Hazardous Environment (Better Version) Flashcards
(19 cards)
What is the difference between continental and oceanic crust?
Continental: Granite, lighter, 30–50km thick
Oceanic: Basalt, denser, 6–8km thick
Continental crust is primarily composed of granite, while oceanic crust is mainly basalt.
What are the four types of plate boundaries?
- Constructive: Plates move apart (e.g. Iceland)
- Conservative: Slide past each other (e.g. San Andreas Fault)
- Destructive: Oceanic subducts under continental (e.g. Andes)
- Collision: Two continental plates crash and form mountains (e.g. Himalayas)
These boundaries define the interactions between tectonic plates.
What causes earthquakes?
Pressure builds as plates move; when released, it sends shockwaves through the Earth.
The movement of tectonic plates is the primary cause of earthquakes.
What is a hot spot?
A weak area in the crust where magma breaks through, forming volcanoes away from plate boundaries (e.g. Hawaii).
Hot spots can create volcanic islands that are not located at tectonic plate boundaries.
How are earthquakes measured?
- Richter Scale: Measures magnitude (energy released)
- Mercalli Scale: Measures damage (intensity)
These scales provide different perspectives on the impact and strength of earthquakes.
What are the two main types of volcanoes and how do they differ?
- Shield volcanoes: Gentle slopes, runny basalt lava, less explosive (e.g. Iceland)
- Composite volcanoes: Steep sides, thick andesitic lava, explosive (e.g. Andes)
The shape and eruption style of a volcano are determined by the type of lava it produces.
Name 3 volcanic hazards.
- Lava flows
- Pyroclastic flows
- Ash clouds
These hazards can pose significant risks to life and property during volcanic eruptions.
Why do people live near volcanoes?
Fertile soil, tourism, geothermal energy, mining opportunities
Despite the risks, volcanic regions can offer economic benefits.
What methods are used to predict volcanoes?
- Tiltmeters (measure swelling)
- Gas emissions (measured by aircraft)
- Boreholes (water temperature)
Monitoring these factors helps scientists anticipate volcanic eruptions.
What were the effects of the 2010 Haiti earthquake?
- 2250 deaths
- 1 million homeless
- Government buildings collapsed
- Port destroyed
- Slow aid
- Long-term need for international support
The earthquake had devastating impacts on infrastructure and the population.
What were the responses to the Haiti earthquake?
- USA sent troops and bottled water
- UNICEF provided food and shelter
- Rebuilding needed $2 billion
International aid was crucial for recovery efforts.
What made Japan more prepared for earthquakes?
- Shock-absorbing buildings
- Earthquake drills (Sept 1st)
- Tsunami warning system
- GIS mapping for rescue services
Japan’s preparedness measures significantly reduce earthquake damage.
What conditions are needed for a tropical cyclone to form?
- Sea temp > 27°C
- Deep water (>70m)
- Low wind shear
- Coriolis force
- Low pressure
These conditions create the ideal environment for tropical cyclones.
What is the eye of the storm?
Calm, low-pressure centre of a tropical cyclone
The eye is surrounded by the storm’s most intense winds and rainfall.
How are tropical storms measured?
Saffir-Simpson Scale (1–5), based on wind speed and damage
This scale helps categorize the severity of tropical storms.
Where do tropical cyclones occur?
Between 5° and 30° north and south of the equator
Tropical cyclones typically form in warm ocean waters.
Name 3 physical impacts of a tropical cyclone.
- Storm surges
- Strong winds
- Heavy rainfall/flooding
These impacts can cause significant damage to coastal areas.
What were the short-term impacts of Cyclone Komen?
- 100 deaths
- 1.2 million displaced
- 2000 homes destroyed
The cyclone had immediate and severe consequences for the affected population.
What were the long-term impacts of Cyclone Komen?
- Wells contaminated
- Months in tents
- Improved early warning systems
- 90% have mobile phones for alerts
The long-term recovery included both challenges and improvements in preparedness.
