Q2 SCI-8 Module 1: Faults and Earthquakes PDF

DEPARTMENT OF EDUCATION MARIGONDON NATIONAL HIGH SCHOOL Marigondon, Lapu-Lapu City, Cebu, Philippines 6015 Telephone Number: 254 -4295 Name of Learn...

DEPARTMENT OF EDUCATION MARIGONDON NATIONAL HIGH SCHOOL Marigondon, Lapu-Lapu City, Cebu, Philippines 6015 Telephone Number: 254 -4295 Name of Learner: _______________________________________ Grade Level:_____________ Teacher: ____________________________ Section:__________ Date:_______________ LEARNING ACTIVITY SHEET Title of the Topic: Subject: QUARTER 2 – Module 1: Faults and Earthquakes SCIENCE 8 Most Essential Learning Competency: Code: Using models or illustrations, explain how movements along S8ES-IIa-14 faults generate earthquakes, S8ES-IIa-15 Differentiate the epicenter from its focus; intensity of an earthquake from its magnitude; active and inactive faults I. CONCEPT NOTES The occurrence of earthquake is inevitable. Nobody knows when and where this phenomenon will happen. Philippines is one of the countries that lie along the Pacific Ring of Fire, thus, earthquakes and volcanic eruptions are likely to occur. Strong earthquakes have caused countless deaths all over the world, even before people have started recording these events. In 2013, Cebu and Bohol experienced a strong tremor which brought death and destruction of various historical sites such as old churches and other infrastructures. It is believed that earthquakes are associated with faults. When a fault suddenly moves, earthquakes take place. Are you familiar with faults? How does a fault look like? How do faults generate earthquake? Try to answer! Study the illustration below and write your answers on the space provided. (Image courtesy of the GEER Association and National Science Foundation) Guide Questions 1. What did you notice with the road? __________________________________ 2. What causes it to look that way? ___________________________________ (Look at the picture above) Fault is a break in the Earth’s crust, and along the break, significant movement has taken place. According to the Department of Science and Technology (DOST), the 1200-km long Philippine Fault Zone is a major tectonic feature that transects the whole Philippine archipelago from Northwestern Luzon to Southeastern Mindanao. This arc-parallel, left-lateral strike slip fault is divided into several segments and has been the source of large-magnitude earthquakes in recent years How do faults generate earthquakes? The second activity shows the occurrence of earthquake. Imagine that the boxes represent the ground and boundary between them as fault. Energy from inside the Earth makes the ground move. This is simulated by pulling on the rubber band. When you pulled the rubber band, the boxes did not move right away because there was a masking tape (friction) that placed in between the two boxes. This means that not all energy released by the Earth leads to such movement since friction is present in the ground. It keeps the rocks in place. Once friction is overcome, the ground suddenly moves, and an earthquake occurs. This process is known as stick and slip. In this process, at first rocks are stuck together due to friction. Later, the rocks suddenly slip (meaning moving quickly), generating an earthquake. Every time a fault slips, the Earth quakes. A. FOCUS AND EPICENTER Back in 2013, a strong earthquake hit Cebu and Bohol. According to the report, it has a magnitude of 7.2 and was located 6 kilometers Southwest of Sagbayan, Bohol. Sagbayan refers to the epicenter of the earthquake. According to Garciano and Taclibon (2013), the strong ground motion was caused by a reverse thrust movement of a newly discovered fault now named as the North Bohol fault. The upward movement caused widespread damage to lives and properties especially on the westside of the fault line. Focus and epicenter are two essential terms that we need to be familiar with in order to fully grasp how earthquakes originate. All earthquakes start beneath Earth’s surface. The focus/hypocenter of an earthquake is the point  DEPARTMENT OF EDUCATION MARIGONDON NATIONAL HIGH SCHOOL Marigondon, Lapu-Lapu City, Cebu, Philippines 6015 Telephone Number: 254 -4295 underground where rocks first begin to move. Seismic waves travel outward from the earthquake’s focus. The epicenter is the point of Earth’s surface directly about the focus. Scientists often name an earthquake after the city that is closest to its epicenter. Where does an earthquake start? In order for the scientists to determine the origin of the earthquake, terms such as focus or hypocenter and epicenter are usually used. Focus or hypocenter is the origin of the earthquake and is hidden “underground.” The spot directly above the focus or hypocenter on the surface of the Earth is called the epicenter. Seismograph is an instrument that records seismic waves created by earthquakes. B. INTENSITY AND MAGNITUDE We all know that threats brought about by the occurrence of earthquakes. When we speak of destruction caused by earthquakes, most of the words that come into our minds are intensity and magnitude. But, do these terms mean the same thing? Earthquake is a phenomenon that can never be predicted by anyone. Once it happens, scientists are likely to take note on the effects it brings. Among the characteristics of earthquakes are magnitude and intensity. The Philippine Institute of Volcanology and Seismology (PHIVOLCS) utilized the PHIVOLCS Earthquake Intensity Scale to determine the intensity of earthquakes in the Philippines. It has been recalled that century-old buildings and churches were severely affected by the 2013 earthquake that took place in Bohol. Aside from the physical destruction, it also created stampedes and commotions to both provinces. A 7.2 quake underneath Bohol island, damaging structures like this old church in Loboc town. Source: https://www.bbc.com/news/world-asia-24530042 Look into the pictures and reflect on how devastating the 2013 Bohol earthquake that has affected the neighboring provinces such as Cebu. How Strong is the Earthquake? The strength of an earthquake is measured by determining its magnitude and intensity. It has been noted in the previous lesson that friction keeps the rocks in place and when the energy from the earth overcomes friction, the rocks suddenly snap and the stored energy is released. The released energy refers to the magnitude of an earthquake. Therefore, the greater is the magnitude, the stronger the earthquake. On the other hand, intensity of an earthquake is based on the effects the earthquake in various places. Moreover, magnitude uses Hindu-Arabic numerals (2,3,4) while intensity employs Roman numerals (I, II, III) in measuring how strong the earthquake is. Richter Scale Source The Richter magnitude scale is a common standard measurement of earthquakes. It was invented in 1935 by Charles F. Richter of the California Institute of Technology as a mathematical device to compare the size of earthquakes.  