Earth Science Handout for Q1 (PDF)

EARTH AND LIFE SCIENCE QUARTER 1 – HandOut 1: Earth and Its Subsystem Earth is the third planet from the sun and the only object in the universe known to harbor life. EARTH SUBSYSTEMS A system is a group of...

EARTH AND LIFE SCIENCE QUARTER 1 – HandOut 1: Earth and Its Subsystem Earth is the third planet from the sun and the only object in the universe known to harbor life. EARTH SUBSYSTEMS A system is a group of related objects or parts that work together to form a whole. The Earth system is all of the matter, energy, and processes within Earth’s boundary. Earth is a complex system made of living and nonliving things, and matter and energy continuously cycle through the smaller systems. A. ATMOSPHERE - The atmosphere is the thin gaseous layer that envelopes the lithosphere. - It also traps some energy from the sun, which helps keep Earth warm enough for living things to survive and multiply. (Greenhouse Effect) - Acts as shield from radiation - It is about: 78% nitrogen, 21% oxygen, and 1% other gases. (Minor gases in the atmosphere include argon, carbon dioxide, and water vapor.) LAYERS OF THE ATMOSTPHERE: 1. Troposphere - It is the lowest layer where the weather forms. 2. Stratosphere - extends to 50 km above the Earth's surface. The ozone layer that protects the Earth from the Sun's harmful UV radiation is found in this layer. 3. Mesosphere - It protects the Earth from the impact of space debris. Meteors usually burn up in this region as they approach our planet. 4. Thermosphere - extends up to 600 km above the Earth's surface. It has charged particles that are affected by the Earth's magnetic field (Ionosphere). The particles create the Auroras or Northern and Southern lights. 5. Exosphere - It is the farthest layer. It extends to about 10 000 km above the Earth's surface. B. BIOSPHERE - The biosphere is the set of all life forms on Earth. - 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 C. LITOSPHERE - The lithosphere is the solid, outer part of the Earth. - It includes the brittle upper portion of the mantle and the crust, the outermost layer of Earth’s structure. D. HYDROSPHERE - Hydrosphere is composed of all the water on Earth in any form: water vapor, liquid water, and ice. - The cryosphere is made up of all of the frozen water on Earth, such as glaciers, ice caps and icebergs. EARTH SYSTEM SCIENCE - The study of the interactions between and among events and Earth’s spheres What makes a planet habitable? 1. TEMPERATURE influences how quickly atoms and molecules move: Life seems to be limited to a temperature range of -15oC to 115oC. In this range, liquid water can still exist under certain conditions. 2. ATMOSPHERE Traps heat, shields the surface from harmful radiation, and provides chemicals needed for life, such as nitrogen and carbon dioxide. Of the solid planets & moons, only Earth, Venus, & Titan have significant atmospheres. Mars’ atmosphere is about 1/100th that of Earth’s, too small for significant insulation or shielding. 3. ENERGY Organisms use light or chemical energy to run their life processes. 4. NUTRIENTS Used to build and maintain an organism’s body. All solid planets & moons have the same general chemical makeup, so nutrients are present. Those with a water cycle or volcanic activity can transport and replenish the chemicals required by living organisms. On the surface: Earth has a water cycle, an atmosphere, and volcanoes to circulate nutrients. Venus, Titan, Io, and Mars have nutrients and ways to circulate them to organisms. Why is the earth special? 1. proximity to the sun—neither too much heat nor too little 2. system of plate tectonics that enables the carbon-silicate cycle regulating temperature  3. earth has the right size (Earth is large enough to hang on to its atmosphere, but not so large to hold on to too much atmosphere and consequently too much heat.) 4. presence of Jupiter 5. having water in its liquid form at the surface, in an amount conducive to life evolving. 6. Considered as the only living planet which is composed of four subsystems known as the biosphere, atmosphere, lithosphere, and hydrosphere where matter and energy flow to make life on earth possible. Right distance from the sun + Right type + Right size + Right Atmosphere + Right Composition or Elements = L I F E (Goldilocks Principle) COMMON ROCK-FORMING MINERALS o Minerals - These are the basic building blocks of rocks. Minerals are naturally occurring, inorganic solid with orderly crystalline structure and a definite chemical composition Characteristics of Minerals: 1. Naturally occurring - Minerals are formed by natural, geologic processes. They are not man-made. 2. Solid earth material - Only crystalline substances that are solid at temperatures encountered at Earth’s surface are considered minerals 3. Generally inorganic - Traditionally, minerals are not biological in origin. They are not formed from living things or the remains of living things 4. Definite Chemical Structure - Minerals are crystalline substances, which means their atoms are arranged in an orderly, repetitive manner. 