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Geography Module-1 Part-1 - Coggle Diagram
Geography Module-1 Part-1
Stars
not scattered regularly in space
they occur in clusters
develop from
large clouds of molecular gas
solar system
all planets revolve
in elliptical orbit
around the sun
Earth shape
squashed shape
known as
Oblate ellipsoid
not a sphere
more accurate representation
Earth´s shape is
geoid
Evidences
supports this
shape of earth?
The circular horizon, Ships visibility, Sunrise and sunset, Lunar eclipse
International Date Line
cross from east to west
loses a day
because east is America west is Japan
180 ̊ meridian at
Bering Strait, Fiji, Tonga
Latitudes and Longitudes
distance btw Meridians of longitude
shorter towards pole
farthest apart at the equator
Latitude are parallel
to the equator
create small variation
away from equator to North and South Poles
east-west extent
decides time zones
Earth’s inclination
axis of earth
inclined to plane of ecliptic at angle of 66º1/2
Earth’s tilted axis 23.5º
causes the seasons
North Pole
tilts toward the sun its summer
in Northern Hemisphere
receives 24 hrs of daylight
for a few months in summer
total darkness for months in winter
Earth's equator only
receive about 12 hrs of light each day
Equinoxes
equal amount of daylight and darkness
at all latitudes
23rd September and 23rd March
summer solstice
occurs when sun directly
over the ToC, located at 23.5 latitude North
21st June
winter solstice
occurs when sun directly
over the ToC at 23.5º latitude South
22nd December
revolution around the sun
earth farthest from the sun
152 million km on 4tth July
called
Aphelion
earth nearest to the sun
147 million km on 3rd Jan
called
perihelion
Dawn & Dusk & Twilight
Dawn occurs before sunrise
before the top of the sun
reaches the horizon
Dusk occurs after sunset
once the top of the Sun
has passed the horizon
Twilight period between
dawn and sunrise or
dusk and sunset
light is still visible in the sky
due to sunlight scattering
off the atmosphere
Earth Crusts
Oceanic crust
found under oceans
about 4 miles thick
still being created
forms brand new segments
of oceanic crust
heavier than continental crust
composed
different types of basalts
SIMA stands for
Silicate and Magnesium
Continental crust
6 and 47 miles thickness
older than oceanic crust
Quebec Canada
found 5 billion year old rock
composed
different types of granites
SIAL stands for
Silicate and Aluminum
Earth’s mantle
mostly composed of
Peridotite
outer silicate solid crust
highly viscous
liquid outer core and solid inner core
less viscous
Earth´s Core
composed mainly
iron and nickel alloy
outer core liquid
adequate to melt
iron and nickel alloy
Inner core solid
temp higher than outer core
Earth's layers
crust and upper portion of mantle
part of single geologic unit
called
lithosphere
Outgassing
release of gas that was
dissolved, trapped, frozen, or absorbed
in some material
mantle solidified
if material stayed in liquid phase
Earth´s crust become brittle
process of differentiation
formation of crust, mantle, and core
Evolution of Lithosphere
due to gradual increase
in density the temp has increased
allowed heavier materials
like iron to sink
towards core
and lighter ones moves
towards surface
Isostasy equilibrium
state of gravitational equilibrium
btw Earth´s crust or litho and mantle
crust floats at elevation
depend on its thickness and density
not all region of earth
are balanced in isostatic equilibrium
Earth´s Crust composed of ig,meta,sedi- rocks
most abundant rocks
in the crust are igneous
formed by cooling of magma
e.g. granite and basalt
formed from
solidification of molten rock material
igneous rocks
high proportion of silica
called acidic igneous rocks
basic IG-RO
denser and darker in color
Intrusive
crystallize below earth surface
slow cooling
e.g. diorite, gabbro,
granite, pegmatite, and peridotite
extrusive
erupt onto the surface
cools quickly
form small crystal
e.g. basalt, dacite, obsidian, pumice, rhyolite, scoria, and tuff.
andesite.
