GSEB Class 8 Social Science Solutions Chapter 5 Natural Disasters

Answer the following questions:

Question 1. Can the disasters mentioned in this unit be called as 'geographical events' ? Why ?
Answer: Yes, the calamities discussed in this unit can be termed 'geographical events'. Earthquakes, volcanoes, tsunamis, floods, droughts, landslides, and similar occurrences happen on the Earth's surface, so we can refer to them as 'geographical events'.
In simple words: Yes, the natural problems talked about here are "geographical events" because they all happen on the Earth's surface, like earthquakes and floods.

Exam Tip: Define 'geographical events' by linking them to occurrences on the Earth's surface and provide clear examples from the chapter.

Question 2. How can you get information about disasters from government?
Answer: Information regarding calamities and their management can be gathered from the following address via post or E-mail: Gujarat State Disaster Management Authority, Block No. 11, Fifth floor, Udyog Bhavan, Gandhinagar: 382 017.
In simple words: You can get details about disasters and how to handle them by writing a letter or sending an email to the Gujarat State Disaster Management Authority at their office in Gandhinagar.

Exam Tip: When asked for government information, remember to provide specific contact details like an address or department name if available.

Question 3. What are the advantages of living in a volcanic region ? How ?
Answer: If I live near a dormant volcano, I will receive the following advantages:
1. Since magma soil is extremely fertile, many crops can be cultivated.
2. There will be abundant agricultural yield in the volcanic soil on the volcano's slopes.
3. Valuable minerals like mercury, lead, antimony, zinc, tungsten, and tin are also obtainable from lava rocks, which find use in industries.
4. Diamonds are found in these locations.
5. In a few spots, there are hot water springs and geysers. This water is helpful for treating specific skin conditions.
In simple words: Living near an old volcano means good soil for farming, lots of crops, useful minerals for factories, diamonds, and hot springs that can help with skin problems.

Exam Tip: For questions about advantages, list specific benefits clearly with supporting reasons for each point.

Question 4. Your friend's village has been affected by flood. What will you do to help him?
Answer: I will do the following to help my friend:
• I will provide him with food grains, clothing, medicines, kitchen utensils, beds, and other essentials.
• I will arrange for his temporary shelter.
• I will advise my friend and the villagers to consume only boiled water.
• I will arrange to supply sufficient grass and drinking water for the cattle at his house.
• With my friends' assistance, I will clear the dirt deposited in his home due to the flood.
• I will join community work to mend the roads harmed by the flood.
• Some non-governmental organizations (NGOs) work in flood-affected regions to offer aid. I will join one such organization.
• I will donate as much money as I can to the Chief Minister's Relief Fund or another fundraising body.
In simple words: I will help my friend whose village flooded by giving food, clothes, medicines, and shelter. I will also tell villagers to boil water, get food and water for animals, help clean homes, repair roads, join NGOs, and donate money.

Exam Tip: When describing assistance in a disaster, provide a comprehensive list of practical, immediate, and long-term actions, including personal efforts and community involvement.

Question 5. Which areas experience landslides more frequently? Why?
Answer: Landslides happen more often in areas with heavy rain and in tectonic zones. This occurs because surface rocks weaken and break apart due to intense rainfall or an earthquake.
In simple words: Landslides happen a lot in places that get heavy rain or have tectonic activity because these things make the ground and rocks unstable and break apart.

Exam Tip: Explain the 'what' (areas) and the 'why' (reasons) clearly and concisely for full marks on such questions.

Question 6. What efforts should be made to prevent drought / famine from occurring? OR What efforts should be made for protection against drought ?
Answer: The following actions should be taken to prevent drought or famine:
1. Each year, more trees ought to be planted and cared for.
2. Stop air pollution to maintain moisture in the atmosphere.
3. Wells should be deepened or refilled to obtain water for drinking and irrigation. Water storage containers or tanks should be built to collect rainwater and storm water.
4. Water needs to be stored by building check dams across small rivers, streams, or water creeks.
5. Attempts should be made to gather rainwater and increase groundwater levels.
6. The length of canals, connected to the main dam, should be extended.
7. Lakes should be made deeper to hold more rainwater.
In simple words: To stop droughts, we need to plant more trees, keep the air clean, make wells deeper, build dams to store water from rivers, and collect rainwater. We also need to make canals longer and lakes deeper.

