Paper 1 Hazards Flashcards
What is the definition of a natural hazard?
A natural event that threatens people or has the potential to cause damage, destruction, and death.
Examples include earthquakes, volcanic eruptions, tropical storms, and floods.
What are atmospheric hazards?
Hazards created in the atmosphere by the weather, by the movement of air and water.
Examples include wind, tornadoes, and snow.
What are geological hazards?
Hazards created by the movement of the Earth’s tectonic plates or surface rock and soils.
Examples include earthquakes and landslides.
What are water-based hazards?
Hazards created by rivers, sea, or oceans.
An example is floods.
What are biological hazards?
Any biological substance that poses a threat to the health of people.
An example includes wildfires.
Fill in the blank: A natural hazard is a natural event that threatens people or has the potential to cause _______.
damage, destruction, and death.
True or False: Geological hazards are caused by atmospheric conditions.
False
Name one example of an atmospheric hazard.
Tornadoes
Other examples include wind and snow.
Name one example of a geological hazard.
Earthquakes
Other examples include landslides.
Name one example of a water-based hazard.
Floods
Name one example of a biological hazard.
Wildfires
What is hazard risk?
The chance or probability of being affected by a natural event
Why do people choose to live in flood-prone areas?
They weigh the advantages and disadvantages and may accept the risk because such events don’t happen very often
What factors affect hazard risk?
- Strength of buildings
- Frequency of events
- Population density
- Magnitude of the event
What is the relationship between population density and hazard risk?
More people in a country can lead to more deaths during a natural event
Fill in the blank: The _______ of a natural event can increase the level of hazard risk.
[magnitude]
True or False: People living in hazardous areas often have complete freedom in choosing where to live.
False
What does a higher magnitude of a natural event imply?
It leads to higher damage and death toll
Fill in the blank: If the frequency of a natural hazard increases, the _______ of that hazard also increases.
[risk]
What is one reason people may not know their area is dangerous?
Lack of knowledge about the risks associated with living in that area
How does the strength of buildings affect hazard risk?
Stronger buildings can reduce the impact of natural events, thereby lowering hazard risk
What is tectonic theory?
A theory that tries to explain how the Earth is structured and what it is made up of.
Tectonic theory encompasses the movement and interaction of tectonic plates.
What are the different layers of the Earth?
The Earth has the following layers:
* Crust
* Mantle
* Outer core
* Inner core
Each layer has distinct properties and compositions.
What is the outermost layer of the Earth called?
Crust
The crust is the thin, outermost layer where we live.
What is magma?
Liquid (molten) rock located beneath the Earth’s surface.
Magma becomes lava when it erupts on the Earth’s surface.
What is the core of the Earth composed of?
Dense hot rock at the center of the Earth.
The core is divided into the outer core and the inner core.
What happens as heat rises from the Earth’s core?
It sets off convection currents in the mantle.
These currents facilitate the movement of tectonic plates.
How fast do convection currents in the mantle move?
About as fast as your fingernails grow.
Despite being slow, this movement is crucial for tectonic activity.
What geological events are caused by the movement of tectonic plates?
Earthquakes, volcanic eruptions, and tsunamis.
These events are often interconnected through tectonic activity.
Fill in the blank: The _______ is a layer of rock between the core and the crust.
Mantle
What is the temperature of the inner core?
Approximately 7000 degrees Celsius.
The high temperature is due to the immense pressure and heat from radioactive decay.
What are convection currents?
Movements within the mantle caused by the heat from the core.
These currents are essential for the dynamics of plate tectonics.
What are the two types of crust mentioned?
- Continental crust
- Oceanic crust
These crust types have different compositions and densities.
What is a shield volcano?
A dome shape (like an upturned shield) with sloping sides and runny magma that flows long distances before it cools. More gentle explosions.
What is a composite volcano?
Steep sided, layers of ash and lava, with viscous (sticky) magma that cools quickly and is very explosive.
What type of plate margin leads to the formation of composite volcanoes?
Destructive plate margins.
What type of plate margin leads to the formation of shield volcanoes?
Constructive plate margins.
What happens at a destructive plate margin?
An oceanic plate is subducted beneath a continental plate, leading to melting and magma formation.
What is andesite?
The magma created when an oceanic plate sinks and melts at a destructive plate margin.
What is formed at a constructive plate margin?
New oceanic crust is formed as magma is injected between two oceanic plates.
What characterizes the magma at a constructive plate margin?
The magma is runny.
What type of earthquakes are caused at a conservative plate margin?
Earthquakes caused by friction as plates slide past each other.
True or False: Volcanoes are formed at conservative plate margins.
