3.1 Characteristics and causes of hazards Flashcards
What is a hazard?
A hazard is an event that has the potential to cause harm to the environment, people, or the economy.
What defines a natural hazard?
A natural hazard is an event caused by environmental processes, which becomes a disaster when it actually causes harm.
Name the three main types of natural hazards.
Tectonic & Geological, Climatic & Meteorological, Biological.
What is a tropical cyclone?
A rotating, low-pressure system (below 950mb) characterized by heavy rainfall, high wind speeds, and storm surges.
What scale is used to measure the magnitude of tropical cyclones?
The Saffir-Simpson Scale, from 1 to 5.
What is an earthquake?
A sudden, violent shaking of the ground caused by the movement of tectonic plates.
How is the magnitude of an earthquake measured?
Using the Richter Scale or the Moment Magnitude Scale.
What are the two main types of volcanic hazards?
Primary hazards (e.g., lava flow, ash) and secondary hazards (e.g., lahars, landslides).
What are the conditions necessary for the formation of a tropical cyclone?
Warm sea surface temperatures (over 27°C), low wind shear, and a deep layer of humid air.
What causes a tropical cyclone to dissipate?
Loss of warm, moist air supply, usually when the cyclone makes landfall or moves over colder water.
Name the four types of plate boundaries.
Constructive (divergent), Destructive (convergent), Collision, Conservative (transform).
What type of volcano is formed at a constructive boundary?
Shield volcanoes, which have gently sloping sides.
Where do most active volcanoes occur?
Around the ‘Ring of Fire’ located around the Pacific Ocean.
What type of volcano forms at destructive plate boundaries?
Composite or stratovolcanoes, which produce explosive eruptions.
What is a tsunami, and how is it caused?
A tsunami is a large ocean wave usually caused by undersea earthquakes or volcanic eruptions.
