GEC EL 3 Midterm Notes PDF

**GEC EL 3 MIDTERM NOTES** **Acid rain -** Rainfall with high acidity due to pollutants. **Air -** Mixture of gases that make up the Earth\'s atmosphere. **Altitude -** Height above sea level. **Amazon Plate** - Tectonic plate in the Amazon region. **Amazon River -** The largest river by discha...

**GEC EL 3 MIDTERM NOTES** **Acid rain -** Rainfall with high acidity due to pollutants. **Air -** Mixture of gases that make up the Earth\'s atmosphere. **Altitude -** Height above sea level. **Amazon Plate** - Tectonic plate in the Amazon region. **Amazon River -** The largest river by discharge in the world, located in South America. **Ammonia -** A compound of nitrogen and hydrogen, used in fertilizers. **Arctic Ocean -** The smallest ocean, located around the Arctic region. **Argon -** A noble gas, inert and used in lighting and welding. **Atlantic Ocean -** The second-largest ocean, between the Americas and Europe/Africa. **Atmospheric layer -** Distinct layers of gases surrounding Earth, like the troposphere. **Bay -** A body of water partially enclosed by land. **Carbon cycle -** The process of carbon movement through the Earth's systems. **Carbon Dioxide -** A greenhouse gas produced by respiration and combustion. **Condensation -** The process of vapor turning into liquid. **Continental drift -** The movement of Earth\'s continents over geological time. **Convection currents -** Circular movements in fluids caused by temperature differences. **Crust -** The outermost layer of the Earth. **Earth -** The third planet from the Sun, supporting life. **Earthquakes -** Sudden ground movements caused by tectonic shifts. **Earth\'s atmosphere -** The layer of gases surrounding the planet. **Earth\'s freshwater -** Water sources like rivers and lakes, not salty. **Earth\'s Lithosphere -** The rigid outer layer of the Earth, including the crust and upper mantle. **Earth\'s rotation -** The spin of Earth on its axis, taking about 24 hours. **Erosion -** The process of wearing away soil and rock. **Estuary -** A coastal area where freshwater meets saltwater. **Evaporation -** The process of liquid turning into vapor. **Exopause -** The region where the atmosphere transitions to outer space. **Exosphere -** The outermost layer of Earth\'s atmosphere, where air is thin. **Fault -** A fracture in the Earth\'s crust where movement has occurred. **Glaciers and ice caps -** Large masses of ice that flow and cover land areas. **Great Salt Lake -** A large saline lake in Utah, USA. **Greenhouse -** A structure that traps heat, or refers to greenhouse gases causing warming. **Gulf -** A large inlet of the ocean partially surrounded by land. **Himalayan Plate -** A tectonic plate that includes the Himalayan mountain range. **Hydrogen -** The lightest and most abundant element in the universe. **Ice -** Frozen water, solid form of H₂O. **Igneous -** Rock formed from cooled magma or lava. **Indian Ocean -** The third-largest ocean, located between Africa, Asia, Australia, and the Indian subcontinent **Infiltration -** The process of water entering the soil. **Inner core -** The solid, innermost layer of Earth, composed mainly of iron and nickel. **Lagoon -** A shallow body of water separated from a larger body by a barrier. **Lake Baikal -** The deepest and oldest freshwater lake in the world, located in Siberia, Russia. **Lake Superior -** The largest freshwater lake by surface area in North America. **Lake Victoria -** The largest lake in Africa and the second-largest freshwater lake by surface area. **Lakes -** Large inland bodies of freshwater or saltwater. **Largest freshwater -** Refers to Lake Baikal as the largest in volume. **Largest ocean -** The Pacific Ocean, covering more area than all landmasses combined. **Lithification -** The process of turning sediments into rock through compaction and cementation. **Magma -** Molten rock beneath the Earth\'s surface. **Mantle -** The layer of Earth between the crust and the core, composed of semi-solid rock. **Mars -** The fourth planet from the Sun, known as the Red Planet. **Mesopause -** The boundary between the mesosphere and the thermosphere. **Lava -** Magma that has reached the Earth\'s surface. **Metamorphic -** Rock that has changed due to heat and pressure. **Metamorphism -** The process by which rocks change form due to heat, pressure, or chemically active fluids. **Methane -** A potent greenhouse gas, composed of one carbon atom and four hydrogen atoms. **Mississippi River -** A major river in the United States, flowing from north to south. **Mount Everest -** The highest mountain on Earth, located in the Himalayas. **Mountain ranges -** Series of connected mountains formed by tectonic forces. **Neptune -** The eighth planet from the Sun, known for its deep blue color and strong winds. **Nile River -** The longest river in the world, flowing through northeastern Africa. **Nitrogen -** A major component of the Earth\'s atmosphere, essential