Exam Tip: When asked about preventive measures, provide a comprehensive list covering reforestation, water conservation, and infrastructure development.

Fill in the blanks with a proper word:

Question 1. The origin of an earthquake is known as focus.
Answer: focus
In simple words: The place where an earthquake starts inside the Earth is called its focus.

Exam Tip: Remember key geological terms like 'focus' when discussing earthquake origins.

Question 2. Forest resources get depleted due to forest fires.
Answer: Forest fires
In simple words: Forest resources decrease because of forest fires.

Exam Tip: Understand the direct causes of resource depletion to answer such questions accurately.

Question 3. Often cyclone strikes in the coastal regions of India.
Answer: cyclone
In simple words: Cyclones often hit the coastal parts of India.

Exam Tip: Associate specific natural disasters with their typical geographical occurrences, like cyclones with coastal regions.

Question 4. Due to landslide, Konkan railway gets obstructed frequently.
Answer: Konkan
In simple words: Landslides often block the Konkan railway line.

Exam Tip: Recall specific examples where geographical features or events impact infrastructure, such as landslides affecting the Konkan railway.

Activities

GSEB Class 8 Social Science Natural Disasters Intext Questions and Answers

Question 1. How will you be helpful to others if there is an earthquake in your area?
Answer:
1. I will arrange for temporary housing for people affected by the earthquake.
2. I will provide them with food, clothing, medicine, cooking utensils, beds, and other necessities.
3. I will try to obtain financial aid from the government and other NGOs to repair or buy new homes for those who lost theirs due to the earthquake.
4. I will help in saving individuals buried under debris.
5. I will give household items and other things found from the debris to the authorized government officer.
6. If possible, I will let earthquake-affected individuals stay in my house for some days.
7. I will offer comfort, show patience, and try to give them strength.
In simple words: If an earthquake happens, I will help people by finding them places to stay, giving them food and clothes, helping them get money to fix their homes, rescuing those trapped, giving recovered items to officials, letting people stay with me, and offering them emotional support.

Exam Tip: When detailing aid efforts during an earthquake, include immediate needs (shelter, supplies), recovery (financial help), and emotional support.

Question 2. Would you like to live in a region of volcano ? Why?
Answer: No, I would not prefer to live in a volcanic region. While dormant volcanic areas can offer advantages such as fertile soil, valuable minerals, and hot springs, active volcanic regions pose significant dangers. The risk of sudden eruptions, lava flows, ash clouds, and toxic gas releases makes such areas extremely hazardous for permanent habitation. The unpredictability of volcanic activity can lead to loss of life, property, and disruption of daily life, making it an unsafe environment despite any potential benefits.
In simple words: No, I wouldn't want to live near a volcano because even though some areas have good soil, active volcanoes are very dangerous due to eruptions, lava, and ash, which can harm people and property at any time.

Exam Tip: When answering opinion-based questions, state your position clearly and support it with multiple well-explained reasons, considering both pros and cons.

Question. See the answer of sub-question (6) of the main Question 1. of guestions And Answers section.
Answer: This question refers to the solution for Question 6 in the earlier "Answer the following questions" section regarding efforts to prevent drought/famine. Please consult that answer for details.
In simple words: Look back at the answer for Question 6 in the section before this one, which talks about ways to stop droughts.

Exam Tip: Always cross-reference previous answers efficiently when instructed, ensuring you understand the connection between different questions in the text.

