Hazards BK 5 - Storm Hazards Flashcards
at what point do hurricanes, typhoons, cyclones or willy-willies occur
when a tropical storm reaches 74mph, until then it’s just called a tropical storm
what’s a tropical storm
intense low pressure weather systems that develop in the tropics
how big in diameter and km usually are tropical storms
200-700km
how do tropical storms form
-begin with an area of low pressure, resulting from surface heating where warm air is drawn in a spiralling manner
-small scale disturbances can enlarge into tropical depressions with rotating wind systems and can grow to be more intense
what are 6 conditions that have to be present for tropical storms to be triggered
- warm ocean surface temperature of 27 degrees
-ocean depth of atleast 70m
-cross winds in the upper atmosphere to be light
-position in relation to the equator to be 5 - 15 N/S
-winds in the lower atmosphere must be converging
-airflow in the upper atmosphere must be rapid
where do tropical storms never occur
on the equator
where do typoons tend to impact
south east asia
where do hurricanes happen the most
north and south america
what has to happen/occur for tropical storms to revolve
where there is a supply of latent heat and moisture to provide energy and low frictional drag on the ocean surface
what are some characteristics of the central eye of a tropical storm
an area 10-15km in diameter in which there’s calm conditions, clear skies and higher temperatures
what’s the coriolis force
when objects appear to be travelling in a straight line they are instead curved
what does the coriolis effect do in terms of tropical cyclones
it causes tropical cyclones to spin anti-clockwise in the norther hemisphere, but clockwise in the southern hemisphere
what 3 things impact the formation of tropical storms the most
latitude and the equator
cloud and precipitation form
the coriolis force
how does latitude impact the formation of tropical cyclones
sunlight directly strikes the equator, compared to both of the poles
meaning tropical storms happen more around the equator
where are wind speeds the strongest witching a tropical cyclone
around the eyewall
what gives the topical storm energy to move
latent heat
why do tropical cyclones cause the most damage to islands and coastal locations
becasue as soon as they reach land they loose warm ocean surface and energy
why do tropical cyclones occur seasonally
because much heat is needed over the course of the summer to warm the ocean to a temperature of almost 27 degrees
describe a tropical cyclone
a violent storm from 200-700km in diameter, revolving around a central eye with wind speeds of atleast 74 mph
define a tornado
a revolving storm that forms over land, featuring a swirling funnel cloud that drops down to earth from the main cloud base
what’s it called when tropical cyclones loose energy inland
tropical decay
what’s another name for a tropical cyclone
a typhoon
why do conditions in the upper atmosphere need to be calm
so that the storm doesn’t get ripped apart
what do sustained wind speeds have to be to categorise a storm as a hurricane
74 mph
what scale does a tropical cyclone get measured on
saffir simpson scale
describe the saffir simpson scale
a five point scale based upon central pressure, wind speed, storm surge and damage potential
what’s the average life span of tropical storms
7-14 days
how many storms develop every year around the world
80-100
what percentage of all storms that develop become tropical revolving storms
80%
what are four impacts of storm hazards
heavy rainfall
strong winds
storm surges
landslides
what can heavy rainfall cause
flooding of low lying, coastal areas
flooding of inland areas near rivers
what can strong winds cause after a storm hazard
damage to buildings and vegetation/crops
damage to shipping and offshore structures
what can storm surges cause after storm hazards
flooding of low lying coastal areas
erosion of cliffs and coastal areas exacerbated
what can landslides cause after storm events
heavy rainfall saturates material
coastal erosion undermines cliffs
how do strong winds cause damage to crops
especially surrounding the eye wall, power is strong enough to life and damage anything in its pathway
how do strong winds end up killing people
people can be tricked into a sales sense of security as eye of storm and surrounding cyclone isn’t as strong therefore people might not leave
how do tropical storms cause mass movement
they can contain water, makes ground saturated so landslides can happen more easily
happens more at higher altitude
where is the level of vulnerability the lowest in terms of tropical storms and why
inland, because storms begin to decay as soon as they move away from the ocean
there’s also a lower chance of flooding, mass movements etc
where are 3 places that have the highest levels of vulnerability
- offshore area
- upland areas with isolated villages
- lowland area
why is vulnerability high in upland areas with isolated villages
high chance of mass movement and little evacuation options due to upland nature, being in LEDCs makes this harder
why is vulnerability high in offshore areas
-no evacuation
-higher risk of floods, erosion and storm surges
-higher risk of death
why is vulnerability high in lowland areas
could be destroyed or cut off by mass movement, there’s a higher risk of this closer to the coast and in LEDCs
on the saffir simpson scale is 1 or 5 a major hurricane
5 is major
what sort of damage and impact would catagory 1 hurricanes cause on the saffir simpson scale
Short term, power outages only last days maybe hours
people can loose communication and some buildings may be damaged, some plants and trees could be uprooted
what sort of damage and impacts will category 3 storms cause on the saffir simpson scale
devastating damage will occur
social, communication and evacuation halted, homes will be majorly damaged and trees will be snapped and uprooted blocking exits
electricity and water supply maybe unavailable for days
what damage and impacts will category 4 and 5 storms cause according to the saffir simpson scale
catastrophic damage
homes and ifs structure will be destroyed or some able to sustain damage, scale is widespread usually
power outages will last weeks and most of the area will be inhabitable for many weeks and months
what’s the difference between a tropical storm and a tropical depression
A tropical depression forms when a low pressure area is accompanied by thunderstorms that produce a circular wind flow with maximum sustained winds below 39 mph. An upgrade to a tropical storm occurs when cyclonic circulation becomes more organized and maximum sustained winds gust between 39 mph and 73 mph.
what’s preparedness like in MEDCS
- More prediction, more advaneed technology to be cuble to trach tropical storms. more able to put warnings
and evacuation in place to aid people.
- Better communication and financially available, e-g. USA government funded
"Nation al Hurricane (entre' use super -computers, saveNice, meterologists.
- Too mang wrong/ false warning, can cause panic but also complecency in people.
what’s preparedness like in LEDCs
-little to no prediction most likey can’t afford the technology, people have to deal with the events as it happens
-can be funded by MEDCs in creating evacuation plans and stabilising more homes
what’s mitigation and prevention like in MEDCS compared to LEDCs
little you can do to prevent in both MEDC and LEDC
more tech and research in MEDC
MEDCs tend to have a mitigation plan, such as outer banks communities in America
what’s adaptation and protection like in MEDCs compared to LEDCs
better emergency service and humanitarian aid response in MEDCs, less likely to have good evacuation plans in place and better built buildings in LEDCs due to less funding and money
land use planning and hard engineering strategies like sea walls and breakwaters can be more easily put in place in MEDCs