for life. **Nitrogen cycle -** The process of nitrogen moving between the atmosphere, soil, and living organisms. **Nitrous Oxide -** A greenhouse gas produced by agricultural and industrial activities. **Outer core -** The liquid layer surrounding the inner core of the Earth, composed mainly of iron and nickel **Oxygen -** A vital element for life, making up about 21% of the Earth\'s atmosphere. **Ozone layer -** A region in the stratosphere containing a high concentration of ozone, protecting Earth from UV radiation. **Pacific Ocean -** The largest and deepest ocean, located between Asia and Australia to the west and the Americas to the east. **Pacific Plate -** A major tectonic plate beneath the Pacific Ocean. **Plate tectonics -** The theory explaining the movement of Earth\'s lithospheric plates and associated geological phenomena. **Precipitation -** Any form of water falling from the atmosphere, including rain, snow, and sleet. **Rift valleys -** Low areas formed by the divergence of tectonic plates. **Rivers -** Natural flowing watercourses, usually freshwater, that flow towards oceans, lakes, or other rivers **Rock cycle -** The continuous process of rock formation, breakdown, and reformation. **Rocks -** Solid aggregates of minerals or mineraloid matter. **Sahara Plate -** A tectonic plate associated with the Sahara Desert region. **Salinity -** The concentration of salt in water, typically measured in parts per thousand. **Saltwater -** Water that contains a significant concentration of dissolved salts, primarily found in oceans. **Sea-floor spreading -** The process by which new oceanic crust forms at mid-ocean ridges and moves away from them. **Seasons -** Divisions of the year marked by changes in weather and daylight, caused by Earth\'s tilt and orbit. **Sedimentary -** Rock formed from the accumulation and compaction of mineral and organic particles. **Sedimentation -** The process of particles settling out of a fluid and accumulating. **Soil -** The upper layer of the Earth, consisting of organic matter, minerals, gases, liquids, and organisms. **Southern Ocean -** The ocean encircling Antarctica, also known as the Antarctic Ocean. **Stratosphere -** The atmospheric layer above the troposphere, containing the ozone layer. **Subduction -** The process where one tectonic plate moves under another and sinks into the mantle. **Sublimation -** The transition of a substance from solid to gas without passing through a liquid phase. **Sulfur Dioxide -** A gas produced by volcanic eruptions and industrial processes, contributing to air pollution. **Tectonic plate -** Large sections of Earth\'s lithosphere that move and interact at their boundaries. **Temperature -** A measure of the warmth or coldness of an environment or substance. **Thermosphere** - A layer of the Earth\'s atmosphere above the mesosphere, characterized by increasing temperatures with altitude. **Tides -** The periodic rise and fall of sea levels caused by the gravitational pull of the moon and sun. **Transpiration -** The process by which water is absorbed by plants and released as vapor into the atmosphere. **Trenches -** Deep, narrow depressions in the ocean floor, often associated with subduction zones. **Troposphere -** The lowest layer of Earth\'s atmosphere, where weather occurs and where most of the mass of the atmosphere is found. **Venus -** The second planet from the Sun, known for its thick, toxic atmosphere and extreme temperatures. **Volcanic eruption -** The explosive release of magma, gas, and ash from a volcano. **Volcanic islands -** Islands formed by volcanic activity, often arising from underwater volcanoes. **Water -** A vital substance for life, composed of hydrogen and oxygen (H₂O). **Water cycle -** The continuous process of water movement through evaporation, condensation, and precipitation. **Water Vapor -** Water in its gaseous state, an important component of the atmosphere. **Weathering -** The breakdown of rocks and minerals due to environmental factors. **Wind -** The movement of air from high to low pressure areas, influencing weather and climate. **1. Important Facts of the Earth** a. Earth is the **third planet from the Sun** and is the largest of the four terrestrial planets namely Mercury, Venus, Earth, and Mars b. The** existence of water in the liquid phase on Earth** is due to the temperature span that exists on the Earth: 0 -- 100 degree Celsius. Water boils at 100 degree Celsius, thus converting it into gas and making it unusable for consumption by living beings including humans, animals, and birds, etc. c. Earth is **the only place in the solar system where water can be present in all the three states -- solid, liquid and gas** d. We are all traveling **around the Sun** at an average velocity of 107,182 kilometers per hour. And at the same time, we are also [spinning with an enormous speed](https://www.scientificamerican.com/article/how-fast-is-the-earth-mov/) -- that could be 1000 miles per hour depending on your position on Earth. e. **Earth receives** between 100 and 300 metric ton of [cosmic dust ](https://www.universetoday.com/94392/getting-a-handle-on-how-much-cosmic-dust-hits-earth/)(the dust which exists in outer space, as well as all over planet Earth) every day (data collected from satellite observations.)  