Question 3. If your house is near the seashore and the government warns you about tsunami, what will you do for your protection?
Answer: For my protection, I will:
1. Collect my important belongings and move to a higher elevation.
2. Avoid the temptation of watching the tsunami at the coastline.
3. Listen to the radio and television for further safety instructions about the tsunami.
4. Take advantage of benefits provided by social service organizations for tsunami safety.
In simple words: If a tsunami warning is given, I will grab my important things and go to high ground. I will not go to the beach to watch, but instead, I will listen to the news for safety tips and use any help offered by relief groups.

Exam Tip: In a disaster scenario, prioritize immediate evacuation to higher ground, stay informed through official channels, and utilize available community support.

Question 4. How will you respond to the situation if the warning for a cyclone is given?
Answer: I will promptly:
1. Go to a safer location.
2. Turn off all electrical connections and stay away from electric poles, large trees, and buildings.
3. Move my livestock to a secure spot.
4. Store my valuable possessions in my house in a safe place.
5. Have enough food and water available.
6. Maintain calmness and resolve.
7. Listen to the weather reports on radio and television and strictly follow safety directives.
8. I will not be swayed by rumors.
9. After the cyclone passes, I will take part in rescue efforts and show sympathy for the affected individuals.
In simple words: If a cyclone warning comes, I will quickly go to a safe spot, turn off electricity, and stay away from dangerous things. I'll move my animals, secure my valuables, stock up on food and water, stay calm, listen to official news, ignore rumors, and then help with rescue after it's over.

Exam Tip: Your response to a cyclone warning should include immediate safety actions, preparedness (food, water), staying informed, avoiding panic, and post-disaster community aid.

GSEB Class 8 Social Science Natural Disasters Additional Important Questions and Answers

Choose the correct alternative from those given below each question:

Question 1. What is the place nearest to the focus of an earthquake on the surface of Earth called ?
(a) Earthquake centre
(b) Epicentre
(c) Focal centre
(d) Landslide centre
Answer: (b) Epicentre
In simple words: The spot on the Earth's surface directly above where an earthquake starts is called the epicentre.

Exam Tip: Distinguish between 'focus' (underground origin) and 'epicentre' (surface point) for earthquake terminology.

Question 2. Due to how many reasons are volcanic eruptions caused ?
(a) Two
(b) Five
(c) Three
(d) Four
Answer: (d) Four
In simple words: There are four main reasons that cause volcanoes to erupt.

Exam Tip: Remember the specific number of causes (four) for volcanic eruptions, which often include internal heat, magma formation, gas pressure, and magma movement.

Question 3. How many types of volcanic mountains are there ?
(a) Three
(b) Four
(c) Two
(d) Five
Answer: (a) Three
In simple words: There are three different kinds of volcanic mountains.

Exam Tip: Classify volcanoes into the three primary types: active, dormant, and extinct.

Question 4. What is the approximate length in kilometres of a tsunami wave ?
(a) 800 to 1200
(b) 500 to 1500
(c) 700 to 1600
(d) 600 to 900
Answer: (c) 700 to 1600
In simple words: Tsunami waves can be very long, usually somewhere between 700 and 1600 kilometers in length.

Exam Tip: Memorize key statistical figures like the approximate length of tsunami waves, as these details can be tested.

Question 5. In which year did the tsunami disaster occur in Japan ?
(a) 2004
(b) 2008
(c) 2010
(d) 2011
Answer: (d) 2011
In simple words: The big tsunami that hit Japan happened in the year 2011.

Exam Tip: Keep track of significant historical disaster events and their dates, especially those mentioned in the curriculum.

Question 6. Which pollution should be reduced for reducing the possibility of drought?
(a) River
(b) Atmospheric
(c) Water
(d) Land
Answer: (b) Atmospheric
In simple words: To help prevent droughts, we need to lessen pollution in the air.

Exam Tip: Understand the link between atmospheric pollution and climate patterns that contribute to droughts.