DEPARTMENT OF EDUCATION MARIGONDON NATIONAL HIGH SCHOOL Marigondon, Lapu-Lapu City, Cebu, Philippines 6015 Telephone Number: 254 -4295 PHIVOLCS Earthquake Intensity Scale ACTIVE & INACTIVE FAULTS We all know the PHIVOLCS has recorded many fault lines in the Philippines. It is very important that we are informed and aware on the existing fault that is present in our community so that prevention of untoward incidences must be put beforehand. Based on the previous lesson, we learned that fault is a break on the Earth’s surface, and along this fracture, a significant movement has taken place. So therefore, earthquakes happen along a fault. There are two types of faults, active fault and inactive fault. Below is the picture as to how an active fault and inactive fault look like. An active fault is one that has moved in the past and is expected to move again. In simple terms, this means that active faults have produced earthquakes and can generate movements in the future. There are so many ways that the scientists have identified the active faults, to wit: Scientists check historical records. It has been noted that historians have documented all the destructive events such as earthquake. Scientists also spend time studying the vibrations that are generated from faults. They also observe their surroundings if there are signs of active and inactive faults. Most of the time, a displaced road or a stream channel that is shifted in a different direction may be a good indicator that a given place has a fault. Why is there a need to know about active and inactive faults? It is very important to know the location of the fault so that we can prevent any severe destruction when earthquake occurs. PHIVOLCS has mapped out the fault lines that run within the country and reminded the public not to construct any significant structures that are situated in a fault line II. LEARNING ACTIVITIES Learning Task 1: Match column A with column B. Write the letter of the correct answer. Column A Column B _____ 1. Fault A. strength of earthquake _____ 2. Magnitude B. break or fracture on the Earth’s surface _____ 3. Friction C. the spot above the focus _____ 4. Focus D. force that keeps the rocks to stay in place _____ 5. Intensity E. origin of the earthquake _____ 6. Epicenter F. effects of earthquake  DEPARTMENT OF EDUCATION MARIGONDON NATIONAL HIGH SCHOOL Marigondon, Lapu-Lapu City, Cebu, Philippines 6015 Telephone Number: 254 -4295 Learning Task II Compare and contrast the following terms. Write your answers on the space provided. IV. REFLECTION Many were also evacuated from buildings, like this hospital in Cebu, where patients were led to safer areas. Source: https://www.bbc.com/news/world-asia-24530042 My Reflection Direction: Write your personal insights and reflection on the pictures that were shown above. What is the message of these illustrations? How does earthquake affect us?  DEPARTMENT OF EDUCATION MARIGONDON NATIONAL HIGH SCHOOL Marigondon, Lapu-Lapu City, Cebu, Philippines 6015 Telephone Number: 254 -4295 Name of Learner: _______________________________________ Grade Level:_____________ Teacher: ____________________________ Section:__________ Date:_______________ LEARNING ACTIVITY SHEET Title of the Topic: Subject: QUARTER 2 – Module 2: Understanding Typhoons SCIENCE 8 Most Essential Learning Competency: Code: Explain how typhoon develops and how it is affected by S8ES-IIf-21 landmasses and bodies of water Trace the path of typhoons that enter the Philippine Area of Responsibility (PAR) using a map and tracking data I. CONCEPT NOTES Lesson 1: Describe what is a typhoon What Is A Typhoon? A Typhoon is an intense area of low atmospheric pressure. Like all low pressure weather systems observed North of the Equator, the air rotates around the center of an area of low pressure in an anti-clockwise direction (clockwise if South of the Equator). The more intense the area of low pressure the higher the wind speeds near the center. Typhoons in the Philippines Typhoons are one of the most destructive natural calamities that often hit our country experiences. A typhoon is a vast (very big) mass of moist (slightly wet) air moving very fast in circles. It is formed in the warm seas. It brings heavy rains, dangerous winds, flashfloods and big rising waves. A typhoon can destroy lives, crops and properties. If you locate the Philippines on the world map, you will see that large bodies of water surround the archipelago. Do you know the oceans that surround the Philippines? Take a look at the map above. What do you see? The Philippines is bounded on the east by the Pacific Ocean and the Philippine Sea. It is bounded on the south by Celebes Sea and on the west by South China Sea. The Philippines is situated near the Western North Pacific Basin. This basin is one of the six areas in the world where most of the typhoons are formed. In most cases, the typhoons that are formed in this area pass along the Philippine territory. This explains why the Philippines often experiences an average of 20 to 22 typhoons yearly. It is said that the Philippines lies along the Pacific typhoon belt. Tropical Cyclone Categories Tropical depression, tropical storm, typhoon, and super typhoon are categories of tropical cyclones (Table 1). In simple terms, a tropical cyclone is a system of thunderstorms that are moving around a center. As the winds intensify or weaken, the category