reviewer in science 10, Lecture notes of Earth science

Download reviewer in science 10 and more Lecture notes Earth science in PDF only on Docsity! Science Reviewer Alfred Lothar Wegener (Nov. 1,1880-1930) -German Meteorologist and Geophysicist - in the early 20th century, he formulated continental drift. -“all of the continents were once joined together in a single landmass (pangea) and had since drifted apart”. (continental drift theory) • Pangaea- in early geologic time, a supercontinent that incorporatedalmost all the landmasses on Earth. • The theory was ignored for many years • Several pieces to support the theory were discovered. • In 1915, he published his evidences in a book titled “Origin of Continents and Oceans”. • Evidence from landforms, fossils, climate • Later a new theory on his ideas and studies emerged. The Theory of Plate Tectonics What is Plate Tectonic? • The crust of the earth is divided into major and minor plates that move on different directions. Major Plates: Minor Plates: • Pacific Plate Philippine Sea Plate • Indo-Australian Plate Nazca Plate • North American Plate Scotia Plate • South American Plate Juan de Fuca Plate • African Plate Carribean Plate • Antarctic Plate Arabian Plate • Eurasian Plate Cocos Plate Indian Plate • Each type of interaction results in a distinct. • Plates are made of lithosphere (other term of crust and upper mantel) • Below the lithosphere is the asthenosphere (TECTONIC PLATES THAT FLOAT ABOVE THE HOTTER PORTION OF THE MANTLE) • An Area where two tectonic plates meet is called plate boundary • The layer of Earth's atmosphere is called mesosphere • Layers of Earth: mantel, crust, innercore (solid), outercore (liquid) • Plates are made of lithosphere which is a rigid material Three Kinds of Plate Tectonic Boundaries: • Convergent (here crust is destroyed as one plate dives under another.) • Divergent (where new crust is generated as the plates pull away from each other.) • Transform (where crust is neither produced nor destroyed as the plates slide horizontally past each other) Convection Current- the result of differential heating. Lighter (less dense), warm material rises while heavier (more dense) cool material sinks. Tectonic Plates and Earthquakes Fault Line- Earth’s crust weakest point Tectonic Plates and Volcanic Activity -Pacific Ring of Fire Volcano- Only happens in convergent and divergemt forms • Convergent forms in mountain ranges • Highest Mountain Range- Mt. Everest, Himalayas in Asia • Earthquake occurs at plate boundaries • Volcanic activities occur at convergent • Earthquakes happen along fault lines, which are cracks in Earth’s crust where tectonic plates collide. They are formed when plate subduct, spread, slip or collide. Lesson 2 Lesson 2 – Science Plate Boundaries Earthquake Focus and Epicenter Focus (Hypocenter) - the spot inside the Earth's crust Epicenter - directly above the focus on the surface of Earth Earthquake waves are also known as seismic waves • Seismic waves- travels in all directions after they are produced at the focus. • two types: Body waves and Surface waves • Body waves Primary Waves Secondary waves • P-waves -S-waves • seismic waves that travel the fastest -not travel as fast as P- waves • compressing and - shake perpendicularly or • expanding the medium transverse • not destructive - more destructive • Surface Waves • slowest and largest of the seismic waves • move in complicated ways: circular or elliptical motion • most destructive Earthquake Measurements • Seismologists- scientists who study earthquakes and seismic waves • Seismograph- the instrument they use to record seismic waves from all over the world Richter Scale - based on measurements of amplitudes, or heights, of seismic waves as recorded on seismographs -the measure of the “strength (size)” of an earthquake (which varies from 1 to 10) 7 STEPS TO EARTHQUAKE SAFETY • PREPARE • Secure your space • Plan to be safe • Organize disaster supplies • Minimize financial hardship • SURVIVE • Drop, Cover, and Hold • Improve safety • RECOVER • Reconnect and restore Volcanism • eruption of molten rock (magma) from inside the Earth to the surface Volcano • the opening through which magma and gases are discharged • magma that reaches the surface is called “lava” Why and where do volcanoes formed? Convergent Zone Oceanic Ridge System Hotspots Forms of Volcanoes • Lava with a high silica content produces explosive eruptions, whereas lava with a low silica content but a high iron and magnesium content produces more fluid eruptions • The amount of water vapor and gasses in the atmosphere influences how volcanoes erupt. • The types of volcanoes include shield, cinder cone and composite volcanoes, and fissure eruptions. • Inactive and Active volcanoes Types of Volcanoes Shield Volcanoes • largest type of volcano • broad volcanoes with gentle slopes • convex shape • basaltic lava Cinder Cone Volcanoes • tephra cones - smallest and the simplest type of volcano • cone-shaped & bowl-shaped crater • less than 300 m in height Composite Volcanoes • stratovolcano - most common type • steep-sided cones shape • felsic magma • form at subduction zones Volcanoes are classified as: Active Volcanoes- one that is erupting or showing signs of erupting soon Dormant Volcanoes- volcano to awaken in the future and become active Extinct Volcanoes- dead volcano; will probably not erupt again PHIVOLCS (Philippine Institute of Volcanology and Seismology) • is a Department of Science and Technology (DOST) service institute primarily charged with designed to mitigate disasters caused by volcanic eruptions, earthquakes, tsunami, and other related geotectonic What you should do during volcanic eruption: • Follow evacuation procedures. • Stay indoors. • Avoid low-lying areas and the areas downwind from the volcano. • For children, elderly, and people who have respiratory problems, wear masks that block small particles of ash. • Make sure the water and food you consume are safe. Mountain Formation OROGENY - is a product of movements of tectonic plates oros - 'mountain' genesis - 'creation' Mountains • a large and elevated landform steep, sloping sides and sharp or slightly rounded ridges and peaks • Mountain Ranges a cluster or chain of mountains have multiple peaks Most FamouS Mountain Ranges in the World -Himalayas • highest mountain range in the world • Jurassic Era • "Himalaya" - Sanskrit language • meaning: "House of Snow" • more than 20,000 ft • Mount Everest • Andes • longest mountain range in the world • three section: Central Andes, Southern • Andes, and Northern Andes • Mount Aconcagua • Mesozoic-Tertiary • The Appalachians • oldest mountain range in North America • Ordovician Period • Mount Mitchell (6,684 ft) • were once an extension of the Caledonian • mountain chain • The Alps • largest mountain system in Europe