Fill in the blanks with a proper word:

Question 1. Earthquake is caused due to internal disturbance in the earth.
Answer: disturbance
In simple words: Earthquakes happen because of inner shaking inside the Earth.

Exam Tip: Recall that internal movements and disturbances within the Earth's crust are the primary cause of earthquakes.

Question 2. Maximum effect of an earthquake is near the epicentre on the surface.
Answer: epicentre
In simple words: The strongest impact of an earthquake is usually felt closest to its epicentre on the surface.

Exam Tip: Always associate the 'epicentre' with the area experiencing the most significant effects of an earthquake.

Question 3. Effect of an earthquake depends on its intensity.
Answer: intensity
In simple words: How much an earthquake affects an area depends on its strength.

Exam Tip: Understand that an earthquake's impact is directly related to its intensity or magnitude.

Question 4. Lava soil is fertile because it contains potassium.
Answer: potassium
In simple words: Lava soil is good for growing plants because it has potassium in it.

Exam Tip: Connect the fertility of lava soil to its mineral composition, specifically potassium, which is vital for plant growth.

Question 5. The fast flow of water in a river is called ' flood'.
Answer: flood
In simple words: When a river's water flows very quickly and heavily, it's called a flood.

Exam Tip: Define key terms clearly; 'flood' specifically describes the rapid and overwhelming flow of river water.

Question 6. An earthquake is recorded with a Seismograph.
Answer: Seismograph
In simple words: We use a seismograph to measure and record an earthquake.

Exam Tip: Remember the instrument used for earthquake detection and recording: the seismograph.

Question 7. Tsunamis and cyclones cause destruction near coastal regions.
Answer: coastal regions
In simple words: Tsunamis and cyclones mostly cause damage in areas along the coast.

Exam Tip: Identify the geographical areas most vulnerable to specific natural disasters like tsunamis and cyclones.

State whether the following statements are true or false:

Question 1. Focus (of an earthquake) is on the surface of the Earth.
Answer: False
In simple words: The earthquake's focus is deep inside the Earth, not on its surface.

Exam Tip: Clearly differentiate between the focus (origin underground) and the epicentre (point on the surface) of an earthquake.

Question 2. Effect of an earthquake depends on its speed.
Answer: True
In simple words: The impact of an earthquake is affected by how quickly its waves travel.

Exam Tip: Recognize that the speed of seismic waves influences the earthquake's overall effect and destructiveness.

Question 3. Heavy gases below the lava push it downwards.
Answer: False
In simple words: Heavy gases beneath lava usually push it upwards, not downwards, during an eruption.

Exam Tip: Understand the role of gas pressure in volcanic eruptions, which typically forces lava upwards.

Question 4. Diamonds are found at few volcanic regions.
Answer: True
In simple words: Yes, diamonds can sometimes be found in some areas near volcanoes.

Exam Tip: Remember specific valuable resources associated with volcanic regions, such as diamonds.

Question 5. More trees should be grown to prevent droughts.
Answer: True
In simple words: Planting more trees helps to stop droughts from happening.

Exam Tip: Acknowledge the role of afforestation in environmental health and drought prevention, as trees help retain moisture.

Question 6. Heavy damage is caused to forests due to forest fire.
Answer: True
In simple words: Forest fires cause a lot of harm to forests.

Exam Tip: Understand the destructive impact of forest fires on ecosystems and natural resources.

Match the pairs correctly:

Answer: (1 – 5), (2 – 1), (3 – 2), (4 – 3).
In simple words: Matching the pairs means: Lava goes with Volcano. Powerful and devastating goes with Tsunami. Drought goes with Heavy damage to forest resources. Earth goes with Shortage of food and water quake.

Exam Tip: For matching questions, ensure each item from the first column is correctly linked to its corresponding item in the second column.

Write answers to the following questions in one or two sentences:

Question 1. Name the natural disasters.
Answer: The names of natural disasters are:
1. Earthquake,
2. Volcano,
3. Tsunami,
4. Flood,
5. Drought,
6. Storm (Cyclone),
7. Forest fire and
8. Landslides.
In simple words: Natural disasters include earthquakes, volcanoes, tsunamis, floods, droughts, storms (cyclones), forest fires, and landslides.

