L1 - Erta Ale Flashcards
Describe the structure of the earth
Inner core (solid), outer core (liquid), Mantle (molten rock, liquid), Upper mantle/ Lithosphere (semi-solid),Crust (solid)
What the device used to measure radiation?
A geiger counter
What feature of volcanos builds pressure leading to a more violent eruption?
A plug
What waves are used to measure how large each section of the earth is?
S waves and P waves.
What is the crust?
The top layer of the Earth, it is a dry brittle surface of recently cooled lava.
What are the two types of tectonic plates?
Oceanic and continental
What is the lithosphere?
The top of the mantle and all of the crust, together form the mantle.
What is the asthenosphere?
Sticky, viscous, dense rock – slowly starts to move. This causes plate tectonics (The movement of plates), its what the plates rest on.
What causes convection currents?
The temperature gradient in the mantle, as you get closer to the core, its hotter.
What is the Magnetosphere caused by?
Its produced by the spinning nickel and iron inner core, which produce a magnetic shield protecting the earth from solar radiation
What are the 3 types of plate margins?
Constructive, destructive, transform
What process usually causes the formation of a trench?
Subduction between 2 Oceanic pates
Where and how is new land formed?
New land is formed at a divergent, constructive plate boundary, as the 2 plates move apart, the magma from below seeps up and dries to fill the gap.
What natural disaster often occurs at a transform plate margin?
An Earthquake
What is the asthenosphere?
The asthenosphere lies beneath the lithosphere and consists of partially molten rock. S waves passing through this layer are significantly slowed
Name a constructive plate margin
The mid atlantic ridge
What landscape features are often found at convergent plate margins?
Trenches, Mountain Ranges, Subduction Zones, Volcanos
What happens to the subducted plate at a convergent plate margin?
The plate is driven down into the mantle where it melts into magama, then that magma rises up and will force its way out of a volcano
Name a mountain range found at a convergent plate boundary.
The Andes mountains, the Himalayas
What factors influence lava viscosity
Silica rich lava is a thin, runny viscosity, usually erupted from active volcanoes
Whilst granite rich causes violent eruptions of thick lava from mainly dormant volcanoes
