NOTE: This is PART 2 of this unit.
PART 1 covers Plate Tectonics. These are lessons 1 - 5. |
Are all earthquakes the same strength? Why do earthquakes cause different amounts of damage? Why does a tsunami form? What to I do during an earthquake? What's inside a volcano? Why do people even live near volcanoes? All these questions will be answered in this unit! Let's gooooo!
The lessons covered in this unit are: 6. Earthquakes 7. Effects of an earthquake event 8. What should I do during an earthquake? 9. Volcanoes 10. Volcanic hazards 11. Effects of a volcano 12. Why do people live near volcanoes? 13. What should I do during a volcanic event? |
6. EARTHQUAKES
🡺 I can locate the area hit by the earthquake.
🡺 I can give the strength of the earthquake on the Richter scale and locate the epicentre of the earthquake. 🡺 I can associate the extent of damage with the proximity to the earthquake’s epicentre. Earthquakes occur when plates move. The point from which a seismic wave starts is called the earthquake focus. The epicentre of the earthquake is the point on the ground surface directly above the focus. Seismic waves spread out from the focus. The waves are felt most strongly at the epicentre, becoming less strong as they travel further away. The most severe damage caused by an earthquake will happen close to the epicentre. An aftershock commonly occurs after an earthquake. It is less strong than the main earthquake, but still may cause damage. How are earthquakes measured? A seismograph is the instrument used to measure the strength of an earthquake. A seismograph uses the Richter Scale as a unit to describe how strong an earthquake is. In Malta, a seismograph is found at Wied Dalam station in Birzebbugia. |
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Geo-check!
1. Label the diagram on the right.
2. Choosing the appropriate words from below, complete the following sentences: Focus / earthquake / Richter / 1 to 9 / seismograph / tsunami / unstable / seaquake Earthquakes tend to occur along plate boundaries where the plates are ____________________. Earthquakes occurring on the sea bed are termed ____________________. Every earthquake starts from a point beneath the earth’s surface called the __________________. A seaquake can generate a _______________ which are huge sea waves that can cause huge disasters. The strength of earthquakes are measured using a special instrument termed _______________________. The ________________ scale is a scale used to describe how strong an earthquake is, and spans from magnitude ________________. |
7. EFFECTS OF AN EARTHQUAKE EVENT
🡺 I can describe the effects of the earthquake.
An earthquake can cause a lot of negative effects:
Seaquakes and tsunamis A seaquake is an earthquake having its epicentre at the bottom of the seabed. In case of a strong seaquake, a tsunami might develop. Tsunami is a large sea wave created as a result of the seabed movements. On the 26th December 2004, a huge tsunami took place in the Indian Ocean killing around 300, 000 people. Tsunamis occur in the Mediterranean as well. For example in 2003 near Algeria; in 1988: near Italy; in 1965 near Greece. |
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Geo-check!
CASE STUDY: JAPAN 2011
On Friday 11 March 2011 at 14:46:24, an earthquake of magnitude nine on the Richter scale occurred. It was at the point where the Pacific tectonic plate slides beneath the North American plate. The epicentre was 30 kilometres below the Pacific Ocean seabed and 129 kilometres off the east coast of Honshu, Japan. This triggered a tsunami. High, powerful waves were generated and travelled across the Pacific Ocean. The area worst affected by the tsunami was the east coast of Honshu in Japan. The 2011 tsunami affected over 500 kilometres of the Japanese coastline Water rushing into the Fukushima No.1 nuclear power plant, after a tsunami triggered by an earthquake The tsunami flooded an area of approximately 561 square kilometres Infrastructure
Social and economic
Responses to build capacity to reduce the risk
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CASE STUDY: NEPAL 2015
On 25 April 2015 a 7.8 earthquake struck Nepal in Asia. The earthquake occurred on a convergent collision plate boundary between the Indian and Eurasian plates. The focus was only eight kilometres deep and the epicentre was just 60 kilometres north-west from the capital Kathmandu. The earthquake triggered an avalanche on Mount Everest, killing approximately 20 people. This made April 25 2015 the deadliest day on the mountain in history. The earthquake triggered another huge avalanche in the Langtang valley, where 250 people were killed. Impacts Infrastructure
Social and economic
Responses to reduce the impacts
Long-term
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CASE STUDY: HAITI 2010
On 12 January 2010, a 7.0 earthquake struck Haiti. The earthquake occurred on a destructive plate margin between the Caribbean and North American plates. The focus was only 12.87 km deep and the epicentre was just 25.75 km from the capital, Port-au-Prince. EFFECTS Primary
Secondary
SHORT TERM
LONG TERM
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8. WHAT SHOULD I DO DURING AN EARTHQUAKE?
