Earth Science Hazards PDF

Hazards What is Hazard -​ Hazard is a dangerous phenomena, a substance, of human activity or condition 1.​ Geological Hazard -​ A natural event that occurs regularly and can cause disruption and destruction, such as earthquakes, volcanoes, tsunamis, erosio...

Hazards What is Hazard -​ Hazard is a dangerous phenomena, a substance, of human activity or condition 1.​ Geological Hazard -​ A natural event that occurs regularly and can cause disruption and destruction, such as earthquakes, volcanoes, tsunamis, erosion, and mass movement. 2.​ Hydrometallurgy -​ This refers to the potential dangers associated with the use of water-based processes to extract metals from ores or recycle metals from waste materials. -​ It involves using chemicals (such as acids or bases) and water to dissolve and separate metals from their ores, and this can pose various environmental, health, and safety risks. Geological Hazards 1.​ Volcanic Eruption -​ A sudden occurrences of a violent discharge of steam and volcanic material -​ Can alter drastically Types of Geological hazards: 1.​ Pyroclastic Fall -​ Volcanic fallout -​ Usually not directly dangerous -​ This refers to the falling of ash, pumice, and other volcanic materials from the sky after a volcanic eruption. 2.​ Lava Flow -​ Viscous -​ Molten rocks that flow out of a volcano -​ Causes severe burns  3.​ Lahar -​ Mud flow made up of volcanic debris -​ Volcanic mudflows or landslides, triggered by volcanic eruptions or heavy rainfall, can bury villages and cause significant damage. 4.​ Volcanic Gases -​ Gases that are released during a volcanic eruption or from a volcano at rest. -​ Most deadly effects of volcanic eruptions -​ Least showy part of a volcanic eruption 2. Earthquake -​ Any sudden shaking of the ground caused by the passage of seismic waves through Earth's rocks. Seismic waves are produced when some form of energy stored in Earth's crust is suddenly released, usually when masses of rock straining against one another suddenly fracture and “slip.” Hazards by Earthquake 1.​Ground Rupture 2.​Tsunami 3.​Landslide 1.​Ground Rupture -​ Occurs when the earthquake movement, deny the fault actually breaks the earth’s surface. 2.​Tsunami -​ Series of ocean waves generated by sudden displacements in the sea floor landslides, or volcanic activity generated by the displacement of water.  3.​Landslide -​ A rapid movement of largeness of earth and rocks down a hill or a mountain (added by gravity) Hydrometeorological Phenomena -​ Atmospheric, hydrological or oceanographic origin. Examples are tropical cyclones (also known as typhoons and hurricanes); floods, including flash floods; droughts; heatwaves and cold spells; and coastal storm surges. Hazard: 1.​Monsoon -​ A seasonal change May to October: Southwest monsoon (habagat) November to February: Northwest monsoon (amihan) 2.​Tropical Cyclones -​ Bagyo -​ This is where PAGASA is on deck to look out for any tropical changes and storms  3.​ Flooding -​ An overflow of water onto normally dry land. The inundation of a normally dry area caused by rising water in an existing waterway, such as a river, stream, or drainage ditch. Ponding of water at or near the point where the rain fell. Flooding is a longer term event than flash flooding: it may last days or weeks. -​ Human casualty 4.​ Tornadoes -​ Violently rotating columns of air that rotate while in contact with the land Marine and Coastal Processes Hazards: -​ Dangers of waves -​ Tides -​ Erosion -​ Floods or submersion -​ Saltwater intrusion 1.​ Coastal Erosion -​ Caused by waves brought by wind and storm 2.​ Submersion -​ Process having land held underwater Coastal Management 1.​ Groynes -​ Groynes are low lying wood or concrete structures which are situated out to sea from the shore. They are designed to trap sediment, dissipate wave energy and restrict the  transfer of sediment away from the beach through long shore drift. 2.​Seawalls -​ A structure made of concrete, masonry or sheet piles. It is built parallel to the shore at the transition between the beach and the mainland or dune, to protect the inland area against wave action and prevent coastal erosion. 3.​Injection Wells -​ Is used to place fluid underground into porous geologic formations. These underground formations may range from deep sandstone or limestone, to a shallow soil layer. Injected fluids may include water, wastewater, brine (salt water), or water mixed with chemicals. Subsystem of the Earth ​ Presence of liquid water ​ Right distance from the sun -​ Habitat zone -​ 149,597, 870 691 m Earth’s rotation -​ 23hrs and 56 min ​ Greenhouse effect ​ Earth systems -​ What is a system? A: Open- parts can either be lost from or added to the system Close- All parts exists in precise amounts, and nothing can be added or lost ​ All systems require energy source to drive them Layers of the Atmosphere 1.​Troposphere: Contains convection currents created by the sun’s heat, which cause most of our weather 2.​Stratosphere: Contains the Ozone layer—prevents some ultraviolet radiation/ UV Light 3.​Mesosphere: Meteors burn up when they hit this layer 4.​Thermosphere: Sublayers: Ionosphere: Radiowave, travel in this layer 5.​Exosphere: Atoms and molecules Hydrosphere (water): The water cycle—Is a continuous cycle.The total amount of water on a planet. The hydrosphere includes water that is on the surface of the planet, underground, and in the air. A planet's hydrosphere can be liquid, vapor, or ice. Biosphere (life): Parts of the plant in which all life exists Lithosphere (outer part of the earth): The solid, outer part of Earth. The lithosphere includes the brittle upper portion of the mantle and the crust, the outermost layers of Earth's structure. Layers of the Earth: 1.​Inner Core -​ Solid sphere ; about 2440km in radius -​ Composed in nickel and silver 2.​Outer Core -​ Liquid ; 2700km thick  -​ Composed in nickel-iron alloy 3.​Mantle -​ 2,900km thick ; comprises of 70% of the Earth’s volume -​ Composed of magnesium -​ Asthenosphere: partially molten 4.​Crust -​ Skin in the Earth -​ Crust is about 8km thick under the ocean (oceanic crust) ; about 32 km thick under the continents (continental crust) Part 1: Rocks and Minerals Jonathan Hutton -​ Developed the concept of the Rock Cycle to show how rocks and natural, physical processes are interrelated Mineral -​ Building blocks of rocks -​ They are crystalline solids meaning their atoms are arranged (it cannot be disarranged) Question: How do Minerals form? Answer: 1.​Cooling of magma -​ Hot, liquid rock and minerals inside the earth from the mantle Fast cooling -​ No crystals (mineraloids) -​ Tmi: If the cooling process is rapid (minutes, hours, days, or years), the components of the minerals will not have time to  become ordered, and only small crystals can form before the rock becomes solid. The resulting rock will be fine-grained (i.e., crystals less than 1 mm). (According to Google) Medium Cooling -​ Small crystals -​ This refers to the rate at which magma or molten rock cools and solidifies to form minerals. It means the cooling process occurs at a moderate rate, allowing for the formation of minerals with intermediate-sized crystals. -​ The cooling rate is neither fast nor slow, often occurring in environments like deeper parts of volcanoes or dikes and sills. Slow Cooling -​ Large crystals -​ It refers to the process where magma or molten rock cools and solidifies within the earth. This slow cooling rate allows the atoms within the magma to arrange themselves into well-ordered, large crystals. 2. Elements dissolved in liquids (usually water) When these liquids cool to a solid state, they form crystals. Uses of minerals: 1.​ Toothpaste (fluorite) 2.​ Tale (baby powder) 3.​ Diamond (jewelry) Criteria of Minerals: 1.​ Solid 2.​ Not man-made = naturally occurring on earth 3.​ Inorganic = not moving from or not made from living things 4.​ Fixed chemical formula, made of specific elements. -​ Quartz (Si02) that contains Silicon and Oxygen bonded -​ Pyrite (FeS2) that contains Iron and Sulfur  5.​ Atoms must be arranged in an orderly structure. (This also contributes the physical structures of a mineral) Group of Mineral ​ Beryl ​ Calcite ​ Amethyst Physical Properties of Minerals (can be used to identify the mineral) 1.​ Color 2.​ Luster 3.​ Streak 4.​ Hardness 5.​ Cleavage and Fracture 6.​ Other properties Color -​ Can be misleading -​ Can vary with the type of impurities -​ In other words, relying solely on color can be unreliable, and it’s better to consider other physical properties. Luster -​ Refers to how light reflects off of the surface of a mineral -​ Surface reflection There are 2 types: 1.​ Metallic - Shiny like metal 2.​ Non-Metallic - Dull How to identify if it’s Metallic? 1.​ Shiny appearance - typically have a bright, shiny surface that reflects light, similar to how a metal reflects light.  2.​ Opaque - metallic minerals usually are opaque, meaning light does not pass through them. Even if the mineral is thin, light will not penetrate it. How will I identify if it’s Non-metallic? 1.​ Observe the reflection of light - they do not reflect light like metal. 2.​ Check the color and transparency - many non-metallic minerals are light-colored or translucent Streak -​ The color of the powdered form of the mineral -​ The color of the streak can be different than the sample -​ Minerals must be softer than the streak plate Hardness -​ How easily a mineral scratches minerals -​ Mohs hardness scale Cleavage and Fracture -​ The way the mineral breaks -​ Cleavage: minerals break along smooth; flat surface -​ Fracture: breaks at random Other properties -​ Specific gravity -​ Attraction to magnets -​ Bending of light -​ Smell and taste -​ Reaction with hydrochloric acid Examples: 1.​ Silicates Characteristics: ​ Contains Oxygen and Silica  ​ The most abundant group of minerals ​ Ex. - Mica ; Quartz 2.