Earth and Life Science 2nd Quarter Reviewer PDF

EARTH AND LIFE SCIENCE SECOND QUARTER REVIEWER Types of Tectonic Forces: 1. Compressional Tectonic Forces a. Direction of force is towards one another on opposite sides of a plane b. Plane is considered ductile (bendable); deformation is possible witho...

EARTH AND LIFE SCIENCE SECOND QUARTER REVIEWER Types of Tectonic Forces: 1. Compressional Tectonic Forces a. Direction of force is towards one another on opposite sides of a plane b. Plane is considered ductile (bendable); deformation is possible without breaking c. Results in convergent plate boundaries d. Compressional forces result into folding e. Folds – wavelike deformation in layered rock or sediment f. When plane can no longer hold compression, it breaks and becomes fault 2. Tensional Tectonic Forces a. Also known as tensile force b. Direction of force is away from one another on opposite sides of a plane c. Results in divergent plate boundaries d. Usually results in formation of faults 3. Shearing Tectonic Forces a. Force that acts parallel to a plane b. Causes rocks on either side of the plane to slide or to be smeared from one another c. Results in transform plate boundaries d. Common whenever there is a shearing force Folds – results from bending or folding on layers of rocks; wavelike deformations in layered rock or sediments Types of Folds 1. Anticline a. Also called “upfolds” b. Upward arches in the layers of rocks c. Highest point is called “anticlinal crest” 2. Syncline a. Also called “downfolds” b. Downward arches in the layers of rocks c. Lowest point is called “synclinal trough” *Fold limbs – layers between the anticlinal crest and synclinal trough Classification of Folds 1. Symmetrical (simple) ▪ Simple fold with the same angle of fold limbs; vertical axial plane 2. Asymmetrical ▪ Compressional forces are not the same with steeper angle; one which axial plane is inclined 3. Overturn ▪ Fold limbs are tilted beyond vertical dip; axial plane inclined that strata on one limb are overturned 4. Recumbent ▪ Fold limbs lie horizontally due to over compression; axial plane is essentially horizontal Faults - Fold receives too much pressure that it can no longer hold, it will break and the breakage is known as fault Types of Faults 1. Dip-slip faults – inclined fractures where the blocks have mostly shifted vertically a. Normal fault – caused by tensional forces; block above the fault has moved downward relative to the block below b. Reverse fault - caused by compressional forces; upper block, above the fault plane. moves up and over the lower block 2. Thrust faults – one section of land slips over another at a low angle when land is compressed a. Caused by compressional forces 3. Strike-slip fault – blocks move mostly horizontally a. Also known as “transform” or “lateral” faults b. Caused by shearing forces Stratified rocks - Layered rocks - Commonly contains fossils - Fossils – valuable in the research and investigation of Earth’s history Formation of Stratified rocks - Lithification – process of transforming sediments into solid sedimentary rocks; involves processes like accumulation, compaction, and cementation Relative and Absolute Dating Relative Dating - Determines the order or arrangement of rocks form youngest to oldest - Follows the Law of Superposition - Law of Superposition – new layer is formed on top of a previous layer - Without using the actual ages or dates of rocks Absolute Dating - Identifies numeric age of rocks - Uses the ratio of isotopes through radioactive dating *Parent isotope – UNSTABLE radioactive isotopes *Daughter isotope – STABLE isotope produced by the radioactive decay of the parent isotope Other Examples of Absolute dating: - Tree rings ▪ Refer to age of a tree by counting the total number of rings - Radiometric dating ▪ Calculates absolute ages of rocks and minerals that contain radioactive isotopes - Varves ▪ Any sediment layer that shows a yearly cycle and are often seen in glacial lakes back to the ice age Geological Time Scale - Chronological schema relating to the stratigraphy of time which is used by a geologist, paleontologist and other scientist to describe the timing and relationship between events that occurred during the long history of the Earth Fossils - preserved remains