🡺 I can demonstrate and relate safe behaviour during an earthquake simulation.
DURING AN EARTHQUAKE If you’re inside:
If you’re outside:
If you’re driving:
AFTER THE EARTHQUAKE
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Geo-check!
1. You are given the task of putting together an emergency kits for the school. Several kits will be placed around the school. What 10 things would you choose for your emergency kit? Explain your choices below
2. Imagine you are the mayor of a city in an earthquake zone. Explain, and give reasons, what you would do in these following situations. Residents in your city just felt very small tremors – what do you do? a. 10 minutes later an earthquake is happening – what do you do? b. The earthquake has damaged a few buildings in the city centre, however houses in the poorer areas have been knocked down and people may be inside them – what do you do? c. A few days have passed. Emergency services are working on getting everything back to normal – what do you do? d. How would you protect your city buildings for the next earthquake? e. How would you protect your residents for the next earthquake? f. What else would you do before the next earthquake hits? |
9. VOLCANOES
🡺 I can label a cross-section diagram of the interior structure of a volcano.
🡺 I can describe the three possible states in the lifecycle of a volcano. Most volcanoes are found along plate boundaries. They form when magma rises through cracks or weaknesses in the Earth's crust. Pressure builds up inside the Earth. When this pressure is released (for example as a result of plate movement), magma explodes to the surface causing a volcanic eruption. Volcanoes can be described in terms of activity depending on how frequently they erupt. They can be: Active - Volcanoes that still erupt frequently. Ex: Etna (Italy) Dormant - Volcanoes that are have not erupted for many years but not fully extinct. Ex: Mount Killamanjiaro (Tanzania) Extinct - Volcanoes that are never likely to erupt again. Ex: Mount Buninyong (Australia) |
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Geo-check!
1. Label the parts of a volcano on the diagram.
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2. Write down the numbers of these volcanoes in the Mediterranean.
a. Etna b. Stromboli c. Vulcano d. Vesuvius e. Santorini |
3. The seven volcanoes are marked on the map below. Write their name and draw a line to their place in the world.
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10. VOLCANIC HAZARDS
🡺 I can describe the hazards associated with volcanic activity.
Volcanoes can be exciting and fascinating, but also very dangerous. Any kind of volcano can create harmful or deadly phenomena, whether during an eruption or a period of calm.
We are going to look at just FIVE hazards, however there are many more!
Volcanoes can be exciting and fascinating, but also very dangerous. Any kind of volcano can create harmful or deadly phenomena, whether during an eruption or a period of calm.
We are going to look at just FIVE hazards, however there are many more!
Geo-check!
