module 6 Flashcards
define sediment.
A deposit of sand and mineral fragments, usually laid down by water.
Define sedimentary rock
Rock formed when heat, pressure, and chemical reactions cement
What is the Earth’s crust?
Earth’s outermost layer of rock
What is Igneous rock?
Rock that forms from molten rock.
What is plastic rock?
Rock that behaves like something between a liquid and a solid.
What is an earthquake?
A trembling and shaking of the earth as a result of rock masses suddenly moving along a fault line.
Define fault.
The boundary between a section of moving rock and a section of stationary rock.
What is the focus?
The point along a fault where an earthquake begins.
Define epicenter.
The point on the surface of the earth directly above the earthquake’s focus.
The earth is divided into 5 distinct sections. What are they?
atmosphere, hydrosphere, lithosphere, mantle and core.
What 2 regions of the earth does the Moho discontinuity separate?
The Moho separates the lithosphere from the mantle.
The Gutenberg discontinuity separates what 2 regions of the earth?
The Gutenberg discontinuity separates the mantle from the outer-core.
What 3 things make up the lithosphere?
soil, sediment, crust
How does sedimentary rock form?
Sedimentary rock forms when sediments are solidified through heat, pressure, and chemical reactions.
How does igneous rock form?
Igneous rock forms when molten rock solidifies.
What is the rock in the mantle like?
The rock behaves sometimes like a liquid and sometimes like a solid- plastic rock.
What is the main thing scientists observe in order to learn about the makeup of the earth’s interior?
Scientists observe seismic waves. The behavior of these waves tell a lot about the make up and properties of the mantle and core.
Which is solid , the inner or outer core and why?
Inner core is solid because of pressure freezing. The pressure is so great that it forces iron atoms close enough together to become solid.
Where is the magnetic field of the earth generated?
in the earth’s core
What causes the magnetic field of the earth?
a large amount of electrical flow in the core.
What are the “plates” in plate tectonics?
large pieces of the earth’s crust floating on the mantle.
Why would life cease to exist without the earth’s magnetic field?
Without the magnetic field, cosmic rays from the sun would hit the earth. These rays would kill all life on the planet.
What can happen when plates collide?
They can grind past each other, push up against one another or slide under another to form a trench.
What is Pangea?
the scientific term referring to the super-continent that might have existed in earth’s past.