Metamorphic rocks
undergone drastic changes
due to heat and pressure
e.g. Slate and Marble
Sedimentary rocks
accumulation of material
at Earth´s surface
e.g. Sandstone and shale
Laccolith
mass of igneous rock
intruded btw sedimentary beds
Sill
Intrusion of molten magma
made horizontally
along the sedimentary rocks
called sill
Dykes
Narrow walls of igneous rocks
within sedimentary layers
injected vertically called Dykes
earth’s volcanoes
Calderas
are most explosive
Composite volcanoes
high viscous and cooler lava
than basalt
and explosive volcanoes
Shield volcanoes
mostly made up of basalt
very fluid lava
and spread to large distance
and don´t attain
much height
Dome volcanoes
lava is thick and sticky
cannot flow very far
cools and hardens
Flood basalt
outpour highly fluid lava
flows for long distance
e.g. deccan traps
tectonic activity
responsible for formation and destruction
of crustal materials
plates move
horizontally over
asthenosphere (mantle) as rigid units
slow movement of hot, softened mantle
lies below rigid plates
driving force behind
plate movement
discontinuities
Conrad discontinuity
btw upper and lower crust
Mohorovicic discontinuity
btw lower Crust and upper Mantle
Earthquake waves
Velocity of P waves is more below
Repiti discontinuity
btw upper and lower mantle
Gutenberg discontinuity
btw lower mantle and outer core
Earthquake waves
Velocity of P wave decreases
and S wave completely
Lehman discontinuity
btw outer and inner core
Earthquakes
Point where the energy released
is called hypocenter
first point to experience
the waves on surface
is called epicenter
Plate Boundary
Divergent
plates are moving
away from one another
this occurs above
rising convention currents
thinning of lithosphere, rift valley, shallow earthquakes, fissure volcanoes
underwater and form
submarine mountain ranges
shows similarities
in terms of period of formation
chemical compositions and magnetic properties
convergent
when 2 plates come together
chain of volcanoes
often forms parallel
powerful earthquakes
creating
continental crust
and oceanic crust is destroying
transform
2 plates sliding past each other
split into pieces
and carried in opposite directions
creating
linear fault valley
or undersea canyon
earthquakes are common
crust is cracked and broken
but is not created or destroyed
Diastrophism
process of deformation of earth´s crust
involves folding and faulting
all process
move, lift, or build up portions
comes under diastrophism
Orogenic processes
mountain building through
severe folding and affecting
long and narrow belts of earth´s crust
Diastrophism
covers movement of solid crust material
volcanism
covers movement of molten material
Continental Drift Theory
continental landmasses
were “drifting” across the Earth
evidence to prove
matching shorelines of continents
presence of fossils
deposits across continents
continents are drifted
by tidal force
Mountains
Block Mountains
due to earth movements
at plate boundaries
place stress and tension
on crustal rocks
get fractures
Tensional Forces occurs
earth crusts are forced
to move apart from each other
cause central portion
let down btw
2 adjacent fault blocks
Compressional Forces occurs
when the earth crusts
forced to move
towards each other
Rift valleys
developed either
tensional or compressional forces
long, narrow depressions
on earth surface
faulting takes place
because of tension or compressional forces
lengthen or shorten the earth´s crust
causing section
subside or rise above surrounding level
Fold Mountains
mainly found at
convergent plate boundaries
destructive in nature
occur along plate margins
continent-continent and
continent-ocean margins
up-fold waves
called anticlines
down-folds
called synclines
Residual Mountains
formed from already existing mountains
which are lowered
by agents of denudation
e.g. Aravalli mountain and Parasnath mountain
weathering
Exfoliation
onion peeling
weathering process
surface layers of rounded boulders
gradually split off
layers looks like
layers of onion
its in-situ process
result of
and due to temp change
mechanical or physical weathering
Spheroidal
process of cracking and splitting off
curved layers
from spherical boulder
Chemical Weathering Processes
caused by rain water reacting
with mineral grains in rocks
to form new minerals and soluble salts
tropical countries
heavy rainfall and warm climate
both promote rapid chemical reaction
while dry climate
inhibits chemical weathering
hydrolysis and oxidation
first stage in production of soils
Red color of iron
upon oxidation turns
to brown or yellow
upon reduction turn
to greenish or bluish grey
Mass Movements
aided by gravity and
no geomorphic like
running water, glaciers, wind, waves
weathering
not a pre-requisite for mass movements
though it aids
mass movements
active over
weathered slopes rather than
over unweathered materials
physical weathering
Weathering describe
breaking down or dissolving of rocks and minerals
on surface of earth
agents of weathering
Water, ice, acids, salts, plants, animals, and changes in temperature
also known as disaggregation
causes rocks to crumble
Seismic waves
Body waves
travel through the earth´s inner layers
P-Waves
move through solid rocks and fluids
particles move in
same direction that wave is moving in
S-Waves
slower than P-Wave
only move through solid rock
surface waves
can only move along the surface or crust
lower frequency than body waves
responsible for
damage and destruction
Rayleigh
Waves
rolls along the ground up and down
like a ocean wave
much larger than
other waves
shaking felt in earthquake
due to Rayleigh wave
Epeirogenic movement
upheavals or depression of land
exhibiting undulations
long wavelengths
and little folding
Eurasian plate consists
both oceanic and continental plates
factors of soil formation
Parent material, Climate, Topography, Organisms, and Time
Erosion
natural process of removal
and transportation of weathered material
from its original location
and deposit in new environment
Playas
erosional landforms
created by winds
contain good deposition of salts
Mushroom Rocks
easily susceptible to wind deflation and abrasion
agents of erosion include
Running water, ground-water, glaciers, wind, waves and gravity.
Stalactites
depositional landforms
by groundwater
Karst region
example of limestone and chalk landform
absence of surface drainage
most surface water has gone underground
only flow over limestone
for short distance and
then disappear underground
solubility of limestone in water and
weak acid solutions
leads to karst landscapes
Desert landforms
Abrasion
responsible for scratching, polishing, and worn away of rock surfaces
very small particles of rocks
hit against the rock surfaces
Deflation
process involves
lifting and blowing
away of loose materials
such as sands, pebbles
from the ground
result in
lowering of the land surface
to form large depressions
called deflated hollows
Attrition
wind-borne particles
roll against one another
in collision
they wear each other away
their sizes
greatly reduced
Denudation
processes that cause
wearing away of earth´s surface
by moving water, ice, wind, waves
leading to reduction in elevation
and in relief of landforms
word of 'denude'
means to strip off or to uncover
Weathering, mass wasting/movements, erosion
and transportation
included
Solar and Lunar Eclipses
LE occurs
when the moon passes
through earth´s shadow
only during in full moon
its mean
earth comes btw sun and moon
block the sun´s rays
from directly reaching the moon
when the moon is on
far side of the earth
from the sun
more common than SE
last about an hour
SE only occurs
during a new moon
when the moon moves
btw earth and sun
3 celestial bodies
form a straight line