plate boundaries
What is a subduction boundary ?
when one lithospheric plate plunges beneath another plate
Where is earthquakes form in & its strongest boundary?
formed at ALL plate boundaries, strongest at transform boundaries
Describe the inner core
a dense sphere of solid iron and nickel at the center of Earth
What can form over hot spots ?
What wave travels faster R waves or L waves?
L waves
What is a Transform boundary?
a boundary between two plates that are sliding past each other
Describe what a fault is
the crack between two sliding plates, occurs at transform boundaries
What is beneath the lithosphere ?
asthenosphere
where is a well known hotspot?
hawaii
what can s waves travel through?
can travel through solid material
Describe the theory of plate tectonics
The theory that the lithosphere is divided into tectonic plates that move around on top of the asthenosphere
Where do ridges form ?
occurs at divergent boundaries, where the land separates enough for magma to be released and a series of close mountains are created by cooled magma
What is below the mantle?
outer core
how many hotspots is there?
125
describe subduction zone
where an ocean and continental boundary meet
Divergent boundaries
Where two plates are moving apart, magma comes up to create new crust
what boundary do volcanoes form in ?
formed at divergent and convergent subduction (at boundaries where magma is released)
Describe the Earths crust
thin, rocky outer layer & various in thickness
What is a plume in a hotspot?
Radioactive decay in the core
what is a P wave?
energy in rock moves parallel to the direction of the waves
Describe a convergent boundary
The boundary between two colliding plates, often associated with mountain building, ocean trenches and volcanic islands
how do volcanoes affect the global climate ?
by lowering the earth's temperatures
what are the 2 parts of the Earths crust?
Continental & Oceanic
Describe hotspots
A small area of the Earth's crust where an unusually high heat flow is associated with volcanic activity, A weak spot in the middle of a tectonic plate where magma surfaces; forms a volcano
Where is the Ring of Fire located?
around the Pacific plate