Tectonics: Global Distribution of Tectonic Hazard

Question 1

Name the major tectonic plates

Answer 1

African
Antarctica
Eurasian
Indo Australia
North American
South American
Pacific

Question 2

How many tectonic plates are there in total?

Answer 2

52

Question 3

Name the minor tectonic plates

Answer 3

Caribbean
Cocos
Arabian
Juan de Fuca
Scotia
Indian
Nazca
Philippine 

Question 4

Two examples of microplates

Answer 4

Nubian
Sunda plate

Question 5

What is an earth quake

Answer 5

Sudden release of energy that generates seismic waves 

Question 6

Where are earthquakes found

Answer 6

Collision, Conservative destructive, divergent


Question 7

Where are volcanoes found?

Answer 7

Divergent and destructive

Question 8

What are hotspots?

Answer 8

Places that are not on a plate Boundry yet have tectonic activities such as Hawaii

Question 9

Where are tsunamis

Answer 9

Destructive plate along the coast

Question 10

Describe oceanic lithosphere

Thickness density, rock type, age, formation, subduction 

Answer 10

Thin, 7 km
more dense 3.3 g/cm³
basaltic
youngest less than 200 million years

Formed at mid ocean ridges from seafloor spreading

subducts

Question 11

Describe continental lithosphere

Thickness density, rock type, age,, subduction



Answer 11

Thicker up to 70 km
less dense 2.7 g/cm³
made of granites ,
oldest more than 1500 million years

does not subduction.
.

Question 12

How is continental lithosphere formed?

Answer 12

Amalgamation of rock formed from volcano’s and hotspots as well as sedimentation

Pass through rock cycle, mountain building and erosion and metamorphism

Question 13

Three ways mantle melts 

Answer 13

Addition of heat, mantle plumes and hotspots.

Addition of water, hydration, melting/slab dehydration at convergent plate, boundaries

less pressure, decompression, melting, divergent boundaries

Question 14

How do convection currents occur

Answer 14

In upper mantle - asthenosphere partially melted - molten magma rises - convection currents occur

Question 15

Describe a Basaltic lava 
Temperature silica, content, gas, content viscosity, where it’s found  lava flow 

Answer 15

1000 to 1200°C
low silica content
Low gas content
low, viscosity
gentle effusive
divergent plate, boundaries, hotspot, and mental plumes 

Question 16

Describe Andesitic Lava

Temperature silica, content, gas, content viscosity, where it’s found lava flow

Answer 16

800 to 1000°C
high silica content
more gaseous
high viscosity,
violent and moderately, explosive eruptions, convergent plate boundaries - hydration melting

Question 17

Why Andesitic Lava more viscous

Answer 17

Do you hydration melting parts of crustless, lisopher and mantle melts together - release minerals 

Question 18

Why do earthquakes occur? 

Answer 18

Along fault lines, plates become locked because of friction

opposing tectonic plates, buildup, pressure and strain

which eventually releases stored energy suddenly as a quake

Question 19

What is the focus?

Answer 19

Focus point of rupture where the strain energy was released from 

Question 20

What is the epicentre?

Answer 20

The point on Earth surface directly above the focus of the earthquake 

Question 21

Describe the global distribution of seismic activity - PDA

Answer 21

distributed, unevenly belts along plate boundaries

examples of pacific ring of fire has the most seismic activity combo of convergent plate in conservative plate boundaries.

Hotspot volcanoes in centre of tectonic plates, intraplate earthquakes

Question 22

Describes a global distribution of volcanicity 

Answer 22

Narrow linear belt along plate, boundaries

continental oceanic, convergence in Mount Saint Helens 

Hotspot working is there such as Hawaii or Yellowstone Deasa more scattered an individual often due to mantle plumes 

Question 23

Describe global distribution of tsunamis

Answer 23

Occurs at the edges where o+o or c+o often caused by earthquakes causing a vertical displacement of water

2011 Japanese tsunami

Tsunamis can occur as a result of a volcanic of activity e.g Krakatau

Question 24

Describe ridge Push and Slab Pull

Answer 24

slap pull - weight of subducting wave pulling a plate in a certain direction
ridge push - force of magma forcing its way thro cracks btw plates and solidifying to form new crust pushing plates apart