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 EarthChapter 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.

Rock that is transformed by heat and pressure .Ex: marble and slate

Metamorphic Rock

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 streamsGroundwater - aquifers

• 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.

Aquifer – an underground layer of porous rock that contains water.

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.

• 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

Troposphere

• 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

Stratosphere

Mesosphere

• Coldest Layer – temps as low as -100JC• Extends up to 85 km above Earth’s surface

Thermosphere • Outermost layer of the atmosphere• Surprisingly the warmest layer – up to 2000J 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.

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!

The Northern Lights

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