1: Introduction to Earth Science Flashcards
Over time, the Earth’s solid center began to decay, composed of ________________.
iron, silicates, and radioactive materials
The ______________, primarily uranium, potassium, and thorium, emitted heat, melting the silicates and iron, forming the Earth’s core.
decaying radioactive materials
There are _________ in the earth which repels solar wind and protects the earth from solar radiation
two magnetic fields
The atmosphere of the earth is ________, which means that it is made up of mainly nitrogen and oxygen
stratified
The earth can be divided into
an outer lithosphere and a plastic asthenosphere
is the layer of air that surrounds the earth. It protects the earth from solar rays. It also circulates the air and gases that plants and animals need to survive.
atmosphere
is made up of living organisms, such as plants and animals. It is important to note that all the biospheres interact with each other.
biosphere
the geosphere is also called?
lithosphere
is made up of the physical earth, such as rocks, magma, and soil.
geosphere / lithosphere
extends from the center of the earth to the dust in the atmosphere, and even includes the sand in the ocean
geosphere / lithosphere
is made up of all the water held on earth.
hydrosphere
The Subsystems of the Earth
atmosphere
biosphere
geosphere
hydrosphere
The Atmosphere
Exosphere
Thermosphere
Mesosphere
Stratosphere
Tropopause
Troposphere
(500 km), this is where the atmosphere merges with space.
Exosphere
(90 km), this is where the space shuttles orbit.
Thermosphere
(50-90 km), this is where meteors burn.
Mesosphere
(12-50 km), this is where the air is stable and is good for planes and jets to fly in.
Stratosphere
(11-12 km)
Tropopause
(0-11 km), the “mixing layer,” all the weather is limited to this layer.
Troposphere
the outermost “skin” of the earth and has various thicknesses.
crust
The ______ crust is under the mountain ranges, and the _____ is under the mid-ocean ridges.
thickest. thinnest
the lower boundary
Mohorivicic discontinuity
_________ separates the crust from the upper mantle. It was discovered in 1909 by ____________.
Mohorivicic discontinuity, Andrija Mohorovicic
two types of crust
the continental crust and the oceanic crust
The crust is composed of just __ elements
8
the most abundant element in the crust
Oxygen
a solid rock layer between the core and the crust
mantle
the mantle is composed of a rock called
peridotite
the ____ mantle sinks and the ____ mantle rises.
cool, hot
Three subdivisions of the mantle
upper, transitional, and lower
The core is an iron-rich sphere with a radius of
3,471 km
The outer core is made of liquid iron, nickel, and sulfur and it’s _______ thick
2,255 km
The inner core is made of solid nickel, iron alloy and has a radius of ______
1,220 km
The universe and the solar system were formed about __________ years ago
4.6 billion
According to the Big Bang Theory, Between ___________, all the matter found in the universe today was found in a small space, a tiny contact point.
13 billion and 15 billion years ago
According to this theory, matter and energy were the same back then.
The Big Bang Theory (1900s)
came about after an explosion.
Expansion
He announced that all of the galaxies that he was studying are moving further and further away from us, at speeds that amount of several thousand miles per second.
Edwin Hubble, 1929
_________ believed the universe was governed by two principles
Fred Hoyle
the universe is uniform in space
the cosmological principle
the universe is unchanging in time
the perfect cosmological principle
Predicts that the universe is expanding, but it also predicts that new matter is being created enough to fill the empty spaces left behind by the universe’s expansion.
The Steady State Theory (1940s)
This theory has been found to be false by astronomers as the average age of stars should be approximately the same if matter is continuously created everywhere .
The Steady State Theory (1940s)
created a new model, since he is a plasma physicist.
Hannes Alfven
___ of the observable universe is made of plasma, which is where the term Plasma Universe is derived from.
99%
An ionized gas that conducts electricity.
Plasma
Discounts the Big Bang Theory and states that the universe is crisscrossed by electromagnetic fields and electric currents.
The Plasma Universe
this theory states that the universe has no beginning and no end.
The Plasma Universe
In the Plasma Universe, the galaxies take as long as ___________ to come together.
100 billion years
The evidence from the Plasma Universe does not come from direct observations of the sky; rather they come from _____________.
laboratory experiments
The size of the earth is about ___________ in diameter, and this was known by the Ancient Greeks.
12,750 km
is brittle and is liable to breaking.
crust
a hot, dense layer of semi- solid rock, denser and hotter compared to the crust because matter is heated by the pressure and temperature inside the earth.
mantle
denser than the mantle because it is composed of an iron-nickel alloy, which is metallic rather than being stony.
core
The core is made up of two distinct layers
the liquid outer core and a solid inner core.
As the earth rotates on its axis, the liquid outer core spins, which creates ____________.
the earth’s magnetic field
is hotter compared to the upper part of the mantle.
deep mantle
composed of semi-solid, hot material, which flows and softens after being subjected to high pressure and temperature.
asthenosphere
is the movement of the lithosphere that influences plate tectonics.
lithosphere
