tectonics Key Words Definitions

Question 1

what was the magnitude of the 2015 Nepal earthquake?

Answer 1

7.8 magnitude

Question 2

define natural hazard?

Answer 2

a naturally occurring process or event that has the potential to affect people

Question 3

define natural disaster

Answer 3

a major natural hazard that causes significant social, environmental and economic damage

Question 4

define vulnerability

Answer 4

the ability to anticipate, cope with, resist and recover from a natural hazard

Question 5

how was nepal vulnerable?

Answer 5

one of the poorest countries in the world 197th on GDP
Weak infrastructure 
tourism is the main money maker
buildings not built to prevent collapse 
most earthquake prone area in the world

Question 6

what are the 4 plate tectonic theories?

Answer 6

1) mantle convection 2)slab pull 3)subduction 4)sea floor spreading

Question 7

describe the theory of mantle convection

Answer 7

heat produced by the decay of radioactive elements in the Earths core heats up the lower mantle - creating convection currents. The hot liquid, magma currents move in a circle in the asthenosphere causing plates to move

Question 8

describe the tectonic theory of slab pull

Answer 8

NEWLY FORMED oceanic crust at mid ocean ridges becomes DENSER and THICKER as it cools. This causes it to sink into the mantle, pulling the rest of the plate down to subduct

Question 9

describe the plate tectonic theory of subduction

Answer 9

as two plates move towards each other, one slides under the other into the mantle, where it melts in an area known as the subduction zone

Question 10

describe the plate tectonic theory of Seafloor Spreading

Answer 10

hot magma is forced up from the asthenosphere and hardens - forming new oceanic crust and pushes the plates apart

Question 11

what are the three main layers of the earth?

Answer 11

the core (inner and outer)
the mantle 
the crust (oceanic and continental)

Question 12

facts about the inner core

Answer 12

hottest part of the earth 6000°c
made out of mostly iron
1200km

Question 13

facts about the outer core

Answer 13

semi molten
mostly consists of iron and nickel
temp: 4500-6000°c
2250km

Question 14

facts about the mantle

Answer 14

2900km

upper part is solid but below is semi molten (asthenosphere on which tectonic plates ‘float’)

Question 15

facts about the crust

Answer 15

oceanic: a thin dense layer (6-10 km thick)
continental: an older, thicker layer (45-50km) makes the earths landmasses. less dense than oceanic

Question 16

Eyjafjallajökull facts

Answer 16

1) 2010
2) 100,000 flights were cancelled
3) airlines lost $1.7 billion revenue
4) 30% of global air capacity was cut
5) European economy lost $5 billion as a result of the disruption

Question 17

primary hazards of volcanoes

Answer 17

lava flows
pyroclastic flows
Tephra and ash falls
gas eruptions