or traces of plants, animals, and other organisms from the past - provides evidence of the past events in Earth’s geological history Arrangement from smallest to largest – Age, Epoch, Period, Era, Eon Earth’s History Precambrian Eon - Occurred a huge bulk of Earth’s history. - About 88% or roughly 4.1 billion years. - Broken into 3 parts (Hadean, Archean, Proterozoic  1. Hadean Era ▪ Chaotic due to meteorites that constantly hit Earth; causing severe volcanic activities ▪ Atmosphere and ocean were formed and the core, crust was also stabilized ▪ Hadean – from the word “hades” meaning “hell” 2. Archean Era ▪ Characterized by the period of Earth became warm ▪ Atmosphere contains only methane and only a few to no oxygen ▪ Most of Earth is still covered with water ▪ Formation of continents supposed to begin in this eon, when mantle is cooled ▪ Orange atmosphere due to abundance of methane 3. Proterozoic Era ▪ Characterized when atmosphere began to have oxygen; cyanobacteria ▪ Eukaryotes spread ▪ Multicellular animals appeared ▪ Continents began to drift away ▪ Lasted 1.9 Giga annum; half the age of Earth Phanerozoic Eon Paleozoic Era (Early/Ancient Life) “age of fishes” - In sedimentary layers, fossils of marine invertebrates which lived near the shallow river were formed - Preserved rocks and fossils of trilobites and brachiopods also found - Marks the formation of the supercontinent, Pangaea 1. In the middle of Paleozoic era, marine life forms had developed shells 2. Devonian period, animals began to inhale air as amphibians came out in the sea. Plants such as marsh plants and giant ferns began to grow and develop 3. Late Paleozoic era, reptiles started to appear. They looked like their amphibian ancestors but they were different in terms that they lay their eggs on land 4. Remains of these plants formed huge deposits in many parts of the world Mesozoic Era (Middle Life) “age of dinosaurs” - Marked by the breakup of the major landmasses - North America began to part from Europe and South America - Africa began to separate from Australia, New Zealand, and India - Dinosaurs – largest creatures that existed during this era which is descendants of the primitive reptiles that survived throughout the Paleozoic era Cenozoic Era (Late Life) “age of mammals” - Periods of ice age played a role of formation of vast geological features on Earth today - Volcanic activities became widespread, forming immeasurable flows of lava and basalt - Warm blooded animals, such as marsupials, and primitive mammals journeyed the land - Humans begin to leave their marks on the land, stone tools were used Geologic Processes - Event which occurs irregularly in time and space and cause negative impact on man and the environment - Examples: Earthquakes, volcanic eruptions, tsunamis (tidal waves), and landslides. Hazards - Phenomenon caused by natural or human forces which poses threat to human, animals, properties and environment. - The Philippines is located within the Ring of Fire; experiencing many earthquakes and volcanic eruptions compared to other countries - Our country is one of the most hazard-prone countries in the world Classification of Hazards - Natural: Earthquakes, volcanic eruptions, landslides and tsunamis (climate and weather-related hazards) - Anthropogenic: Deforestation, mining and climate change (man-made) Earthquake - One of the most violent natural phenomena - Exceeds all other natural disasters in terms of: number of victims and destructive force - Can cause tsunamis when they happen under the ocean - PHIVOLCS – Philippine Institute of Volcanology and Seismology Hazards caused by an earthquake: A. Ground shaking - Vibration of the ground during an earthquake - Hazard created by earthquakes - Trigger for other hazards such as liquefaction and landslides B. Surface faulting - Displacement that reaches the earth’s surface during slip along a fault - Commonly occurs with shallow earthquakes (epicenter of less than 20 km) - May accompany a seismic creep or natural or man-induced subsidence C. Landslide - Movement of a mass of rock, debris, or earth down a slope - Type of mass wasting; down-slope movement of soil and rock under the direct influence of gravity - Landslide = 5 movements; falls, topples, slides, spreads, and flows D. Liquefaction - Soil liquefies during ground shaking - Can undermine the foundations and supports of buildings, bridges, pipelines, and roads; causing them to sink into the ground, collapse, or dissolve E. Tsunamis - Giant waves caused by earthquakes of volcanic eruptions under the sea - Can injure or kill many people and cause significant damage to buildings and other structures - Speed of tsunami waves depends on ocean depth rather than the distance from the source of the wave. - Tsunami waves may travel as fast as jet planes over deep waters, only slowing down when they reach shallow water Landslides - Also known as landslips, slumps or slope failure - Occurrence in which soil, rocks and vegetal debris are transported suddenly or slowly down a slope due to insufficient stability - May happen when ▪ There is continuous rainfall ▪ Earthquake and/or volcanic eruption accompanied by a very loud noise - Can be resulted from the failure of the materials to make up the hill slope, and get driven by the force of gravity Human activities that speed up or trigger landslide: - Overloading slopes - Mining which uses explosives underground - Excavation or displacement of rocks - Land use such as modification of slopes by construction of roads, railways, buildings, houses, etc. - Quarrying which includes excavation or pit, open to the air, from which building stone, slate, or the like is obtained by cutting, blasting, etc. - Land pollution which is the degradation of earth’s land surface, exploitation of minerals and improper use of soil by inadequate agricultural practices. - Excavation which pertains to exposure, processing, and recording of archaeological remains - Cutting Trees that can lead to deforestation and may encourage landslide Human activities cause several effects of landslides - Property damage - Injury and death - Adversely affect a variety of resources after slide event ▪ Water supplies ▪ Fisheries ▪ Sewage disposal systems ▪ Forests ▪ Dams ▪ Roadways ▪ Water availability, quantity and quality - Negative economic effects of landslides ▪ Cost to repair structures ▪ Loss of property value ▪ Disruption of transportation routes ▪ Medical costs in the event of injury ▪ Indirect costs such as lost timber and lost fish stocks ▪ Costly geotechnical studies and engineering projects to assess and stabilize potentially dangerous sites Hydrometeorological Phenomena and Hazards - Philippines is located along the typhoon belt in Pacific Ocean - We experience an average of 19 to 22 typhoons - Hazards brought about by typhoons ▪ Floods ▪ Storm surges ▪ Strong winds ▪ Landslides Hydrometeorological hazard - Condition that causes harm to properties, infrastructures and human life as a result of hydrometeorological processes like tropical cyclones, monsoons, and ipo-ipo Tropical cyclone - Rapidly rotating low-pressure system - Forms over tropical oceans - Called typhoon when it enters the Philippines Typhoons - Enter the Philippine Area of Responsibility (PAR) - Given local name by Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) - *PAGASA – agency that monitors and disseminates information about weather disturbances Tropical Cyclones - Form over oceans where sea surface and air temperature are greater than 26°C. - Can only form over oceans EXCEPT South Atlantic Ocean and South Eastern Pacific due to cooler temperature - Develop at latitudes usually greater than 5° from the equator - Reach greatest intensity while located over warm tropical water - Weaken when they move inland; but often not before they cause great destruction Hurricanes, Cyclones, and Typhoons Hurricanes - Form over North Atlantic Ocean and Northeast Pacific Cyclones - Formed over the South Pacific and Indian Ocean - Philippines is prone to tropical cyclones due to its geographical location; produce heavy rains and flooding of large areas life and destruction of crops and properties Typhoons - Formed over the Northwest Pacific Ocean Hydrometeorological Hazards - Processes of atmospheric, hydrological or oceanographic nature that may cause loss of life or injury, property damage, social and economic disruption or environmental degradation - Examples; tropical cyclones, monsoon rains (habagat and amihan), tornado or ipo-ipo, and thunderstorms, floods, drought, wildfire and storm surges