Hello! had volleyball today during pe lesson and my wrist area was kind of bruised. seemed like someone slap my arm a thousand times hehehe. but it was kind of fun and sad because this will be the last volleyball lesson with mr desmond wong and mr i forgot his surname. and followed by that would be 2.4km run which i hate the most. like seriously. im like already dying after i run about 100m. my thigh muscles would start to feel sore :-( then will get stitch also. im a lousy runner hahaha.
currently studying for geog though im just putting the notes in front of me hahahha. shall post the stuff i need to study over here so that i can study in the night later if i want to cus i can't on the light and study, my mum would stab me. well, i know that would affect my eyesight but hey i want good grades and this is the first time im going to do this omg. im a studying-in-darkness virgin. LOL what an example.
anyway, im a lousy friend omg. didn't give any presents to my friends during their birthdays. i should change already, and start saving money soon. like so bad. yeah and i hope tomorrow's test would be easy please, pretty please, handsome please, ugly please, cute please? and i would complete my chemistry worksheet by then because I DON'T HAVE ENOUGH TIME NOW. if it's my mum, she would tell me that everyone has 24 hours and its depending on how you use it, if you waste your time then you've less time to spend.
i think im currently on the sad pms mood. did i ever tell anyone i don't get angry even when i pms? i just become sad hahah. okay shall start typing my geog stuff already.
mah bruised arm if you can see properly.LOL i'm tired after typing all these down and now im going to sleep instead hahahha.
Gudbye.
GEOGRAPHY .
-A volcano is a landform formed by magma ejected from the mantle onto the earth's surface.
-Vulcanicity is the upward movement of the magma both into the earth's crust and onto the earth's surface.
-Viscosity refers to the lava's resistance to flow
-Volcanoes vary in shapes and sizes due to the characteristics of the lava
Structure of a volcano
Parts of a volcano
- Magma is molten rock found below the earth's surface and builds up within the crust to form a magma chamber.
- Magma chamber : A reservoir of molten rock beneath the earth's crust
- Vents are openings in the earth's surface with a pipe leading into the magma chamber.
- Magma that is ejected onto the surface is known as lava.
-Crater is the bowl shaped opening
- Caldera : the summit of a volcano may be blown off during an explosive eruption, the sides of the crater collapse inwards due to the loss of structural support, forming a large depression known as a caldera.
Formation of volcanoes
- When temperature becomes too great, mantle becomes molten forming magma.
- By rising magma contains gases like sulphur dioxide and carbon dioxide.
- Magma and gases are kept under pressure within the earth's crust.
- Pressure is released when folding or faulting at plate boundaries creates vents, cracks or fissures.
- Together with other volcanic materials like ash, cinder, dust, smoke and gases, magma pours out through vents and fissures and accumulate as lava, ash and cinder layers around the vent, building up a cone-shaped or dome-shaped mountain.
The nature and composition of Lava
Basic lava :
- 1100 - 1200'C
-Flows easily and quickly
- Low in viscosity = low in silica
-Solidifies less quickly
Acidic Lava :
- 800 - 1000'C
- Flows slowly, resists flow
-High viscosity
-Solidifies more quickly
TYPES OF VOLCANOES
Shield Volcanoes
- A gentle sloping volcano that is flat near the top.
-Usually formed from fluid basic lava, low in viscosity, that flows over a wide area before solidifying
-Cools and solidifies slowly
- Frequent but gentle and quiet eruptions
Eg. Mauna Loa , Hawaii ( active
Stratovolcanoes/ composite volcanoes
- A highly common volcano which consists of alternating layers of ash and cinder and lava.
- Steep towards the top and gentler at bas
- Large and cone shaped
- Violent eruption of ash and cinder is followed by lava
-Wind sorting of volcanic material by size accounts for appearance
- Smaller particles are blown further away from the crater
- Violent explosions
-Lava may escape via secondary cones
- Stratovolcanoes develop from successive eruptions of lava and ash.
Risk of living near volcanic areas.
-Destruction by volcanic materials
-Landslides
-Pollution
-Effects on weather
Benefits of living near volcanic area
-Fertile volcanic soil
-Precious stones and minerals, building materials
-Tourism
-Geothermal energy
Distribution of volcanoes
-Often found along or near plate boundaries when oceanic and continental plates meet as well as when oceanic and oceanic plates meet
-Also found at hotspots, far away from plate boundaries
Impact on earthquakes
-Collapse of infrastructure
-Fires
-Landslides
-Tsunamis
-Loss of lives
-Economic losses
-Spread of diseases
-Trauma
-Job disruption