5. Definite Chemical Formula - The elements that make up the minerals are combined in definite proportions Quartz has the formula which indicates that quartz consists of silicon (Si) and oxygen (O) atoms in a ratio of one-to-two. Properties of Minerals: 1. Color - Although probably the most obvious feature, color is the least diagnostic physical property of most minerals. Color can vary due to chemical impurities and oxidation (exposure to air and water changing the color of the mineral) 2. Streak - Streak is the color of a powdered mineral and is considered to be the true color of a mineral. Different specimens of a mineral may have different colors, but the powdered streak is constant. 3. Luster - describes how light is absorbed or reflected by a mineral surface, which affects the mineral’s appearance. Luster can be metallic or non-metallic. Nonmetallic luster includes: VITREOUS (glassy), DULL OR EARTHY (a dull appearance like soil), PEARLY (such as a pearl or the inside of a clamshell) SILKY (like satin cloth), or GREASY (as though coated in oil) ADAMANTINE (brilliant, such as a cut diamond) 4. Hardness - a measure of the resistance of a mineral to abrasion or scratching. 5. Tenacity - describes a mineral’s toughness, or its resistance to breaking or deforming. Brittle - Minerals that are ionically bonded, such as fluorite and halite, tend to be brittle and shatter into small pieces when struck. Malleable - Minerals with metallic bonds, such as native copper, are malleable, or easily hammered into different shapes. Sectile - Minerals, including gypsum and talc, that can be cut into thin shavings Elastic - Minerals that bend and snap back to their original shape after the stress is released such as micas. 6. Crystal Habit - The external shape of a crystal or groups of crystals is displayed as these crystals grow in open spaces. The form reflects the supposedly internal structure (of atoms and ions) of the crystal (mineral). It is the natural shape of the mineral before the development of any cleavage or fracture. 7. Cleavage - It is the property of some minerals to break along parallel repetitive planes of weakness to form smooth, flat surfaces. These planes of weakness are inherent in the bonding of atoms that makes up the mineral. 8. Fracture - is exhibited if the mineral does not have a cleavage plane, thus it exhibits broken surfaces that are irregular and non-planar EARTH AND LIFE SCIENCE QUARTER 1 – HandOut 2: Classification of Rocks and the Minerals Important to Society A rock is a naturally occurring solid aggregate of minerals, sometimes with nonmineral solid particles. Petrology is the science that is concerned with the study of rocks. CLASSIFICATION OF ROCKS 1. IGNEOUS ROCKS - Igneous rocks are formed through the cooling and solidification of magma or lava. Types:  According to Formation: a. Extrusive Igneous Rocks (Volcanic) - When molten rock solidifies at the surface (example: Basalt) b. Intrusive Igneous Rocks (Plutonic) - When magma solidifies at depth (example: Granite) According to rate of cooling and texture: a. Phaneritic - Magma cools slowly beneath the earth’s surface. Individual crystals are large enough so that the materials can be identified with the naked eye. (COARSE- GRAINED) b. Aphanitic - If the lava cooled quickly on or near earth’s surface. Individual crystals are hard to see with the naked eye (FINE-GRAINED) c. Porphyritic - A combination of different crystal sizes d. Glassy - If the molten rock crystallizes immediately, the result is a rock that shines like glass According to color and composition: Color varies with silica content. Silica-rich minerals such as quartz and feldspar are light-colored. Silica-poor mineral such as amphibole, biotite mica are dark-colored. 2. SEDIMENTARY ROCKS - Sedimentary rocks are formed by the deposition and cementation of mineral or organic particles on the floor of oceans and other bodies of water at the Earth surface. They can be classified as clastic, chemical and organic sedimentary rock. Types: a. Clastic sedimentary rocks - It is formed from the mechanical weathering debris of rocks. Examples are breccia, conglomerate, sandstone, siltstone, and shale. b. Chemical sedimentary rocks - It is formed when dissolved materials precipitate from solution. Examples of these are rock salt, iron ore, flint, some dolomites. c. Organic sedimentary rocks - Formed from the build-up of plant or animal debris. These may contain fossils of plants and animals trapped in the sediments as the rock was formed. 3. METAMORPHIC ROCK - Metamorphic rock forms from existing rock types called “parent rock (protolith)” in the process called metamorphism, which means change in form. The original rock which can be an igneous, sedimentary or another metamorphic rock is subjected to extreme heat and pressure, causing a profound chemical or physical change. Metamorphism is a process that produces fundamental change in the mineralogy and texture of the rock. Contact metamorphism - Rocks are heated by nearby magma which result to a change in composition. NONFOLIATED METAMORPHIC Regional metamorphism - Large pieces of the Earth’s crust collide and the rock is deformed and chemically changed by heat and pressure – FOLIATED METAMORPHIC Types: a. Foliated metamorphic rock - Formed through pressure due to compression of rocks that create bands called foliation. b. Nonfoliated metamorphic rock – It has no foliation or bands. Examples of metamorphic rocks: 1. Marble (parent rock: limestone) 2. Quartzite ( parent rock: sandstone) 3. Gneiss ( parent rock: granite) The rock cycle shows how one type of rocks transform to other types of rocks.  