Tackling Volcano Exam Questions (2)

Volcano Sample Question (2)

Explain why some volcanic eruptions are more violent than others. (4 marks)

Command Word: Explain

Key Words: Volcanic eruptions, more violent, others

Plan

What factors make volcanoes more violent?

-Type of plate boundary? (Destructive)

-Type of volcano? (Composite)

-Type of lava (Acidic lava, more viscous lava)

-Amount Of gases (A higher amount of gas, the lava becomes under higher pressure)

-Eruption Frequency? (long dormant periods, irregular eruptions)

Ans: There are certain factors that make volcanoes more violent than others. Firstly, the type of plate boundary it’s on makes the difference. A more gentle volcano rests on a constructive plate, where the plates move apart and lava oozes out, a more violent volcano rests on a destructive boundary, where one crust is subducted under the under and is destroyed under high heat and pressure.

The type of lava also plays a role, a gentle volcanic eruptions tends to erupt basic lava that contains less silica while a more violent volcano erupts acidic lava, which has a higher silica content making it more explosive. Next, the volcano type determines it’s violence level. A shield volcano such as Mount Loa tends to be more gentle and causes little to no impact to humans while a composite volcano for example Montserrat is more destructive and causes large impacts to humans.

Not only that, the amount of gases in the lava also plays a role, a lower concentration of gases ensures that the magma is under low pressure making the eruption gentle while a high concentration of gases causes the magma to be under higher pressure causing the eruptions to become more violent. Lastly, the volcano eruption frequency also plays a important role, a volcano that eruptions frequently makes the volcano more gentle as the pressure does not build up in the volcano while a volcano that have long dormant periods and irregular eruption frequency causes a “plug” to form on the mouth of the volcano thus pressure builds causing a more violent eruption

Success Criteria 30/1/12 Monserrat Eruption Report

1. To be able to use the PEE (Point Evidence Explain) method
2. To be able to create a report suitable for revision
3. To be able to create a report with at least a B grade

Tackling Volcano Exam Questions (1)

View- Geo book- Tackling Volcano Exam Questions 1

See results and comments in book

Disaster Response Curve

Each stage represents either prevention, protection and preparation as described below. The timeline above shows the different stages of time where either relief, rehabilitation or reconstruction is commenced. The words on the left of the the graph, show the quality of life, economically, socially and environmentally and corresponds to the stage and time of the incident .

Stage 1: In this stage, the quality of life is normla before disaster strikes, people try their best to prevent and prepare if such events should happen by either educating the public on how to act when disaster strikes, prepare supplies, putting medical teams on standby etc.

Stage 2: This stage happens when the event happens, immediately the quality of life sheerly drops, and people use protection and prevention methods such as putting barricades, evacuating people, building trenches to stop water, lava etc.

Stage 3: After the incident has occurred, this is the period of time followed with stage 2 called relief where medical attention, rescue services and overall care is given out, This period in time can last from days to weeks. The quality of life has seemingly stopped decreasing and beginning to slowly move up.

Stage 4/5: This stage is called the rehabilitation stage, where people try to return the state of things back to normal, by providing food, water and shelter for those who are derived from those basic needs. Stage 5 moves to the reconstruction period where infrastructure, crops and property are reconstructed or regrown. During this stage people use preparation and prevention to improve from the mistakes of this disaster to respond better to the next one.

Further stages: In future stages, people will use preparation or prevention to either return to the state before the disaster struck or improve themselves even further and do much better coping with any other future disasters.

The Three P's- Prepare, Predict and Prevent

Preparation
In the preparation stage, people can either be educate or educate others on the hazards of an incident and how it can be managed.
Law officials can also place building laws on where to place buildings to minimize loss, death and injury during the event

Prediction
-This is basically trying to forecast when an incident will occur
- We can use various methods such as satellites, river flow meters etc

Prevention
-Methods that can be put into place to stop or at least minimize damage, loss, injury or death due to an incident
-

Short/Long Term Management/Response definition

Short Term Response/Management: Action people take immediately or shortly after an incidence happens (Give medical attention, Manage immediate threats etc.)

Long Term Response/Management: Action people take after a period of time after the incident has occurred (Rebuild buildings, replant crops etc.)

Definition of mitigation/ preparation, management, response to a volcano

Definition Of Mitigation: The action to reduce the severity, seriousness, painfulness of the event

How do you think people PREPARE, RESPOND to and MANAGE a volcanic eruption?

