Welcome to our blog! Here you will be able to post and share the information you have gathered about different natural and man-made disasters and possibe ways to deal with them. We hope that you enjoy making this blog and learning from the materials and resources posted here! Claudia and Yamina
TABLE OF CONTENTS:
Storms
Earthquakes
Tsunamis
Hurricanes and Tornados
Volcanoes
Floods
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"Storms are associated with periods of strong often damaging winds, heavy flood-producing rainfall, thunder and lightning, heavy snowfall or blizzard conditions. They are classified by how strong the winds are or by how heavy the rainfall, lightning or snow are" (https://www.niwa.co.nz/education-and-training/schools/students/storms). These are the main types of storms:
(http://www.macmillandictionary.com/thesaurus-category/british/types-of-storm, https://stormdamagecenter.org/common-storm-types.php, http://news.nationalgeographic.com/news/2013/09/130923-typhoon-hurricane-cyclone-primer-natural-disaster/ and http://education.nationalgeographic.com/encyclopedia/hail/) Click here to learn about a famous dust storm that happened on "Black Sunday".
If you are interested in learning about lightning, one of the most incredible natural phenomena, click here to watch a National Geographic video.
What causes storms?
Storms are formed when the movement of cold and warm air currents creates extreme air pressure difference. Extreme air pressure is created at an atmospheric level as warm wet air rushes, causing cold air to move towards the area where air pressure is lower, eventually creating a rotation. The rotational movement of cold and warm air in the atmosphere is centered around an area of low air pressure that is surrounded by a high pressure system. The movement of the earth and the atmosphere starts this rotation, which then generates wind that is centered around it. The winds rotate clockwise in the southern hemisphere and counter-clockwise in the northern hemisphere. A low and high air pressure system can be generated at a local level as hot air rises off the ground. This creates relatively small air disturbances such as whirlwinds or dust devils. The type of storm that is generated varies depending on temperature and weather conditions around the system. Cold storm systems can take the shape of an ice storm, blizzard or snowstorm. In dry or desert areas, firestorms, windstorms or a dust devil can be generated. Storms in tropical areas can take the form of a tropical cyclone or a thunderstorm. (http://www.ask.com/science/causes-storms-1bc6db6f4066aa04)
What are the effects of storms?
Storms may lead to: 1. Interruption of public services: Due to severe storms, flights are cancelled, schools closed and public transport is halted. Massive power cuts (outages AmE) may take place leaving many areas without electrical power and water supplies may also be cut off. 2. Property damage: Massive power cuts may cause electrical goods to break down (http://abcnews.go.com/US/wireStory/storms-lightning-close-la-beaches-power-outages-32544156). When hail storms hit, hails can crack or smash windows, damage roofs, dent cars and cause damage to trees, plants and crops (https://stormdamagecenter.org/hail-storm.php). Flying objects and debris caused by the strong winds may cause window, paint, brick or roof damage. Heavy snow on roofs can cause roof collapse (https://stormdamagecenter.org/common-storm-types.php) 3. Injuries and even loss of lives: If during a hail storm a person is directly hit with large hail, it could cause serious bodily injury, or death (https://stormdamagecenter.org/hail-storm.php). During an electric storm, a bolt of lightning may hit and injure or even kill a person (http://abcnews.go.com/US/wireStory/storms-lightning-close-la-beaches-power-outages-32544156). In January 2014, for example, a lightning strike killed 3 and injured 22 people who were on the beach in Villa Gesell (http://www.theguardian.com/world/2014/jan/10/lightning-strike-in-argentina-kills-three). Lightning can also hit aircrafts and cause severe accidents. Low visibility during downpours, snowstorms and blizzards can cause car accidents (http://news.nationalgeographic.com/news/2014/01/140103-blizzard-snow-storm-winter-climate-weather-science/) 4. Floods: Floods can cause all kinds of serious damage including flooded basements, ruined furniture, damage to your home's exterior and landscaping, and much more (https://stormdamagecenter.org/tropical-storms.php). 5. Fires: Lightning that hit trees and the ground can cause wildfires and structure fires (https://stormdamagecenter.org/common-storm-types.php).
Preventive measures
Prepare your home for different types of storms:
Trim back tree branches away from the roof and large windows, as fallen limbs and broken tree branches can do a substantial amount of damage to your roof, windows and exterior
Clean gutters regularly, keep them free of leaves and other debris.
Check storm drains near your home or business and remove any debris, including leaves, plastic bags and trash bags.
If a storm is approaching or if a severe thunderstorm warning is issued:
Stay indoors or seek shelter to avoid being struck by lightning or hit by hail.