is upgraded or downgraded accordingly. The term typhoon is used only in the northwestern part of the Pacific Ocean. In the northeastern part of the Pacific Ocean and in the northern part of the Atlantic Ocean, the equivalent term is hurricane. Thus, a hurricane on one side of the Pacific Ocean will be called a typhoon if it crosses into the other side. In the Philippines, we use the same word for all categories of tropical cyclones. We call it bagyo whether it is a tropical depression, a tropical storm or a typhoon. Philippine Area of Responsibility The Philippines is in the western part of the North Pacific Ocean. This vast area encompasses many countries in Oceania and the eastern parts of Asia. Tropical cyclones can form over warm waters anywhere within this area. This poses a significant challenge to the forecasters in different countries within this region. To make monitoring easy for the forecasters, this large  DEPARTMENT OF EDUCATION MARIGONDON NATIONAL HIGH SCHOOL Marigondon, Lapu-Lapu City, Cebu, Philippines 6015 Telephone Number: 254 -4295 region of the Pacific Ocean is broken into smaller domains called "areas of responsibilities". Here, forecasters will only have to monitor those TCs that are relevant to their country. Picture Paths of Typhoons in the Philippines Shown below are the tracks (paths) of four tropical cyclones that entered the PAR in the past years. The tracks were plotted by PAGASA. Study the maps and answer the following questions. From the maps, you can see that tropical cyclones generally move in a northwest direction. The reason is because there are large-scale winds that push the tropical cyclones in that direction. This is similar to the way a whirlpool is carried along by a flowing stream. As you can observe, all four tropical cyclones struck the northern part of the Philippines. Now you know why the southern part of the Philippines is often untouched by tropical cyclones. Where do you think should a tropical cyclone form so it would hit the Mindanao area? Three of the tropical cyclones mentioned above weakened and died out near land. Agaton dissipated in Luzon, Yoyong in Taiwan, and Huaning near Mainland China. This means that when tropical cyclones reach land, they die out because they are cut off from the warm ocean waters that keep them going. Now you know where tropical cyclones start to form, why they form there, and in what direction they generally move. Can you now explain why the Philippines is prone to typhoons? Over the broad area where a cyclone forms, the water is warmer than the surroundings area. Its temperature is higher than 26°C.The warm moist air above it rises, creating a low- pressure area. The wind from the surroundings area spirals counterclockwise (in the Northern Hemisphere) as it flows into the low-pressure area. Refer to Figure 3. It shows three conditions necessary for the formation of a cyclone. a. The supply of rising warm moist air is continuous. b. The air at the center rises high enough. c. The exit of air above is continuous, thus, permitting a continuous flow of rising air from below. Unless these conditions are maintained, the wind will weaken and the low- pressure area will dissipate. Tracking a Tropical Cyclone Use the latitude and longitude (lat-long) in the table below to track the location of Sendong. Plot each lat-long pair on the map with the PAR. Sendong started out in the Pacific as an area of low pressure. Because it was just a low-pressure area, it was not given a name. Then it intensified into a tropical depression. Again it was not yet given a name because it was still outside the PAR. When it finally entered the PAR, it had already strengthened into a tropical storm. Since it was within the PAR by then, PAGASA gave it a name— Sendong— from its prepared list. Internationally, the tropical storm was called Washi. Sendong brought hours of torrential rains to Mindanao. Some places received more than 200 mm of rain. Because of the excess rain, flash floods and landslides took place. Nearly a thousand people were killed, many in the cities of Cagayan de Oro and Iligan. Damage to houses, roads, and bridges reached up to 2  DEPARTMENT OF EDUCATION MARIGONDON NATIONAL HIGH SCHOOL Marigondon, Lapu-Lapu City, Cebu, Philippines 6015 Telephone Number: 254 -4295 billion pesos. After the Sendong disaster, who would have thought that another tropical cyclone would again hit Mindanao the following year. Tropical cyclone Pablo (international name, Bopha) was so strong it was categorized as a super typhoon. Clearly, we need to learn about tropical cyclones in order to survive. Inside the Tropical Cyclone The lowest air pressure is at the eye of a tropical cyclone. In fact, all tropical cyclones have low air pressure at the center. This is the reason why the air in the surroundings move toward the eye. At the eye of a tropical cyclone, wind speed is low. But in the dense clouds surrounding the eye, at the eyewall itself, the wind speed is great. When newspapers report that a tropical cyclone has sustained winds of 200 km/hour, for instance, they are referring to the winds at the eyewall. When the eye of a tropical cyclone passes over a certain place, it is the winds at the eyewall that wreak a lot of damage. As it approaches, one side of the eyewall brings strong winds blowing in one direction. Then comes the eye with its somewhat calm weather. As it leaves, the other side of the eyewall brings strong winds again, but this time in the opposite direction. The public storm warning system (PSWS) is as follows: PAGASA(Philippine Atmospheric, Geophysical and Astronomical Services Administration ).warns the people of approaching typhoons using typhoon signals. Typhoon signals are sent out at least 24 hours before typhoons hit land to give people time prepare and protect themselves from strong winds and rain. What precautionary measures should people undertake in case warnings of an approaching typhoon are issued by PAGASA? PSWS No. 1: The first signal indicates that the area affected should expect intermittent rains within at least 36 hours. Winds of 30 kph to 60 kph should be expected, although it is unlikely that they will cause significant damage. As