-    Run away (Evacuation)

-    Set up blockades

-    Monitor the volcanic activity

-    Use remote sensing (satellites)

-    Frequent news reports on volcano status

-    Give medical attention to casualties

Success Criteria (19/1/12) Volcanic Hazard Management

Success Criteria (19/1/12)

1. I can explain 3 short/long term responses
2. I can use what I know so far to apply in this lesson, thus improving my learning
3. I can record what I did today effectively

Success Criteria 16/1/12 (Volcanic Hazard Management) (Part 1)

I can understand how people adapt and prepare for natural hazards
I can know a large range of short/long term strategies  to manage a volcanic eruption
I can use what I know in the previous lessons to enhance my learning further in this lesson

Montserrat Volcano Question Sheet

MONTSERRAT VOLCANO ERUPTIONS 1995-1998

1.   Describe the location of Montserrat (2 marks)

The location of Montserrat can be described as mountainous and filled with pine trees, it is located in Caribbean and it’s other name is called “the emerald island of the Caribbean’ due to the reason it is covered in lush emerald green plant life

2.   Explain why Montserrat is a volcanic island (3 marks)

Montserrat is a volcanic island due to the fact that a volcano, the Soufriere Hills formed in the destructive boundaries between the North American and Caribbean plate.

3.   List the Primary and Secondary hazards of the Soufriere Hills volcano (6 marks)

Primary Hazards

Lava Flow, Ash Cloud, Tephra

Secondary Hazards

4.   Which part of the island was evacuated first, and when did this take place ? (2 marks)

The south part of the island, specifically the river valleys were evacuated in August 1995

5.   What is a pyroclastic flow ? Describe how this hazard has affected the people of Montserrat (4 marks)

A pyroclastic flow is a huge rapidly moving cloud of superheated rock, gases and ash, the boulders that follow can flatten trees and other objects. The pyroclastic flow affected the people of Montserrat because it scorched the vegetation located on the island. Also, it killed 19 people 

6.   How is the hazard of the volcanic activity 'managed' ? (4 marks)

The hazards of the volcanic activity were managed by using a seismograph to calculate the movement of the earth, Also, A satellite with GPS were used to track ground movement.

Plus, the PH value of rainwater was collected to see how much magmatic gases were found in the water, as an increase of it may indicate a upcoming eruption. Lastly, geologists often flew to the most dangerous parts of the volcano to check flow deposits, measure cracks and observe the dome to see if swelling occurs, as all these factors may lead to a volcanic eruption

7.   How is risk calculated ? (2 marks)

Risk is calculated by the formula people, property x risk x hazard

8.   Why is the fact that the south of the island has been most badly hit a particular problem for the people of Montserrat ? (4 marks)

Due to the fact that many of the facilities and the infrastructure are located on the south side of the island people had to cope with homelessness, joblessness, and shortages of land to rebuild.

Also, quite a lot of vegetation were planted in the south, when the volcano destroyed it all, it caused starvation, lack of resources and since the lava had hardened over the soil and the lahar had washed away mots of the soil’s humus layer, it was difficult for the people to start replanting

9.   What role did the British have to play in the evacuation of the island ? (3 marks)

The British helped to pay compensation to the people who were affected by the Montserrat eruption, a total of 2,400 euros were offered to each adult as compensation for destroyed property and other objects.

Primary and Secondary Impacts

See geo book

Success Criteria (12/1/12) DME Monserrat Eruption

Success Criteria

I can identify more in 2 primary and secondary impacts
I can quickly make decisions based on events
I can use what I have learned so far to help me understand during this lesson

Monserrat Eruption Timeline

Volcanic Hazards Primary and Secondary

Volcanic Hazards

Hazards

Tephra: Air borne materials that if they are hot enough they could clump together to form pyroclastic material or tuffs.

Effects: -Covers crops and plants and cause them to die

-Stays in the stratosphere for some time and can    stop air traffic

- Large amounts of it can fall onto building, causing the building to collapse under it immense weight

Lahar: A rushing flow of volcanic ash mixed with water, lahar’s are common in snow or glacier capped mountains.

They are very desne and move extremely quickly

Effects:

-It’s speed and weight can destroy buildings and other objects

-Humans can get swept away or drown

-Riverbanks will overflow and crops by riverbanks will be destroyed

Lava bombs: Smooth, glassy blobs of basaltic lava which cool as they fly through the air, they come in many shapes and sizes, some even as big as boulders

Effects:

-Could crash into building an damage them severely

-May hit people and cause serious injury or death

Pyroclastic flow: Extremely hot gases, ash and rock that move down the volcano and lighting speed. The boulders that follow the pyroclastic flows have highly destructive force and can flatten objects.