If you are outdoors, go to a safe place immediately (a building or a car with the windows shut). If there is no shelter around you, stay away from trees, water and metalic objects. Crouch down in the open area, put your feet together and place your hands over your ears to minimize hearing damage from thunder. If you’re with a group of people stay about 15 feet from each other
Bring in outdoor furniture, toys, pots and gardening tools to avoid flying objects
Shut your garage door and make sure doors and windows are secured.
(https://stormdamagecenter.org/wind-damage.php and http://www.weatherwizkids.com/weather-thunderstorms.htm)
The Earth's crust is divided in continental and oceanic plates called techtonic plates, which are in constant movement and can shift because of underlying movement in the Earth's mantle; and an an earthquake is the sometimes violent shaking of the ground caused by the energy released by these movements.
Most of them are situated along the Ring of Fire, in the Pacific Ocean.
The shifting of
one plate causes it to rub against or push under or over an adjacent plate.
The places where two techtonic plates meet are called fault lines, and it's at these fault lines that earthquakes can
occur. Aditionally, earthquakes are often followed by smaller aftershocks,which
can occur over days or weeks as the plates settle into equilibrium.
WHAT ARE THEIR EFFECTS?
The effects of an earthquake may —and actually do— vary depending on its magnitude, which is measured by seismometers
and seismographs that rate it on the Richter scale. This scale was developed in
1935 and it grades the energy released from 1 to 10.
Earthquakes measuring less than 4.0 magnitudeextend
over a small area from its epicenter
and may not even noticed, much less cause any damage.
From 4.0 to 5.9 magnitude: they cover a larger area and they are
felt. They may move some lamps, shake products off store shelves or
even crack some windows but no more serious damage.
Over 6.0 degrees on the Richter scale,
earthquakes can be dangerous and devastating depending, of course, on the
distance from it's center; as its energy
waves may cause buildings to show visible cracks or even collapse. For
instance, the eartquake's measuring 7.0 and 9.0 respectively in Haiti (2010)
and Japan (2011) caused massive deaths and major levels of destruction.
In the same way, earthquakes can also lead to other natural disasters, such as:
Avalanches and landslides:Earthquakes can shake snow, soil, and rock right off a sloped surface.
Surface faulting: Surface faulting is a change in the relative positions of things on opposite sides of a fault line. For instance, a straight section of railroad track that runs across a fault line might have a nasty curve in it after an earthquake, rendering it useless for train travel.
Tsunamis:Tsunamis are a series of waves that are caused by the sudden displacement of large amounts of ocean water, usually because of underwater earthquakes. When tsunamis hit land, they can knock over buildings, wash away cars, and cause massive flooding.
Liquefaction:Liquefaction occurs when water-logged soil acts like a liquid and causes sections of ground to sink or slide. As well as damage to roads and buildings, liquefaction can lead to flash floods.
PREVENTIVE MEASURES
If an
earthquake of a certain intensity occurs, try to focus your attention on
avoiding risks and take into account the following recommendations:
If you are inside a building, it is important to:
Seek shelter beneath door lintels or solid furniture
such as tables or desks, or next to a column or load-bearing wall.
Stay away from windows, glass, cabinets, partitions
and objects that may fall and hit you.
Do not use the elevator, as the impact of the
earthquake could result in its falling or you could get trapped inside.
Avoid using candles, matches, or any kind of flame
during or immediately after the quake, as it could cause an explosion or fire.
If
the shock surprises you outside, it is advisable to:
Go to an open area and stay away from damaged
buildings. After a major earthquake, other smaller ones follow, called
aftershocks, that may be strong enough to cause additional damage.
Try not to approach or enter damaged buildings. The
greatest danger from falling debris, coatings, glass, etc. is vertically below
façades.
If travelling by car, stay inside the vehicle and be
careful to stay away from bridges, utility poles, damaged buildings or
landslide areas.
Try
to answer calls for help and collaborate with the Services involved, but do not
go to the affected areas without being requested to do so by the authorities. People snickering around these areas after a natural disaster not only put themselves in danger but also obstruct rehabilitation work.
A
tsunami is a series of ocean waves that sends surges of water,
sometimes reaching heights of over 100 feet (30.5 meters), onto land.
These walls of water can cause widespread destruction when they crash
ashore.
Tsunamis
race across the sea at up to 500 miles (805 kilometers) an hour—about
as fast as a jet airplane. At that pace they can cross the entire
expanse of the Pacific Ocean in less than a day. And their long
wavelengths mean they lose very little energy along the way.
In
deep ocean, tsunami waves may appear only a foot or so high. But as
they approach shoreline and enter shallower water they slow down and
begin to grow in energy and height. The tops of the waves move faster
than their bottoms do, which causes them to rise precipitously.