a precaution, classes in all public and private pre-schools are automatically suspended. PSWS No. 2: The second warning signal is raised in areas that will experience winds of 60 kph to 100 kph within at least 24 hours. Light to moderate damage is expected. Some trees may be uprooted and roofs blown away. People traveling by air and sea are cautioned, and disaster preparedness agencies should be alerting their respective communities. Classes from pre-school to high school are suspended. PSWS No. 3: When the third warning signal is raised, people are advised to seek shelter inside strong buildings, evacuate low-lying areas, and stay away from coasts and riverbanks as moderate to heavy damage is expected. Winds of 100 kph to 185 kph are expected within at least 18 hours. The winds could topple trees and destroy crops and houses made of light materials. Widespread disruption of electrical power and communication services is also expected. Classes at all levels are automatically suspended. PSWS No. 4: The fourth storm warning signal indicates that a very intense typhoon with winds of more than 185 kph may be expected within at least 12 hours. The typhoon is potentially very destructive. Large trees are expected to be uprooted and residential and institutional buildings could be severely damaged. Travels and outdoor activities should be cancelled. PSWS No. 5: This recently added storm warning signal is raised when a super typhoon will affect an area. Very powerful winds of more than 220 kph may be expected in at least 12 hours. This typhoon is "extremely destructive or catastrophic" to the community as almost total damage to structures is expected. Most residential and institutional buildings may be severely damaged, and only a few crops and trees will be left standing. Evacuation to safer shelters should be completed early as it may already be too late if it hasn't begun. The disaster coordinating councils concerned and other disaster response organizations should be fully responding to emergencies by this time or completely ready to immediately respond to the calamity. To further help citizens prepare for heavy rains and flooding, PAGASA also has the following color-coded rainfall or storm surge advisory system: Yellow Rainfall Advisory: Citizens should expect flooding in low-lying areas as 7.5-15 mm of rainfall (8 liters per square meter/hour) is expected within one hour and is likely to continue in the next two hours. There is also a possibility of a storm surge of.5-1 meter high. Everyone is advised to monitor the weather condition because the rainfall warning could be raised. Orange Rainfall Advisory: Intense rains of 15-30 mm (15-30 liters per square meter/hour) are expected within one hour and flooding is considered a definite threat in communities under this alert. Rainfall is expected to continue in the next two hours and storm surges 1 meter to 3 meters high are expected. Red Rainfall Advisory: This rainfall advisory is issued when downpours constitute an emergency. It is raised when the torrential rainfall is more than 30 mm within one hour or if it has continued for the past three hours and has risen to more than 65 mm (30 liters per square meter/hour). Storm surges over 3 meters high are expected and will most likely cause severe damage to coastal and marine infrastructure. Serious flooding is expected in low lying areas and evacuation to road or a stream channel that is shifted in a different direction may be a good indicator that a given place has a fault. II. LEARNING ACTIVITIES Learning Task 1: Instructions: Modified True or False. Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement correct.  DEPARTMENT OF EDUCATION MARIGONDON NATIONAL HIGH SCHOOL Marigondon, Lapu-Lapu City, Cebu, Philippines 6015 Telephone Number: 254 -4295 _________1. The lowest air pressure is at the eye wall of the tropical cyclone. _________2. At the eye of a tropical cyclone, wind speed is higher. _________3. Tropical cyclones require warm ocean waters to be able to develop at least 25.6 °C or greater. _________4. Tropical depression generally moves in a northeast direction with an average speed of 19-20 km/hr. _________5. Weather forecasting is a prediction on the general weather conditions of the atmosphere in the next 20 hours. _________6. You help Father check the roof of the house for possible leak, and also things that be blown away. Help him cut small branches of plants and trees near the house. Your sister helps Mother store enough food to last for 3 to 4 days. Then you listen over radio about developments of the approaching tropical cyclone. This means that you are preparing for a _____ a. PSWS#4 b. PSWS#3 c.PSWS#2 d. PSWS #1 _________7. Which of the following should you do before a typhoon? a. Wear additional clothing to avoid catching cold or other respiratory diseases. b. Close windows or nail them with piece of wood. c. Stock foods that will last for 7 days d. All of the above _________8. The expected hour before a PSWS#2 tropical cyclone hits the locality is a. 12hr b.18hr c.24hr d.36hr _________9. The meteorological condition of a PSWS#1 has a wind of _____ a.30-60 kph b. 60-100 kph c.100-185kph d. less than 185kph _________10. What causes damage in a hurricane/typhoon? a. winds b. storm surge c. flooding d. all of the above _________11.It forecasts weather conditions A. PAGASA b. DPWH c. DOH d. DENR _________12. Which of the following is not an emergency supply? a. medicine b. flashlight c. first aid kit d. anemometer _________13. Why do we prepare for typhoons? a. to prevent typhoon-related accidents c. all of the above b. to avoid destruction of life and property d. none of the above _________14. Which of the following is caused by a typhoon? a. damages to infrastructures (buildings, bridges, etc.) b. destruction of lives c. damages to crops d. all of the above _____ _________15. Wind speed is greater than 200 km/h a. Supertyphoon b. Typhoon c. Tropical Depression d. Tropical Storm Learning Task II (PERFORMANCE TASK – Write this in a short bondpaper, make it creative) Instructions: Have you experienced a typhoon hitting your place or locality? Which of the Philippine forecast areas does your place or