Transcript Slide 1 - Educator Pages

Introduction to Earth and Space Science
Earth and Space Science are split into several different sciences…
Geology-study of the physical Earth
Oceanography-study of the Earth’s seas
Meteorology- study of Earth’s atmosphere
Astronomy- Study of the Universe
What is the Earth?
The Earth is
… a large mass of solid, liquid, and gaseous matter
…that revolves around the sun
…rotates on an axis
…and has one solid moon that revolves around it
What is the difference between rotation and revolution?
Rotation- turning around an axis
Revolution- moving around another object
Earths rotation affects us every day.
-it gives us our 24 hour day
-it causes us to alternate between night and day
Earth’s revolution also affects us.
-Earths axis causes us to have seasons as it revolves around the sun.
Inside the Earth
What is the earth made of?
The earth is divided into three main layers, the crust, the mantle, and the core.
The Core - dense center of the earth made mostly of iron with small amounts of nickel.
-it has two parts, the inner core (solid) and the outer core (liquid)
-the movement of the metals inside the core create earth’s magnetic field
The Mantle-molten rock layer between the crust and the core
-it has three parts, the mesophere (part extending down to the core), the
asthenosphere (part on which the pieces of the lithosphere slide), and the lithosphere
(the rocky crust and mantle with which it interacts)
The Crust- thin, solid outer layer of earth above the mantle and below the
atmosphere.
-There are two types of crust, continental (thicker but less dense part on
which we live) and oceanic (thinner but denser between the continents)
What are tectonic plates?
The Lithosphere is broken into pieces called tectonic plates that float and move on
the denser Mantle.
These plates include some oceanic crust, continental crust, and some of the
mantle beneath them.
Earth’s Tectonic Plates
What is going on inside the
earth?
• The particles of fluids (like most of the
inside of the earth) can move freely.
• They move from warmer areas to cooler
areas, from higher pressure areas to lower
pressure areas.
• The hotter things become, the more
particles spread out, the less dense they
become and the better they float…
This means…
• That the liquid outer core flows in a current
around the inner core.
– When metals spin close to other metals,
electrons start to be pulled around and a
magnetic field is produced.
• That the fluids in the mantle heat up and
rise towards the surface. As they near the
surface, they cool and sink back down.
– These patterns of rising and falling are called
convection currents
• Moving fluids in the mantle push around
and occasionally break through the
tectonic plates.
– This results in continental drift, earthquakes,
and volcanoes.
• The magnetic field produced by the
spinning core protects us from radiation
from the sun and helps maintain our
atmosphere.
Climate, Weather,
and the Atmosphere
One way to describe a place is to examine its climate. What is a climate?
Climate is similar to weather but more general and over a longer period.
Describing what it is like right now is describing the weather.
Describing what it is usually like is describing the climate. Climate is the
average weather conditions for a particular area.
The two things that make one climate different than another is the precipitation (amount
and how it falls) and temperature (how hot, cold, and variable).
Precipitation- it could rain a small amount frequently, it could rain a
large amount seasonally, or it could barely rain at all.
Temperature- it could be cold most of the year (polar), it could be hot
most of the year (tropic), or it could change a lot being hot in the
summer and cold in the winter (temperate).
Climate affects the type of plants that grow in a particular area and the type of soil.
Climate is decided by the amount of solar radiation (heat from the sun), the
movement of the atmosphere, and the movement of the oceans.
-The oceans and atmosphere move because of temperature gradients
caused by uneven solar radiation (different parts of the earth getting more heat
from the sun) and the rotation of the earth.
***more detail on ocean and atmospheric currents will come later in the unit
How much sun a place gets is
decided by its distance from the
equator (latitude) and the
revolution of the earth, on an
axis, around the sun (causing
seasons).
Elevation can also affect temperature.
Atmospheric pressure decreases at higher elevations, so temperatures also
decrease.
Large bodies of water also affect temperature.
Water transfers heat slower than land does, so areas around large bodies of water
have more moderate temperatures.
Because climate varies so much place to place, areas of earth are categorized
into different biomes.
-Biome- a region of earth with a certain type of climate and certain types
of plant communities.
Color Quiz
-The atmospheric conditions right now is an area’s ____________.
Blue- weather
Red- climate
-Both precipitation and ____________ affect climate.
