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THE EARTHSINTERIORIntroduction

In Module 1, you have learned about the different processes and landforms along plate boundaries that slowly shaped the Earths surface. In Module 2, you will learn the connection between these processes with the internal structure and mechanisms of our planet.

What to expect: This module will help you visualize and understand the composition and structure of the Earths interior.

It provides you scientific knowledge that will help you describe the different layers of the Earth as well as understand their characteristics.

You will also learn concepts that explain the physical changes that it underwent in the past. This module also consists of activities that will help you develop your critical thinking skills to have a deeper understanding about the planet where you live.

Key Questions:1. How do the structure and composition of the Earth cause geologic activities and physical changes?

2. What are the possible causes of the lithospheric plate movements?

3. What proves the movement of the tectonic plates?

Studying the Earths InteriorScientists tried to explore and study the interior of the Earth. Yet, until today, there are no mechanical probes or actual explorations done to totally discover the deepest region of the Earth.

How did they know?The Earth is made up of three layers: the crust, the mantle, and the core. The study of these layers is mostly done in the Earths crust since mechanical probes are impossible due to the tremendous heat and very high pressure underneath the Earths surface.

Reading Resources and Instructional ActivitiesRead the given resources and answer Act. 1.

Activity 1A: Amazing Waves!Objectives:Define seismic waves scientifically.Differentiate the different types of seismic waves.Recognize the importance of seismic waves in the study of the Earths interior.

Procedure: (1whole)Construct your own organizer that shows necessary information and summarizes the concept about seismic waves.

Answer Q1 and Q2.

Seismic WavesSeismic waves from earthquakes are used to analyze the composition and internal structure of the Earth.What are seismic waves?

Seismic wavesEarthquake is a vibration of the Earth produced by the rapid release of energy.This energy radiates in all directions from the focus in the form of waves called seismic waves.

Earthquake: Seismic Wave

Wave DirectionFaultEpicenterFocus

Types of Seismic WaveSurface waves

Body Waves

Surface Wavescan only travel through the surface of the Eartharrive after the main P and S waves 2 Types of Surface WavesLove WavesRayleigh Waves

Love Wavenamed after A.E.H. Love, a British mathematician who worked out the mathematical model for this kind of wave in 1911.faster than Rayleigh waveit moves the ground in a side-to-side horizontal motion, like that of a snakes causing the ground to twistcause the most damage to structures during an earthquake.

Love Wave

Rayleigh Wavenamed after John William Strutt, Lord Rayleigh, who mathematically predicted the existence of this kind of wave in 1885wave rolls along the ground just like a wave rolls across a lake or an oceanup and down or side-to-side similar to the direction of the waves movementshaking felt from an earthquake

Rayleigh Wave

Body wavescan travel through the Earths inner layersthey are used by scientists to study the Earths interiorhigher frequency than the surface waves

Body waves2 typesP-Waves (Primary waves)

S-waves (Secondary waves)

P-waves (Primary)is a pulse energy that travels quickly through the Earth and through liquidstravels faster than the S-waveit reaches a detector first

P-waves (Primary)compressional waves, travel by particles vibrating parallel to the direction the wave travel move backward and forward as they are compressed and expandedthey travel through solids, liquids and gases

S-waves (Secondary/Shear)pulse energy that travels slower than a P-wave through Earth and solidsMove 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

S-waves (Secondary/Shear)cannot travel through any liquid medium led seismologists to conclude that the outer core is liquid

Seismic Waves movement

Cross section of the Earth as seismic waves travel through it

Propagation of Seismic Waves Through Earths Interior

Longitudinal waves travel through both solids and liquids.Transverse waves travel through solids only.