locality belong to? Think of the strongest typhoon that has ever hit your locality. Try recalling the typhoon’s name and describe how strong it was. Write down your answers below. You may also discuss your experience with your family. Learning Task III Instructions: How do you prepare for typhoons? What should you do before, during and after a typhoon? List down at least three things that you should do in the table below. BEFORE DURING AFTER IV. REFLECTION Instruction: Complete the statement: I have learned that typhoons…  DEPARTMENT OF EDUCATION MARIGONDON NATIONAL HIGH SCHOOL Marigondon, Lapu-Lapu City, Cebu, Philippines 6015 Telephone Number: 254 -4295 Name of Learner: _______________________________________ Grade Level:_____________ Teacher: ____________________________ Section:__________ Date:_______________ LEARNING ACTIVITY SHEET Title of the Topic: Subject: QUARTER 2 – Module 3: Inside the Earth SCIENCE 8 Most Essential Learning Competency: Code: Explain how earthquake waves provide information about the interior of the earth. I. CONCEPT NOTES We often thought that earthquakes are phenomena that bring out destruction to lives and properties. But, the occurrence of earthquakes has helped scientists in figuring out what is inside the Earth. We were already informed that when a fault suddenly moves, an earthquake is generated. The shaking begins from the focus and spreads out. An example of this scenario is when you throw a pebble into a pond. You will notice the ripples that move out in circles. The vibrations from the focus are something like that. The vibrations are more properly called seismic waves. As seismic waves travel through the body of the Earth, they behave in different ways, depending on what they encounter along the way (Figure 1). Seismic waves travel outward in all directions from where the ground breaks at an earthquake. These waves are picked up by seismographs around the world. Two types of seismic waves are most useful for learning about Earth’s interior. https://courses.lumenlearning.com/geology/chapter/reading-inside-the-earth/ P-waves (primary waves) are fastest, traveling at about 6 to 7 kilometers (about 4 miles) per second, so they arrive first at the seismometer. P-waves move in a compression/expansion type motion, squeezing and unsqueezing earth materials as they travel. This produces a change in volume for the material. P-waves bend slightly when they travel from one layer into another. Seismic waves move faster through denser or more rigid material. As P-waves encounter the liquid outer core, which is less rigid than the mantle, they slow down. This makes the P-waves arrive later and further away than would be expected. S-waves (secondary waves) are about half as fast as P-waves, traveling at about 3.5 km (2 miles) per second, and arrive second at seismographs. S-waves move in an up and down motion perpendicular to the direction of wave travel. This produces a change in shape for the earth materials they move through. Only solids resist a change in shape, so S- waves are only able to propagate through solids. S-waves cannot travel through liquid. By tracking seismic waves, scientists have learned what makes up the planet’s interior. P-waves slow down at the mantle core boundary, so we know the outer core is less rigid than the mantle. S-waves disappear at the mantle core boundary, so the outer core is liquid. Seismologists study shock, or seismic, waves as they travel through the Earth’s interior. These waves originate from natural sources like earthquakes, and from artificial sources like man-made explosions. Knowing how the waves behave as they move through different materials enables us to learn about the layers that make up the Earth. Seismic waves tell us that the Earth’s interior consists of a series of concentric shells, with a thin outer crust, a mantle, a liquid outer core, and a solid inner core. P waves, meaning primary waves, travel fastest and thus arrive first at seismic stations. The S, or secondary, waves arrive after the P waves. THE EARTH'S LAYER Core, mantle, and crust are divisions based on composition: 1. The crust is less than 1% of Earth by mass. The oceanic crust is mafic, while continental crust is often more felsic rock. 2. The mantle is hot, ultramafic rock. It represents about 68% of Earth’s mass. 3. The core is mostly iron metal. The core makes up about 31% of the Earth.  DEPARTMENT OF EDUCATION MARIGONDON NATIONAL HIGH SCHOOL Marigondon, Lapu-Lapu City, Cebu, Philippines 6015 Telephone Number: 254 -4295 Lithosphere and asthenosphere are divisions based on mechanical properties: 1. The lithosphere is composed of both the crust and the portion of the upper mantle that behaves as a brittle, rigid solid. 2. The asthenosphere is partially molten upper mantle material that behaves plastically and can flow. Crust The crust is the thin outer layer of the Earth where we live. Well, it looks thin on the picture and it is thin relative to the other layers, but don't worry, we're not going to fall through by accident anytime soon. The crust varies from around 5km thick (in the ocean floor) to around 70km thick (on land where we live called the continental crust). The continental crust is made up of rocks that consist primarily of silica and alumina called the "sial". Mantle The next layer of the Earth is called the mantle. The mantle is much thicker than the crust at almost 3000km deep. It's made up of slightly different silicate rocks with more magnesium and iron. Outer Core The Earth's outer core is made up of iron and nickel and is very hot (4400 to 5000+ degrees C). This is so hot that the iron and nickel metals are liquid! The outer core is very important to earth as it creates something called a magnetic field. The magnetic field the outer core creates goes way out into space and makes a protective barrier around the earth that shields us from the sun's damaging solar wind. Inner Core The Earth's inner core is made up of iron and nickel, just like the outer core, however, the inner core is different. The inner core is so deep within the earth that it's under immense pressure. So much pressure that, even though it is so hot, it is solid. The inner core is