Summary

This document provides an overview of Earth's subsystems, including the lithosphere, atmosphere, hydrosphere, and biosphere. It also details concepts like the Continental Drift Theory, Plate Tectonics Theory, relative and absolute dating, and the study of fossils. The document appears to be a set of notes or a study guide.

Full Transcript

Earth’s Subsystems Lithosphere is the solid outer section of the Earth. Includes the Earth’s crust and upper mantle. The lithosphere is broken into plates laying on the asthenosphere (a partially molten layer of rock). Continental Drift Theory Alfred Wegener proposed the Continental Drift Theory -...

Earth’s Subsystems Lithosphere is the solid outer section of the Earth. Includes the Earth’s crust and upper mantle. The lithosphere is broken into plates laying on the asthenosphere (a partially molten layer of rock). Continental Drift Theory Alfred Wegener proposed the Continental Drift Theory - in which he believed every continent was part of a single landmass called Pangaea. The evidence supporting his theory are as follows: - Identical rocks on both sides of the Atlantic ocean. - Similar landmasses in different locations. - Ancient fossils spread through continents The theory was disproved because he couldn’t explain how the continents moved. Plate Tectonics Theory The Plate Tectonics Theory explains how they move. There are three types of tectonic plate boundaries: Divergent (Away) - It creates rifts, volcanos, mountains. It creates more land on the ocean floor. Convergent (Against each other) - Creates trenches, causes earthquakes, also creates volcanoes. Destroys parts of the ocean floor. Transform (Side by side) - Earthquakes. Atmosphere Layers of gases surrounding a planet or celestial body. The Earth’s atmosphere consists of: 78% nitrogen, 21% oxygen, 1% trace gases. 30% of solar radiation is reflected by it. 25% is absorbed, and 45% is absorbed by the Earth’s surface. Extras: - Carbon dioxide is used for photosynthesis. - Oxygen makes it livable for living organisms. In humans, it’s for respiration that allows our cells to function. Troposphere (closest) - Airplanes, clouds, weather - Highest air pressure - Water vapor and carbon dioxide present Stratosphere - The ozone layer - Cold but gets warm upon reaching the ozone layer - Weather balloons! Mesosphere - Coldest layer - Meteors burn here / Shooting stars! Thermosphere - Hottest layer - Auroras present - Low air pressure Exosphere (furthest) - Satellites, international space station orbits here - Lowest air pressure - Blends into cold regions of outer space Hydrosphere All the water on our planet. (Ice and vapour too). Nearly three quarters of the Earth. Fun Fact: The current deepest point is the Mariana Trench Horizontal Zones (Ocean Zones) divide the ocean from land. - Coastal Zone - Sea bottom exposed during low tide. Covered in high tide. - Pelagic Zone - Regions of lakes, rivers, oceans not associated with shores or the bottom. Nutrient poor. Vertical Zones (Ocean Zones) divide the ocean through depth. They’re as follows: Epipelagic (Sunlight Zone) - 90% of marine life due to sunlight accessibility. Mesopelagic (Twilight Zone) - 1% of sunlight Bathypelagic (Midnight Zone) - No sunlight Abyssopelagic (Abyssal Zone) - Only a few organisms adapted to survive here - High pressure - Low temperature Hadalpelagic (Hadal Zone) - 400 known species in this zone. - Largely unexplored. Biosphere Parts of Earth where life exists. RelativeDating Used to arrange geological events and rocks into a sequence. Reading the order is called Stratigraphy. The basic principles of relative dating are as follows: Principle of Original Horizontality - States sedimentary rocks are originally deposited in flat horizontal layers that get tilted by faults and folding. - Layers of sediment are deposited horizontally from gravity. Principle of Superposition - States layers of rocks are superimposed (laid down on each other). Oldest rocks on the bottom, youngest on top. - Critical as basis for relative geologic time scale. Principle of Cross-cutting Relationships - Any geologic feature that crosscuts (modifies another feature) must be younger than the rocks it cuts through. - The cross-cutting feature is younger because there must be something there to cut through. - Can include folds, faults, igneous