What
causes a tsunami?
These
awe-inspiring waves are typically caused by large, undersea
earthquakes at tectonic plate boundaries. When the ocean floor at a
plate boundary rises or falls suddenly it displaces the water above
it and launches the rolling waves that will become a tsunami.
Most
tsunamis, about 80 percent, happen within the Pacific Ocean’s “Ring
of Fire,” a geologically active area where tectonic shifts make
volcanoes and earthquakes common.
Tsunamis
may also be caused by underwater landslides or volcanic eruptions.
They may even be launched, as they frequently were in Earth’s
ancient past, by the impact of a large meteorite plunging into an
ocean.
Effects
Being a giant,
fast-moving wave carrying an enormous amount of energy, it doesn’t
come as a surprise that the effects of a tsunami are devastating,
instantaneous and long-lasting. However, the severity of a tsunami’s
effects depends on a number of factors, for example the magnitude of
the phenomenon which originated the tsunami in the first place: while
small tsunamis are nearly undetectable, larger tsunamis sweep away
everything in their path and have effects which are often
irreversible. The impact of this natural disaster brings on
destruction and damages, death, injuries, diseases, financial loss,
psychological problems, among others.
Destruction
and damage The impact of the waves
knocks down infrastructure, damages property and permanently alters
the landscape (by severely eroding the foundations of the coastline),
leaving behind a mass of solid waste and debris, as well as toxic
substances and industrial raw materials –leaked as a result of
property damage-, that is almost impossible to clean up, which causes
all kind of problems in the long run. Severe flooding plus the
initial impact gravely damages sewer systems, water supplies and
soil, which becomes salinized from sea water and debris. If the
tsunami hits poor and less-developed countries which are not built
strongly enough to withstand such a natural disaster, the
consequences are catastrophic.
Death and
Injuries Because there is very
little warning before a tsunami hits, coastal residents do not have
much time to escape, which leads to massive loss of human life either
by drowning, being hit by collapsing buildings, electrocution, fires,
explosions or diseases, and many people are reported missing. Animals
and vegetation are also washed away.
Diseases Tsunamis
cause the area closest to the coast to flood, this leads to the
outbreak and rapid spread of diseases such as malaria, which forms
from the stagnant and contaminated water. Disease can also spread
from dead bodies; this is why it is recommended to burn the dead
instead of burying them. Often the damage induced to the sewage and
fresh water supplies makes it more difficult for people to stay
healthy and for diseases to be treated; therefore, an environment is
created where more illnesses, infections and death are easily spread.
Financial
loss When a tsunami happens, there
is immediately massive cost, and the great need for financial and
material assistance lingers for months –even years- after the
disaster itself. The immense monetary cost of this situation covers
the expenses for rescue teams, aid to the tsunami-hit area, clean up
cost, etc. Specifically, the money goes to surveying and monitoring
for infectious and water-transmitted diseases, diverting medical
supplies, restoring normal primary health services and assisting the
community to recover both, mentally and socially once the crisis has
subsided. There is also loss of earnings in the local economy as well
as future losses, since the damaged area will be so for a while.
Psychological
problems Those who survived a
tsunami are prone to suffer psychological problems after the event;
these might continue for years or even their lifetime. The most
common problem that victims present is the post traumatic stress
disorder (PTSD), but they also may suffer from anxiety, grief and
depression.
Preventive
Measures
The
best defense against any tsunami is early warning that allows people
to seek higher ground. The Pacific Tsunami Warning System, a
coalition of 26 nations headquartered in Hawaii, maintains a web of
seismic equipment and water level gauges to identify tsunamis at sea.
Similar systems are proposed to protect coastal areas worldwide.
A
tsunami’s trough, the low point beneath the wave’s crest, often
reaches shore first. When it does, it produces a vacuum effect that
sucks coastal water seaward and exposes harbor and sea floors. This
retreating of sea water is an important warning sign of a tsunami,
because the wave’s crest and its enormous volume of water typically
hit shore five minutes or so later. Recognizing this phenomenon can
save lives.
A
tsunami is usually composed of a series of waves, called a wave
train, so its destructive force may be compounded as successive waves
reach shore. People experiencing a tsunami should remember that the
danger may not have passed with the first wave and should await
official word that it is safe to return to vulnerable locations.
Tsunamis
can wreak havoc on coastal populations and landscapes. The December
26, 2004, tsunami in the Indian Ocean claimed some 150,000 lives and
cleared the landscape on millions of acres of oceanfront terrain.
