geo term 2

what are earthquakes?

they are the sudden vibrations of the Earth’s surface due to the collision of the plates​

the distribution of earthquakes are:

• The Circum-Pacific belt –the Ring of Fire​

• The Mediterranean-North Indian Belt​

• The Mid-Atlantic belt​

what are parts of an earthquake:

• epicenter

• plate movement

• focus

• seismic waves

whats the ‘epicenter’?

the point on the Earth’s surface which receives the strongest shock waves​

whats the ‘focus’?

the point in the Earth’s crust where an earthquake originates​

whats the ‘fault’?

its a break in the rocks that make up the Earth’s crust ​

whats the ‘seismic waves’?

the are vibrations that travel through the Earth carrying the energy released during earthquake

the primary impacts of earthquakes to people and the environment are:

• building collapse

• road cracks

• furniture falls over

• topped bridges

• windows shattered

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the secondary impacts of people and the environment are:

• fires caused by the broken glass

• diseases caused by dead bodies

• contaminated water supplies

the long term effects are of earthquakes on people and the environment are:

• loss of jobs for people

• crops damaged

• electricity lines were brought down

• schools damaged

• tress troppied

what can be the strategies to reduce the impacts of earthquakes?

• install adequate warning system

• construct earthquakes

• educate the public

• earthquake drills

• emergency plans

river transport:

a river uses its energy to carry or transport eroded materials

what are the 4 river transport processes?

• traction

• saltation

• suspension

• solution

what are the 4 river erosion?

• attrition

• hydraulic action

• solution

• corrasion/abrasion

what is corrasion/abrasion?

the grinding at rock fragments carried by the river against the banks and bad at the channel

what is attrition?

its the knocking of the rock fragments in the water against each other

what is solution/corrosion?

its the process by which water in the river reacts chemically with soluble minerals in the rocks

when does river deposition occur?

deposition occurs when a river lacks enough energy to carry its lead and bumps the sediments

what are the necessary conditions for river deposition to deposit the sediments?

• discharged from the river drop

• floods subside

• Inside a meander bends, and when rivers enter the sea, it slows the current

how do rivers reduce their speed?

rivers reduce their speed when they enter flat land

what river feature is this

v-shaped valley and interlocking spurs (upper course)

how does the v-shaped valley form?

the river forms a winding course as the river cuts downwards forming a v-shapes valley

what river feature is this

waterfall (upper course)

how are waterfalls formed?

it forms when a river flows across rocks or different resistance

what river feature is this

plunge pool (upper course)

what river feature is this

gorge (upper course)

how do gorges form?

the river forms faster than the sides can be worn away.verticle erosion continuous to produce a narrow. steep-sided valley

what river feature is this?

meander (middle course)

how do meanders form?

theyre formed when the moving water in a river erodes the outer banks and widens the valley

what is a meander gets cut off from the main stream?

it forms and oxbow lake

what are some 3 characteristics of river in the middle course?

• a greater discharge

• erosion

• deposition

what are some 3 characteristics of river in the lower course?

• flat and wide floor plain

• an even greater gradient

• very wide and deep shallow

how does number 1 form?

with constant erosion of the concave banks and deposition on the convex banks, a meander gets separated by a narrow of land

how does number 2 form?

when the neck becomes more narrow with continued erosion and deposition

how does number 3 form?

when the river breaks through the narrow neck and flows straight through the channel

how does number 4 form?

the meander that is cut off forms an oxbow lake

what are floodplains?

its the flat piece of land in the lower section of the river

what are levees?

levees are raised edges along riverbanks.

how are levees formed?

they are formed when flooding happens repeatedly and heavier soil build up on the sides of the river

what is a ‘delta’

its a low-lying area of landformed at the mouth of a river where the stream loses velocity and drops part of its sediment load

how are deltas formed?

theyre formed when its deposited more quickly than the sea’s currents and tides remove it

what is a river system?

it refers to many inter-connected streams if different sizes and lengths

whats the drainage basin?

its the area drained by the river system

whats a watershed?

its a stretched of land that forms the boundary around a drainage basin

whats drainage density?

its the total length of a river per unit area in a drainage basin

formula: total length of river distribution
area of the surface of the drainage basin

what pattern is this

dendritic pattern

how is a dendritic formed?

its formed by the river network of the main river and it often resembles a tree

what pattern is this?

trellis pattern

how are trellis patterns formed?

theyre formed by bricks in a wall

what pattern is this?

radial pattern

how are radial patterns formed?

radial patterns radiates from the top of a hill or volcanic cone

what pattern is this?

centripetal pattern