the hottest part of the Earth, and, at over 5000 degrees C, is about as hot as the surface of the sun. Comparing model observations and data (https://serc.carleton.edu/teachearth/activities/181505.html) Based on your own direct experience (e.g. digging a hole, visiting a cave or quarry, driving past a road cut) you are probably aware that below the soil is a layer of rock. Let’s begin our investigation into Earth’s interior by assuming that the simplest solution is correct. Thus, we will start from a hypothesis that Earth is made up entirely of this same rock material. This would mean an Earth where rock extends all the way to the center of Earth. This homogeneous Earth model is illustrated in Figure 1. Since the model is comprised of the same material throughout, we can assume that seismic waves will travel at a constant velocity (in this case, we will assume the P-waves travel at a velocity of 11km/s in our model), and in straight lines. We can use this model and these assumptions to make some predictions and calculations that test the accuracy of our hypothesis. For example, we can use the model to predict how long it should take seismic waves to travel from an earthquake, through Earth, to various points on Earth’s surface. This is indicated in Figure 1 as “seismic wave paths”. This can be accomplished using the basic equation T = D/S where the time (T) it takes for a seismic wave to travel a certain distance, (S) is the speed the waves travel and (D) is the distance between the earthquake and the seismic station. As previously mentioned we are assuming that the speed (S) of P-waves is 11km/s. Since our model is a physical scale model, we can measure the length of the seismic wave paths from the earthquake’s location to various points on the model’s surface. Model measurements can be scaled up to real Earth distances. This has been done for you and the predicted arrival times for our homogeneous Earth model are illustrated in Figure 2 on the left  DEPARTMENT OF EDUCATION MARIGONDON NATIONAL HIGH SCHOOL Marigondon, Lapu-Lapu City, Cebu, Philippines 6015 Telephone Number: 254 -4295 II. LEARNING ACTIVITIES A. Learning Task 1: Modelling the Earth’s Interior Procedure: 1. Prepare one “Cloud 9” chocolate bar. 2. Cut the chocolate bar in half as neatly as possible. Once done cutting the chocolate bar, label the parts of the chocolate bar with that of the Earth’s interior 3. Students will answer the observation questions provided. Q1. What did you observe about these layers? ___________________________________________________ ___________________________________________________ __________________________________________________ Q2. How do you think this chocolate bar relates to the Earth? __________________________________________________ __________________________________________________ __________________________________________________ B. Learning Task II Direction: Read the selection very carefully and complete the table below. Seismic Waves Seismic waves are also known as earthquake waves. There are three types of seismic waves primary waves, secondary waves and surface waves. Primary waves (also called P-waves) travel the fastest of all the waves. They are also unique in the aspect that they travel through all states of matter- solids, liquids, and gases. P-waves are considered push-pull waves. They push and pull the it moves through just like sound waves push and pull the air. Secondary waves (also called S- waves) are not as fast as P-waves. They cannot travel through liquids and gases. S- waves travel in a side to side motion, like a piece of rope that you wiggle. Finally, surface waves (also called L-waves) are the slowest wave. They move along the earth’s surface similar to the way waves travel in the ocean, up and down. They are the most destructive wave because of the damage they create directly to the earth’s surface.  DEPARTMENT OF EDUCATION MARIGONDON NATIONAL HIGH SCHOOL Marigondon, Lapu-Lapu City, Cebu, Philippines 6015 Telephone Number: 254 -4295 III. ASSESSMENT Answer the summative exam found in Module 4 (Module 3 and 4 Assessment is combined. IV. REFLECTION Direction: Use a metacognition starter phrase to highlight what you have learned about seismic waves and the interior of the Earth. My chosen word is SEISMIC WAVES I know that I know about ___________________________. First, I know _____________________________________ In addition, I know ________________________________ Finally, I know ___________________________________ Now, you know something that I know ________________.  DEPARTMENT OF EDUCATION MARIGONDON NATIONAL HIGH SCHOOL Marigondon, Lapu-Lapu City, Cebu, Philippines 6015 Telephone Number: 254 -4295 Name of Learner: _______________________________________ Grade Level:_____________ Teacher: ____________________________ Section:__________ Date:_______________ LEARNING ACTIVITY SHEET Title of the Topic: Subject: QUARTER 2 – Module 4: Comets, Meteors and Asteroids SCIENCE 8 Most Essential Learning Competency: Code: Compare and contrast comets, meteors and asteroids. I. CONCEPT NOTES Comets and asteroids are referred to be astronomers as Near-Earth Objects (NEO). Comets are icy bodies or objects while asteroids are rocky fragments. They are remnants from the formation of our solar system 4.6 billion years ago. A. Shape and Size Both comets and asteroids have irregular shapes and varied sizes. They both reflect light from the Sun at varying amounts depending on the size and composition. The presence of more silicates allows a comet or asteroid to reflect light. Silicates are minerals that contain the elements silicon, oxygen, and at least one metal. If an asteroid has smaller amounts of silicates relative to its other components, it would be more difficult to see it even with a telescope because only a small area of the asteroid can reflect light thus it may appear smaller than what it really is when viewed. B. Origin of Comets and Asteroids Comet and asteroid both orbit the Sun and move relatively slow when viewed from Earth. This means, you can see a comet for up to a year in the night sky (or even during the morning if the comet is bright enough). Their major difference is their origin