Introduction+to+Earth+Science+(chapter+1)

=Unit 1: Introduction to Earth Science (Chapter 1)=

Essential Questions:
Earth Science Standards: 1.1, 2.1, 12.2, 1.3, 3.8, 3.9 Scientific Inquiry Skills Standards: 1-4
 * 1) ==How does the earth's interior drive/influence the features on its exterior?==
 * 2) ==Explain how the earth is composed up of an array of subsystems.==

=Question of the Day: What is Earth Science?=
 * .All sciences that collectively seek to understand Earth and its neighbors in space.
 * **Geology:** study of Earth
 * physical: studies the material composing the earth and the processes that operate beneath and upon its surface.
 * historical: study the origin of earth and development of the plant over time
 * **Oceanography**: study of the oceans in all their aspects and relationships using chemistry, physics, geology, and biology.
 * **Meteorology**: study of the atmosphere and processes that produce weather and climate
 * **Astronomy**: study of the universe

Earth Science, People & the Environment

 * Everything that surrounds and influences an organism is referred to as **environment**. There are **biotic** (biological and social) factors and **abiotic** (nonliving) factors. Nonliving factors are referred to as the physical environment.
 * Regards to Earth Science, environmental refers to those aspects that focus on the relationships between people and their natural environment.
 * The formation and occurrence of resources along with maintaining supplies and the environmental impact of their extraction and use is a key focus of Earth Science.
 * **renewable resources** are those sources that cane be replenished over short time spans; such as: food (plants/animals), natural fibers for clothing, forest products for paper/lumber, energy from flowing water/wind/sun.
 * **nonrenewable resources** are those sources where processes that form the sources are much slower to accumulate (millions of years), fixed quantities of these resources. Examples like aluminum, oil, copper, natural gas, coal.
 * Population Growth affects the amount of resources available. The rate at which mineral and energy-resources are being used has more than rapidly climbed compared to the overall growth of population. Sustainability is a huge push into today's society.
 * Environmental Problems can be local, regional and even global events. Developing nations and developed nations face major problems. Urban air pollution, acid rain, ozone depletion and global warming pose significant threats. Other issues involve loss of fertile soil due to erosion, depletion of water resources, desertfication, droughts, habitat destruction. Human-induced and human-accentuated problems along with natural hazards cause environmental problems.

Early Evolution of Earth

 * Geological time scale divides 4.5 billion years of earth's history into time frames. Eons contain larger periods of time. Eras are found within eons and are smaller periods of time. Periods are found within eras and are even smaller periods of time. Epochs are found within periods and are even smaller periods of time. The time scale is away to relate how processes on earth have shaped earth's surface since these processes take hundreds of year to work. Space uses light years and astronomical units since the distance between planets and stars and other astronomical objects.




 * Several hypotheses are used to explain how the solar system became. Major theory is the Big Bang theory which states that a large explosion sent matter flying through space and in doing so over time planets and stars formed. The nebular theory states that the planets formed from a nebulae (cloud of gas and dust).