Blue- plant communities
Red- temperature
-The revolution of the earth around the sun causes ____________
Blue- seasons
Red- day and night
-As elevation increases, what happens to temperature?
Blue- decreases
Red- increases
-The movement of the oceans can affect an area’s climate?
Blue- false
Red- true
-An area’s ______________ also affects its climate.
Blue- latitude
Red-longitude
-The main driving force of weather/climates on earth is _________________.
Blue- ocean movement
Red- solar radiation
How would you describe Massachusetts’ climate?
Biome Diversity- These are averages. Local information varies based on geography
Tropical:
-Rainforests- 77-82°, 200+ cm precipitation. Heavily leached soil
-Savannas- 80-90°, 100cm precipitation, usually poor dry soil
-Deserts- 61-120°, 0-25cm precipitation, poor soil
Temperate:
-Forests- 32-82°, 76-250 cm precipitation, very fertile soil
-Grasslands- 21-78°, 38-76 cm precipitation, most fertile soil
-Chaparrals (Mediterranean)- 51-78°, 48-56 cm precipitation, rocky, poor soil
-Deserts- 34-120°, 0-25 cm precipitation, poor soil
Polar:
-Taiga- 14- 59°, 40-61 cm precipitation, acidic soil (because of pine trees)
-Tundra- -17-41°, 0-25 cm precipitation, frozen soil most of the year
What is a microclimate?
A microclimate is the climate for a small, specific area. The size can vary.
e.g. Western Oregon is kept warm by ocean currents and heavy cloud cover
e.g. Cities are usually a few degrees warmer than the surrounding area
e.g. It can be a few degrees cooler in the shade of a blade of grass
The cells of all living organisms are filled mostly with water.
It is also a key component in Photosynthesis and other organic processes.
Water is constantly moving, but how?
The water cycle is the continuous movement of water from the surface of the earth
to the atmosphere and back,
Water on earth’s surface evaporates (turns into water vapor) and moves up into
the atmosphere.
When it cools, it condenses (turns back into liquid water) and sticks to dust
particles in the air, forming clouds.
When there is too much water in the air for the clouds to hold (saturation),
precipitation (rain, snow, sleet, or hail) falls.
On the ground, water either percolates/infiltrates (seeps into the soil and
becomes part of the groundwater) or it runs-off (flows in rivers and streams
towards the ocean).
Any time that it is on the surface it has the potential to evaporate again.
Some water molecules can get stuck in the ocean or in glaciers for years, but they
always eventually rejoin the water cycle.
All of the water on earth is linked, constantly flowing from one body to the next.
Rivers and streams (runoff) that run into the same body (an ocean, lake, or larger
river) together form a river system.
The streams or rivers giving water to larger rivers or lakes
are called tributaries.
All of the land contributing water to a particular
river system is called a watershed.
Most of the water on earth is in the
ocean, but individual water molecules
are constantly moving.
Ocean Currents
Surface ocean currents are affected by several things, movement of the air, the
Coriolis Effect, the position of continents, and temperature.
Liquids and gases tend to move from warm places (lots of energy and
pressure) to cool places (less energy and pressure).
-As a result warm air and water from the equator tends to move
towards the poles.
Since the earth is rotating, water trying to go north or south gets pushed to
the side.
-This is the Coriolis Effect
-In the Northern Hemisphere currents are pushed in a clockwise
direction
-In the Southern Hemisphere they are pushed in a counterclockwise direction
There are also deep ocean currents, but they depend more on temperature and
how dense the water is (changes depending on how much salt is in the water).
Ocean Current’s effect on climate
Since water changes temperature much slower than air does, a prevailing wind
that comes from over a warm ocean current will be warmer and bring that warm
air to the land.
Places like the British Isles and the Pacific Northwest have milder
climates because of this warming effect.
These same prevailing winds also send a lot of moisture onto land and cause
these places to be frequently cloudy and rainy.
Lands alongside cold ocean currents are often dryer (Southern California)
Water temperatures do change periodically, which affects the ocean currents,
and weather around the world (storms, drought, etc).
El Nino- a shift in the Pacific currents
El Nina- a shift in the Atlantic currents
Atmospheric currents
Air moves from areas of high pressure to low pressure (wind).