EARTH AND LIFE SCIENCE QUARTER 1 – HandOut 3: Exogenic Processes Exogenic processes are geologic processes on Earth’s surface. Exogenic processes include weathering, erosion and deposition. These processes act in concert, but in differing relative degrees, to bring about changes in the configuration of the Earth’s surface. WEATHERING - It is the breakdown or disintegration of rocks and their minerals into smaller fragments and/or decay and transformation into other substances. Weathering occurs in place, that is, particles stay put and no movement is involved. Classification: 1. Physical / Mechanical Weathering It is the disintegration and breakdown of rocks into smaller pieces without changing its chemical composition Examples: a. Abrasion - wearing away of rocks caused by impact and friction, and by constant collision of loose particles b. Biological Activity - humans, plants, and animals act as agents of mechanical weathering (e.g. digging, plant’s growing roots, burrowing animals) c. Frost Wedging - when water gets inside the fractures and joints, alternate freezing and thawing episodes occur, causing the rock to break apart. 2. Chemical Weathering the composition of rock is changed due to the chemical reactions Water is the most important agent in chemical weathering. Examples: a. Dissolution b. Hydrolysis c. Oxidation EROSION - the incorporation and transportation of material or weathering products by a mobile agent such as water, wind, or ice. Agents of Erosion: Running water, Ocean or sea waves, Glaciers , Wind , Groundwater, Gravity DEPOSITION – is the process in which the weathered rock materials carried out by erosion settle down in a particular location. EARTH AND LIFE SCIENCE QUARTER 1 – HandOut 4: Endogenic Processes The Earth is made up of 3 layers: CRUST, MANTLE, CORE (Liquid outer core, Solid inner core) 1. PLUTONISM - is the process by which magma rises through the crust and crystallizes as an intrusive igneous rock beneath or within the Earth’s surface. 2. VOLCANISM - Volcanism is the process of bringing up the magma. When the magma reaches the surface of the Earth it becomes lava. Lava is a stream of molten rocks that cool and solidify at Earth’s surface to form extrusive igneous rocks or volcanic rocks. 3. MAGMATISM - the process known as the formation and movement of magma under the Earth’s crust. When rocks are subjected or exposed to high temperature and pressure melt and become the magma. EARTH AND LIFE SCIENCE QUARTER 1 – HandOut 5: Rock Deformation and Dating Rocks DEFORMATION - Changes in the shape or position of a rock in response to stress. STRESS - A force that acts on a rock unit to change its shape/volume or position. Types of Differential Stress 1. COMPRESSION – Push together. Squeezing the rock. As crustal rocks are compresses, they are pushed both higher and deeper down. 2. TENSION – Pulling rocks apart. It becomes thin in the middle. 3. SHEARING - It pushes crustal rock in two opposite, horizontal directions. They break or bend apart.  Methods to Determine the Age of Stratified Rocks There are two methods of determining the ages of rocks: relative dating and absolute dating. Relative dating is a method of arranging geological events based on the rock sequence. Absolute dating is a method that gives an actual date of the rock or period of an event. Relative Dating Relative dating cannot provide actual numerical dates of rocks. It only tells that one rock is older than the other but does not tell how old each of the rock is. Principles of Relative Dating ▪ The law of superposition states that, in any sequence of layered sedimentary rocks, the top layer is younger than the bottom layer. It is important in the interpretation of the Earth's history because it indicates the relative age of the rock layers and fossils. ▪ Principle that states that younger rocks lie above older rocks, if the layers have not been disturbed. ▪ The law of original horizontality states that most sediments were originally laid down horizontally. However, many layered rocks are no longer horizontal. Based on the law of original horizontality, the rocks that were tilted may be due to later events such as tilting episodes of mountain building. ▪ The law of lateral continuity states that rock layers extend laterally or out to the sides. These layers may cover broad surfaces. Erosion may have worn away some parts of the rock, but the layers on either side of the eroded areas still match. ▪ The law of cross-cutting relationship states that fault lines and igneous rocks are younger features that cut