Remember:P-waves are detected on the other side of the Earth opposite the focus. A shadow zone from 103 to 142 exists from P-wavesSince P-waves are detected until 103, disappear from 103 to 142, then reappear again, something inside the Earth must be bending the P-waves

Remember:existence of a shadow zone, according to German seismologist Beno Gutenberg (u t n bk), could only be explained if the Earth contained a core composed of a material different from that of the mantle causing the bending of the P-wavesTo honor him, mantlecore boundary is called Gutenberg discontinuity

Remember:From the epicenter, S-waves are detected until 103, from that point, S- waves are no longer detectedS-waves do not travel all throughout the Earths bodyknowing the properties and characteristics of S-waves (that it cannot travel through liquids), and with the idea that P-waves are bent to some degree, this portion must be made of liquid, thus the outer core

Remember: 1936, the innermost layer of the Earth was predicted by Inge Lehmann, a Danish seismologistdiscovered a new region of seismic reflection within the coreEarth has a core within a core

Remember: the outer part of the core is liquid based from the production of an S wave shadow and the inner part must be solid with a different density than the rest of the surrounding materialsize of the inner core was accurately calculated through nuclear underground tests conducted in Nevada. echoes from seismic waves provided accurate data in determining its size

Bring the ff. (by grp)15g cornstarch2 small cupsMedicine dropperStirring rod or spoon

Act. 1B. Simulating PlasticityProcedure: Put 15 g cornstarch into one of the beakers. Put 10 ml water into the other beaker.Add one drop full of water to the cornstarch. Stir the mixture.How does the mixture react like; solid, liquid or gas?

Continue to add water to the mixture, one drop full at a time. Stir the mixture after each addition.Stop adding water when the mixture becomes difficult to stir.Pour the mixture into your hand.Roll the mixture into a ball and press it.

Answer the ff. questionsHow does the mixture behave like?How is the mixture of cornstarch and water similar to the earths mantle?How is it different from the earths mantle?How does the plasticity of the earths mantle influence the movement of the lithospheric plates?

Bring the ff: (by grp)hardboiled egg/s bread knifeused paper/newspaper to work on

Activity 1C: Hard Boiled EarthPROCEDURE:1. Prepare the materials. (hardboiled egg, bread knife, used paper to work on)2. Place used paper or newspaper on your working area. Cut the egg into halves using a knife or a cutter.

Procedure:Using qualitative observation, describe the parts of the egg from the outermost to the innermost by completing the table. Write your answer on a piece of paper/ short bond paper.

PARTS OF THE EGGDECSRIPTIONEQUIVALENT TO THE EARTHS LAYERDESCRIPTION

Procedure:4. Draw the appearance of the cut hard-boiled egg.5. Answer the ff.A. How many layers does a hard-boiled egg have?B. Which is the largest part? The thinnest?C. Compare the parts of the egg to the model of the earth. D. Aside from the hard-boiled egg, what other things can you compare to the earths interior layers?

Reminder: A.E.H LoveAugustus Edward Hough Love

OUR HOME PLANET, EARTHOur Earth is about average among the planets in the Solar System, in many respects:largest and most massive of the four terrestrial planets, but smaller and less massive than the four giant, or Jovian, planetsthird in distance from the Sun among the four terrestrial planetshas a moderately dense atmosphere; 90 times less dense than that of Venus but 100 times denser than that of Mars

OUR HOME PLANET, EARTHEarth is also unique in many respects:the only planet with liquid water on its surface.the only one having a significant (21%) proportion of molecular oxygento our best current knowledge, the only planet in the solar system having living organismsthe only terrestrial planet having a moderately strong magnetic fieldthe only terrestrial planet having a large satellite

OUR HOME PLANET, EARTH

The Solid Earthgeology -the study of the structure, history, and activity of the solid Earth, including its interactions with the atmosphere, hydrosphere, cryosphere, and biospheresolid Earth contains four major zones: the core (which is divided into inner and outer zones), the (upper and lower) mantle, the asthenosphere, and the lithosphere

The Solid Earththe outer zones is not uniform and fixed over the surface of the Earth, but shows much variability with position and time.The field of plate tectonics deals with this spatial and temporal variability.Geological phenomena such as earthquakes, volcanoes, and continental drift are accounted for by plate tectonics.

The Composition of the Earths Interior

Seismic Waves: Interior Part

Activity 2: Our Dynamic Earth Objectives:Describe the properties of the layers of the Earth.Tell the composition of the layers of the Earth.

Procedure:1. Label the drawing corresponding to the Earths layers.2. Describe the different layers of the Earth using symbols.3. Choose from the response grid on the right the symbol that you need to finish the figure on the left.4. Draw the symbol/s in the corresponding layer of the Earth.

Refer to the image below.

Answer Q3-Q9.

