Point 2 Flashcards
What are earthquakes?
Sudden movement and shaking that occurs on the earth’s surface resulting from shock waves moving from the initial point of origin
Earthquakes are caused by the movement of tectonic plates along faults.
What causes earthquakes?
Movement of tectonic plates along faults
Where do most earthquakes occur?
Along plate boundaries, particularly in the Pacific Ocean along the ring of fire
What percentage of the largest earthquakes occur in the Pacific Ocean?
81%
How many people have been affected by earthquakes in the last 10 years?
118 million people
How many earthquakes does Australia experience each day?
Over 100
What is a drought?
A deficiency of precipitation over an extended period resulting in a water shortage
Where are droughts most likely to occur?
In semi/arid areas such as Africa and parts of Australia
How many people are affected by droughts annually?
Estimated 55 million people
What percentage of all natural disasters do droughts represent?
15%
What is the definition of a landslide?
The movement of mass rock, soil and debris down a slope
What causes landslides?
Heavy rainfall, earthquakes, volcanic activity, or human activities
Where do landslides commonly occur?
In rocky or mountainous areas, particularly around the Andes mountain range in Peru and the Himalayas in Nepal
How many deaths per year are landslides responsible for?
4500 deaths
How many people were affected by landslides between 1998 and 2017?
4.8 million people
What is a flood?
Occurs when land is submerged by an overflow of water, normally caused by melting ice, snow or large amounts of rain
Where do floods typically occur?
Anywhere, but particularly in plains and low-lying areas close to streams and rivers or urban areas with poor drainage
What is the most frequent natural disaster?
Floods
What is the estimated global damage caused by floods annually?
$40 billion
What is the definition of a bushfire?
An unplanned vegetation fire, including grass fires, forest fires, and scrub fires
Also referred to as a wildfire.
What are the main causes of bushfires?
Dry weather, high temperatures, and flammable vegetation, often triggered by human activities or lightning
These conditions create an environment conducive to uncontrolled fires.
In which regions are bushfires most commonly found?
Australia, South America, and parts of the USA such as California
Australia is notably the most prone to bushfires.
What significant event occurred during the 2019/20 Australian bushfire season?
19 million hectares of land burned
This event is referred to as the ‘Black Summer’.
How many bushfires are recorded in Australia each year?
10,000 or more
This high frequency highlights the country’s vulnerability to such natural disasters.
What is the definition of a volcano?
An opening in the earth’s crust through which lava, volcanic ash, and gas erupt
Volcanoes are significant geological features associated with tectonic activity.
What causes volcanic eruptions?
Movement of tectonic plates
This movement can create pressure and lead to eruptions.
Where are most of the world’s active volcanoes located?
On the edges of continents, along island chains, or beneath the sea, forming large mountain ranges
More than half of the active volcanoes are part of the Ring of Fire.
What percentage of all natural disasters are represented by volcanic eruptions?
15%
This statistic underscores the impact of volcanic activity on global disaster rates.
What is the definition of a tropical storm?
A low-pressure system characterized by strong winds and heavy rainfall
Includes hurricanes, cyclones, and typhoons.
What causes tropical storms?
Warm ocean waters, where rising moist air forms powerful storm systems
This process is essential for the development of tropical storms.
In which areas do most tropical storms form?
Between the equator and tropic Cancer/Capricorn, with 90 percent forming within 20° north or south of the Equator
This geographic distribution is critical for understanding storm patterns.
How many tropical storms does Australia typically experience each season?
13
This average highlights the frequency of these storms in the region.
What was the wind speed of Cyclone Yasi in Northern Queensland?
Category 5 winds of 285 km/h
Cyclone Yasi was one of the most severe cyclones to impact Australia.
How many people were killed by tropical storms in 2019?
2225
This statistic reflects the devastating impact of tropical storms on human life.
