Transcript EE Chapter 1 [1]x - FHS gators love Science

Environmental Science
Megalocerous
•Megalocerous or “Irish Elk” lived during the
ice ages.
• Even though it’s name is Elk, it is really
a type of deer
•Stood over 12 feet tall!
•Lived in Eurasia in the last ‘ice age’
•Went extinct about 20,000 years ago
•May have gone extinct due to malnutrition or
anthropogenic causes.
•Anthropogenic means caused by man
(probably due to hunting)
Thylacine – Tasmanian Tiger
Video of Tasmanian Tiger
Thylacine
•Lived in the 20th century until 1936
•It was the largest marsupial mammal
•Lived in Australia
•Tasmanian Wolves (aka Tas Tigers, but really is neither!) were
hunted to extinction because they sometimes killed livestock
•What happened to this strange and unique animal?
•Over 98% of all documented species are now extinct
•What changes in Earth have occurred that have caused so
many extinctions?
What, if any, effect has man had on the rate of extinctions?
Has man had any other effects on Earth?
Planet Earth
Chapter 1
•To look at the questions, we have to
understand earth as a system. We must
learn about:
•the components of Earth
•The processes on earth
•The cycling of materials on earth
•Biomes, food webs and food
chains
•Energy level pyramids
•biodiversity
•Relationships between species in
a community
•How different factors effect
populations and ecosystems
What you need to learn:
• Be able to define:
– Atmosphere, Biosphere, hydrosphere,
geosphere, core, mantle, crust, lithosphere,
troposhpere, stratoshpere, mesosphere,
thermosphere ,ionosphere
• Describe the layers of the the geosphere
• Describe the layers of the atmosphere
• Identify the origin and composition of the
earth’s 4 spheres
1.1 Planet of Life
• Living things are called
organisms.
– They are found in the land, sea,
water and air
The Earth is divided into 4 spheres
–
–
–
–
Lithosphere
Hydrosphere
Atmosphere
Biosphere
The Spheres Interact
• Lithosphere interacts with the Hydrosphere
when toxins from a factory run off into a water
system and poison fish in a body of water
• Hydrosphere interacts with the Atmosphere
when water evaporates and forms clouds
• Atmosphere interacts with the Lithosphere
when acid rain falls and dissolves limestone
Unique Earth
• Earth is the only planet in our solar system,
and perhaps the entire cosmos, that can
support life. Why?
• One reason is water
– Water exists elsewhere, but only as ice or
vapor, never as a liquid.
– Water has several benefits
• It stores heat during warm periods and releases it
during cold periods, helping to maintain several
benefits
• Organisms need water to support life, chemical
reactions necessary to life occur mainly in water
Unique Earth
• Earth also has another factor necessary to
support life ~ an atmosphere
– air is a mixture of gases, nitrogen, oxygen,
carbon dioxide and water vapor
– These gases act as insulation to help keep earth
warm
– gases have to be the right mix in order for us to
breathe and obtain oxygen for energy
– Plants need carbon dioxide
• All these interactions between nonliving
and living parts of the earth are the subject
of ecology
Is the sun important?
•Supports life on Earth by
transmitting energy to us in the
form of light
•Light travels to Earth in the
form of waves
•Most waves are invisible
•Visible light makes up only a small portion of the energy given off
by the sun
•Each type of wave has a specific wavelength
Why is the sky blue?
• A clear cloudless day-time sky is blue
because molecules in the air bend blue light
like a prism from the sun towards you and
your eyes (called refraction).
• At sunset, we see the red and orange colors
because the light is coming at us from an
angle that bends those autumn colors
towards us instead of the blue.
Lithosphere
• The lithosphere is the layer of land that forms
Earth's surface.
– It includes the rocks, soil and sand that make up
land.
• Varies in thickness from 10-200 kilometers
• 3 Main rock types that make up the lithosphere
– Sedimentary, Igneous, and Metamorphic
– Are classified on the basis of how they were
formed
When liquid rock cools, it becomes
Igneous rock. Ex: Granite or basalt
forming from a lava flow.