Effects:

-The superheated pyroclastic flow can kill people and wildlife in its path

-The boulders that follow can flatten trees, destroy buildings and pose a risk to human life.

Lava flow: A flowing river of molten rock known as lava, lava can be divided into two categories basaltic and acidic, basaltic lava is usually found in gentle eruptions while the latter is found in explosive eruptions.

Effects:

-       The molten lava can start fires in trees, houses and buildings.

-       The fires poses a threat to human life

Landslides: A large amount of dirt, soil and debris movement under the force of gravity, in volcanic landslides, they can move very fast and sizes vary from small to enormous.

Effects:

-Can flatten trees, buildings or any other object in their path

-Humans and wildlife are usually killed in the path of a volcanic landslide.

Volcanic ash: Old lava and rock that are pulverized by violent eruptions, it are a jagged and glassy feel and look and can travel for miles on end

Effects:

-Airborne volcanic ash can stop air travel due to bad visibility

-Large amount of it can collapse a building due to the immense weight.

- Can cover vast areas of cars, buildings, objects, crops with volcanic ash that cause damage and loss

Success Criteria (9/1/12) Volcanic Hazards

Success Criteria

• I can classify at least 4 hazards
• I can make at least 4 links
• I can understand what is a good comparison case study

Hotspot Volcano Charecteristics

Hotspot Volcano

Characteristics	Description
Formation	A magma plume rises from the core and is forced up into the lithosphere, the magma then rises to the crust and forms a volcano, but since the crust is moving away, the plume is cut off and the volcano becomes extinct, this process is repeated as the magma plume rises and is cut off by the moving crust
Plate Boundary	Either conservative or destructive
Features	-Produces mainly lava -Very viscous lava - A shield like volcano -Magma is basaltic  -Very little pyroclastic material is erupted
Nature of eruption	Gentle oozing
Named Example	Mauna Loa, Hawaii

Success Criteria (5/1/12) Hotspot volcano/Hazards

Success Criteria

• I can explain the characteristic+formation  of hotspot volcanoes
• I can explain at least 4 volcanic hazards
• I can use what I know so far to better understand what I am doing this lesson

MEDC Comparison Case Study- (Mount. Etna)

MEDC Case Study-  Mount. Etna, Italy

Diagram explanation of the cause of Mount Etna eruptions.

Diagram	Stages
	The denser Eurasian plate is subducted under the lighter African plate, forming a subduction zone
	The denser Eurasian plate is destroyed under the immense heat and pressure turning it into lava
	The magma rises through fissures in the ground and a a a large swell occurs
	Finally, the magma erupts form Mount Etna, this volcano has frequent eruptions.

Fact Zone

Year: 1971

-Mount Etna erupts and the lava destroyed ski slopes, cable car station and observatories.

Year: 1983

-Millions of tonnes of lava gushed out from the side of Mount Etna, engulfing several buildings, the lava travelled up to speeds of 15 km an hour

Year: 27 Oct 2002

-       A short period of seismic activity was felt

-       -Lava was ejected from two fissures

-       The hot lava stated forest fires ad destroyed wildlife

Year: 2003

-Mount Etna seemed to be dormant, until the next eruption that took place in 2005

Diagram of location of Mount Etna

What were the…

Primary effects?

-Buildings, crops and land were destroyed or ruined by the lava and ash

-Communication and public services were halted

Secondary effects?

-Ash, dust and smoke would block and clog the air

-Wildfires from the flying burning debris and lava

-People had to be moved from their homes

Short-term responses?

-Economic problem due to rebuilding efforts

-Possible shortages of shelter for people affected by the volcano

-Limited movement, people could not get around

Long-term responses

-The government may have to pay compensation to the people affected by the volcano

Why did so few people die?

-Early warning system, people were alerted soon enough to escape safely

-Efficient rescue service, they were able to deal with the after effects of the volcano quickly and efficiently

Comparison

Mount Etna	Traits	Montserrat Eruption
The subduction of the denser Eurasian plate and forms magma that is forced upwards.	Cause?	Frequent earthquakes causes magma to be forced upwards
Mostly property and wildlife damage	Major Effects?	Property, wildlife and human lives were taken
Very violent and frequent eruptions	Volcano’s Characteristics	Eruptions were violent but volcano eventually became dormant
Plants and wildlife were destroyed	Physical Geographical Effects?	Plants and wildlife were destroyed
Property was destroyed	Human Geographical Effects?	Human lives were taken and property destroyed
-Early warning system -Efficient rescue and healthcare	Why were the effects so?	-Poor warning system -Late rescue and bad healthcare services -Bad infrastructure

Completed diagrams version is located in Geo notebook