geoscienci iia

8/13/2019 Geoscienci IIA

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UGMGraduate School Gadjah Mada University, Yogyakarta Phone/Fax. (0274) 564239Website http://www.geo.ugm.ac.id, www.geoinfopasca.ugm.ac.id and

http://www.itc.nl/pub/study/programmes/joint-educations

INDIVIDUAL ASSIGNMENT

MODUL A

GEOSCIENCE AND ITS APPLICATION

LECTURER:

PROF. DR. SUTIKNO.

By:

MUHAMMAD ATHTHAAR NAZIM

(13/357422/PMU/08061)

SEPTEMBER 2013

Double Degree MSc ProgrammeGEO-INFORMATION FOR SPATIAL PLANNING AND

DISASTER RISK MANAGEMENT


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1. What are the scope of geological science, and which one of them have

importance role for disaster mitigation and natural resources evaluation?

Geology means, literally, the study of the Earth. Explore this section to

understand the structure of the Earth and its surface features, what causes

earthquakes and tsunamis, and why volcanoes form and erupt. Learn aboutminerals, which form the building blocks of rocks, and how rocks are made

and destroyed.

Geological science have many scopes such as Mineralogy, Petrography,Paleontology, Structural geology, Hydrogeology, Seismology, Stratigraphy,

etc. Many scopes of geological science which have important role for disaster

mitigation and natural resources evaluation.

Hydrogeology, which deals the interaction between groundwater movement

and geology, can contribute on slope stabilisation method in rock or in the

earth, so, the landslide can be avoided.

Seismology is the study of earthquakes and seismic waves that move through

and around the earth. A seismologist is a scientist who studies earthquakes

and seismic waves.

http://www.windows2universe.org/earth/geology/geology.html

http://www.geo.mtu.edu/UPSeis/waves.html

2. What is the difference between mineral and rocks?

A mineral is a solid inorganic compound with a unique chemical composition

and crystal structure with specific colour and hardness. A rock is a solid,stony mass composed of a combination of minerals or other organic

compounds. For example, quartz and feldspars are minerals, but when

formed together, they make a rock, granite. Or limestone is a sedimentary

rock composed almost entirely of the mineral calcite.

http://gallery.usgs.gov/audios/126

3. Why acid rocks more dominant in the earth surface compare to basic rocks?

Based on the compound of silica igneous rocks classified as acid rocks and

basic rocks. Acid rocks contain a lot of silica, SiO2(greater than 63% byweight). Basic rocks have around 50% or less silica and a lot of magnesium

and iron.

Acid rocks tend to be much lighter in colour than basic rocks, they tend to

disintegrate around the mineral crystals, and they often weather into coarse

textured and rather infertile soils.


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Igneous rock is formed 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.

Intrusive igneous rocks are formed from magma that cools and solidifieswithin the crust of a planet. Extrusive igneous rocks are formed at the crust's

surface as a result of the partial melting of rocks. They are formed by the

cooling of molten magma on the earth's surface and thats way acid rocks

were dominant on earth surface.

http://www.galleries.com/rocks/igneous.htm.

http://en.wikipedia.org/wiki/Igneous_rock

4. What is correlation between texture and rock types of the igneous rocks.

An igneous rock is any crystalline or glassy rock that forms from cooling of amagma. Based on on its location and its composition there are two types of

igneous rocks; Extrusive and Intrusive.

The difference between an Extrusive and Intrusive igneous rock is the way in

which they cool. An Extrusive igneous rock cools very fast on the surface andis created by lava which have very small crystals (fine grained). On the other

hand an Intrusive igneous rock cools very slowly beneath the surface and is

created by magma, that makes intrusive igneous rocks have very large

crystals (coarse grained).

Texture is determined by the grain size of igneous rock which is determined

by the rate of cooling. For example a smooth igneous rock was cooled veryfast because it is has small crystals and it must be an extrusive rock. Igneous

textures are used by geologists in determining the mode of origin igneous

rocks and are used in rock classification. There are six main types of textures;

phaneritic, aphanitic, porphyritic, glassy, pyroclastic and pegmatitic

http://www.archaeology.ncdcr.gov/ncarch/GeoArcheo/IgneousA.htm

http://www.tulane.edu/~sanelson/eens212/textures_igneous_rocks.htm

5. Describe at least five geologic structures that have closed relation to natural

disaster, and why?

There are five geological structures that have closed relation to natural

disaster:

Fault; is a structure with major displacement of rock material along a

crack in a rock. It is a geological structure which closely related to

earthquake disaster. Large faults within the Earth's crust result from the

action of plate tectonic forces, with the largest forming the boundaries

between the plate. Active faults is the cause of most earthquakes.


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Folds; are warps in rock layers and occur bended upwards, downwards,

or sideways--compressional forces are the prime causes of foldsfolds

are important causes of mountain formation and also earthquake. Fold

occurs when one or a stack of originally flat and planar surfaces. Graben; graben is a depressed block of land bordered by parallel faults.

