MODULE2 SCIENCEEEEEEEEEEEEEEEEEEEE10.ppt
- 1. MODULE 2 THE EARTH’S INTERIOR Add a footer
- 2. EARTH LAYERS Add a footer
- 3. SEISMIC WAVES Add a footer SEISMOGRAPH a device used to record earthquake waves
- 4. Types of Seismic Waves
- 5. Types of SURFACE WAVE 1. Love waves Add a footer named after A.E.H. Love, a British mathematician who worked out the mathematical model for this kind of wave in 1911. faster than Rayleigh wave it moves the ground in a side-to-side horizontal motion, like snake Love waves cause the most damage to structures during an earthquake.
- 6. Types of SURFACE WAVE 2. Rayleigh waves Add a footer named after John William Strutt, Lord Rayleigh, who mathematically predicted the existence of this kind of wave in 1885. it move rolls along the ground just like a wave rolls an ocean. it moves the ground either up and down or side-to-side Most of the shaking felt from an earthquake is due to the Rayleigh wave.
- 7. Types of BODY WAVE 1. P-wave (primary wave) Add a footer is a pulse energy that travels quickly through the Earth The P-wave travels faster than the S-wave also called compressional waves, travel by particles vibrating parallel to the direction the wave travel. They force the ground to move backward and forward as they are compressed and expanded. they travel through solids, liquids and gases.
- 8. Types of BODY WAVE 1. S-wave (secondary wave or shear wave) Add a footer is a pulse energy that travels slower than a P-wave through Earth and solids. move as shear or transverse waves, and force the ground to sway from side to side, in rolling motion that shakes the ground back and forth perpendicular to the direction of the waves. The idea that the S-waves cannot travel through any liquid medium led seismologists to conclude that the outer core is liquid.
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- 11. EPICENTER •Is a point in the Earth’s surface directly above the focus. •The farther away from the epicenter means the longer time interval between the arrival of P and S Add a footer Focus Epicenter Fault Seismic wave
- 12. • In 1909, Yugoslavian seismologist Andrija Mohorovičić (moh-haw-rohvuh-chich) found out that the velocity of seismic waves changes and increases at a distance of about 50 kilometers below the Earth’s surface. • This led to the idea that The boundary between these two layers crust and mantle is called MOHOROVIČIĆ DISCONTINUITY in honor of Mohorovičić, and is short termed MOHO Add a footer
- 13. P-WAVE • can travel through liquids, solid •are detected on the other side of the Earth opposite the focus. A shadow zone from 103° to 142° exists from P-waves •a shadow zone, according to German seismologist Beno Gutenberg could only be explained if the Earth contained a core composed of a material different from the mantle •mantle–core boundary is called Gutenberg discontinuity. S-WAVE •can travel through solid only •From the epicenter, S-waves are detected until 103o , from that point, S- waves are no longer detected. •This observation tells us that the S-waves do not travel all throughout the Earth’s body. Add a footer
- 14. • P-waves are bent to some degree, this portion must be made of liquid, thus the outer core • In 1936, the innermost layer of the Earth was predicted by Inge Lehmann, a Danish seismologist. • He discovered a new region of seismic reflection within the core. So, the Earth has a core within a core. Add a footer •Outer part of the core is liquid •Inner part must be solid with a different density
- 15. • The size of the inner core was accurately calculated through nuclear underground tests conducted in Nevada. Add a footer
- 16. Activity 1 Amazing Waves! Add a footer
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- 18. CRUST • the thinnest and the outermost layer of the Earth. • from the surface to about 32 kilometers below. • the thickness extends to 72 kilometers. • is subdivided into two regions: the continental crust & oceanic crust Add a footer
- 19. TWO REGIONS/LAYERS OF CRUST 1. Continental crust • Most thickness (35-40 km) • Found under land masses • made of less dense rocks such as granite 2. Oceanic crust • Most thin (8 km) • found under the ocean floor • made of dense rocks such as basalt. heavier Add a footer
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- 21. MANTLE • It’s 2900 kilometers from the Earth’s surface. • It makes up about 80% of the Earth’s total volume and about 68% of its total mass. • made up of silicate rocks & it is solid, since both S-waves and P-waves pass through it. • mostly made of the elements silicon, oxygen, iron and magnesium. • The temperature and the pressure increase with depth. Add a footer
- 22. 1. UPPER MANTLE • made of the elements silicon, oxygen, iron and magnesium • Less dense 2. LOWER MANTLE • made of the elements silicon, oxygen, iron and magnesium • Most denser because consists of more iron Add a footer TWO LAYER OF MANTLE
- 23. Lithosphere -it called to crust and the uppermost part of the mantle Add a footer -form a relatively cool and outermost rigid shell. - 50 to 100 kilometers thick -The lithosphere, with the continents on top of it, is being carried by the flowing asthenosphere.
- 24. THE CORE 2. inner core -has a radius of 1300 kilometers. -temperature reaches to about 5000o C -made up of solid iron and nickel -The extreme temperature could have molten the iron and nickel but it is believed to have solidified as a result of pressure freezing
- 25. Some clues that the inner core and the outer core are made up of iron include the following: • Iron and nickel are both dense and magnetic. • The overall density of the earth is much higher than the density of the rocks in the crust. • Meteorite analysis have revealed that the most common type is chondrite. • Chondrite contains iron, silicon, magnesium and oxygen; some contains nickel. • The whole earth and the meteorite have same density, thus the Earth’s mantle rock and a meteorite have same density. Add a footer
- 26. Activity 2: Our Dynamic Earth Add a footer
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Editor's Notes
- #7: After an earthquake, it reaches a detector first (the reason why it is called primary).
- #8: After an earthquake, it reaches a detector first (the reason why it is called primary).
- #21: The high temperature and pressure in the mantle allows the solid rock to flow slowly.
- #27: Ok, that’s all for today. Goodbye, class!