1. Eyjafjallajökull is a volcano in Iceland. On the 14th April, an eruption occurred directly underneath the glacier. The meltwater got into the vent of the volcano creating an explosive eruption sending an ash cloud many kilometres into the air. The diagram below shows the ash cloud at its peak.
a. What hazard do you think caused most damage? b. How the ash can reach far away places? c. List the types of damage the ash cloud caused to the following industries:
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2. In 1985, the volcano Nevado del Ruiz erupted in central Colombia. Four enormous lahars went down its slopes at 60 km/h. The lahars picked up speed and coursed into the six major rivers at the base of the volcano; they engulfed the town of Armero, killing more than 20,000 people.
a. Why is a lahar so dangerous? b. Explain the damage a lahar can do. |
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3. On the 22nd August 79 AD at around 1 pm Mount Vesuvius violently erupted, spewing up a high-altitude column from which ash and pumice began to fall, blanketing the area. Later on at night, pyroclastic flows in the close vicinity of the volcano began.
a. What materials are in a pyroclastic flow?
b. Why is a pyroclastic flow dangerous?
Pliny was the Commander of the Roman Navy at the time. He said: “It was daylight now elsewhere in the world, but there the darkness was darker and thicker than any night.”
c. Why did Pliny say that? What was making everywhere dark?
a. What materials are in a pyroclastic flow?
b. Why is a pyroclastic flow dangerous?
Pliny was the Commander of the Roman Navy at the time. He said: “It was daylight now elsewhere in the world, but there the darkness was darker and thicker than any night.”
c. Why did Pliny say that? What was making everywhere dark?
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4. Fill in the blanks with the words here:
rumbling / cloud / cattle / consciousness / died / 25 Lake Nyos, in Cameroon (West Africa), had long been quiet before it happened. In 1986, farmers living near the lake heard ______________. At the same time, a spray shot hundreds of feet out of the lake, and a white cloud collected over the water. From the ground, the __________________ grew to 100 meters tall and flowed across the land. When farmers near the lake left their houses to investigate the noise, they lost ____________________. The heavy cloud sunk into a valley and into settlements. People in the affected lost consciousness or died in a few breaths. In the village of Nyos, everyone but four inhabitants on high ground _______________. The cloud killed people up to ______ kilometres away from the lake. Over the next two days, people from surrounding areas entered the valley to find the bodies of humans and cows lying on the ground. Around 1,700 people and 3,500 __________________ had died. |
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11. EFFECTS OF A VOLCANO
🡺 I can relate a volcanic event and the effects it had on its environment.
Volcanoes have a large effect on their locality. They produce ash, lava, volcanic bombs, pyroclastic flows and lahars. Ash from large volcanoes has been known to affect global climates. Here are some negative effects of volcanoes:
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Geo-check!
The questions for this lesson must be done in class.
12. WHY DO PEOPLE LIVE NEAR VOLCANOES?
🡺 I can differentiate between the negative and positive aspects of living in tectonic-ally active zones.
People choose to live in volcanic areas despite the risks of an eruption. Volcanoes can provide people with many benefits such as these: Fertile soil Ash ejected by the volcano acts as a good fertiliser for soils. Ex: Citrus and pistachios near Etna Building materials Lava can be used for building houses and roads. Ex: Hawaii Geothermal energy Geothermal energy a renewable energy. It is where heat from within the earth is used to generate electricity. Ex: New Zealand Minerals Minerals are contained in lava such as diamonds, aluminium, nickel and gold. Ex: Diamonds in South Africa Tourism Volcanoes attract many tourists. Tourism increases money to the local economy. Ex: Vesuvius, Italy |
Geo-check!
The questions for this lesson must be done in class.
13. WHAT SHOULD I DO DURING A VOLCANIC EVENT?
🡺 I understand what to do in a volcanic event.
Volcanoes are a lot easier to predict than earthquakes because they normally give some warning signs. As a volcano becomes active, it gives off several warning signs. These warning signs are picked up by volcanologists and the volcano is monitored. WARNING SIGNS
MONITORING TECHNIQUES
If you’re in an area where there is an active volcano:
If an eruption happens near where you are:
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Geo-check!
1. Why is it important for scientists to monitor volcanoes for the following people?
2. Fill in the table here. 3. Describe what can happen if emergency officials:
4. List at least THREE factors that will be different in a volcanic event will be in a richer country to a poorer country? |
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