Unit 2: The Dynamic Earth Mr. Ross Brown Brooklyn School for Law and Technology

In this unit we will learn about: The origins of the Earth The Earth’s 3 major parts How water, oxygen, and other elements move through the environment How we define weather and climate Short- and Long-term changes that happen on the Earth

How can we understand the physical Earth? 4.6 billion years old Began as molten rock, formed from debris crashing together

How can we understand the physical Earth? 3 parts: – Crust: surface, rock and soil. Continental crust and oceanic crust. Oceanic is heavier.

How can we understand the physical Earth? Mantle: can become softer due to heat and then flow like a liquid.

How can we understand the physical Earth? Core: center. High in iron. Very hot.

How can we understand the physical Earth? Gases: from volcanoes and vents. Became our atmosphere. Other elements came from meteorites and comets.

How can we understand the physical Earth? Earliest life – Similar to bacteria, began in warm oceans. Single celled. Lived without oxygen. – About 2.5 billion years ago, cyanobacteria made food from sunlight and produced oxygen as waste.

Homework #3, part 1 22 February 2016 Why could the very young Earth not support life? Provide 2 reasons.

What three parts make up Earth’s environment? 23 February 2016 Do now: What animal has adapted to survive on land, in the water, and in the air?

What are the parts of Earth’s environment? Biosphere: the parts of the Earth where things live.

What are the parts of Earth’s environment? Lithosphere: Earth’s solid surface and interior – The crust is like the shell of our hard-boiled egg Surface is in pieces, or plates, which move over the mantle.

What are the parts of Earth’s environment? The plates move about the surface. Where they meet we find geologic activity (volcanoes, earthquakes) We call this movement plate tectonics.

What are the parts of Earth’s environment? Hydrosphere: Earth’s water layer – Oceans, lakes, rivers, also groundwater and water in the air. Water covers 70% of the Earth Your body is 50-75% water Necessary for chemical reactions

What are the parts of Earth’s environment? Water helps regulate the Earth’s temperature – Can absorb more heat than a hard, rocky surface – And water stores heat to keep us from getting too cold – Remember Goldilocks

What are the parts of Earth’s environment? Atmosphere: The air around the Earth – 78% nitrogen, 21% oxygen, 1% other – We live and breathe in the troposphere All weather occurs here, up to 16km – Stratosphere, between km, contains ozone – Above this mesosphere and then thermosphere

What are the parts of Earth’s environment?

Atmosphere helps keep extreme heat out but holds enough heat in. Ozone layer protects us from ultraviolet (UV) radiation. Small amounts important for vitamin D, too much  cancer.

Homework #3, part 2 23 February 2016 Describe three things that might happen if the atmosphere did not exist.

How do elements cycle through the Biosphere? 24 February 2016 Do now: – Where is most of the water on Earth stored? Where is most of the freshwater on Earth stored? From where do we get our drinking water?

Where does NYC get the water that you use? The Water Cycle, or Hydrologic Cycle

How do elements cycle through the Biosphere? Evaporation: water changing from liquid into gas Transpiration: liquid water drawn up through plants and released as water vapor – Evapotranspiration Condensation: water vapor cools and forms clouds made of small droplets Precipitation: Clouds release water back to the Earth

How do elements cycle through the Biosphere? 70% of Earth covered by water….. But only 2.5% of water is freshwater….. And only 1% of that is available to use

How do elements cycle through the Biosphere? 6 elements make up 95% of all living things – Carbon, Oxygen, Hydrogen, Nitrogen, Phosphorus, Sulfur You breathe in Oxygen & exhale Carbon Dioxide – Why don’t we run out of Oxygen?

How do elements cycle through the Biosphere? Oxygen Cycle – Oxygen in, Carbon Dioxide out – Plants use CO 2 for food and then release O 2 Carbon Cycle – Plants produce sugars for food, carbon-based – Animals return the Carbon as CO 2

What determines our weather? 25 February 2016 Do now: What is the difference between weather and climate?

What determines our weather? Weather: moment by moment atmospheric conditions Climate: Long-term average weather conditions for a particular place.

What determines our weather? The Sun – Warms the ground, water, and air – Strikes different places differently – Earth’s axis is tilted, and this results in seasons

What determines our weather? The Air – Moves in response to temperature differences – The Earth’s spin affects wind patterns Coriolis Effect

What determines our weather? Wind Patterns – The Jet Stream: a rivers of air that determine much of the planet’s weather

What determines our weather? Air Pressure: the weight of the atmosphere pushing down on the Earth

What determines our weather? Water Content – Humidity: the amount of moisture in the air.

What determines our weather? The shape of the land – Mountains will determine things like rate of precipitation

What determines our weather? Climate affects how we live – Rain forest vs. desert vs. countryside

How has our Earth changed over time? 29 February 2016 Leap day! Do now: What are some of the ways we can learn about what Earth was like in the past?

How has our Earth changed over time? Plate tectonics – From Pangea (225 million years ago) to today

How has our Earth changed over time? Plate tectonics and continental drift have affected water currents and global climate patterns

How has our Earth changed over time? Other changes – Mountain building and erosion – Volcanoes and earthquakes – Ice ages and glaciers

How has our Earth changed over time? Ice ages

How has our Earth changed over time? How do we measure past geologic change? – Radioactive half-life – Sedimentary rocks – Fossils

How has our Earth changed over time? How else do we measure past change? Rings in a tree Coral Air bubbles in glaciers

Homework #4, part 1 29 February 2016 What are some ways your environment changes every day?