intrusions. (Forms when magma cools and solidifies before reaching the surface). Principle of Inclusion - States a rock containing another rock is younger than that rock. - Sedimentary rocks can contain clasts of other rocks (like pebbles) - Can contain xenoliths (foreign rock fragments), ripped from surrounding rocks due to magma. AbsoluteDating Measures physical properties of objects to calculate age. - Radiocarbon dating uses radioactive decay (unstable isotopes undergoing continuous decay) - Isotropes are atoms with the same number of protons but different number of neutrons. Fossils Preserved remains of plants and animals buried under sediments. We study fossils as they are evidence for evolution and adaptation of living beings to their environments. Mold Fossil - Sometimes remains create imprints in sediments. Cast Fossil - Imprints filled in by minerals that harden into rock. Trace / Ichno Fossil - Footprints and nests. Traces of life. Fossilised poop is called coprolite lmao. True Form Fossil - Actual preserved bodies of animals / plants. Animals get stuck into sap, frozen in amber, or frozen in ice, etc. Can include limbs, torsos, fingers, heads. Rocks&Minerals Rocks can be classified into three main types. Igneous Rocks - Intrusive (Formed beneath surface) / Extrusive (Formed on surface) - Created when magma or lava cools and hardens. - Sizes determined by speed of cooling. - Slow cooling of magma forms large crystals / Rapid cooling makes small crystals - Examples: Granite, basalt, obsidian Texture: - Coarse-grained: Grains seen with bare eyes - Medium-grained: Grains can only be seen through hand lens - Fine-grained: Grains seen through microscope - Light colored igneous rocks - High in silica. Pale shades like white, pink, light gray. (Examples: Granite, Rhyolite) - Medium colored igneous rocks - Intermediate levels of silica. Gray to light brown. (Examples: Diorite, Andesite) - Dark colored igneous rocks - Low in silica. Black, dark gray, green, dark shades. (Examples: Basalt, Gabbro) Sedimentary Rocks - Lithification: Formed from accumulation and compaction of sediments over time. - Contains fossils and clues of past environments. - Compaction: Presses the sediment particles closer together by squeezing out water and air. - Cementation: Glues sediment particles together with minerals that crystallises from water. - Examples: Limestone, Sandstone, Shale EXTRAS - Record of Past Environments: Reflect ancient landscapes and conditions where they formed, helping reconstruct historical environments. - Fossil Record: Preserve fossils that provide insights into past life forms and ecosystems. - Earth’s Climate History: Contain evidence of past climates and climate changes through features like glacial deposits and coal beds. - Geological Processes: Help understand sedimentary processes such as erosion, transport, and deposition. - Resource Exploration: Source of valuable natural resources like coal, oil, natural gas, and minerals. - Stratigraphy: Enable dating and sequencing of geological events through the study of layered rock formations. Metamorphic Rocks - Formed from alteration of pre-existing rocks (parent rocks) from heat, pressure, and chemical processes. Process is called metamorphism. - Examples: Marble, Slate, Schist - Foliated Metamorphic Rocks: Caused by combinated of directed pressure (sometimes with heat) rearranges minerals in the rocks in parallel layers / bands. - Non-Foliated Metamorphic Rocks: Doesn’t have layered appearance, instead being more random. Minerals Naturally occurring, specific chemical composition and crystalline structure. (Extra: The difference between rocks and minerals are: Rocks are made up of minerals, minerals of elements. Rocks are classified by formation, minerals by specific properties.) - Crystal Structure: Patterns of atomic structures are seen directly through crystalline structure. (Basically saying the atoms’ structure are exactly what we see) - Crystal Habit: Overall shape. - Needlelike (Acicular) - Plantlike (Dendritic) - Kidney-shapes (Reniform) - Elongated in one direction (Prismatic) - Broad and flat (Tabular) - Hardness: Ability to resist scratches. Uses Moh’s Hardness Scale. - Color: Visible color of mineral in natural form - Streak: Color of material in powdered form. Unexpected colors are a result