or where they came from in space. Comets usually come from the Oort Cloud which is beyond our Solar System, and a few from Kuiper Belt which is just beyond Neptune’s orbit. Long-period comets come from the Oort Cloud, while short-period comets come from Kuiper Belt. Comet Halley, the most famous comet of the 20th century is the only known short-period comet. It takes 75-79 years for Comet Halley to orbit the Sun. We see it in the sky every time it makes its nearest approach to the Sun. All other comets that have been identified are classified as long-period comets and takes 200 to hundred millions of years to complete their orbit around the Sun. Asteroids, on the other hand, originate from the Main Asteroid Belt between Mars and Jupiter. This belt is theorized by scientists to be remnants of a planet that did not completely form. C. Orbit The orbit of an asteroid is more rounded and less elliptical than the orbit of a comet. In February 2013, Asteroid 2012 DA14 made a very close approach to Earth as it orbited the Sun. Distance in space is measured in light years and this Asteroid was just 0.4 light year away from Earth; the closest that any asteroid has ever been close to Earth. In December 2012, during the midst of the dooms day prophecies, Asteroid Toutatis also made a near approach to Earth but not as close as Asteroid 2012 DA14. D. Composition Another stark difference between a comet and an asteroid is their chemical composition. Comets are icy objects while asteroids are rocky fragments. Sometimes, comets may contain other elements like sodium or argon, which is specific to a comet. Through further studies, scientists learned that Comet Hale-Bopp’s contained Argon which was believed to explain the very bright appearance of the comet in 1997. Scientists also discovered a faint sodium tail, a third type of comet tail to add to the well-known dust and plasma (or ion) tails. On the other hand, an asteroid is mostly composed of rock (silicates) and metals (iron and nickel being the usual metals referred to). Parts of a comet The composition of a comet is important in helping scientists understand how Earth has liquid water, which in turn made the planet livable. During Earth’s formation, scientists theorized that the planet must have been too hot to have liquid water on its surface. By studying comets’ orbits and the chemical composition of materials found in impact craters found all over Earth, soil and ice samples collected from drilling down Earth’s crust and marine layers, scientists theorized that the early impact of comets on Earth brought liquid water to the planet.  DEPARTMENT OF EDUCATION MARIGONDON NATIONAL HIGH SCHOOL Marigondon, Lapu-Lapu City, Cebu, Philippines 6015 Telephone Number: 254 -4295 The chemical composition of an asteroid is important in providing clues for scientists to discover more about the chemical composition of Earth and the other planets in the Solar System, as well as how life on Earth was affected by impacts in the past. It is the scientists’ belief that Earth, other planets, and asteroids are essentially similar in composition. In fact, asteroids are also called minor planets or planetoids. Asteroids are mostly composed of metals like iron and nickel; the same metals that are theorized to make up Earth’s core. How do Meteors, Meteoroids and Meteorites differ from each other? ▪ A meteoroid can be as small as a grain of sand or as big as a boulder. When it enters Earth’s atmosphere, the air in front of the meteoroid heats up, causing materials to burn up. From Earth, these glowing materials appear as a streak of light or a fast-moving bright object that appears to have a tail just like a comet. What differentiates the two when we see them in the sky is that a comet moves slowly and appears in the sky for a longer time. A meteor moves swiftly and seems to fall on the ground. It “shoots” from a point in the sky, making people think that it is a shooting or falling star. Also, a comet is difficult to see with the unaided eye because it is farther from Earth compared to a meteoroid entering Earth’s atmosphere. Sometimes, a comet can be bright enough to be seen by the unaided eye, but this is rare, just like in the case of Comet Hale-Bopp. ▪ A meteoroid usually all burns up when it enters Earth’s atmosphere. But when a fragment from the meteoroid survives and makes it to the ground, this space rock fragment is now called a meteorite. So if you heard from the news on radio or television or read the news from newspapers about a meteorite exploding over Russia in February 2013, their use of the word meteorite is inaccurate. Instead, a meteoroid exploded over Russia. The space rock fragments they collected on the ground is the meteorite. ▪ Earlier, we mentioned that a meteoroid can come from comets. Comets orbit the Sun and leave fragments on their orbit as they continue their journey around the Sun. These fragments continue to orbit the Sun just like their parent comets. When Earth orbits the Sun and passes through the orbit of a comet where these comet fragments are found, we observe many streaks of light from Earth which is called a meteor shower. During a meteor shower, meteors seem to originate from only one point in the sky because the meteoroids are traveling in parallel paths with the same velocity. The meteor shower is named after the constellation where they seem to originate from, but this does not mean that the meteoroids come from the associated constellation. Remember: a meteor and a meteor shower are light phenomena; they are not stars. ▪ Meteorites are of importance to scientists in studying the occurrence of different elements and compounds on Earth. This information is in turn important in studying our mineral resources which is an important industry in any country. Generally, there are three types: stony, stony-iron, and iron meteorites. In the Philippines, there are only five meteorites that have been accepted internationally. Superstitious beliefs about Comets and Asteroids Celestial visitors like comets, asteroids, and meteors have always captured the imagination of ancient civilizations. They have been thought of as bad omens or signs of great change or challenge