Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Tectonics > Unit 2 Notes > Flashcards

Unit 2 Notes Flashcards

(75 cards)

Start Studying
1
Q

What are the main types of volcanoes?

A

Shield, Composite.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a Shield Volcano?

A

Built of fluid lava flows. A group of vents build a gently sloping cone of a flat dome shape. Flow pours in all directions. Lavas often erupt from vents along fractures.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is an example of a Shield Volcano?

A

Mauna Loa.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a Composite Volcano?

A

Steep sided, symmetrical cones of large dimension built of alternating layers of lava flows. Crater at the summit, which have a central vent. Erosion destroys the cone.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is an example of a composite volcano?

A

Mount Fuji.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a Cinder Volcano?

A

Built from particles and blobs of congealed lava ejected from a single vent. Lava breaks into small fragments that solidify and fall as cinders. Bowl shaped crater at summit.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is an example of a Cinder volcano?

A

Cerro Negro.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the characteristics of Composite volcanoes?

A

Tall, cone shaped, bigger peaks, lava flow, cracks allow magma to flow.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the characteristics of Cinder volcanoes?

A

Cinder cone crater, magma chamber, and magma conduits.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is Viscocity?

A

How thick a substance is, based on how easily it can flow.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is an explosive eruption?

A

Pressure of gases builds due to high viscocity, they blast magma apart. Forms volcanic ash. Gases find it harder to escape, more explosive when ice is near lava.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is an effusive eruption?

A

Occurs on divergent plate boundaries, gas is released due to low viscocity. Gas can escape easily. When magma is viscous, it can’t flow when it reaches the surface, so it builds up.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does Magma Viscosity affect the way a volcano erupts?

A

High Viscosity - Gas bubbles have a hard time escaping from Magma. Will push more material up. Low Viscosity - Gas bubbles will escape more easily, lava won’t erupt as violently.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How does dissolved gas affect the way a volcano erupts?

A

Erupting force comes from internal gas pressure, magma is formed from dissolved gases. If magma contains more gas bubbles, it will erupt more violently. If it contains less gas, it erupts more calmly.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the VEI?

A

The volcanic explosivity index - a logarithmic scale which ranges between 0-8. Each step is an increase by a factor of 10.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which factors affect the impacts of volcanoes?

A

Magnitude, Predictability, Frequency, Duration, Aerial extent, Speed of onset.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How does magnitude affect volcano impact?

A

The greater the VEI, the more explosive the eruption, more severe the impact.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How does Frequency affect volcano impact?

A

Once a large eruption happens in an area, it’s unlikely a second one will occur immediately. It’s possible to monitor volcanic activity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How does Aerial extent affect volcano impact?

A

An effusive eruption is likely to impact on a smaller area than an explosive eruption.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How does duration affect volcano impact?

A

Duration doesn’t necessarily correlate with severity, because impacts can be larger or smaller. It’s important that management strategies are suited to the volcanic eruption style.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How does speed of onset affect volcano impact?

A

How fast the eruption occurs varies depending on the type of volcano. Effective monitoring ensures that eruptions can be managed effectively.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the Local hazards caused by Volcanoes?

A

Pyroclastic flow, Lava flow, volcanic landslides.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the regional hazards caused by volcanoes?

A

Lahar, Jokulhlaups.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the international hazards caused by volcanoes?