Exam Tip: Be ready to list various natural disasters and provide a brief explanation for each if asked to elaborate.

Question 2. What is an earthquake ?
Answer: Due to sudden powerful movements like plate collisions or intense pressure inside the Earth, its weak upper crust experiences quick shaking. This phenomenon is called an 'earthquake'.
In simple words: An earthquake is when the Earth's upper layer shakes suddenly because of strong movements or pressure deep inside it.

Exam Tip: Define an earthquake by mentioning the key causes (plate movements, pressure) and its immediate effect (shaking of the Earth's crust).

Question 3. What is an Epicentre ?
Answer: The closest point on the Earth's surface directly above the focus, perpendicular to it, is called the 'Epicentre'.
In simple words: The epicentre is the spot on the Earth's surface that is exactly above where an earthquake begins deep underground.

Exam Tip: Clearly state that the epicentre is on the surface and directly above the earthquake's focus.

Question 4. Which instrument records earthquakes ?
Answer: Earthquakes are recorded with a Seismograph.
In simple words: An instrument called a seismograph is used to detect and record earthquakes.

Exam Tip: Remember the specific scientific instrument, 'seismograph', used for detecting and measuring earthquakes.

Question 5. What are the reasons for an earthquake ?
Answer: There are three primary reasons for earthquakes:
1. Earthquakes caused by volcanic eruptions (Volcanic Earthquakes),
2. Earthquakes caused by strike-slip faults (Tectonic Earthquakes) and
3. Earthquakes caused by subduction in an active subduction zone (Plutonic Earthquakes).
In simple words: Earthquakes happen for three main reasons: from volcanoes erupting, from large cracks in the Earth's crust slipping, and from one part of the Earth's crust sliding under another.

Exam Tip: Categorize the causes of earthquakes into volcanic, tectonic (faults), and plutonic (subduction) types.

Question 6. What is a volcanic mountain ?
Answer: When a volcanic eruption happens, ash, large rocks, and lava are deposited around the volcanic crater, forming a cone-shaped small or large hill. Frequent eruptions increase the height of the hill, transforming it into a volcanic mountain.
In simple words: A volcanic mountain forms when a volcano erupts, and ash, rocks, and lava pile up around the opening, building a cone-shaped hill that gets taller with more eruptions.

Exam Tip: Define a volcanic mountain by describing its formation process, including the deposition of materials around a crater and the gradual increase in height.

Question 7. What are the reasons for the volcanic eruption ?
Answer: When the tectonic balance is disturbed, hot magma, rock material, ash, water vapor, and other gases rush towards the surface with great speed. These materials are forced out through a crack or a vent in the rock layers. This process is known as 'volcanic eruption'.
There are four specific reasons for volcanic eruptions:
1. Very high temperature inside the Earth,
2. Formation of liquid magma,
3. Formation of gases and water vapor and
4. Movement of magma towards the Earth's surface.
In simple words: Volcanic eruptions happen when the Earth's plates move, causing hot liquid rock, ash, and gases to quickly escape through cracks to the surface. The four reasons are high inside temperature, magma forming, gases and vapor building up, and magma moving up.

Exam Tip: List both the general process (tectonic disturbance, material expulsion) and the specific internal geological factors (temperature, magma, gases, movement) that cause volcanic eruptions.

Question 8. How many types of volcanoes are there ? Which are they?
Answer: There are three distinct types of volcanoes. They are:
1. Active volcano,
2. Latent (dormant) volcano and
3. Extinct (dead) volcano.
In simple words: There are three kinds of volcanoes: active ones that erupt often, dormant ones that are sleeping, and extinct ones that will never erupt again.

Exam Tip: Remember the three classifications of volcanoes: active, dormant, and extinct, and be able to briefly describe each type.