f. Despite the fact that **the earth is made up of more than 70% of water,** do not be surprised to learn that water accounts for less than 1% of Earth's mass. g.  In size, **Earth is slightly larger than Venus.** h. Although the Earth was form 4.5 billion years ago, life appeared 3.8 billion years ago, and hominids only 6 million years ago. If Earth's history was represented in a day, life appeared at 4 a.m., and humans at almost 11:59 p.m. i. The **force of gravity in the Hudson Bay region of Canada** is less than that on the rest of the planet.  j. It is also interesting to note that** more than 95% of Earth's ocean are still unexplored.** k. Tides in oceans on Earth happen due to the force of gravitation between the Earth and the moon. Moon pulls up water in oceans and even in lakes, due to its gravitational force. l. Earth has just one moon whereas Jupiter has 67 moons. m. It is a fascinating fact to note here that** 99% of all species that ever existed on the Earth are now extinct.** n. Earth is **the only known planet that supports life.** However, attempts are underway to help life survive on other planets like Mars. o. ** **Earth is **composed of four main layers** -- inner core, outer core, mantle, and crust. p. The **thickest of all the four layers of the earth is the mantle,** which is 2900 kilometers thick. This layer has a consistency of caramel and is composed of a hot mixture of molten rock. q. The **thinnest of all the layers is the crust,** which is on an average 30 kilometers deep on an average on the ground. r. Earth is also known as the **"Blue Planet"** because of its bluish appearance from the outer space. Almost 70% of Earth's surface is covered with water. s. There are **five**[ layers in Earth's atmosphere](https://www.nasa.gov/mission_pages/sunearth/science/atmosphere-layers2.html) including -- the Troposphere, the Stratosphere, the Mesosphere, the Thermosphere, and the Exosphere. [Earth's atmosphere](https://thefactfile.org/atmosphere-facts/) is the thickest from ground level up to a height of 50 km and extends up to 10,000 km. t. The **pressure and density go on decreasing** as we move farther away from the Earth's surface and travel towards space. u. Earth is the only planet that **contains 21% oxygen** in its atmosphere and liquid water on its surface. v. The Earth is** the fifth largest planet** in terms of size and mass. w. **Light from the Sun reaches the Earth** in approximately 8 minutes and 20 seconds. x. Almost **70% of the earth's surface is covered by oceans** that contain 97% of the planet's water. These oceans are home to great mysteries and tons of geographical features that are not even available on the land. E.g. Earth's longest mountain range is also underwater. y. It is estimated that** life initiated in the oceans some 3.8 billion years ago. ** z. **The Earth has no rings.** **2. The Earth's Atmosphere** A diagram of the atmosphere Description automatically generated  **3. The Earth's Hydrosphere** **-  hydrosphere refers collectively to all forms of water on Earth. It includes surface water bodies like rivers, oceans, lakes, and ponds, groundwater, water vapor (clouds and fog) in the atmosphere, and ice.** a. Oceans: It is the largest reservoir of water on Earth. The water here is salty. b. Fresh water: It is less abundant than salt water and is available as: a. Surface water: The water present in lakes, rivers, and streams b. Groundwater: The water present beneath the Earth's surface in rock pores and the fractures of rock formations c. Glacial water: The water that melts from glaciers d. Water vapor: The water present in the atmosphere **Hydrosphere and the Water Cycle** a. Evaporation: The heat of the sun causes surface water bodies to evaporate into the atmosphere. Plants also lose water from their aerial parts through transpiration. In this way, the hydrosphere interacts with the atmosphere. b. Condensation: Water vapor in the air cools off, becomes dense, and forms droplets. This process is called condensation. When the droplets are tiny and light enough to stay suspended in the air, they form clouds. c. Precipitation: When the water droplets in the air fall, it is called precipitation. Some common forms of precipitation are rain, snow, sleet, and hail. **4. The Earth's Lithosphere** **- the solid, outer part of Earth, including the brittle upper portion of the mantle and the crust.**  **5. The Earth's Biomes** **- Biomes are regions or landscapes of the world that are divided on the basis of climatic conditions, vegetation, and adaptation of flora and fauna.** World map biome vector illustration(tom\_tk)s