​ Non-Silicates (No silica but still has Oxygen) Characteristics: ​ Make-up only 5% of the Earth’s crust ​ Include some of the most important minerals ​ Ex. Iron; Copper; Gold 3.​ Native Elements Characteristics: ​ Single Elements (can stand on it’s own) ​ Ex. Diamond; Silver; Gold What are types of rocks: 1.​ Igneous Formed when magma or lava cools and solidifies Types of rocks: 1.​ Extrusive Rock -​ Cool on the Earth’s surface -​ Cool relatively fast -​ Ex. Khyolite, Ardesite, Basalt 2.​ Intrusive Rock -​ Cool beneath Earth’s surface -​ Cool very slowly -​ Ex. Granite, Diorite, Gabrro Question: How will I easily remember the differences between Extrusive and Intrusive rock? Answer: Extrusive: “Exit” - forms when magma exits the Earth (erupts as lava) and cools on the surface Intrusive: “Inside” - forms when magma cools inside the Earth (beneath the surface) 2.​ Sedimentary Formed from layers of sand, silt, dead plants, and animal skeletons -​ Weathered, Eroded, and Transported -​ Form from the compaction and cementation of sediments There are types: 1.​ Clastic - Rock is just made of a different combination or size of sediments 2.​ Crystalline 3.​ Bioclastic - Living things stuck together → 1. Conglomerate and 2. Coal (e.x coquina) 3.​ Metamorphic Formed when existing rocks are changed by heat, pressure, or reactive fluids There 2 types: 1.​ Foliated - Parallel arrangement Ex. Flornfels 2.​ Non-Foliated - Do not have aligned mineral crystals Ex. Quartzite How are minerals formed? -​ Minerals form in a variety of different ways, some from when salt water evaporates or when chemicals come out of hot fluids. Others are made when hot gases or molten rock cool or when heat or pressure change pre-existing minerals. Part 2: Endogenic Process Earth’s internal heat Sources of Earth’s internal heat 1. Primordial Heat The formation process happens in two ways: a.accretion b.differentiation 2. Radiogenic Heat The key elements contributing in radiogenic heat include: U-238 and U-235, Th-232, and K-40 What is a Geothermal Gradient? -​ Is the rate at which the Earth’s temperature increases with depth beneath its surface. It reflects how heat from the Earth’s interior is conducted outward. factors affecting the heat distribution: 1. Tectonic Activity - Refers to the movement and interaction of the Earth’s lithospheric plates, which are large, rigid sections of the Earth’s outer layer that float on the semi-fluid asthenosphere below. 2. Geothermal Anomalies - Refers to areas where the Earth’s temperature is significantly higher or lower than the normal geothermal gradient for a given depth. These anomalies indicate unusual heat flow patterns caused by specific geological processes or structures. 3. Crustal Thickness - Refers to the depth or thickness of the Earth’s crust, which is the outermost layer of the Earth. It varies depending on the type of crust and geological setting. Question: What could be the reason for the heat inside the earth? Answer: The Earth’s internal heat is fundamental driver of various geological processes that shape the planet’s surface. Including plate tectonics, volcanism, metamorphism, and geothermal energy 1.​ Tectonic Plates -​ The crust of the Earth is broken into many pieces called tectonic plates. The plates "float" on the soft, semi-rigid asthenosphere Tectonic Theories: 1.​ Plate tectonics - Is the scientific theory that explains the structure and movement of the Earth’s Lithosphere (outer shell), which is divided into large, rigid plates that float on the semi-fluid asthenosphere beneath them. This theory helps explain the formation of many geological features and processes, such as mountains, earthquakes, and volcanic activity. 2.​ Wegner’s Theory of Continental Drift - Alfred Wegener, a geophysicist and meteorologist, believed that all of the continents were connected as one large land mass (he called Pangaea) about 200 million years ago. “Gradual movement of the continents over time.” Question: Was the Continental Drift Theory accepted? Answer: No. Because there is no acceptable hypothesis explaining the movement of continents. 2. Plate Tectonics -​ Is the widely accepted theory that Earth's crust is fractured into rigid, moving plates. In the 1950s and 1960s, scientists discovered the plate edges through magnetic surveys of the ocean floor. Plate Boundaries 1.​ Divergent Boundary ( ) -​ Is a type of plate boundary where 2 tectonic plates move AWAY from each other. -​ This movement results in the creation of new crust and is associated with various geological features and processes. -​ There are 2 Geological Features: 1.​ Mid-Ocean Ridges -​ The most well-known divergent boundary occurs along mid-ocean ridges, such as the Mid-Atlantic Ridge, where oceanic plates are pulling apart. 2.​ Rift Valleys: -​ On land, divergent boundaries can create rift valleys, such as East African Rift, where continental plates are pulling apart. 2. Convergent Boundary (--->