Weather Hazards Flashcards
What are tropical storms?
Tropical storms are areas of intense or very low air pressure (spinning masses of clouds) that generally develop between the tropics.
Where do tropical storms form?
Tropical storms form in tropical regions as the intense heat makes the air unstable/rise rapidly
Where are tropical storms called hurricanes?
In the Atlantic and eastern Pacific regions (e.g. North America, Europe)
Where are tropical storms called cyclones?
South-east Asia (e.g. India, Bangladesh, and Australia)
Where are tropical storms called typhoons?
In Japan, China and the Philippines
What conditions are needed for tropical storms to form?
- Large areas of tropical oceans where the ocean temperature is above 26-27°C
- A considerable depth of warm water - at least 70m
- An intense low pressure resulting in the strong upward movement of warm, moist air
- Winds generally blowing in the same direction
How are tropical storms distributed?
- Most tropical storms tend to occur between the tropics (between 5° and 20° north and south of the equator)
- They tend to move in a westerly direction (occurring in the easterly wind belt) and usually strike the east coast of continents
Why don’t tropical storms form at the equator?
Tropical storms do not occur on the equator (between 0° and 5°) as the ‘spin’ from the earth’s rotation (Coriolis effect) isn’t strong enough.
How do tropical storms form?
- Rising air causes water to evaporate over a warm ocean surface
- Thunderstorms develop as evaporated air cools and condenses, releasing heat which powers the storm, resulting in more evaporation
- More thunderstorms join together into a larger storm which spins due to rotation of the earth
- Cooler air then begins to descend resulting in the development of the eye - the most intense weather conditions (strongest winds an heaviest rainfall) develop in the ‘eyewall’ on the outer edge of the eye
- The storm continues to gain strength as it moves over warm oean surfaces.
- Upon reaching land it weakens rapidly as it gets cut off from its energy source (warm moist air) and experiences friction with the land, slowing winds down.
How many °C have ocean temperatures risen over the last 20 years?
0.5°C
What country experienced Typhoon Haiyan?
Philippines
What is a landslide?
The movement of earth or rock from a slope as a result of it becoming unstable, usually from heavy rainfall
What is infrastructure?
Networks such as transport, power supplies and telecommunications
What are the immediate risks of tropical storms caused by?
- Winds - can damage builidings, infrastructure, trees and crops. Flying objects can cause damage to people and property.
- Heavy rainfall - torrential rain can lead to flooding
- Strom surges - These are caused by a combination of very low air pressure and strong winds which cause the sea level to rise by seeral metres and cause large waves
What were the primary effects of Typhoon Haiyan?
- Storm surges - people drowned by the storm surge
- Homes damaged or flattened by the wind - people displaced and 90% of Tacloban city destroyed
- Tacloban airport terminal damaged - people stranded, flights delayed
- Fishing boats destroyed - people lost their income
- Strong winds - damaged buildings, power lines and crops destroyed
- Heavy rainfall - caused flooding
What were the secondary effects of Typhoon Haiyan?
- People left homeless - 14 million people affected and most have lost their source of income
- Flooding - caused landlslides and blocked roads which cut off aid to remote countries
- Ferry services and airline flights disrupted - slowed down aid efforts
- Shortage of water, food and shelter - this affected people leading to outbreak of diseases such as cholera
- Shops destroyed, jobs lost - loss in income
- Hospitals and schools damaged - difficult to help people as not enough resources to support the injured. Disruption in people’s education
- Looting and violence - people felt unsafe, increase in crime
What were the immediate responses to Typhoon Haiyan?
- International government and aid agencies - provided food, water and temporary shelter
- US aircraft carrier and helicopters - assisted with search and resuce and delivery of aid
- 1200 evacuation centres set up - to help the homeless
- UK government sent shelter kits - provided emergency shelters for families
- French, Belgium and Israeli field hospitals set up - to help the injured
- Philippins Red Cross - Delivers basic food aid such as rice, canned food and cooking oil
What were the long-term responses to Typhoon Haiyan?
- The UN, US and UK, Australia and Japan donated aid - such as financial aid, supplies and medical support
- Rebuilding - roads, bridges and airport facilities
- ‘Cash for work’ programmes - people paid to help clear debris and rebuild the city
- Foreign donors - e.g. US and EU supported new livelihood opportunities
- Rice farming and fishing re-established - to help people get income
- Aid agencies e.g. Oxfam - Supported the replacement of fishing boats
- Cyclone shelters built - To accomodate people evacuated from coastal areas
What are the three P’s?
Monitoring and Prediction, Protection and Planning
What is the cone of uncertainty?
The area defined by forecasters where a tropical storm may cause damage
What is mandatory evacuation?
An evacuation that is commanded by authorities
What is monitoring?
Monitoring agencies like the National Hurricane Centre in Florida and the Joint Typhoon Warning Centre in Hawaii identfy storms and track their paths and strength
What is prediction?
Weather agencies use this information to update tropical storm forecasts. These forecasts cover a large area known as the cone of uncertainty
What are the two levels of warning issued by the National Hurrican Centre?
- Hurricane Watch - advises that hurrican conditions are possible
- Hurricane Warning - Advises that hurricane conditions are expected and that people should take immediate action e.g take shelter or evacuate