False.
What occurs when an oceanic plate meets a continental plate?
The denser oceanic plate is subducted beneath the less dense continental plate.
What is the result of pressure building up at a destructive plate margin?
Earthquakes occur due to friction.
Fill in the blank: At a constructive plate margin, new oceanic crust is formed in the _______.
gap created by two oceanic plates moving apart.
What type of volcanoes form at constructive plate margins?
Shallow sided volcanoes.
What is the term for the area where two tectonic plates collide?
Collision plate margin
Collision plate margins are characterized by the interaction of tectonic plates, leading to geological phenomena.
What happens to plates when they buckle?
They form mountains
Buckling occurs when two continental plates move towards each other, resulting in mountain formation.
What is an example of a continental plate?
Indo-Australian plate
The Indo-Australian plate is one of the major tectonic plates that consists of the continent of Australia and the Indian subcontinent.
What is the mantle?
The layer of the Earth between the crust and the core
The mantle is composed of semi-solid rock and plays a critical role in tectonic activity.
What geological feature is formed by the collision of continental plates?
Fold mountains
Fold mountains are created when two continental plates collide and buckle, leading to the uplift of material.
What is another example of a continental plate?
Eurasian plate
The Eurasian plate is one of the largest tectonic plates, covering much of Europe and Asia.
What are mountain roots?
The deep, underlying structures of mountain ranges
Mountain roots are formed as a result of tectonic forces and the uplift of continental crust.
What occurs when two continental plates are moving towards each other?
They buckle and form mountains
This process is responsible for creating significant mountain ranges like the Himalayas.
What natural disasters are associated with the collision of continental plates?
Powerful earthquakes
While earthquakes are common, volcanic activity does not occur in these regions due to the density of the plates.
True or False: Colliding continental plates can lead to the formation of volcanoes.
False
The density of continental plates prevents them from sinking into the mantle, which is necessary for volcanic activity.
What are the primary effects of a tectonic hazard?
Primary effects are caused by the shaking of the earth, including:
* Buildings collapsing
* People being injured or hurt
* Electricity and water supplies being cut off
Primary effects occur immediately during or right after the tectonic event.
What are secondary effects of a tectonic hazard?
Secondary effects occur after the initial event, including:
* Tsunamis
* Fires
* Landslides
* People becoming homeless
Secondary effects can have long-term impacts on communities and infrastructure.
True or False: Secondary effects of tectonic hazards occur simultaneously with primary effects.
False
Secondary effects happen after the initial event, while primary effects occur during the event.
Fill in the blank: Primary effects are caused by the _______ of the earth.
[shaking]
This shaking can lead to immediate damage and disruption.
List three examples of primary effects of tectonic hazards.
- Buildings collapsing
- People being injured or hurt
- Electricity and water supplies being cut off
These effects are direct results of the tectonic activity.
List three examples of secondary effects of tectonic hazards.
- Tsunamis
- Fires
- Landslides
Secondary effects can exacerbate the situation and lead to further destruction.
What was the magnitude of the earthquake that struck Nepal on April 25, 2015?
7.9 on the Richter Scale
What caused the 2015 Nepal earthquake?
Collision of the Indo-Australian plate with the Eurasian plate
At what rate do the Indo-Australian plate and Eurasian plate collide?
45 mm per year
How deep was the earthquake in Nepal on April 25, 2015?
15 km beneath the ground
How many people died as a result of the Nepal earthquake?
9000 people
How many people were injured in the Nepal earthquake?
20,000 injured
What fraction of Nepal’s population was affected by the earthquake?
One-third of Nepal’s population
How many people were left homeless after the earthquake?
3 million people
What was the estimated cost of damage from the Nepal earthquake?
Over US$5 billion
What organization raised US$126 million for emergency aid after the earthquake?
The UK
How many temporary shelters did the Red Cross set up for earthquake victims?
225,000 people
What type of supplies did the UN distribute to the worst hit areas?
Medical supplies
True or False: Social media was used in the search and rescue operations after the earthquake.
True
What natural disasters were triggered by the ground shaking from the earthquake?
Landslides and avalanches
How many people were killed by the avalanches on Mount Everest?
At least 19 people
Fill in the blank: The avalanche in the Langtang region left ______ people missing.
250 people
What river was blocked by a landslide after the earthquake?
Kali Gandaki River
What were two long-term responses to the earthquake in terms of infrastructure?
Thousands of homes were repaired Stricter building controls in the future
What economic activity resumed after the earthquake?
Tourism sites reopened
What training was provided to locals after the earthquake?
Training on maintaining and repairing irrigation equipment