Here are some measures you can take to avoid trouble if you're caught
in a tsunami.
Safety
Tips
When
in coastal areas, stay alert for tsunami warnings.
Plan an evacuation route that leads to higher
ground.
Know
the warning signs of a tsunami: rapidly rising or falling coastal
waters and rumblings of an offshore earthquake.
Never
stay near shore to watch a tsunami come in.
A
tsunami is a series of waves. Do not return to an affected coastal
area until authorities say it is safe.
Hurricanes, Cyclones and Typhoons are all the same weather phenomena. They can be defined as violent low-pressure systems in which the central core is warmer than the surrounding winds. They all have strong rotating or swirling winds, lightning, thunders, lots of rain and low pressure. The difference between them is given by the location in which these phenomena take place:
•In the Atlantic and Northeast Pacific, the term hurricane is used.
•The same type of disturbance in the Northwest Pacific is called a typhoon
•Cyclones occur in the South Pacific and Indian Ocean.
What are Tornadoes?
A tornado can be defined as a destructive and dangerous windstorm whose clouds are shaped like a funnel. The funnel or whirlwind extends from the bottom of a cumuliform cloud to the ground and moves over land and destroys everything in its path. Not all tornadoes are visible as funnel clouds. The Fujita Scale is a scale that tells how severe a tornado is based on wind speed and damage being caused.
Where do they take place?
Tornado Alley: an area in the western portion of the US that runs from the western side of Texas up to North and South Dakota, known for its many tornado strikes. This is an area prone to tornadoes. However, this does not mean that tornadoes cannot take place elsewhere; in New Zealand, Australia, South America, Africa and Eastern Europe tornadoes have occurred.
Similarities and Differences between Hurricanes and Tornadoes
In the structure of both a hurricane and a tornado, there is a relatively calm, clear area at the center. Winds blow in a spiral around this roughly circular center called the eye. Both tornadoes and hurricanes contain strong rotating winds that can cause damage.
The truth is, there is still a lot we don’t know about how tornadoes form. The conditions that may give rise to one tornado won’t necessarily cause another. But the most likely possibility of forming them is a thunderstorm; but not any thunderstorm. Just the ones that have sufficient instability and wind shear present in the lower atmosphere; they are called “supercells.”
Instability refers to unusually warm and humid conditions in the lower atmosphere, and possibly cooler than usual conditions in the upper atmosphere. Wind shear in this case refers to the wind direction changing, and the wind speed increasing, with height. Winds near the surface blow in one direction, while winds above blow in another direction. The difference between them creates a horizontally rotating mass of air. Rising warm air creates an updraft, pulling the rotating air upright.
Now the thunderstorm forms a rotating vortex, or a mesocyclone that then creates the funnel cloud. Most researchers believe that the funnel starts from above and drops down to a region where the air pressure is lower.
Loss of Life: Tornadoes typically kill 60 to 80 people per year and injure more than 1,500. Most deaths come from flying or falling debris, and occur in the most violent tornadoes, which account for 70 percent of tornado deaths.
Property Damage: Another significant effect tornadoes have on humans is the property damage. Weak tornadoes can take the roofs off buildings and break windows. Stronger tornadoes have been shown to destroy entire buildings.
A house after a tornado hit Ocklahoma in May 2013
Effects on Nature: Trees and plants can be uprooted, and diseases in the soil are spread. Wildlife loses their lives or habitat. Their effects on the environment are not just restricted to uprooting of trees though, but go well beyond that - as they also contribute to environmental pollution. This environmental pollution can be attributed to the huge amount of dust that these tornadoes bring in from dry regions, flying debris of structures brought down by them, etc. Even the fluid that is leaked from the vehicles; which are reduced to junk by tornadoes, contribute to environmental pollution by polluting soil and water.
There are simple ways to prepare and keep safe before and during a tornado.
Before the tonado
PUT TOGETHER A FAMILY EMERGENCY PLAN: Discuss with your family how to get to a safety place, how to communicate with one another, and where are you going to meet after the event is over. Find out where local shelters are and the fastest way to get there. Practise periodic drills so that you and your family members know what to do if a tornado warning is issued.
PREPARE ANEMERGENCY KIT: It should help you and your family get by without heat or electricity for at least 72 hs. Use a bag or cardboard box and pack it with some basic items such as bottled water, non-perishable food, first aid kit, a portable radio and other essential items.
If a storm is approaching, keep your radio on and LISTEN OUT FOR ALERTS ISSUED BY THE NATIONAL WEATHER SERVICE:Tornadoes rarely appear without warning. They usually come together with severe thunderstorms.
A tornado watch is issued when weather conditions are favourable for the development of severe thunderstorms that are capable of producing tornadoes.