through older features of rocks. Absolute Dating Absolute dating or radiometric dating is a method used to determine the age of rocks by measuring its radioactive decay. A radioactive isotope in the rock decays into a stable daughter isotope. The decay occurs at a predictable rate, so the age of the sample could be determined. If you know the rate of decay for a radioactive element in a rock, you can figure out the absolute age of the rock. Half-life is the time needed for half of a sample of a radioactive substance to undergo radioactive decay. After every half-life, the amount of parent material decreased by one-half. Examples Carbon-14 – 5730 years K-Ar dating - 1.3 billion years U-Pb dating – 4.5 billion years After every half-life, the amount of parent material decrease by one-half. EARTH AND LIFE SCIENCE QUARTER 1 – HandOut 6: Geologic Time Scale THE GEOLOGIC TIME SCALE The geologic time scale is a record of the geologic history of the Earth. It is made up of time units that divide Earth’s history based on the appearance or disappearance of life forms (supported by fossil remains) in specific times. This scale helps us to study and interpret the history of life on Earth. ▪ Epoch – half a billion years or more ▪ Era – several hundred million years ▪ Period – one hundred million years ▪ Epoch – tens of millions of years ▪ Age – million of years In the geologic time scale, Eons have the biggest spans of time. Eons are divided into smaller units called eras. Eras are subdivided into periods. Periods are subdivided into even smaller time spans called epoch. FOSSILS When plants and animals die, their remains and imprints are buried in rocks or sediments. These preserved remains or traces are called fossils. Fossils are pieces of evidence that life has happened in the past. Information from these fossils are used to construct the geologic time scale. Fossils are remains of plants and animals of past ages. Fossils are classified into two major types: 1. BODY FOSSILS - are true form fossils, which are preserved remains where an organism's body tissue, or parts thereof, become fossilized in an altered or actual state. The most common body fossils found are from the hard parts of the body, including bones, claws and teeth. More rarely, fossils have been found of softer body tissues. 2. TRACE FOSSILS - Are geological records of biological activity. Examples of trace fossils are animal tracks, trails, burrows, borings, impressions, molds and casts. MAJOR EVENTS IN GEOLOGIC TIME SCALE ▪ Hadean eon– also known as chaotic eon, Earth was bombarded with meteorites and there was severe volcanism. ▪ Archean eon– continent formation began, photosynthetic prokaryotes (blue green algae) emerged and started releasing oxygen to the atmosphere ▪ Proterozoic eon– It was the time of great changes: Oxygenation of the atmosphere Origin and diversification of eukaryotic life Appearance of multicellular animal life (soft – bodied animals) Motion of the continental drift ▪ Phanerozoic eon– Eon of “visible life” , The eon during the plant and animals have existed. o Paleozoic era - The most common life forms early in this era were INVERTEBRATES (animals without backbones) ex. Trilobites, brachiopods ▪ Six periods: Cambrian, Ordovician, Silurian, Devonian (Age of Fishes), Carboniferous Permian o Mesozoic era – age of the dinosaurs, Pangaea began to break apart o Cenozoic era – age of recent life or age of mammals EARTH AND LIFE SCIENCE QUARTER 1 – HandOut 7: Geologic, Hydrometeorological Processes and Hazards Geologic processes and hazards are events which occur irregularly in time and space and cause negative impact on man and the environment. Earthquakes, volcanic eruptions, tsunamis (tidal waves), and landslides are the geologic hazards. 1. EARTHQUAKE – this geologic hazard happens from the vibrations or shaking of the Earth’s surface caused by the rapid movement of rocks in the crust 2. VOLCANIC ERUPTION - is a natural phenomenon in which molten rock, gas, and other materials are ejected from a volcano's vent or fissure onto the Earth's surface or into the atmosphere. 3. TSUNAMI - A tsunami is a series of ocean waves triggered by a significant disturbance, usually associated with underwater earthquakes, volcanic eruptions, or landslides. 4. LANDSLIDES - refers to the sliding down of a mass of earth or rock from a mountain or cliff Hydrometeorological hazards are processes of atmospheric, hydrological or oceanographic nature that may cause the loss of life or injury, property damage, social and economic disruption or environmental degradation. Examples of this are tropical cyclones, monsoon rains (like habagat and amihan), tornado, ipo-ipo and thunderstorms, floods, drought, wildfire and storm surges. MARINE AND COASTAL PROCESSES Coastal processes are activities or events happening in the marine environment. These are driven by the different environmental factors such as atmospheric pressure, temperature, movement of the Earth, moon, and other dynamic changes in the ocean. Coastal processes include waves, tides, sea level change, crustal movement, and storm surge.