Earth's Internal Structure & Seismic Waves PDF

MATERIALS NEEDED Hard boiled Plastic bag egg Old PVC/ plastic card newspaper LESSON 1A: INTERNAL STRUCTURE OF THE EARTH THE EARTH’S INTERNAL STRUCTURE CRUST MANTLE...

MATERIALS NEEDED Hard boiled Plastic bag egg Old PVC/ plastic card newspaper LESSON 1A: INTERNAL STRUCTURE OF THE EARTH THE EARTH’S INTERNAL STRUCTURE CRUST MANTLE OUTER CORE INNER CORE Did you know? Earth is 4.54 Billion years old!  01 02 CRUST MANTLE LAYERS OF THE 03 EARTH 04 OUTER CORE INNER CORE THE CRUST ❑ Solid in state CRUST ❑ 5-100 km thick ❑ The thinnest layer, only 1% of Earth’s Volume.  Elements that THE CRUST composes the Crust: CRUST  TWO TYPES OF THE CRUST CRUST CRUST ❑ Continental crust – 35 to 40 km thick, made mostly of granite. ❑ Oceanic crust – 5 to 10 km thick, made up of mostly basalt. KOLA SUPERDEEP BOREHOLE ❑ a.k.a. the “deepest hole in the world”. ❑ Located in Murmansk, Oblast Russia KOLA SUPERDEEP BOREHOLE  01 02 CRUST MANTLE LAYERS OF THE 03 EARTH 04 OUTER CORE INNER CORE THE MOHOROVICIC DISCONTINUITY ❑ Boundary between the earth's crust and the mantle. ❑ Named by a Croatian seismologist Andrija Mohorovicic, THE MANTLE ❑ Is the thickest layer of the Earth. MANTLE ❑ 2900 km thick ❑ It comprises 84% of the volume & 70% of Earth’s mass.  Upper Mantle THE MANTLE Lithosphere - Compose of crust and upper mantle. Asthenosphere -Where Convection currents occur THE MANTLE Lower Mantle -Extends from about 660 km to about 2,700 km beneath Earth’s surface. -Hotter and denser.  Elements that THE MANTLE composes the Mantle: MANTLE  01 02 CRUST MANTLE LAYERS OF THE 03 EARTH 04 OUTER CORE INNER CORE THE GUTENBERG DISCONTINUITY ❑ Boundary between the lower mantle and the outer core. ❑ Named by Beno Gutenberg, German-American seismologist. THE OUTER CORE OUTER CORE ❑ 2,300 km thick. ❑ Has a temp of 2,000 degrees Celsius. ❑ Made up of liquid Nickel and Iron. THE OUTER CORE ❑ Did you know that the outer core generates MAGNETIC FIELD.  01 02 CRUST MANTLE LAYERS OF THE 03 EARTH 04 OUTER CORE INNER CORE THE LEHMAN DISCONTINUITY ❑ Boundary that separates the outer core from inner core. ❑ Named by Inge Lehmann, Danish seismologist. THE INNER CORE INNER CORE ❑ 1,220 km in diameter ❑ Has a temp of 5,000 degrees Celsius. ❑ Made up of solid Nickel and Iron. QUICK RECAP LESSON 1B: SEISMIC WAVES Where do SEISMIC WAVES come from? -From the FOCUS of an Earthquake. PARTS OF AN EARTHQUAKE ❑ FAULT - is a fracture or zone of fractures between two blocks of rock. WHAT IS SEISMIC WAVE? ❑ SEISMIC WAVE - waves of energy that travels through Earth’s layer. What instrument do we use to record seismic waves? SEISMOMETER/ SEISMOGRAPH  Seismic Stations in the Philippines 65 stations 29 manned 30 unmanned 6 volcanic stations Which government agency is responsible for monitoring ground activities? Use this site to locate the nearest valley fault in your location: http://faultfinder.phivolcs.dost.gov.ph/ How many types of seismic waves are there?  SEISMIC WAVES SURFACE BODY WAVES WAVES  Surface Waves Wave which travels along Earth’s surface.  SURFACE WAVE RAYLEIGH LOVE Wave Wave  Rayleigh wave Named after “John William Strutt, Lord Rayleigh”. Moves the ground either up or down, side-to-side.  Love wave Named after “Augustus Edward Hough Love”. Faster than Rayleigh Moves side-to-side horizontally. WHICH AMONG THE TWO TYPES OF SURFACE WAVES IS CONSIDERED THE MOST DESTRUCTIVE? LOVE WAVE  SEISMIC WAVES SURFACE BODY WAVES WAVES  Body Waves Wave which travels through the earth’s interior.  BODY WAVES P- WAVE S-WAVE  P – wave Aka “PRIMARY WAVE” Compressional/ Longitudinal wave. Travels faster than S-wave.  P – wave Can travel and pass through solid and liquid. Travels at a rate of 6 km per second. If P – wave can pass through liquid and solid, which layer of the Earth can it penetrate? Mantle, Outer and Inner core  BODY WAVES P- WAVE S-WAVE  S – wave Aka “SECONDARY WAVE” Transverse/ shear wave. Travels slower than P – waves.  S – wave Can only pass through solids. Travels at a rate of 4 km per second. If S – wave can pass through solid, which layer of the Earth it can penetrate? Mantle HOW ARE WE GOING TO LOCATE THE EPICENTER OF AN EARTHQUAKE? TRIANGULATION METHOD  Triangulation method A way to determine earthquake’s epicenter. Uses selected seismograms from the seismograph stations.  Steps in Locating an Epicenter 1. Study the data showing the difference in the arrival time of P and S waves from different seismograph stations.  Steps in Locating an Epicenter Recording Time difference Distance of Station in the arrival time Epicenter from of P-wave and the Station(km) S-wave(seconds) Batangas 44.8 s Puerto Princesa 32 s Davao 38.4 s  Steps in Locating an Epicenter 2. Compute the distance of the epicenter from each of Wherein: the stations using this d= distance Td= time difference formula: in arrival of P- wave and S- wave.  Steps in Locating an Epicenter Recording Time difference Distance of Station in the arrival time Epicenter from of P-wave and the Station(km) S-wave(seconds) Batangas 44.8 s 560 km Puerto Princesa 32 s 400 km Davao 38.4 s 480 km  Steps in Locating an Epicenter 3. Convert distance in km to cm using this conversion factor: 1 cm=100 km  Steps in Locating an Epicenter Recording Time difference Distance of Computed Station in the arrival Epicenter from distance on the time of P-wave the Station(km) map (cm) and S-wave(second s) Batangas 44.8 s 560 km Puerto 32 s 400 km Princesa Davao 38.4 s 480 km  Steps in Locating an Epicenter Recording Time difference Distance of Computed Station in the arrival Epicenter from distance on the time of P-wave the Station(km) map (cm) and S-wave(second s) Batangas 44.8 s 560 km 5.6 cm Puerto 32 s 400 km 4 cm Princesa Davao 38.4 s 480 km 4.8 cm