EALS REVIEWER.docx

**REVIEWER IN EALS** **What is earth and life sciences?** It presents the history of the Earth through geologic time. It discusses the Earth\'s structure, composition, and processes. **Theory**- is a coherent group of tested general propositions (tried-and-tested hypothesis) **Hypothesis**- is a...

**REVIEWER IN EALS** **What is earth and life sciences?** It presents the history of the Earth through geologic time. It discusses the Earth\'s structure, composition, and processes. **Theory**- is a coherent group of tested general propositions (tried-and-tested hypothesis) **Hypothesis**- is an idea that is not proven yet but that leads to further study or discussion. **[UNIVERSE]** Universe is everything. Universe begins **13.7 Billion years ago.** The UNIVERSE is the totality of known or supposed objects and phenomena throughout space. **Hydrogen, helium, and lithium** are the three most abundant elements. It is the whole cosmic system of matter and energy. Consists of everything that exists anywhere in space **A [galaxy]** - is a **cluster of billions of stars** and **clusters of galaxies** form **superclusters.** **[Stars]** - the building block of galaxies - are born out of clouds of gas and dust in galaxies. **[Protostar]** - the hot core of a future star as **thermonuclear** reactions set in. **Cosmology** - is the study of the origin, development, structure, history, and future of the entire universe. **[THE BIG BANG THEORY (1931) ]** **[George Lemaitre]** -- "the one who [ ] made the big bang theory" **[THE BIG BANG THEORY -]** Is the generally accepted cosmological theory for the origin, properties, and evolution of the universe. **The universe began** as a **tiny, dense, fireball** called **singularity** that exploded and it expanded. \"**all the matter and energy** in the **universe** are **crammed into a tiny compact point** sometimes **called \"singularity\"** **[EVIDENCES OF BIG BANG THEORY ]** **Galaxies moving awa**y Presence of **Cosmic Microwaves Background (CMB).** **Abundance of Light elements like Helium, Hydrogen, Deuterium, and Lithium.** **[OTHER THEORIES ]** **Evolutionary Theory**- Density of matter decreases over time **Steady State Theory**- Density of matter is constant over time. **Oscillating theory**- All the matter in the universe would get hotter and brighter and eventually collapse together in an event called \"BIG CRUNCH\" or \"BIG BANG\" **Inflation Theory**- Believed to happen just 10-36 seconds after the Big Bang. **SOLAR SYSTEM** IS THE **GRAVITATIONALLY BOUND SYSTEM OF THE SUN** AND THE OBJECTS THAT ORBIT IT. IT CONSISTS OF THE **SUN, 8 PLANETS, DWARF PLANETS, ATEROIDS, COMETS & METEORS.** **Pnemonics** **M**ang **V**ictor **E**spinosa **M**ag **J**ogging **S**a **U**maga **N**ang **l**umakas **Types of planets in our solar system** **The inner four planets** closest to the sun - **[Mercury, Venus, Earth and Mars]** - are **often called the \"terrestrial planets\"** **because** their **surfaces are rocky.** **The four large outer worlds** - **[Jupiter, Saturn, Uranus and Neptune]** - are **sometimes called the Jovian or \"Jupiter-like\" planets** **because** of their **enormous size** relative to the terrestrial planets. - **They\'re also mostly made of gases like hydrogen**, **helium and ammonia** - **astronomers believe some or all of them may have solid cores.** - **Jupiter** and **Saturn** are sometimes called the **gas giants** - **Uranus** and **Neptune** have been nicknamed the **ice giants.** **SUPERNOVA** **The solar system** was **formed** as a **result of** the **condensation of hydrogen gas and dust** **SUPERNOVA** might have caused the dust and gas cloud to collapse to form the Sun and Planets. **WHY DID IT COLLAPSED? -** The gas and dust cloud collapsed due to the force of gravity. **THE BIRTH OF THE SUN** **The sun** is by far the **largest object** in our solar system, **containing 99.8% of the solar system\'s mass** **Planets orbit the sun** in **oval-shaped** paths **called ellipses** Sun was born **4.6 billion years old ago** **EARTH** - **Earth is the only place** in the known universe confirmed to **host life.** - **Earth** is characterized by its **blue water,** **Compositional Layer Subsystem** **1. Crust 1. Lithosphere** **2. Mantle 2. Hydrosphere** **3. Core 3. Atmosphere** **4. Biosphere** **System** - **A set of interconnected components** that are interacting **to form a unified whole.** **ATMOSPHERE** - The **Atmosphere** is **the thin gaseous layer.** - The present atmosphere is composed of 78% **Nitrogen** **(N**), 21% **Oxygen (0),** 0.9% **Argon (Ar)** and trace amount of other gases. - **The Green house gases** help **keep our planet\'s temperature** to **level conductive to life.