A

Toxic gases, Ash falls.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is Ash Fall?
The deposition of volcanic ash onto the ground after an explosive volcanic eruption.
26
What are the causes of Ash fall?
The eruption produced an ash cloud which was carried into the atmosphere. Subglacial volcano - covered by a glacial water rapidly vaporises.
27
What is the example of Ash Fall?
E15 - Iceland.
28
What were the key facts about the E15 Eruption?
March-June 2010 - VEI 3. Constructive/Divergent Plate margin.
29
What were the local impacts of the Eruption?
800 people evacuated, areas were flooded. Agricultural land was damaged. Ash fall poisoned animals in nearby farms, some roads destroyed.
30
What were the international impacts of the Eruption?
100,000 flights cancelled between 14-21 April 2010. Businesses lost trade, perishable goods were wasted, as they couldn't be transported.
31
What is Pyroclastic flow?
Avalanches containing hot volcanic gases, ash and rock. Fast moving. Have the power to destroy buildings, and flatten trees.
32
What is an example of Pyroclastic flow?
Montserrat, 1995.
33
What are the causes of Pyroclastic flow?
Dome collapse resulted in pyroclastic flows. The capital was buried under pyroclastic flows. 4.5 Million m of the lava dome were unloaded during eruption.
34
What are the key facts about the 1995 Montserrat eruption?
1995-1997. VEI 3. Puerto Rico trench subduction zone.
35
What were the short term responses to the 1995 Montserrat eruption?
Evacuation to UK and neighbouring islands, Abandonment of capital city. British government gave £2400 to each person for compensation. Unemployment rose due to collapse of tourist industries.
36
What are the long term benefits of the 1995 Montserrat eruption?
Exclusion zone set up in the volcanic region, Volcanic observatory built to monitor the volcano. New roads, a new airport. Services in the north of the island.
37
What is a Lahar?
A mudflow created when water mixes with volcanic ash - can be metres think, as hard as cement.
38
What are the causes of Lahars?
Eruptions, pyroclastic flows, lava flows, crater lake eruptions.
39
What is an example of a Lahar?
Nevado del Ruiz, Colombia.
40
What are the effects of Lahars?
The Lahar in Colombia killed 20,000 people in Armero, where 70% of the town's residents were killed. They can go up to 60km/hr.
41
How was bad governance involved in the Colombia eruption and Lahar?
An evacuation was ordered, but abandoned as activity reduced, then 4 towns were buried.
42
What is a Lava Flow?
A stream or river of molten rock that erupts from a volcano, and flows across the Earth's surface.
43
What are the potential impacts of lava flows?
They can destroy everything in their path.
44
What are lava flows caused by?
Magma erupting from a volcanic vent onto Earth's surface during an effusive eruption.
45
What did Lava flows lead to in Hawaii?
Summit collapse, lava flows covered land southwest of the park. They covered 13.7 square miles of land, and 30 miles of road infrastructure.
46
What were the key facts about the Hawaii lava flows?
May-August 2018, 0 deaths. 700 homes destroyed, displaced more than 2000 people.
47
What were the key facts about lava flows in Congo?
May 2021, Constructive boundary, 32 deaths.
48
What were the primary impacts of lava flows in the DRC?
450,000 people displaced or evacuated. 17 villages directly impacted by lava flows.
49
What were the secondary impacts of lava flows in the DRC?
Earthquakes occurred after the eruption, C02 was released, and built up. 8000 people migrated to Rwanda. 10 people were killed during evacuation.
50
What was the primary response to lava flows in the DRC?
Charities supported search and rescue operation.
51
What were the secondary responses to lava flows in the DRC?
6 temporary camps set up by government, UNHCR supported 1300 families with accommodation, charities raised money to rebuild homes.
52
What is a volcanic landslide?
A landslide which occurs when the scope of a volcano fails due to volcanic activity.
53
What is an example of a volcanic landslide?
Mount St. Helen's, USA.
54
What was the effect of a volcanic landslide in Mount St. Helen's?
It removed the side of the mountain, so volcanic gases exploded out the side of the volcano. The north side of the mountain collapsed, and coincided with a large explosion.
55
What were the Key facts about the eruption in Mount St. Helen's?
March 1980, Destructive plate boundary, 57 deaths.
56
What were the impacts of the eruption in Mount St. Helen's?
Covered 23 Sq. miles, travelled up to 150mph. Transport infrastructure was damaged, reducing the ability to move - 1000 flights were cancelled due to airborne ash. Total economic cost - $1 Billion.
57
What were the responses to the eruption?
Evacuation by emergency services, long term response allowed the area to naturally recover, increased monitoring to mitigate impacts in the future.
58
What is Volcanic toxic gas?
Harmful substances released during volcanic activity, such as C02 and Sulfur dioxide.
59
What are the causes of Volcanic toxic gas?
Acid rain, contributes to climate change, causes water contamination. Causes respiratory problems.
60
What are the key facts of Toxic gas release in Cameroon?
August 1986, Located in the crater of an extinct volcano, 1746 deaths.
61
What were the impacts of Toxic gas in Cameroon?
1/4 of a mile of C02 was released from the solution within. The event occurred at night, so killed the residents, and 3500 livestock.
62
What were the responses to Toxic gas in Cameroon?
In 2001, pipes were installed to degas the lake in a controlled manner. Today, 20% of the gas had been released. The lake is now constantly monitored.
63
What were the key facts about the gas eruption in New Zealand?
December 2019, Convergent subduction zone, 21 deaths, 26 injured.
64
What were the impacts of the 2019 New Zealand Gas eruption?
Victims were tourists, rock and ash launched up to 3km from the site, deaths caused by inhaling Sulfur dioxide.
65
What were the responses to the 2019 New Zealand gas eruption?
23 people were rescued from the island, less than 50 people on the island. Seven helicopters dispatched to the island to the eruption. The owners of the island were prosecuted in October 2023.
66
What is a Jokulhlaup?
A glacial burst - A sudden, large release of water from a glacial lake or reservoir, triggered by dam failure or volcanic activity.
67
What are the triggers of Jokulhlaups?
Volcanic activity, dam failure, overtopping.
68
What can Glacial bursts cause?
Significant flooding, erosion, damage to infrastructure, posing a hazard to people and ecosystems.
69
What is another example of a glacial burst case study?
Lake Thorthormi - made up of numerous supraglacial ponds which have enlarged and become interconnected.
70
What would the impacts be if Lake Thorthormi burst?
53 million m of water would be released, 117 buildings, 362 people would die, and 16 monuments fell. 5.22km of road could be affected.
71
What are the Primary impacts from a volcano?
Increased precipitation, deaths within local population, damage to property and businesses.
72
What are the secondary impacts from a volcano?
Summer cooling of northern hemisphere, global cooling, winter warming of northern hemiephere.
73
Why is there increased precipitation after an eruption?
H20 is released in larger quantities during eruptions.
74
Why does summer cooling of the Northern hemisphere occur?
Sulphur dioxide blocks insolation.
75
Why is there winter warming in the northern hemisphere after a volcano?
Stratospheric absorption of long and short wave radiation.

Tectonics (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions