geo l3

Fold mountains

Fold mountains

Mountains created due to convergent boundaries of both

1) O-C (Rockies, Andes) 2) C-C (Himalayas, Alps)Compressive forces of platesYoungest mountains on earth

True mountains

Fold mountai

ns

Geomorph

1)Extensive mountain chain2) Great heights•3) Formed along unstable parts of the earth4) Sedimentary deposits of marine origin (C-C)

Characteristics of Fold mountains

• Pull of descending limb of convection current

• great pressure of compressive force exerted by the convection cells

Phases of mountain building

• Elongated, narrow depression on continental margins

• Here sediments from both land and ocean accumulate

Geo-syncline

• Sediments from continental crusts of both plates + geo-syncline folded

• Because of sediments of geo-syncline – marine origin

C-C collision

Fold mountains of the world

Pamir Knot

Hindu kush, Kirthar and Sulaiman Ranges

Sulai

man

ra

nge

Kirt

har r

ange

Mountains in Europe

1) Alaska range2) Southern Alps3) Dinaric Alps4) Atlas mountains5) Pyrenees6) Caucasus 7) Apennines8) Taurus 9) Elburz and Zagros

9) Hindukush10) Kirthar range11) Kunlun Shan12) Urals mountains13) Appalachian mountains14) Great Dividing Range

List of mountains to locate

• understanding of the origin and evolution of earth’s crust.

• At the time of the formation of the earth crust, first basaltic crust of ocean - breaking and melting - a lighter continental crust developed.

• collide with one another = a larger land mass.• The joints = fold-mountains.

Importance of mountain building process

Urals Mountains

mountains

Fold mountains

Block mountains

Types of mountains

Block mountains formation

• Fault-block mt.• Due to forces within

interior of the earth• Uplifted part = horst• depressed part =

Grabben• Horst => block

mountains• Grabben => rift valley

Block mountains

Phases of Divergent continental crust

African rift valley – block mountains

EuropeIndia

Example of block mountains

Fold mountains• True mountains• Compressive force - folding• Due to collision of plates (C-

C, O-C)• Folding of sedimentary

rocks

• Not true mountains• Tensile force -faulting• Diverging plates (Conti)• Differential erosion of horst

of fault – looks like mountains

Block mountains

comparison

Mountains

Plateaus

Plains

Landforms on earth

Meaning:Flat, Table land, upland, higher than surrounding areas

Plateaus

• Raised land during mountains building process• Deposition from lava• Deposition from wind• Eroded due to glaciers

Formation of Plateaus

Intermontane plateau

• Bolivia plateau• Tibetan plateau• Columbia plateau• Colorado plateau• Anatolia Plateau

(Turkey)

• Deccan plateau• Katanga plateau• Ozark plateau

(USA)• Ethiopian

highland

Continental plateau

Types of plateau

Glacial plateau• Grahwal

plateau• Laurentian

plateau (Canada)

• Columbia-snake plateau (USA)• Deccan Plateau• Shan plateau

(Myanmar)

Lava plateauTypes of Plateau

Bolivia plateauColumbia- colorado

Ozark plateauAnatolia plateau

Loess plateauLaurentian plateau

• Origin of River Congo and Zambezi

• Dense equatorial forest• Known for resources- Gold, diamonds, Copper

Katanga Plateau

• Equatorial region• Dense rainforest• Known for gold

reserve

Plateau of Mato Grasso, Brazil

• Plateau crossed by Salween river

• Irrawaddy river passed in eastern side

• Shan plateau- chief source of lead, zinc and silver Myanmar

• Known for teak forest(Burmese Teak)

Shan plateau, Myanmar

“Roof of the world” – highest and largest plateau• Source of Indus,

Brahmaputra, Salween, Mekong, Yangtse, Hwang He

• Imp role in Indian monsoon

Tibetan plateau

• Granite• Less mobile,

cannot move upward

• Backbone of fold mountains

Batholith

Mountains

Plateaus

Plains

Landforms on earth

Plains

• Meaning• Flat areas with low

heights• Best for human

habitation• Most populated areas

of the world – alluvial plains of rivers

• Depositional plains- Rivers- Sea (sub-merged coast)

• Erosional plains- Erosion of plateau

Asia Europe

Africa

South America

North America

Indus Danube

Nile Amazon

Mississippi – Missouri

Ganga –Brahmaputra

Rhine Congo Parana- Paraguay

Colorado

Yangtze (China) Rhone Niger St. Lawrence

Hwang He (China)

Po Zambezi

Yukon

Ob- Irtysh (Russia)

Don Orange

Mackenzie

Mekong (SE Asia)

Euphrates - Tigris

Important river basins of the world

Yangtze river, China

• Yangtze – 3th longest river in the world• Navigable river – 35% of China’s population• Sichuan basin – rice cultivation• Shanghai – biggest port of China• Wuhan – Iron and steel• Nanjing – textile, iron and steel • Chengdu – oil and gas• Three gorge dam• Yun ho canal – connect Yangtze with Hwang He

Important locations

Euphrates- Tigris river, Iraq

• Lake Van, • Lake Urmia• Important centers in Iraq:• Baghdad, Mosul, Kirkuk, Al Basra

Locations near Euphrates-Tigris

Amazon river, Brazil

• Largest, 2nd longest river • Selvas – equatorial rain forest • Tin, rubber in Selvas • Sertao – ranching region• Petroleum reserve at the mouth• Manaus – Iron ore, navigable • plateau of Mato Grasso – gold reserve

Locations near Amazon river

Mississippi , USA

• Temperate grasslands – Prairies• Wheat, corn and cotton cultivation• Important cites: • Kansas – agriculture• St. Pittsburg – iron and steel• New Orleans – port, ship building

Locations near Mississippi basin

Murray-Darling basin, Australia

• Temperate grassland – downs• Wheat cultivation• Sheep rearing ,Animal husbandry• Wool and dairy production

Location near Murray-darling basin

Landforms on earthMountains (fold and block)

PlateausPlains

Natural Catastrophic events

volcanism

earthquake

Tsunami

complete sequence of processes of creation and movement of magma + creation of volcanic landforms

Volcanism is not random

Reason associated with volcanism is also not random

Volcanism

Geomorpho

• 1st

• Pacific Ring of Fire• O-O convergence• O-C convergence

Distribution of Volcanism

O-O : Volcanic arcO-C :Volcanic mountains

Plate movements

2nd • O-O divergence• Basaltic – peaceful

eruption

Mid Oceanic Ridge

3th • Breaking up of

Mediterranean plates into multiple blocks

• Andesitic eruption• Frequent interaction• Mt. Etna, Mt.

Vesuvius

Mediterranean volcanism

• Mediterranean sea is residual part of Tethys sea

• Tethys sea was located between – Laurasia and Gondwana

• Collision of Africa to Laurasia – breaking up of plates of Mediterranean sea

History of Mediterranean sea

• 4th • Magma From

deep interior -Basaltic

• Fixed place - Plate movement – Island arc

• Direction of plate• Hawaii, Reunion,

Kurile, Aleutian

Hot Spot Volcanoes

Aleutian Islands

Basaltic eruption • Occur at mid-oceanic ridge

and hot spot volcanism• Basalt highly fluid – mobile• Spread across easily• Quite eruption

• Volcanic arcs, volcanic mountains

• Andesite – less fluid – less mobile

• Solidifies at short distance- intense pressure develop inside –explosive

Andesitic eruption

comparison

Basaltic eruptionAndesitic eruption

comparison

Landforms

Extrusive

Volcanic plateau

Volcanic cones

Intrusive

Dykes etc.

Volcanic Landforms

Intrusive Landforms

Intrusive Landforms• Intrusion of Magma in sedimentary rocks• Sills (Horizontal)• Dyke (Vertical)• Laccolith – magma which could not come out• Lopolith – saucer-shaped• Phacolith – shape like waves • Batholith – intrusive granitic rock

Intrusive Volcanic Landforms

Extrusive

Volcanic Plateau

Volcanic cones

Shield volcano

Cinder vol.

Composite vol.

Extrusive volcanic Landforms

• Hot spot volcano on continental crust

• Cracks on continental crust –Basaltic eruption

• Spread across the land • Layer over layer• EX. Deccan lava trapps

Lava plateaus

• Indian plate passed over a hot spot near Reunion Island

• Basaltic eruption• Layer over layers – looks

like steps => Deccan lava traps

• Soil – black soil ‘regur’

Indian Deccan trap

Spatial distribution of Lava Plateau

• Columbia-snake plateau, USA

• Ozark plateau, USA• Parana-Patagonia, S.

America• Adamawa plateau,

Africa• Bie plateau, Africa• Katanga Plateau, Africa

Deccan plateau, India• Arabian plateau• Balkan plateau, Europe• Siberian plateau, Russia• Yunan Plateau, China• Shan plateau, Myanmar• Kimberly plateau,

Australia

List of lava plateaus of the world

Extrusive

Volcanic Plateau

Volcanic cones

Shield volcano

Cinder vol.

Composite vol.

Extrusive volcanic Landforms

• Volcanic Islands (Hot spot)• Highly fluid lava

(basaltic) build dome • Gentle slope• Quite volcano• Volcanoes of Hawaii

Shield / Dome volcano

• O-C collision – volcanic mountains• Less fluid lava

(Andesitic) explode violently• Viscous lava

solidifies at short distance

• Mt. Paricutin, Mexico

Cinder cones

Volcanic mountainsEach new eruption – new layers of ash or lava

Mt. Stromboli, Mt. Vesuvius, Mt. Fuji

Composite Cones

Shield/ dome Cinder Composite

Highly fluid Less fluid / highly viscous

Fluid + viscous

Silent flow Violent eruption

Multiple and violent eruption

Gentle slope Steep slope Highest volcanoes

Small volcanoes

Small volcanoes

Large volcanoes

Types of Volcanic cones

• Geysers =fountains of Hot water

• Ground water heated by shallow source of magma

• Old faithful geyser, Yellow stone park, USA

Geysers

• Hot Spring: • Water reach deep

enough – heated by interior

• Locate any part of the world

Hot Spring

• Geyser – G/w heated by shallow magma source

• Hot spring – g/w heated by either magma source or heated rocks

• Geyser – chamber in interior – pressure – comes out like fountain

• Hot –spring - quite

Difference between geyser and Hotspring

geyser• Geysers are rare• Hot water dissolved with

silica accumulated on surface – gives different colours

• USA, - Yellowstone park

• Found anywhere• They gets different colors

from heat-loving bacteria, like cyanobacteria

• Medicinal values• Can be helpful in harness

geo-thermal energy

Hot spring

comparison

• Heated water is taken out – used for moving turbine – generation of electricity

• Cooled water flown back into interior

Geo-thermal energy

• Difficult to locate a good source of geothermal reservoir with current technology

• Difficult to dig a deep well with hard and hot bedrock

• Harmful gases can escape from the earth interior while exploration – GHG gases and dissolved toxic elements

Limitations of geo-thermal energy

volcanism

earthquake

Tsunami

Sudden movement or vibration in earth’s crust.

Release of the energy due to intense pressure + active internal dynamism of the earth

Earthquake

Geomorpho

1) Shallow focus EQ2) Intermediate focus EQ3) Deep focus EQ

Shallow focus – destructive

Types of Earthquake

At Junction of 3 plates Subduction of Pacific plate

Earthquakes in Japan

1st Collision of Plate boundariesO-O collisionO-C collisionC-C collision

Reasons behind EQ

2nd

Divergent Plate boundaries

O-O divergence MOR

Reasons behind EQ

• 3th• Transverse plate

boundaries• Friction developed

between two plates

Reasons behind EQ

4th Mediterranean sea regionNumerous small platesFrequent interactions

Reasons behind EQ

5th Craton = stable part of crustRe-emergence of old fractures

6th Human Induced 1) RIS2) mining3) Nuclear testing

Reasons behind EQ

volcanism

earthquake

Tsunami

Submarine EQSudden disturbances of underlying plates transmit the shock waves to surface waves

Tsunami

Geomorpho

Normal wavesSpeed – 100 kmphCover shorter distancesWavelength ~100 km

• Speed – 700 kmph• Cover longer distances• Wavelength – > 150 km

Tsunami waves

comparison

• Distance between two crests of troughs = wavelength

• Waves of Tsunami are wider than normal waves of the ocean water

wavelength

• EQ on ocean crust – uplift the water upward

• Tsunami wave generated

• Vessels in the mid-sea cannot recongnise the tsunami waves

• Sea water recede at the shore

Phase 1

• At coast – depth decrease – wavelength decreases – wave height increases

• A huge wall of water – 10-12 floor high created

• Enormous energy released at the shore

Phase 2

• Hit the coast• Tsunami- not a single

wave but multiple waves

• 4th and 8th waves are the most dangerous

• Time lapse between each waves – 15 to 50 minutes

Phase 3

Phases of tsunami

• Tsunami Early warning system- gives warning in 10 minutes of submarine earthquake

• Indian National centre for Ocean Information Sciences (INCOIS),Hyderabad

• To capture Tsunami wave amplitude on 24x7 basis• real time sea-level sensors with bottom pressure

recorders• HF radars for coastal currents• Coastal tide gauge stations

Indian preparedness against Tsunami

Catastrophic events on earth

Their reasons and distributions

VolcanismEQTsunami