One Note - plate margins and magma plumes

Question 1

where is Hawaii located?

Answer 1

15,000 miles in the pacific ocean

Question 2

how much taller is Hawaii to Everest?

Answer 2

2 times taller

Question 3

whats the most active volcano in Hawaii?

Answer 3

Kellaway which has been continuously been erupting since 1943

Question 4

what was the first Hawaiian island?

Answer 4

Kaui and since then many islands have built up together from it

Question 5

what is a magma plume? full

Answer 5

A magma plume is a hotter area of molten rock compared to the lava from the rest of the sea floor which comes from deep within the Earth’s mantle.

This vertical column of heated material rises because of the lower density which is fuelled by radioactive decay within the mantle.

As the magma plume reaches the Earth’s crust and melts it creates a hotspot.

The magma plume itself stays stationary.

Over time, as the Pacific Ocean plate moves over this hotspot, a chain of volcanoes forms, such as the Hawaiian Islands.

These islands feature shield volcanoes, which have gentle slopes shaping like a shield as the lava can travel further due to the low viscosity of lava that comes from the plume.

Question 6

where does a magma plume come from?

Answer 6

deep within the earths mantle

Question 7

why does the vertical column of heated material rise?

Answer 7

because of the lower density which is fuelled by radioactive decay within the mantle

Question 8

what happens as the magma plume reaches the Earth’s crust?

Answer 8

melts and creates a hotspot

Question 9

what is the benioff zone?

Answer 9

where the subducted plate is melting

Question 10

what percentage of volcanoes are found on plate boundaries and what percentage is found on magma plumes?

Answer 10

95% of volcanos are on plate boundaries and 5% magma plumes

Question 11

how many active and dormant volcanoes are there?

Answer 11

1500

Question 12

how many active volcanoes does indonesia have?

Answer 12

76

Question 13

what are the features of a cinder cone volcano?

Answer 13

• Common
  
  • Less dangerous than the others
  • 1000 feet tall single eruption
  • Paricutin Mexico

Question 14

what are the features of a shield volcano?

Answer 14

• Big not dangerous
  
  • No pyroclastic material
  • Tall broad
  • Less steep slopes
  • Less viscos lava
  • Multiple eruptions

Question 15

what are the features of a strata volcano?

Answer 15

• Big
  
  • Rise 8000-10000 feet
  • Explosive
  • Pyroclastic material
  • Pompeii
  • Symmetrical
  • Mount fuji