Earth's Spheres

 * Viewing earth from space, one can see 3 distinctive features: water, air, land. These features help make up the spheres of Earth.
 * **Hydrosphere**
 * water portion of the planet: both salt and fresh water.
 * 71% of surface is water. Of this, 97% is salt water and 3 % is fresh water. Of the fresh water, 85% is frozen and the other 15% is in liquid form but isn't equally distributed around the world.
 * **Atmosphere**
 * gas portion of the planet
 * smallest of the 4 spheres
 * Most abundant gas in the atmosphere is Nitrogen (78%), then Oxygen (21%), then Carbon Dioxide (<1%).
 * Energy exchange between atmosphere and earth's surface and the atmosphere and space produce our weather and climate.
 * **Geosphere**
 * solid portion of the planet
 * largest of the 4 spheres
 * ==What are the 3 distinctive layers of the earth?==
 * compositional and density differences formed the crust, mantle, core
 * Crust is a thin, rocky layer consisting of the continental crust and the oceanic crust. Oceanic crust is denser and made up of basaltic rock whereas the continental crust is less dense and made up of granite.
 * Mantle makes up 82% of the Earth's volume. Distinct boundary between crust and mantle based upon the chemical composition of rock (peridotite). Upper mantle is the **lithosphere** and consists of the entire crust and upper mantle. Rock is solid and brittle. Asthenosphere is below the lithosphere and is a softer, weaker layer allowing for plasticity to occur. Lower mantle is stronger due to pressure from layers above.
 * Core is made up of Iron and Nickel with some oxygen, silicon, and sulfur. Two regions: Outer core (liquid layer which is responsible for the earth's magnetosphere) and the Inner core (solid layer due to extreme pressure.
 * [[image:TGA234t.jpg width="480" height="360" align="left"]]
 * Continental Drift theory, proposed by Wegner, suggests that a superlandmass Pangea broke apart and the continents drifted to their present day location. Evidence used to support his theory were rock samples from different continents with same composition, fossil remains on continents separated by large bodies of water were the same, and the appearance of how the continents fit like a puzzle. Mechanism for how this worked wasn't discovered until the discovery of seafloor spreading. Emerging theory is now called Plate Tectonics.
 * lithospheric plates are irregular shaped slabs of rock that are in continuous motion. Some plates can move towards each other, away from each other, or side-by-side each other. Where plates come in contact are referred to as plate boundaries. Plate movement is due to the unequal distribution of heat within the Earth. Convection currents cause material to move in turn causing the plates to move. Earthquakes, volcanic eruptions, tsunami are some natural hazards caused by movements of tectonic plates.
 * [[image:TGA261t.jpg width="400" height="300"]]
 * Convergent Plate boundaries: two plates that come together. Can form subduction zones, trenches, mountain ranges, volcanic island arcs. Can be oceanic-oceanic plates, oceanic-continental plates, continental-continental plates.
 * Divergent Plate boundaries: two plates that move away from each other. Form rift valleys and new ocean floor.
 * Transform Plate boundaries: two plates that slip past each other. Also called strike-slip boundaries. Form transform faults.
 * ==How does Continental Drift Theory and Plate Tectonics work together?==
 * Features on the earth's surface can be divided into the ocean basins and the continents. Difference in density has allowed features to form on these locations.
 * Largest features found on the continents can be divided into the uplifted regions (mountain belts) and the flat stable regions (shields).
 * ===How do you think mountain belts have formed?===
 * ===What do think is older: Belts or Shields?===
 * Features on the ocean basin can be divided into three regions: continental margins, deep-ocean basins, and mid-ocean ridges.
 * Continental margins are made up of the continental shelf, continental slope, and continental rise.[[image:TGA244t.jpg width="480" height="360"]]
 * Deep-Ocean basin has features such as the abyssal plains, deep-ocean trenches, seamounts, Guyots.
 * Mid-ocean ridges are the most prominent feature of the ocean floor.
 * **Biosphere**
 * life portion on the planet
 * extreme environments and creatures that have adapted, micoorganisms in the atmosphere, plants on the surface, creatures in the water.
 * Maintain and alter the physical environment.

Earth as a System

 * ==How do you think the earth works as a system?==
 * Interacting parts (subsystems) that are forming a complex whole.
 * Driven by sources of energy that move matter and/or energy from one place to another
 * **Closed Systems** are self-contained in regards to matter so therefore no matter enters or leaves the system.
 * **Open Systems** are where both energy and matter can flow into and out of the system.
 * Feedback mechanisms can enhance change or resist change thus stabilizing the system.
 * Negative systems work to maintain the system as it is (status quo).
 * Positive systems work to enhance or drive change.
 * ===What are some ways mater is recycled over and over again in the Earth system?===
 * ===Where does the energy come from that drives the earth system?===