Did you know?The deepest mine in the world, the gold mine in South Africa, reaches a depth of 3.8km.But...You would have to travel more than 1,600 times that distance-over 6000km-to reach the earths center.

The Composition of the Earths Interior

DENSITY AND TEMPERATURE VARIATION IN DEPTH

The Crust

The Crustthinnest and the outermost layer of the Earth that extends from the surface to about 32 kilometers belowContinentalOceanic

Stanley, 1989, p. 14Continental

Stanley, 1989, p. 14ContinentalRootMohoOceanicLithosphereAsthenosphere

Continentalmainly made up of silicon, oxygen, aluminum, calcium, sodium, and potassiummostly 35-40 kilometersfound under land massesmade of less dense rocks such as granite

Oceanicoceanic crust is around 7-10 kilometers thick which its average thickness is 8 kilometers. found under the ocean floormade of dense rocks such as basalt heavier than the continental crust.

The Crust: Continental

GRANITE -crystalline igneous rock composed primarily of quartz and feldspar.forms from slowly cooling magma that is subjected to extreme pressures deep beneath the earth's.

The Crust: Oceanic

BASALT -volcanic rock forms from lava flows along mid-ocean ridges and also in igneous intrusions such as dikes and sills. Columnar jointing, pictured here at Devil's Tower, Wyoming, occurs when molten basalt cracks as it cools, producing separate, polygonal fractures on the surface of the rock.

Elements in the Crust

Moho DiscontinuityWhile studying the speed of earthquake waves, Croatian geophysicist Andrija Mohorovii discovers a boundary between Earth's crust and mantle, which becomes known as the Mohorovii, or Moho, Discontinuity.

The MantleBeneath the crust is the mantleextends to about 2900 kilometers from the Earths surfaceabout 80% of the Earths total volume about 68% of its total mass mainly made up of silicate rocksand contrary to common belief, is solid, since both S-waves and P-waves pass through it

The Mantlemostly made of the elements silicon, oxygen, iron and magnesiumlower part of the mantle consists of more iron than the upper partlower mantle is denser than the upper portiontemperature and the pressure increase with depthhigh temperature and pressure in the mantle allows the solid rock to flow slowly

Remember:The ability of the asthenosphere to flow slowly is termed as plasticity. crust and the uppermost part of the mantle form a relatively cool, outermost rigid shell called lithosphere (Gk.lithos means stone) and is about 50 to 100 kilometers thick

Remember:Beneath the lithosphere lies the soft, weak layer known as the asthenosphere (Gk. asthenes means weak) made of hot molten material, about 300 800o Cupper 150 kilometers has a temperature enough to facilitate a small amount of melting, and make it capable to flowfacilitates the movement of the lithospheric plateslithosphere, with the continents on top of it, is being carried by the flowing asthenosphere.

Layers

The Core2000-5000o Ccore is subdivided into two layers: the inner the outer core.

Outer Core2900 kilometers below the Earths surface2250 kilometers thick made up of iron and nickeltemperature reaches up to 2000oC at this very high temperature, iron and nickel melt

Outer CoreAside from seismic data analysis, the Earths magnetic field strengthens the idea that the Earths outer core is molten/liquidmainly made up of iron and nickel moving around the solid inner core, creating Earths magnetism

The Inner Coremade up of solid iron and nickel and has a radius of 1300 kilometersabout 5000oCextreme temperature could have molten the iron and nickel but it is believed to have solidified as a result of pressure freezing, which is common to liquids subjected under tremendous pressure

The Inner CoreAside from the fact that the Earth has a magnetic field and that it must be iron or other materials which are magnetic in nature, the inner core must have a density that is about 14 times that of water. Average crustal rocks with densities 2.8 times that of water could not have the density calculated for the core. So iron, which is three times denser than crustal rocks, meets the required density.

Clues that the inner core and the outer core are made up of ironIron and nickel are both dense and magnetic.overall density of the earth is much higher than the density of the rocks in the crustsuggests that the inside must be made up of something denser than rocks

Clues that the inner core and the outer core are made up of ironMeteorite 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 roughly have the same density, thus the Earths mantle rock and a meteorite minus its iron, have the same density.

HW4Write a short story that describes the most exciting part of your own imaginary journey to Earths center.Bring the ff. (by group)scissorsold magazinesletter envelope