such as ushering disasters and wars. But with new scientific processes and tools, as well as greater access to scientific information, these celestial visitors have gained the appreciation and interest of many people, scientists and non-scientists included, all over the world. II. LEARNING ACTIVITIES Learning Task 1 A. Complete the table that lists the comparison between comets and asteroids. CHARACTERISTICS COMETS ASTEROIDS Origin Shape Size range of diameter(kilometer) Chemical composition Orbit Orbital Period B. Learning Task II Direction: Choose the letter of your best answer. ____1. Which of these is called a meteor? A. A chunk of metallic or stony matter found on Earth’s surface B. A streak of light caused by something entering the Earth’s surface C. A chunk of metallic or stony matter found in space ____2. Which of these is called a meteoroid? A. A chunk of metallic or stony matter found on Earth’s surface  DEPARTMENT OF EDUCATION MARIGONDON NATIONAL HIGH SCHOOL Marigondon, Lapu-Lapu City, Cebu, Philippines 6015 Telephone Number: 254 -4295 B. A streak of light caused by something entering the Earth’s surface C. A chunk of metallic or stony matter found in space ____3. Which of these is called a meteorite? A. A streak of light caused by something entering the Earth’s surface B. A chunk of metallic or stony matter found in space C. A chunk of metallic or stony matter found on Earth’s surface ____4. What causes the light of a meteor? A. It is the same as a comet. B. It is the same as the sun C. It is caused by friction with the Earth’s atmosphere ____5. Most meteoroids that cause meteors are about the size of a pebble. A. True B. False ____6. There are three types of meteorites based on ___________________. A. What they are made of B. What they have been found C. How big they are C. Learning Task III: The formation Trace the formation of meteoroid, meteor and meteorite by suppling the needed information below. III. ASSESSMENT INSTRUCTION: Read the questions before answering the test, USE THE ZIPGRADE ANSWER SHEET (NO ERASURES) in answering the test. 1. Which of the statements is correct? A. Only asteroids collide with Earth. B. Comets are ball of ice, dust, and metal. C. Meteoroids are streak of light produced when comet enters Earth’s atmosphere. D. Only asteroids can be found in the solar system. 2. What do you call the fragments or debris that resulted from the collision of asteroids or comets? A. meteors B. meteoroids C. Oort Cloud D. Kuiper Belt 3. What is the bright glow around the “head” of a comet? A. coma B. crown C. halo D. ring 4. What is the name of the famous comet that can be seen from Earth every 75 to 76 years? A. Hale Boop B. Comet Halley C. Comet Tempel 1 D. Shoemaker Levy-9 5. What is the correct term for a “shooting star”? A. asteroid B. comet C. falling star D. meteor 6. What is an Asteroid Belt? A. It has rocks crossing the Sun, Mars, and Jupiter. B. It has rocks crossing the Sun, Jupiter, and Uranus. C. It is an area between Mars and Jupiter where most asteroids are found.  DEPARTMENT OF EDUCATION MARIGONDON NATIONAL HIGH SCHOOL Marigondon, Lapu-Lapu City, Cebu, Philippines 6015 Telephone Number: 254 -4295 D. It has rocks between the Earth and Jupiter where most asteroids are found. 7. What is a meteorite? It is a __________. A. dim meteor C. meteoroid that lights up B. bright meteor D. remains of meteoroids that hit the Earth 8. What is a comet? It is a/an __________. A. rock from Mars B. class of smaller inner solar system bodies that orbit around the sun C. icy ball of rock that displays a coma, a fuzzy temporary atmosphere, or a tail when it travels close to the sun D. natural object from small to huge that originates in space and survives the impact on the earth’s surface 9. What composes silicate? A. silicon, oxygen, and at least one metal C. silicon, methane and a rock B. silicon, carbon, and at least one metal D. iron, nickel, and argon 10. Why do scientists study comets? A. They are valuable minerals. B. They could provide Earth with rocks. C. They can help make the Earth a habitable planet. D. They provide information how the Earth obtained liquid water. 11. Why would global temperature of the Earth drop when struck by a massive asteroid? A. The resulting cloud would block out sunlight. B. The low temperature of asteroid would chill the oceans. C. The impact would move the Earth farther from the Sun. D. The ice in the asteroid would increase the Earth’s reflective power. 12. When objects strike a surface of a planet, they leave a deep impression on the surface called ____________. A. canyon B. crater C. plateau D. pothole 13. Meteoroids are formed when asteroids collided and crushed into pieces. Based on this statement, where did the meteoroids originate? A. Asteroid Belt B. Mars C. Moon D. Sun 14. Which best describe what is the picture below? A. meteorite C. comet with coma and ion tail B. meteoroid with dust D. asteroid that falls to the Earth 15. What celestial body is shown below? A. meteors B. meteorites C. asteroids D. meteor shower 16. They study shock or seismic waves as they travel through the earth’s interior. A. Astrologist B. Meteorologist C. Seismologist D. Astronomist 17. What waves travel the fastest, it moves in compression/expansion type motion, and bend slightly when they travel from one layer into another? A. P-waves B. S-waves C. Love waves D. Rayleigh waves 18. What waves move in an up and down motion perpendicular to the direction of wave travel and can only propagate through solids? A. P-waves B. S-waves C. Love waves D. Rayleigh waves 19. Which of the following is not true about the layer of the earth’s divisions based on its composition? A. The crust is less that 1% of Earth by mas. B. The mantle is hot, ultramafic rock and represents about 68% of Earth’s mass C. The core is mostly iron metal D. The oceanic crust is felsic while continental crust is often more mafic rock 20. It is the thin outer layer of the Earth and varies from around 5 km to 70 km from the ocean floor to the land where we thrive. This layer is also made up of silica and alumina called sial. What layer of the earth is this? A. Crust B. Mantle C. Inner Core D. Outer Core IV. REFLECTION