29 September
1993
Maharashtra, India 6.3 9,800
16 January
1995
Kobe, Japan 7.2 5,500
17 August
1999
Turkey 7.4 14,095
21 September
1999
Taiwan 7.6 2,256

20. Fault
A planar break in rocks, along which the rock formations on
either side have moved relative to one another called fault. Fault
involve displacements, or offsets ranging from the microscopic
scale to hundreds of kilometers. Large offsets along a fault are
the result of the accumulation of smaller movements (meters or
less) over long periods of time. Large motions cause detectable
earthquakes
Faults produce lines of weakness on the Earth’s surface
(along their strike) that are often exploited by processes of
weathering and erosion. Coastal caves and geos (narrow inlets)
often form along faults and, on a larger scale; rivers may follow
the line of a fault.

21. Types of Fault
 Normal Faults – these occur when the hanging wall moves down
relative to the footwall. It occur where rocks on the either side have
moved apart.
- It happen in areas where the rocks are pulling apart (tensile
forces) so that the rocky crust of an area is able to take up
more space.
- The rock on one side of the fault is moved down relative to
the rock on the other side of the fault.
- Normal faults will not make an overhanging rock ledge.
In a normal fault it is likely that you could walk on an
exposed area of the fault.

22.  Reverse Faults – these happen where the hanging wall has moved up
relative to the footwall. A reverse fault that forms low angle with the
horizontal plane is called a thrust fault. It occurs where the rocks on
either side have been forced together.
-Reverse faults happen in areas where the rocks are pushed together
(compression forces) so that the rocky crust of an area must take up
less space.
-The rock on one side of the fault is pushed up relative to rock on the
other side.
-In a reverse fault the exposed area of the fault is often an overhang.
Thus you could not walk on it.
• Lateral fault or strike – slip fault – the occurrence happens where
the relative movement along the fault plane is sideways.

23. • Transform Fault – it is a major strike – slip fault along a plate
boundary, that joins two other plate boundaries – two spreading
centers, two subduction zones, or one spreading center and one
subduction zone.
-The movement along a strike slip fault is horizontal with the block of
rock on one side of the fault moving in one direction and the block of
rock along the other side of the fault moving in the other direction.
- strike slip faults do not make cliffs or fault scarps because the blocks of
rock are not moving up or down relative to each other.

24. Normal dip-slip fault
Reverse dip-slip fault
Transform (strike-slip) faults

25. Seismic Wave
Seismic wave is the energy wave generated by sn earthquake or an
artificial explosion.
Types of Seismic Waves
 Body waves – Seismic waves that travel through the Earth’s interior.
 P - Waves or Primary Waves – longitudinal waves whose
compressions and refractions resemble those of the sound wave.
 S - Waves or Secondary Waves – transverse waves or shear
waves that involve a back and forth shearing motion at the right
angles to the direction the wave is traveling.
 L - Waves or Love waves – these waves are transverse waves and
considered the slowest since it trapped in a subsurface layer due to
different densities in the rock layers above and below. They have a
horizontal side – to – side shaking motion transverse (at right
angles) to the direction wave is traveling.

26.  Surface Waves – Surface waves travel in the surface and subsurface
layers of the crust.
 Rayleigh waves – surface that travel along the free surface (the
uppermost layer) of a solid material. The motion of particles is
elliptical, like a water wave, creating rolling motion often felt during
an earthquake.

27. typical seismogram (Figure)

28. Plate Tectonic
A theory formulated in the 1960s to explain the phenomena
of continental drift and seafloor spreading, and the formation of
the major physical features of the Earth’s surface. The Earth’s
outermost layer, the lithosphere, is regarded as a jigsaw puzzle
of rigid major and minor plates that move relative to each other,
probably under the influence of convection currents in the mantle
beneath. At the margins of the plates, where they collide or move
apart or slide past one another, major landforms such as
mountains, rift valleys, volcanoes, ocean, trenches, and ocean
ridges are created. The rate of plate movement is at most 15
cm/6in per year.
There are 3 types of Plate Boundaries; Constructive margins
(Diverging Boundaries), Destructive margins (Converging
Boundaries), and Conservative margins (Transform fault)

30. Constructive margins (Diverging Boundaries) – Where two plates are
moving apart from each other, molten rock from the mantle wells up in
the space between the plates and hardens to form crust, usually in form
of an ocan ridge (such as the Mid – Atlantic Ridge). The newly formed
crust accumulates on either side of the ocean ridge causing the seafloor
to spread; the floor of the Atlantic Ocean is growing by 5cm or 2in each
year because the welling up of new material at Mid – Atlantic Ridge.
Destructive margins (Converging Boundaries) – where two plates are
moving towards each other, the denser of the two plates may be forced
under the other into a region called the subduction zone. The
descending plate melts to form a body of magma, which may then rise to
the surface through cracks and faults to form volcanoes. If the two plates
consist of more buoyant continental crust, subduction does not occur.
Instead, the crust crumples gradually to form ranges of young
mountains, such as the Himalayas in Asia, the Andes in South America,
and the Rockles in North America. This process of mountain building is
termed orogenes.

31. Conservative margins (Transform fault) – sometimes two plates will slide
past each other – an example is the San Andreas Fault, California, where
the movement of the plates sometimes takes the form of sudden jerks,
causing the earthquakes common in the san Francisco – Los Angeles
area. Most of the earthquake and zones of the world are found in regions
where two plates meet or are moving apart.

32. Causes of Plate Movement
 It has been known for some time that heat flow from the interior of the
earth is high over the mid – ocean ridges, and so various models of
thermal convection in the mantle have been proposed;
 The geometry of the flow in any convective system must be complex, as
there is no symmetry to the arrangement of ridges and trench systems
over the Earth’s surface. It seems likely that plume of hot, molten
material rises below the ridges and is extruded as basaltic lava.
 In zones of descending flow, at deep ocean trenches, the surface
sediment is scraped off the descending plate onto the margin of the static
plate, causing it to grow outwards towards the ocean while the basaltic
rocks of the descending plate, together with any remain ing sediment,
suffer partial fusion as they descend. This gives rise to large volumes of
molten rock material, or magma, which ascend to form andesitic lavas
and intrusions of diorite or granodiorite at the margin of the overlying
continent.