A tornado warning is issued when a tornado has actually been detected on radar
If threatened by an approaching tornado
INDOORS
HEAD TO THE LOWEST LEVEL OF THE BUILDING: If you have no basement, get to the lowest floor of the house or building take shelter in a small inside room near the centre of the house, such as a closet, a bathroom, or under a sturdy desk or table.
STAY AWAY FROM OUTSIDE WALLS, WINDOWS AND DOORS: The idea is to put as many walls between you and the tornado as you possibly can, so you will be safe when debri starts being blown at the house.
OUTDOORS
If you are caught outside, get as low to the ground as possible and protect your head from the flying debri. Lie down in a ditch, for example. If you are driving, head away from the tornado’s path and look for a building to shelter in. If the tornado is too close, get out of the car and get down on the ground (In a car is one of the most dangerous places to be)
In the aftermath of a tornado
Look out for downed power lines or dangerous debri.
A flood occurs when water overflows or inundates land
that's normally dry. This can happen in a multitude of ways.
Types and Causes of Flooding
Most common is when rivers or streams overflow their
banks. Torrential rains from decaying hurricanes or tropical systems, a
ruptured dam or levee, rapid ice melting in the mountains, or even an
unfortunately placed beaver dam can overwhelm a river and send it spreading
over the adjacent land, called a floodplain. These floods are called riverine or river floods.
As land is converted from fields or woodlands to
roads or parking lots, it loses its ability to absorb rainfall. Urbanization
increases runoff 2 to 6 times over what would occur on natural terrain. During
periods of urban flooding (also called areal flood), streets
can become swift moving rivers, while basements can become death traps as they
fill with water.
Winds generated from tropical storms and hurricanes or
intense offshore low pressure systems can drive ocean water inland and cause
significant flooding. Escape routes can be blocked off and blocked by high
water. Coastal flooding or estuarine flooding can also be produced
by sea waves called tsunamis, sometimes referred to as tidal waves. These waves
are produced by earthquakes or volcanic activity. Most floods take hours or
even days to develop, giving residents ample time to prepare or evacuate.
Others generate quickly and with little warning. These
flash floods can be extremely
dangerous, instantly turning a babbling brook into a thundering wall of water
and sweeping everything in its path downstream. Most flash flooding is caused
by slow-moving thunderstorms, thunderstorms repeatedly moving over the same
area, or heavy rains from hurricanes and tropical storms, however, a dam or
levee failure, or a sudden release of water held by an ice jam also can result
in flash floods.Furthermore, flash flood-producing rains can also trigger catastrophic
mud slides. The two key elements are rainfall intensity and duration.
Topography, soil conditions, and ground cover also play an important role.Most flood deaths are due to FLASH
FLOODS.
Watch here an interesting video about types of floods.
Some negative effects floods may have on people are:
Drowning
Homelessness
Diseases and Infections
On the Economy:
Infrastructure Damage
High cost of rebuilding to society and governments
Damage to Agriculture
On the environment:
Pollution of water
Disruption of the Ecosystem
There is also something good about floods,
especially those that occur in flood plains and farm fields. Floodwaters
carry lots of nutrients that are deposited in the plains. Farmers love
such soils, as they are perfect for cultivating some kinds of crops.
Preventive Measures
Before a flood
Install backflow valves or standpipes to prevent sewer lines from backing up.
Elevate your washer, dryer, water heater, oil tank, furnace and electrical wiring on concrete blocks. Install a sump pump system if you have below-grade floors.
Landscape with plants and vegetation that resist soil erosion.
Store irreplaceable family items and important documents somewhere safe.
Install a flood-detection device that sounds an alarm or calls your phone if it senses water.
During a flood
Try to stay calm. Keep your family safe, but if you have time:
Turn off utilities at the main power switch.
Move valuables, important papers and clothing to upper floors.
Sanitize your bathtub and sinks and fill them with fresh, clean water in case the water supply becomes contaminated.
Never try to drive through a flood. Abandon the car and move to higher ground.
Don't walk through flood areas. Just 6 inches of water can sweep you away.
Stay away from downed power lines.
After a flood
After emergency officials have given permission to re-enter your home:
Check for structural damage before going inside.
If it’s dark, use a flashlight – not matches, a candle or a lighter.
Listen for reports to see when drinking water is safe again.
Don’t turn your power on until an electrician has inspected your system.
Use your cell phone or other camera to photograph damage, which can help get your claim started sooner.
Begin initial cleanup as soon as waters recede. When cleaning, wear a mask, gloves and coveralls to minimize exposure to possible hazardous materials.