Pressure is highest at the surface of the earth where there is a lot of atmosphere
above pushing down and lowest at high elevations.
Pressure is also affected by temperature
-high temperature equals high pressure
Changes in temperature causes air to rise and fall, which brings it into areas
of high or low pressure
Air rises, falls, moves from high pressure to low pressure and settles into
predictable patterns or convection belts.
There is one belt between 0° and 30° latitude, one between 30°and 60°, and one
between 60°and 90°.
Air is also affected by the Coriolis Effect, so it has the same left right movement
as the ocean surface currents.
Winds coming from the west are called Prevailing Westerlies
Winds coming from the east are called Trade Winds
Most of the world’s deserts are located around 30°N or S, because the cool
falling air usually does not contain as much moisture as the air rising from the
earth’s surface.
Massachusetts’ climate
As a result of the ocean current in the Northern Atlantic, the ocean is usually
warm.
However, because of the Coriolis effect, most of our weather comes from our
west, so our air is not warmed as much by the water as the Pacific Northwest or
British Isles.
Our latitude (approximately 42 degrees north) and air currents mean that we get
enough precipitation to have healthy forests, but not enough to be rainforests.
-it also means that our days during the winter are shorter than during the
summer, which gives us very different temperatures in the winter and summer.
Atmospheric composition
The atmosphere is composed primarily of Nitrogen gas (78%).
Oxygen is the next most abundant at 21%.
All other gases, including water vapor and carbon dioxide,
combine to make up a total of 1%.
Air is not “nothing”, it is full of matter. It is a mixture
of gases that have mass and weight.
Atmospheric pressure is greatest at low elevations
because all the mass and weight of high elevation gases
push down on the lower gases.
The atmosphere is broken down into layers, each with a different composition
and properties (troposphere, stratosphere, mesosphere, and thermosphere).
What things do living things do (biological processes) that affect the atmosphere?
We constantly pull gases out of the air and put new ones into it.
Cellular respiration- oxygen in, carbon dioxide out
Photosynthesis- carbon dioxide in, oxygen out
Nitrogen fixation- nitrogen gas turned into usable molecules
Decomposition- some compounds into the ground, others back to the
atmosphere
What does the physical earth do (geological processes) that affects the atmosphere?
Fires- put carbon dioxide and other gases into the atmosphere
Volcanoes- release carbon dioxide and sulfuric gases into the atmosphere
Evaporation- liquids (mostly water) turn into gases and enter the
atmosphere
How do people affect the atmosphere?
The biggest impact is on the carbon/oxygen ratio.
-We burn fossil fuels, putting carbon dioxide and other greenhouse
gases into the air.
-We cut down forests, which are responsible for taking out carbon
dioxide and putting in oxygen.
We also release CFCs (chlorofluorocarbons) which bloke the ozone layer’s
(upper layer of the stratosphere) ability to absorb dangerous forms of solar
radiation.
Why do we need an atmosphere?
The oxygen that almost all living things need for cellular respiration comes from
the atmosphere.
The carbon dioxide that plants use for photosynthesis comes from the
atmosphere.
All of the proteins in the bodies’ of every living thing are made of nitrogen atoms
that at one time were in the atmosphere.
Animals, like insects and arachnids, that don’t actively suck in oxygen can’t grow very
big. However, when oxygen concentrations in the atmosphere are higher, they can
evolve larger bodies.
Another reason we need the atmosphere is global warming.
The atmosphere acts like a blanket, keeping some of the heat we receive
from the sun here, instead of letting it bounce out into space.
Too thin an atmosphere and temperatures become extreme, too hot
during the day and too cold at night.
Too thick an atmosphere and earth retains too much heat.
The moon doesn’t has an atmosphere:-233°C at night, 123°during the day
Venus has a thick atmosphere: 460°C all day
Earth has a moderate atmosphere:10°C at night, 20°C during the day
Increasing the amounts of greenhouse gases in the atmosphere (e.g. carbon
dioxide and water vapor) makes our atmosphere thicker.
So what is weather?
Weather is atmospheric conditions right now.
It is a result of the temperature, atmospheric pressure, moisture, and
movement of the atmosphere over a given area.
These things are ultimately controlled by the same things as climate, the
movement of the earth, radiation from the sun, and the earth’s physical
and chemical features. When they change weather changes.