Warm - Up 1. What is the shape of Earth called? 2. How do scientists know what the inside of the Earth looks like? 3. What are the 4 compositional layers of the Earth? 4. What are the 3 structural layers of the Earth? 5. What is the difference between mass and weight?

Section 2: Energy in the Earth System

Earth-Science Systems Organized group of related objects or components that interact to create a whole Matter Energy

Types of Systems Closed System Energy exchanged Matter not exchanged Example: Sealed container

Types of Systems Open System Earth System? Both matter and energy exchanged Example: Open container Earth System? Almost closed

Earth’s Four Spheres

Earth’s Four Spheres Atmosphere Blanket of gases surrounding Earth 78% Nitrogen, 21% Oxygen, 1% other gases

Hydrosphere Covers 71% of Earth’s surface 97% of surface water—Oceans Freshwater— Lakes, rivers, streams

Earth’s Four Spheres Geosphere Mostly solid part of earth Rock and soil on continents, ocean floor Includes solid and molten interior of Earth

Biosphere All forms of life in geosphere, hydrosphere and atmosphere Non-decomposed organic matter Extends from deepest parts of oceans to a few km above surface

Earth’s Energy Budget Earth’s 4 main spheres-stores of energy and matter

Internal Sources of Energy Earth’s formation Heated by radioactive decay, gravitational constriction Since formation Amount of heat by radioactive decay has declined Convection Current

Earth’s Cycles - Water

Nutrient Cycles Nutrients – all chemical substances that an organism need to survive Needs to build tissue and carry out life functions

Nutrient Cycles 3 nutrient cycles in the biosphere play critical roles in organism survival 1. Carbon Cycle 2. Nitrogen Cycle 3. Phosphorous Cycle

Carbon Cycle Key ingredient in all living things Air, oceans, and rocks as well 1. Biological Processes – photosynthesis, respiration, and decomposition

Carbon Cycle 2. Geochemical – release of CO2 gas from volcanoes

Carbon Cycle 3. Mixed Biochemical Processes – burial of carbon rich remains and conversion into fossil fuels

Carbon Cycle 4. Human Activity – mining, burning of fossil fuels and forests

Nitrogen Cycle All organisms need nitrogen to make amino acids, which are used to build proteins Nitrogen gas – 78% of atmosphere

Phosphorous Cycle Forms parts of DNA and RNA Not very common Doesn’t enter atmosphere Found mostly in rocks and ocean sediments Moves through food webs Rock worn down and travels to rivers

Threats Human Activity Altering habitats Over hunting Pollution Introducing foreign species

Habitat Fragmentation When land develops – natural habitats are destroyed Habitat fragmentation – splits ecosystems into pieces Habitat Islands Central Park Fewer biodiversity

Pollution - DDT DDT – widely used pesticide Drained into rivers Cheap Active for a long time Killed variety of insects Drained into rivers Can not eliminate from bodies Non-biodegradable Not broken down by plants or animals

Silent Spring 1962 – biologist Rachel Carson Osprey, Brown Pelican, Bald Eagle Threatened extinction Made eggs fragile 1970’s DDT banned

Invasive Species Invasive Species – plants or animals that have migrated to places where they are not native Reproduce rapidly No natural predators Zebra Muscles