Tectonic Hazards Flashcards
LA and Nepal earthquake facts
What type of plate boundary does Los Angeles lie on?
Conservative plate boundary
Where is California located?
(Country, ocean, close to)
Located on the west coast of the USA on the Pacific Ocean and is close to Mexico
When did the Los Angeles earthquake occur?
(Time, date, year)
04:30am on the 17th January 1994
(Michelle Obama’s birthday)
What is the name of the plate boundary LA lies on, and what two plates is it in the middle of?
San Andreas fault, Between the pacific and North American plate.
Los Angeles Earthquake magnitude
6.7
Los Angeles earthquake depth of focus
18.4km
Give 3 primary impacts of the Los Angeles earthquake
Eg: Primary
• 57 deaths
• 12,000 injuries
• 12,500 buildings damaged
• Cost: 15 billion dollars
How many people died in the Los Angeles earthquake?
57
How much did the Los Angeles earthquake cost?
15 billion dollars
How many injuries in the Los Angeles
Earthquake?
12,000
Give 3 secondary effects of the Los Angeles earthquake
eg:
15,000 aftershocks
Some died from indirect causes like stressed induced cardiac arrest
Numerous fires were also caused by broken gas lines from houses shifting off their foundations or unsecured water heaters tumbling
Valley fever outbreak - This respiratory disease is caused by inhaling airborne spores of the fungus.
it is believed that the spores were carried in large clouds of dust created by seismically triggered landslides.
Some people didn’t die directly from the earthquake in Los Angeles, give an example
Induced cardiac arrests
How did the Los Angeles earthquake trigger a valley fever outbreak?
Scientists predicted the spores were carried in large clouds of dust created by seismically triggered landslides.
Give 2 short term responses of the LA earthquake
California created the CEA (California earthquake authority)
ordinary citizens who are members of the Los Angeles Fire Department’s Community Emergency Response Team program rescued people
Give 2 long-term responses of the LA earthquake
A substantial effort was also made to reinforce freeway bridges against seismic shaking
A law requiring water heaters to be properly strapped was passed in 1995
Nepal is an LIC ranked ____ out of 188 countries, nearly _____ people live on less than ____ a day
145, 8 million, $1.26
What type of plate boundary did Nepal lie on?
Destructive Collision
Which 2 plate boundaries is Nepal in between of?
Indian and Eurasian (near Himalayas)
Just a check in, how well do you think you are doing so far? :)
You got this <3
Name Nepal’s capital and how far the earthquake is from it.
The epicentre was 80km away from Kathmandu
What time did the Nepal earthquake hit?
(Time, Date, Year)
Around 6am, on the 25th April 2015
(World Penguin Day)
Magnitude of the Nepal earthquake?
7.9
Depth of focus of the Nepal earthquake
15km
Give 3 primary effects of the Nepal earthquake
eg:
9,000 people died
20,000 injured – 8 million affected
Estimated cost around 5 million dollars.
Electricity and water supplies affected
50% of shops destroyed
Death toll of the Nepal earthquake
9,000 :(
How many injuries in the Nepal earthquake
20,000
How many were affected by the Nepal earthquake?
8 million
How much did the Nepal earthquake cost?
Estimated at 5 million dollars
How many people went missing in Langtang?
250
Give 3 secondary effects of the Nepal earthquake
eg:
Widespread avalanches and landslides hampered rescue efforts
Avalanche on Mount Everest killed at least 19 people
Avalanche in Langtang caused 250 people to be missing
Give 3 immediate responses of the Nepal earthquake
Internation search and rescue team found 16 survivors.
Water and medical supplies arrived from UK, China and India
Charities like the Red Cross set up field hospitals
How much did the USA give to Nepal to rebuild?
700 million dollars
Give 3 long term responses of the Nepal earthquake
UNESCO is helping to restore 700 damaged temples, palaces and museums
Roads fixed and landslides cleared, trek on Mount Everest fixed to allow tourists to come.
US gave 700 million dollars to help rebuild disaster resilient homes.
Name the four types of tectonic plate boundary:
Destructive
Destructive-Collision
Constructive
Conservative
What is a constructive plate boundary?
When two plates move apart.
What is a conservative plate boundary?
Where tectonic plates move alongside each other.
What is a destructive plate boundary?
Where oceanic and continental crust collide.
What is a destructive-collision plate boundary?
When two continental plates collide.
Explain why earthquakes can occur at a conservative plate boundary:
- Two plates grind past each other (either in opposite directions or at different speeds) at a fault.
- The plates can sometimes get stuck, causing pressure to build up.
- Eventually, energy around this point (the focus) is released as an earthquake.
Explain why both volcanoes and earthquakes can occur at constructive plate boundaries:
- Two plates move apart.
- Magma rises from the gap between them, and cools to form new crust (e.g. Mid-Atlantic Ridge)
- This can cause shield volcanoes to form.
- Additionally, the movement of the plates can cause vast amounts of seismic energy to be released as earthquakes.
Explain why both volcanoes and earthquakes can occur at destructive plate boundaries:
- Two plates are moving towards each other.
- Oceanic crust is subducted as it is denser than continental crust.
- Friction between the two plates during subduction causes strong earthquakes.
- As the oceanic plate is forced downwards, heat from the mantle melts it and turns it into magma.
- The magma forces its way up to form a composite volcano.
Describe the movement of convection currents:
- Rock in the mantle is heated to become magma.
- This heated magma expands, becoming less dense, and rises to the surface, pushing magma above sideways.
- Once it reaches the crust, the magma cools, becoming denser, and sinks.
- The circular motion of the magma rising and descending as it warms and cools is a convection current.
What are some ways of predicting when earthquakes may occur?
- Looking at changes in animal behaviour.
- Looking at changes in electromagnetic fields.
- Looking at rising water levels
- Using seismometers to detect foreshocks.
- Using tiltmeters to detect rock movement.
- Looking at changes in radon levels.
However, there are no reliable ways of predicting earthquakes completely.
What are some ways of planning for an earthquake?
- Creating emergency grab bags.
- Constructing aseismic buildings.
- Practicing emergency drills (such as Great California Shakeout).
- Constructing emergency shelters.
- Educate the public on risks.
- Set aside emergency funds.
- Map out areas that would be most at risk.
What are some ways of “earthquake proofing” buildings?
- Very deep foundations.
- Strong double-glazed windows.
- Rubber shock absorbers between foundations.
- Automatic shutters to reduce risk from broken glass.
- Disconnected from foundations to reduce vibrations and tremors.