of chemical reactions to exposure to oxygen. - Transparency: How much light can pass through. - Transparent: Light passes clearly, can see objects. - Translucent: Light still passes, murky objects kind of seen. - Opaque: You can’t see nothin! - Luster: Ability to reflect light. - Metallic: Like metal. Shiny… - Vitreous (Glassy): Shiny…. - Dull (Earthy): Matte. Little to no light. - Cleavage: Tendency of minerals to break on certain planes. Weakest point in a rock. When a mineral is broken along a plane, it forms a smooth surface. - Fracture: Cleavage but messy. - Specific Gravity: Water weight of a mineral. - Low specific gravity: Less than 3.0. Light. - Moderate specific gravity: 3.0 and 5.0. - High specific gravity: Greater than 5.0. Dense, heavier than size. Rocks&Minerals Rocks can be classified into three main types. Igneous Rocks - Intrusive (Formed beneath surface) / Extrusive (Formed on surface) - Created when magma or lava cools and hardens. - Sizes determined by speed of cooling. - Slow cooling of magma forms large crystals / Rapid cooling makes small crystals - Examples: Granite, basalt, obsidian Texture: - Coarse-grained: Grains seen with bare eyes - Medium-grained: Grains can only be seen through hand lens - Fine-grained: Grains seen through microscope - Light colored igneous rocks - High in silica. Pale shades like white, pink, light gray. (Examples: Granite, Rhyolite) - Medium colored igneous rocks - Intermediate levels of silica. Gray to light brown. (Examples: Diorite, Andesite) - Dark colored igneous rocks - Low in silica. Black, dark gray, green, dark shades. (Examples: Basalt, Gabbro) Sedimentary Rocks - Lithification: Formed from accumulation and compaction of sediments over time. - Contains fossils and clues of past environments. - Detrital (Clastic) Sedimentary Rocks- Formed from the accumulation and cementation of physical fragments of pre-existing rocks and minerals. (LITHIFICATION) - Compaction: Presses the sediment particles closer together by squeezing out water and air. - Chemical Sedimentary Rocks- formed from the evaporation of water or the precipitation of minerals from solution. These rocks form when dissolved minerals in water precipitate out and accumulate. (COMPACTION) - Cementation: Glues sediment particles together with minerals that crystallises from water. A way that sediments are converted into sedimentary rocks. - Examples: Limestone, Sandstone, Shale EXTRAS - Record of Past Environments: Reflect ancient landscapes and conditions where they formed, helping reconstruct historical environments. - Fossil Record: Preserve fossils that provide insights into past life forms and ecosystems. - Earth’s Climate History: Contain evidence of past climates and climate changes through features like glacial deposits and coal beds. - Geological Processes: Help understand sedimentary processes such as erosion, transport, and deposition. - Resource Exploration: Source of valuable natural resources like coal, oil, natural gas, and minerals. - Stratigraphy: Enable dating and sequencing of geological events through the study of layered rock formations. Metamorphic Rocks - Formed from alteration of pre-existing rocks (parent rocks) from heat, pressure, and chemical processes. Process is called metamorphism. - Examples: Marble, Slate, Schist - Foliated Metamorphic Rocks: Caused by combinated of directed pressure (sometimes with heat) rearranges minerals in the rocks in parallel layers / bands. - Non-Foliated Metamorphic Rocks: Doesn’t have layered appearance, instead being more random. NaturalDisasters Are extreme, catastrophic events caused by natural forces resulting in widespread damage. Important Terms Disaster- Major disruption with widespread damage. Disaster mitigation- Minimize impact beforehand Disaster preparedness- Being to respond / recover from disasters. Disaster response- Immediate help provided during or after disasters. Hazard- Can potentially cause harm, leading to more disasters Rehabilitation- Rebuild and recover from disasters Risk- Possibility of harm / loss from disasters. Risk management- Identify risks to reduce them beforehand. Vulnerability- Factors making a community likely to be harmed by disasters. Government’s ways to help REPUBLIC ACT 10121 Philippine Disaster Risk Reduction and Management Act of 2010. Provides framework for disaster risk reduction and management in the Philippines. Emphasizes the importance of disaster preparedness, response, and recovery at all levels of government, as well as community-based approaches to disaster risk management. National Disaster Risk Reduction and Management Plan (NDRRMP) The Office of the Civil Defense (OCD) was tasked in formulating and implementing the NDRRMP. It aims to strengthen the capability of both local and national government on how to build disaster resilient communities. 