** **Layer of Atmosphere** - **EXOSPHERE** - **THERMOSPHERE** - **MESOSPHERE** - **STRATOSPHERE** - **TROPOSHERE** **Troposphere** - **First layer**, lying closest to the Earth\'s surface which **extends about 8-16 km above Earth** - **\"weather zone\"** **Stratosphere** - The layer above the troposphere **extending up to 50 km high** - **Where the ozone layer is found** **Ozone layer** **- absorbs UV radiation** from the **sun.** **Mesosphere** - **Temperatures tend to drop** with increased altitude. - **Acts as a layer for meteors to burn.** **Thermosphere** - **Temperatures increase until they approach 1100 C** at **noon** - **The air is so thin** that there **is practically a vacuum** **Exosphere** - This **is the outermost layer of the atmosphere.** - In this layer, **atoms** and **molecules escape into space** and satellites orbit the earth. - **The Earth** is **surrounded by a blanket of air** called **the atmosphere.** - It **protects us from high-energy radiation** and frigid the surface ofEarth. **HYDROSPHERE** - **Hydro means Water** - **Hydrosphere** can be in **form of liquid**, **vapor** and **ice** **such as glaciers, ice caps and ice bergs**. This **frozen part** is called **Cryosphere.** - About **71% of Earth** is **covered with liquid water (Hydrosphere)** and **much of it** is in the **form of ocean water.** Only **3%** of **Earth\'s water is fresh**: **two- thirds** are in the **form of ice**, and the **remaining one-third is present in streams, lakes, and groundwater.** **GEOSPHERE** - **Geo** means **Ground** - It is believe that at **the beginning of the Earth,** the continents are all into huge landmass **called Pangea** as **proposed by Alfred Wegener.** - **The Geosphere** includes **the Crust** and **the upper part of the Mantle**. **BIOSPHERE** - **Bio** means **Life** - **Composed of all Living Things**. It is sometimes referred to as the **\"zone of life\"** **The term "Biosphere\"** was **coined by Geologist Edward Suess 1875.** **it covers all ecosystems**-from the **soil to the rainforest**, from **mangroves to coral reefs**, and **from the plankton-rich ocean surface to the deep sea.** **THE INTERNAL STRUCTURE** **CRUST** - **Earth\'s solid exterior**, **very thin layer** composed of variety of rock types that respond in diverse ways **Two distinct types** - Continental crust - Oceanic crust **Oceanic crust** - The oceanic crust is **the component of the earth\'s crust** that **makes up the ocean basins.** - **density of around 3.0 g/cm3**, is **made up of dark basalt rocks** that contain minerals and substances **silicon, magnesium, and oxygen** **Continental crust** - **part of the crust that makes up the earth\'s surface.** - **40% of the surface of the earth** is made up of - this layer. - **made up of light-colored granite** rich in minerals and **substances like aluminum, oxygen, and silicon.** **PLATE TECTONICS** - **theory which proposes that the earth\'s crust and upper mantle** to be **composed of several large, thin, and relatively rigid plates** that **move relative to one another.**  **MANTLE** - **Thicker portion of the Earth\'s layer** made up of **Silicon, Oxygen, Iron and Magnesium** - **It is divided** into an **upper mantle and a lower mantle** Middle layer of the earth between the crust and the core; **makes up about 83%** of Earth\'s interior **LITHOSPHERE** - **Comprises the uppermost mantle and overlying crust** which is **relatively cool and made up of hard and strong rocks** **ASTHENOSPHERE** - **Partially molten, plastic like material that flows slowly** - l**ayer of weak, ductile rock in the mantle**; situated **below the lithosphere**. **CORE** - **Earth\'s innermost section and has a radius of about 3 360 km**, larger than Mars - **outer core is in a liquid** state whereas **inner core is in solid** - **Composed** primarily of **Iron and Nickel.** **OUTER CORE** - It is **composed mainly of liquid Iron and Nickel** - **Earth\'s magnetic field is generated in region.** **INNER CORE** - A very hot dense ball of iron **MINERAL AND ROCKS** **MINERALS** - is a **homogeneous solid** that can be **made of single native element or more usually a compound.** - Naturally occurring - Inorganic - Homogenous solid - Definite composition - **Minerals are around us everywhere**- some are quite valuable (**Diamond, Sapphires and Emeralds)** **Mineralogy** - Study of minerals. **Minerals** Diamond Sunstone Sodalite Hackmanite Onyx Jade **Minerals classification** is based on **both physical and chemical properties** **IDENTIFICATION OF MINERALS** **Optical Properties** **Luster** - **the quality of light being reflected by the surface of minerals**. Some have metallic surface such as gold, silver and cooper. **Types of luster:** **Metallic** - looks like shiny metal **Non-metallic** - glassy, earthy, pearly, or greasy **Optical properties** - ability to transmit light Types: **Opaque** - light that strikes the object but does **not pass through.