Earth Sciences Set 1 Flashcards
What is geology?
Geology is the study of the earth, the rock that makes it, and the processes that change the earth
What is the core?
The core is the centre of the earth.
What are the two layers of the core?
The two layers of the core are the inner core and the outer core.
Describe the inner core.
The inner core is 1216km thick, 4000degrees C, solid iron with some nickle
Describe the outer core.
The outer core is 2270 km thick, 3600 degrees C, LIQUID IRON with some nickle.
What is between the inner and outer core?
There is a liquid-solid boundary between the two layers.
Why is the outer core liquid and not the inner core?
The outer core is liquid because there is less pressure pushing on it that the inner core.
How does the solid inner core move?
The solid inner core rotates within the liquid outer core.
How is the earth magnetic?
The rotation of the solid iron and nickle inner core generates the magnetism.
What is the source of the earth’s internal heat?
The heat comes from radioactive materials that release heat as they break down. This happens in the core.
What is outside the core?
The mantle is outside the core.
How many parts does the mantle have?
The mantle has two parts, lower and upper
Where is the asthenosphere?
The asthenosphere is in the upper mantle
What is the mantle made of?
The mantle is made of hot, dense, semi-solid rock.
Describe the lower mantle
The lower mantle is 2885km thick and is 84% of the earth’s total volume. Cooler than the core at 3000 degrees C.
Which is denser (more solid) the upper or lower mantle?
The lower mantle is denser than the upper mantle.
What is between the upper and lower mantle?
The transitions zone is between the two mantle layers.
Where is the mesosphere?
The mesosphere is in the lower mantle.
How far below the earth’s surface is the transition zone?
The transition zone is 400-660km below the surface of the earth.
How big is the upper mantle?
The upper mantle goes from the crust down to about 400km below the surface.
What does asthenosphere mean?
Asthenosphere means without strength and ball… a soft flowing rock.
What floats on top of the asthenosphere?
The crust floats on top of the asthenosphere.
What is the crust?
The crust is a solid layer of rock.
Describe the crust.
The crust is 5-80km thick, outside temp to an internal temp of 500degrees,
Where are the thickest parts of the earth’s crust?
the continental crust is the thickest part of the crust.
Where are the thinest parts of crust found?
The thinest parts of the earth’s crust are found on the ocean floor….the ocean crust.
Do people know more about the universe or what’s below the earth’s crust?
They know more about the universe.
What are seismic studies?
Seismic studies are the studies of the energy waves made by the earth when it shakes…an earthquake monitor
What are the energy waves of the earth called?
The earth’s energy waves are called seismic waves.
How do we get direct evidence of the composition of the earth?
We get evidence of the earth’s make up by digging deep.
What did science fiction writer, Jules Verne, think was at the center of the earth?
Verne thought dinosaurs lived at the center of the earth. He was wrong.
Why can we not know for sure what is at the centre of the earth?
We can’t get to the center of the earth, so we don’t know for sure what is there.
Why do we know more about the moon than the center of the earth?
We can get to the moon but not the center of the earth.
What was Project Mohole?
Project Mohole was a race to dig as deep as possible.
Why was it named Project Mohole?
It was short for Mohorovic Discontinuity, which is the boundary between the curst and the mantle.
What is the boundary between the crust and the mantle called?
The boundary between the crust and the mantle is called the Mohorovic Discontinuity
Who discovered the Mohorovic Discontinuity?
Scientist Andrija Mohorovicic found the Mohorovic Discontinuity.
What was Project Mohole?
To dig five holes in the ocean floor as deep as possible.
Why was Mohole dug in the ocean and not on land?
The ocean floor crust is the thinest place to dig.
Why was Mohole a failure and a success?
They did not continue to dig below 183 m, but they learned a lot about ocean deepwater drilling.
What was the Kola Superdeep Borehole?
Russians drilled into the Kola Peninsula near Finland, They got to 12 262m deep and it is the deepest artificial point on earth. (not naturally made)
What did they learn in Kola?
At this depth, the crust is 180 degrees not the 100 that they thought, the rock was turning to goo so they had to stop.
In 2011 what was drilled?
In 2011 the Russians drilled the longest extended-reach well (long, diagonally slanted) 12 345m to get oil and gas at Sakhalin island.
What is the IODP and the ship Chikyu?
Chikyu is the largest research ship ever build and aboard is the Integrated Ocean drilling program (IODP)
What does the IODP hope to achieve?
The IODP hope to drill to the core and have already set a new drilling research hole record and got to 2466 m in 2012
Why is it important to drill to the core?
Scientists do not know a lot about the core and their assumptions from seismic data may not be correct. They hope to use their learning to better predict earthquakes and tsunamis.