When the earthquake is occured, normal fault makes a depressed block

called a graben.

Horst; horst is the raised fault block bounded by normal faults or graben.

A horst is formed from extension of the Earth's crust. It is very same with

graben, when the earthquake is occured, normal fault makes a raised

block called a horst.

Rift Valley; rift valley is a linear-shaped lowland between several

highlands or mountain ranges created by the action of a geologic rift or

fault. The creation of rift valley involves earthquakes.

http://nationalatlas.gov/articles/geology/a_geohazards.html

http://courses.missouristate.edu/emantei/creative/glg110/geostruct.html

6. Describe the main aspects of the geomorpholgy and their relation to natural

hazard.

Geomorphology is an area of geology concerned with the study of landforms,

with the forces and processes that have shaped them, and with the

description and classification of various physical features on Earth.

Aspect of geomorphology which have relation with natural hazard are:

Morphology, the study of the structure of rocks and landforms

Morphogenetic, the formation of landforms or other structures.

Morphochronology, the science of locating events in time from variety of

landforms.

Morphoarrangement, spatial arrangement and corelation between

landforms and the process of its formed.

http://www.thecanadianencyclopedia.com/articles/geomorphology

7. Why there are some landform unit on the earth surface?

Tectonic plates move and interact with each other constantly. Their activities

lead to earthquakes, volcanic eruptions and the splitting of the Earth's crust.These events change the surface of the Earth by creating different landforms.

A landform is a term that describes the shape of a natural land feature.

Landforms are created by different forces of nature. For example, mountains,

oceans, valleys and deserts can be called landforms. A group of landforms in

one area makes up a landscape. The view from an aeroplane or from the top

of a hill gives a good picture of a landscape.


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Some natural landforms are mountains, oceans, rivers, hills, volcanoes,

valleys, desserts, waterfalls, caves and cliffs.

http://www.skwirk.com.au/p-c_s-4_u-460_t-1243_c-4746/vic/science/-from-the-earth-

s-core-to-the-crust-/the-creation-of-landforms/types-of-landforms

8. Why geomorphologic or landform units can be used for identification of

natural disaster types and evaluation on natural resources.

Natural resources and natural hazard actually could be studied by various

disciplines. The difference between environmental geomorphology and other

disciplines to study on natural resources and natural hazard is the approach.

The landform characteristics that consist of relief, materials (lithology and

structure) and geomorphic processes are very relevance to the natural

resources and natural hazard factors. Relief is the product of interactionbetween lithology and structure and geomorphic processes, it mean that relief

reflected lithology and structure, and geomorphic processes ( van Zuidam,

1983).

Landform unit approach has been used widely for assessment of naturalresources potential and natural hazard zoning for mitigation purposes. To

apply geomorphology for natural resources and natural hazard must be

founded by basic theory and principles in geomorphology (Thornbury,1959;

Summerfield,1991), geomorphological survey and mapping (van Zuidam,

1985; Verstappen, 1983), and should be supported by related subject such as

geology, climatology and hydrology. Remote sensing technique and GIS has

importance contribution and tools for geomorphological surveys and mapping.

http://indonesiangeography.blogspot.com/2009/01/need-and-prospect-of-

environmental_3990.html

9. What kind of geomorphologic factors that influence of mass-wasting

susceptibility?

Mass movement or mass wasting is movements of masses of bodies of soil,

bed rock, rock debris, soil, or mud which usually occur along steep-sided hills

and mountains because of the pull of gravity. This slipping of large amounts

of rock and soil is seen in landslides, mud slides, and avalanches.

Mass movements are caused by various conditions:

Volcanic activity many times causes huge mudflows when the icy cover ofa volcano melts and mixes with the soil to form mud as the magma in thevolcano stirs preceding an eruption.


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Mudslides can also develop when water rapidly accumulates in theground, such as during heavy rainfall or rapid snow melt, changing theearth into a flowing river of mud or "slurry.".

Earthquake shocks cause sections of mountains and hills to break off andslide down.

Human modification of the land or weathering and erosion help loosenlarge chunks of earth and start them sliding downhill.

Vibrations from machinery, traffic, weight loading from accumulation ofsnow; stockpiling of rock or ore; from waste piles and from buildings andother structures.

On the left is an example of creep(Creep, Marathon, TX (Photo from NOAA)). On the rightis a displaced Curb, Photo by DH, 3/4/84).

Yungay, Peru's Main Plaza before(left) and after(right) pictures of landslide's destruction.

http://www.ngdc.noaa.gov/seg/hazard/resource/hazdir.html http://www.geo.duke.edu/geo41/mmo2.htm

10. What kind of geomorphologic factors that influence of flood susceptibility?

River floods are a major hazard in many areas of the world, causing loss of lifeand destruction of agricultural land and property. They may occur due to high

rainfall, melting of snow in spring, landslides, or the emptying of lakes when anatural or artificial dam is breached

Flood-intensifying conditions are linked to basin, network andchannel characteristics some of which are stable while others are variable,primarily as a result of human activities in the river basin.

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