** **Translucent** - some light passes through the mineral. **Transparent** - almost all the light will completely pass through. **Color** - A property of a mineral that is easiest to identify **Streak** - The color of mineral in powder form. **Mineral Strength** - It **determines how easy mineral breaks or deforms** when exposed to stress. **Tenacity**- **refers to the minerals resistance** to breaking or deforming. **Hardness** - a minerals resistance to scratching or abrasion. To **determined the hardness of mineral,** a comparative hardness scale a**ssigning numerical values to the hardness of a minera**l was **Friedrich Mohs** **Friedrich Mohs** - A **German minerologist** prepared a **scale of hardness with a number of 1-10** in increasing hardness. **MOHS SCALE** Diamond, 10 Corundum, 9 Topaz, 8 Quartz, 7 Orthoclase, 6 Apatite, 5 Flourite, 4 Calcite, 3 Gypsum, 2 Talc, 1 **Cleavage** - the tendency of some minerals to break along distinct planes and smooth flat surfaces **Fracture** - irregular or random breakage of mineral. **Minerals that do not cleave have no planes of weakness** in their structure, **therefore do not break in the uniform manner.** **Some Break like glass**, **some into splinters or fiber.** **Specific Gravity** - ratio of a minerals weight to the weight of an equal volume of pure water. - Many minerals have specific gravities between 2-3 (in other words, 2 to 3 times as heavy as water.) - Some minerals have a significantly higher specific gravity. **Minerals-Silicates** - Mineral that contain Oxygen and silicon - Silicates are the most abundant family of rock-forming minerals in the crust. Examples: **Quartz, Feldspar, Mica, Amphibole, Pyroxene** **Minerals-Non-silicate** **Carbonates** - minerals form when the carbonate ion H 2CO 3 combine with certain metals **Example:** **Calcium Carbonates, Zinc Carbonates, Iron Carbonate.** **Non - Silicate** **Oxides** - Minerals form through the bonding of Oxygen ions with metallic ions **Example:** **Brucite, Cassiterite, Corundum, Cuprite** **A sample of Chemical Test is** **a.) Taste Test** - **NaCl** (common table salt) **has a distinctly salty taste.** **b.) Fizz Test** - carbonate minerals is hydrochloric acid, giving of bubbles of carbon dioxide gas. **ROCKS AND MINERALS** - A rock is any solid that is naturally found on Earth. - It consists of minerals, and other pre-existing organic debris. - Some rocks can contain just one mineral while others can include a composite of several minerals **Rocks - Igneous** **Igneous rock** - a type of rock formed from a molten material that has cooled and solidified. **Magma** - molten rock material that originates deep within the Earth. - Rocks that solidify from magma, beneath the Earth\'s surface, **are called \"intrusive\" igneous rocks.** **Lava** - molten rock material that reaches the Earth\'s surface due to a volcanic eruption. - At the surface, rocks that solidify from lava are **called \"extrusive\" igneous rocks.** **Types of Igneous Rocks** **Volcanic Rocks** - rocks formed from magma erupted from a volcano, the most common rock type on Earth\'s surface is basalt. **Plutonic Rocks** - crystallized slowly cooling magma below the surface of the Earth -- Granite **ROCKS -- SEDIMENTARY** **Sedimentary rock** - rocks that form at or very near the surface of the Earth due to compaction and cementation of sediments. - The sediments that comprise sedimentary rocks come from three general sources: 1\) Rock fragments due to erosion of pre-existing (older) rocks 2\) Minerals chemically precipitated from solution 3\) Plants or animal remains (fossil) **Types of Sedimentary Rocks** **clastic sedimentation** - consists of fragments of rocks and minerals being transported and lithified (sedimentation) **chemical sedimentation** - occurs when the material is dissolved in water, and chemically precipitates from the water **organic sedimentation** - accumulation of organic matter, such as at the bottom of a swamp **ROCKS -- METAMORPHIC** **Metamorphic rock** - forms by the alteration of a pre- existing rock due to the effects of pressure, high temperature, and/or a chemical change - Metamorphism generally occurs well **below the surface of the Earth** **Metamorphic rocks** are formed from other pre-existing rocks **by the action of heat and pressure** **[Metamorphic rocks are not made from melting rock.]**