Question 9. What is a Tsunami ?
Answer: Tsunami is a Japanese term where 'Tsu' means ports and 'nami' means waves. Due to a volcanic eruption or an earthquake on the sea/ocean floor, huge, very powerful, and abnormally high and incredibly long waves are generated. These are called 'Tsunami'.
Their length is approximately 700 to 1600 km, and they travel with great velocity and force. By the time these waves reach the coast, they become extremely destructive. They gain immense height and power, causing significant devastation on the coast.
Tsunami waves are created one after another. As a result, destruction near the coastal region persists for many hours. India experienced a tsunami calamity on 26th December 2004, and Japan on 11th March 2011.
In simple words: A tsunami is a huge, powerful ocean wave, often caused by undersea earthquakes or volcanic eruptions. These very long waves travel fast and cause massive damage when they hit the coast, often striking repeatedly for hours. India had one in 2004, and Japan in 2011.

Exam Tip: Provide a clear definition of 'tsunami', explain its origins (volcanic eruption/earthquake), describe its characteristics (length, speed, height), and mention its destructive impact along with historical examples.

Question 10. What is a 'flood'? Which areas are more affected due to floods ?
Answer: A 'flood' occurs due to heavy and continuous rainfall in the upper part of a river, or when a dam bursts, causing water to flow at high speed. Low-lying areas along the riverbed are most severely impacted by floods.
In simple words: A flood is when too much rain fills a river or a dam breaks, making water rush out very fast. Places near the river, especially low areas, get hit the hardest.

Exam Tip: Define a flood by its causes (heavy rain, dam burst) and identify the specific vulnerable areas (low-lying regions near rivers).

Question 11. What is a 'drought'?
Answer: A drought means the absence of rainfall. This condition arises when there is no rain or very little rain, which leads to the drying up of underground water. This situation is called 'drought'.
Droughts result in a scarcity of food grains and water.
In simple words: A drought is when it doesn't rain for a long time, causing the ground and underground water to dry up. This leads to shortages of food and water.

Exam Tip: Explain drought as a lack of rainfall leading to water scarcity and its direct consequences, such as food shortages.

Question 12. When is a storm created?
Answer: A storm forms when a low-pressure area develops over land or sea, and strong winds blow towards this area from the surrounding regions. When these winds blow powerfully alongside rainfall, a storm is created.
In simple words: A storm starts when a low-pressure area forms, pulling strong winds and rain from nearby places, creating powerful weather.

Exam Tip: Describe storm formation by focusing on the creation of a low-pressure zone that draws in strong winds and often brings rain.

Question 13. What is a 'forest fire'?
Answer: In thick forests, dry branches of larger trees often rub against each other due to winds. This creates fire, which quickly spreads throughout the forest. Such fires also happen for other reasons. This type of fire is called a 'forest fire'. Significant damage is caused by forest fires.
In simple words: A forest fire starts when dry tree branches rub together in the wind, or for other reasons, and the fire quickly spreads, causing great harm to the forest.

Exam Tip: Define forest fire by mentioning its common causes (friction, other factors) and its rapid, destructive spread.

Answer the following questions:

Question 1. What is an earthquake ? Explain the process of an earthquake.
Answer: Due to powerful (sudden) movements, such as the collision of plates or immense pressure within the Earth's interior, the weak upper crust of the Earth experiences sudden tremors. This event is called an 'earthquake'.
The point where these movements begin is termed the 'Focus'. The earthquake's focus is deep inside the Earth.
The seismic waves generated by an earthquake travel at varying speeds in different directions. The nearest spot on the Earth's surface, directly above the earthquake's focus, is called its 'Epicentre'. The area around the epicentre experiences the most severe damage. The earthquake's impact diminishes as one moves further away from the epicentre. The overall effect of an earthquake depends on its intensity.
Seismographs positioned at various centers on the surface record the earthquake very precisely. The exact location of the focus and the intensity of the earthquake can be determined using a seismograph. There are three types of earthquakes:
1. Volcanic,
2. Tectonic and
3. Plutonic.
In simple words: An earthquake is when the Earth's upper crust shakes due to sudden plate movements or pressure. It starts at a "Focus" deep inside, and the spot directly above it on the surface is the "Epicentre," where damage is worst. Instruments called seismographs record these shakes. There are three kinds: volcanic, tectonic, and plutonic.