4 Priority areas of the NDRRMF (National disaster risk reduction framework) - Disaster prevention and mitigation- Avoid hazards and mitigate their potential impacts by reducing vulnerabilities and exposure, and enhancing capacities of community. - Disaster preparedness- Establish and strengthen capacities of communities to anticipate, cope, and recover from the negative impacts of emergency. - Disaster response- Provide life preservation and meet the basic subsistence needs of affected population based on acceptable standards during or immediately after a disaster. - Rehabilitation and recovery- Restore and improve facilities, livelihood and living conditions and organizational capabilities, and reduce disaster risk in accordance with the “building back better” principle. In 2005, the United Nations Educational, Scientific and Cultural Organization (UNESCO), in partnership with University of the Philippines National Institute for Science and Mathematics (UP NISMED), published Primer on Natural Disaster Preparedness and Coping Mechanisms. Its primary objective is to equip students with knowledge and skills toward disaster preparedness and hazard mitigation. In 2008, the DepEd, in partnership with the United Nations Children’s Fund (UNICEF), produced a Disaster Risk Reduction Manual (Safer Schools Manual). The manual serves as a guide to education officials, school administrations, teachers, and students on what to do before, during, and after an onslaught hazard. GeologicProcessesandHazards - The Philippines is in the Pacific Ring of Fire, and lies within 2 tectonic plates which makes it likely to experience earthquakes and volcanic eruptions. Earthquakes The shaking of Earth’s surface. Sudden energy releases in the lithosphere makes seismic waves that makes the ground shake. Intensity- Measures the shaking in a certain location Magnitude- Measured the energy released at the Earthquake’s source. Volcanic Eruption Caused by movement of magma in the Earth’s crust, driven by heat in the planet’s interior. Through great pressure, the magma breaks through the surface, resulting in eruptions. Landslides A landslide is the movement of rock, soil, and debris down a slope due to gravity. It can occur suddenly or slowly, depending on various factors. Weathering- Rocks breaking down into sediments. Erosion- Movement of the debris through air, water, or ice. Transport- Moving away. Tsunamis Series of large ocean waves from sudden disturbances in bodies of water. Usually from earthquakes, volcanic eruptions, or landslides. HydrometeorologicalandCoastalProcessesandHazards Mosoon These are seasonal winds that cause heavy rain during one part of the year, and another that is dry. Caused by temperature differences between land and ocean. Habagat: Provides heavy rainfall, which is essential for agriculture but can also lead to flooding and other weather-related challenges. Amihan: Brings dry, cooler weather, offering relief from the heat but can lead to droughts if prolonged. Cyclones are storms that form in the Indian Ocean and Southwest Pacific. Typhoons form in the Northwest Pacific Hurricanes form in the Atlantic. - “Tropical Cyclone” is used by most countries to describe cyclonic storms that originate over tropical oceans. Tropical cyclone is referred to as “bagyo”. There are 19-20 tropical storms enter the Philippines. PAGASA assigns local names to these storms in alphabetical order. Storm Surge Color-Coded System Storm surge is a coastal flood or tsunami-like phenomena It is locally known as “daluyong”. A storm surge is caused by the combination of strong winds and low pressure associated with a tropical cyclone. The winds push seawater towards the shore, and the low atmospheric pressure allows the sea level to rise even further.

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