Metamorphic Rock
Rock that is transformed
by heat and pressure .
Ex: marble and slate
Sedimentary Rock
Rock that is formed from smaller
particles that are squeezed together
due to pressure.
Asthenosphere
• The asthenosphere is a portion of the upper
layer just below the lithosphere that is
involved in plate tectonics
• Lithosphere is cold, solid and rigid whereas
as Asthenosphere is partially molten
• Includes rocks, soil and sand
Hydrosphere
• More than
70% of Earth
is covered in
water.
• 97% of it is
Salt water and
3% Fresh
water
• 2/3 or 66% of Freshwater is in our ice caps.
As our ice caps melt
our freshwater
decreases and our
saltwater increases.
Surface water –
ponds, lakes, and
streams
Groundwater aquifers
Aquifer – an underground layer of porous rock that contains water.
• Artesian Well – Wells in
which water flows to the
surface due to high
pressure underground.
• Wells do not replenish as
they once did due to
personal demand and the
amount of pavement.
1.3 The Atmosphere
• 4 Atmospheric layers based on
temperature change.
•
•
•
•
Thermosphere (Highest)
Mesosphere
Stratosphere
Troposphere (Lowest)
• The atmosphere becomes less
dense the farther you travel
from Earth.
Troposphere
• The layer of the
atmosphere that
touches the surface of
Earth
• Contains most of the
water vapor
• Most weather occurs
here.
• Extends 8-18 km
above Earth’s surface
• The most dense layer
Stratosphere
• Beyond the troposphere, reaching a height of 50
km above earth
• Above weather disturbances
• Ozone Layer
– Ozone – gas that filters UV rays
– Contains 3 oxygen molecules
– Without it, UV radiation would
destroy most life on Earth
Mesosphere
• Coldest Layer – temps as low as -100̊C
• Extends up to 85 km above Earth’s surface
Thermosphere
•
•
•
•
•
Outermost layer of the atmosphere
Surprisingly the warmest layer – up to 2000̊ C
Furthest from the surface
The least dense layer
Air pressure is one ten-thousandth of earth’s
surface
• Aka ionosphere because gas molecules are
bombarded with rays from sun, causing
molecules to lose electrons and become ions.
The Northern Lights
Video of the Aurora Borealis
• The aurora is formed when protons and electrons from the
Sun travel along the Earth's magnetic field lines.
• These particles from the Sun are very energetic. We are
talking major-league energy, much more than the power of
lightning: 20 million amps at 50,000 volts is channeled
into the auroral oval.
• It's no wonder that the gases of the atmosphere light up
like the gases of a streetlamp!
Northern Lights
• The aurora is also known as the northern and southern
lights. From the ground, they can usually be seen where
the northern and southern auroral ovals are on the Earth.
• The northern polar auroral oval usually spans Fairbanks,
Alaska, Oslo, Norway, and the Northwest Territories.
• Sometimes, when the Sun is active, the northern auroral
oval expands and the aurora can be seen much farther
south.
• The lights of the aurora come in different colors. Oxygen
atoms give off green light and sometimes red. Nitrogen
molecules glow red, blue, and purple
Facts about the Atmosphere
• US winds blow from the west to the east.
What is air composed of ?
What would happen to levels of CO2 if there were fewer
plants?
1.4 The Biosphere
• Anywhere that life can and is supported.
• It is 20 km thick
• All organisms obtain the materials they need to
live from the biosphere.
– Each individual organism may live mostly on land,
water or air, all organisms depend on materials from
each of these 3 areas
– Ex. you live in the lithosphere, breathe air of the
atmosphere and drink water from the hydrosphere
1.4 The Biosphere
• Limiting Factors – things that limit life in
the biosphere:
• Temperature
• Oxygen
• Depth
• Sunlight
• Pressure
• Food