Exam Tip: For a comprehensive explanation of earthquakes, cover the definition, the process from focus to epicentre, wave propagation, how intensity affects impact, and the different types of earthquakes.

Question 2. What is a volcanic eruption ? OR What is the process of a volcano ? State the reasons for a volcanic eruption.
Answer: When the tectonic balance is disturbed, hot magma, rock material, ash, water vapor, and other gases rush towards the surface at high speed. These are ejected through a fissure or a vent in the rock layers. This entire process is known as 'volcanic eruption'.
There are four primary reasons for volcanic eruptions:
1. Extremely high temperature within the Earth's interior,
2. Formation of liquid magma,
3. Formation of gases and water vapor and
4. Movement of magma towards the Earth's surface.
In simple words: A volcanic eruption happens when Earth's plate movements push hot magma, rocks, ash, and gases quickly out through cracks. The main reasons are intense heat inside the Earth, magma forming, gases and vapor building up, and magma moving upwards.

Exam Tip: To explain volcanic eruptions, describe the expulsion of materials from the Earth's interior and list the four key geological factors contributing to their occurrence.

Question 3. How is a volcanic mountain formed ? What are the types of volcanoes? OR Write short notes: Composition of a volcano
Answer: Due to internal pressure, there is significant movement of molten lava deep inside the Earth. The temperature of water that has seeped into the upper soil layers increases, causing it to eventually turn into water vapor. This water vapor demands much more space than liquid water, creating immense pressure in all directions. As a result, weaker sections of the Earth's crust crack with a loud sound, forming fissures. Initially, water vapor is expelled through these fissures, followed by ash, rock fragments, mud, and then the hot magma. This magma spreads in all directions and creates a cone-shaped hill or a mountain. Such a mountain is termed a 'volcano'. This is the process of volcano formation.
There are three main types of volcanoes:
1. Active volcano,
2. Dormant (latent) volcano and
3. Extinct (dead) volcano.
In simple words: A volcanic mountain forms when pressure inside the Earth pushes hot lava and gases up through cracks. Water vapor builds up, causing the crust to break, and then ash, rocks, and magma come out, piling up to make a cone-shaped hill. There are three kinds of volcanoes: active, dormant, and extinct.

Exam Tip: For a detailed answer on volcanic mountain formation, explain the role of internal pressure, water vapor, fissure creation, and the sequence of expelled materials, along with classifying the types of volcanoes.

Question 4. State the benefits of a volcanic eruption.
Answer: The benefits of a volcanic eruption include:
• These eruptions spread a large layer of lava on the Earth's surface, forming lava soil. This lava soil is very fertile and beneficial for agriculture.
• Abundant crops can be cultivated with the help of potassium-rich soils formed from volcanic residues.
• Volcanic regions consist of igneous rocks. Valuable minerals like mercury, antimony, lead, zinc, tungsten, and tin are obtainable from these rocks.
• When lava cools and solidifies in the volcanic pipe, and carbon comes under high pressure, it transforms into diamonds.
• In some places within the volcanic region, there are hot water springs and geysers that are useful for treating certain skin conditions.
• Small pebbles ejected from the volcano are called 'Lapilli'. These can be shaped and molded easily.
In simple words: Volcanic eruptions make the soil very rich for farming because of lava. They also give us valuable minerals like mercury, lead, and tin from igneous rocks. Diamonds can form when lava cools under pressure, and hot springs from volcanoes can help with skin problems. Even small volcanic pebbles, called 'Lapilli', can be useful.

Exam Tip: When discussing benefits, remember to include both agricultural advantages (fertile soil), economic benefits (minerals, diamonds), and therapeutic uses (hot springs).

Question 5. What is a tsunami ? Explain.
Answer: 'Tsunami' is a Japanese word, where 'Tsu' means ports and 'nami' means waves. Due to a volcanic eruption or an underwater earthquake on the sea/ocean floor, massive, very strong, and incredibly high and long waves are generated. These powerful waves are known as 'Tsunami'.
Their length is approximately 700 to 1600 km, and they travel with immense speed and force. By the time these waves reach the coastline, they become extremely destructive. They gain significant height and power, causing widespread devastation on the coast.
Tsunami waves are produced consecutively. As a result, destruction near coastal areas continues for many hours. India experienced a tsunami disaster on 26th December 2004, and Japan on 11th March 2011.
In simple words: A tsunami is a huge, powerful ocean wave, often caused by undersea earthquakes or volcanic eruptions. These very long waves travel fast and cause terrible damage when they hit the coast, sometimes for hours. Notable tsunamis happened in India in 2004 and Japan in 2011.

Exam Tip: Define 'tsunami' by its etymology, causes (volcanic eruption, earthquake), physical characteristics (size, speed), and destructive impact, including historical examples.

Write short notes:

Question 1. Devastating waves
Answer: When a storm or a cyclone forms in the ocean, large and powerful waves are generated. After the storm subsides, the shape of the waves changes. They gain height, develop longer lengths, and spread up to hundreds of kilometers from their origin point. When they reach the coastline, they cause severe damage. Therefore, these waves are called 'devastating waves'.
In simple words: When ocean storms or cyclones happen, they make huge, strong waves. After the storm, these waves grow taller and longer, traveling far. When they hit the shore, they cause a lot of destruction, which is why they are called "devastating waves."

Exam Tip: For short notes, explain the origin (storms, cyclones), characteristics (size, spread), and impact (severe damage) of devastating waves concisely.

Question 5. What is a tsunami ? Explain.
Answer: Tsunami is a Japanese word where 'Tsu' refers to harbors and 'nami' signifies waves. Due to a volcanic eruption or an earthquake on the sea or ocean floor, huge, very powerful, and unusually high and incredibly long waves are formed. These are named 'Tsunami'. Their approximate length is between 700 to 1600 km, and they travel with great speed and force. By the time these waves arrive at the coast, they become extremely damaging. They achieve great height and power, causing significant destruction on the coastline. Tsunami waves are generated one after another. As a result, devastation near the coastal area often continues for many hours. India experienced a tsunami disaster on 26th December 2004, and Japan faced one on 11th March 2011.
In simple words: A tsunami is a huge ocean wave caused by undersea earthquakes or volcanoes. It travels quickly and causes great destruction when it hits the shore. Japan and India have both faced these disasters.

Exam Tip: Remember to mention the origin (Japanese word), cause (volcanic eruption/earthquake), characteristics (huge, powerful, long waves), and impact (destruction) when explaining tsunami.

Write Short Notes:

Question 1. Devastating waves
Answer: When a storm or a cyclone forms in the ocean, very large and strong waves are created. After the storm finishes, the waves' form changes. They get taller, grow longer in length, and extend for many hundreds of kilometers from where they began. When these waves reach the shoreline, they cause significant harm. Therefore, these waves are known as 'devastating waves'. Also, when a big rock or ice mass breaks off near the coast and drops into the sea, or if a meteor falls into the sea, similar huge waves happen.
In simple words: Devastating waves are very big, strong waves that form during storms or cyclones. They get very tall and wide, causing much damage when they hit the coast. Similar waves can also happen if large objects fall into the sea.

Exam Tip: When writing about devastating waves, explain their cause (storms, cyclones, falling objects), characteristics (large, powerful, long, tall), and their destructive effect on coastal areas.