Natural
Disasters
INDEX
LINKS
WORD FILES – A PROCESS OF
INFORMATIVE AND
CREATIVE WRITING – Pg 2
and 3
INDEX OF NATURAL
DISASTERS
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Volcanoes
Tornadoes
Tsunamis
Earthquakes
Lightning
Drought
Hurricanes
Avalanches and Landslides
Flash Floods
Storms and Blizzards
OVERALL ASSIGNMENT
A series of lessons that result in a PowerPoint created by the group. The slides in the
PowerPoint are episodes created by each member of the group. They tell a story of their
journey from a place they have emigrated from to a place they have immigrated to, and
the natural disasters they survive along the way.
PowerPoint Presentations Directions
Creative Writing: Lessons That Change Writers
An overview of the creative writing lessons that result in each student having
their own story.
Evaluation:
B.C. Quick Scale Grade 6 Writing Stories
Four-Point Rubric from Writing Traits Classroom – Scholastic Teaching
Resources
Rubric to evaluate Voice from Writing Traits Classroom – Scholastic
Teaching Resources
To Index
Hand-outs and Examples of Student Work – Word files
Writing for Excellence Process
Text highlighted to build a 3-word outline– student work example
Outlines – student work example
Paragraphs with Voice – student work example
Openers
Outlines and Paragraphs
Paragraphs Only
- prepositions word list/ ‘ly’ word list
- ‘ing’ and ‘ed’ word list
Dress-ups
- ‘ly’ word list
- strong adjectives/ strong verbs
Graphic Organizer
Lessons That Change Writers
Main Character Questionnaire
Considerations in Creating a Character
Ways to Develop a Character
Some Ways To Include Thoughts and Feelings
Narrative Leads
Check Your Essay Lead
Experiment with Essay Leads
PowerPoint Examples of Student Work (These links will open the Powerpoints)
Group One
Group Two
To Index
Volcanoes
To Index
Description of a Volcano
A Volcano consists of a fissure in the earth's crust, above which a cone
of volcanic material has accumulated. At the top of the cone is a bowl-shaped
vent called a crater. The cone is formed by the deposition of molten or solid
matter that flows or is ejected through the vent from the interior of the earth. The
study of volcanoes and volcanic phenomena is called volcanology. Most
volcanoes are composite landforms built up partly of lava flows and partly of
fragmental materials. Italy's Mount Etna, in Sicily is an example of a composite
cone.
In successive eruptions, the solid materials fall around the vent on the
slopes of the cone, while lava streams issue from the vent and from fissures on
the flanks of the cone. Thus, the cone is built up of layers of fragmental materials
and flows of lava, all inclined outward away from the vent. Some enormous,
craterlike basins, called calderas, at the top of long-dormant or extinct volcanoes,
are eventually occupied by deep lakes, such as Crater Lake in Oregon. Some
calderas are the result of cataclysmic explosions that destroy the erupting
volcano. Others form when the subterranean magma chamber, emptied by
repeated eruptions, can no longer support the weight of the volcanic pile above it.
Therefore it collapses.
Glossary of Volcanic Terms
Popocatepetl is stratovolcano in the central volcanic belt of Mexico. On Dec. 6, 1997
Popocatepetl showed noticeable activity. It erupted large clouds of ash and volcanic rocks. The ash rose
over 1/2 a mile into the air. Ash fell on towns over 60 miles away.
The dome at Popocatepetl continues to grow at a high rate and is at least 150 ft. tall. On
October 28 an explosive eruption at Popocatepetl took place. The large eruption sent ash to the west and
produced a ash cloud that climbed to a height of 27,000 ft.
Observations of the summit crater showed a new vent had formed in the lava dome that was
active from March to July, 1996. Fumaroles continue to release gas from the crater and the lava dome.
Scientists had believed that new magma was being added to a large magma chamber beneath the
volcano.
On June 19, 1997 Popocatepetl threw ash and steam over one mile high. The activity lasted for
three minutes. Popocatapetl threw ash 7.5 miles into the air on June 30 during its largest eruption since
1925. Lava was also thrown 1500 feet into the air. This event led to the first ash fall in Mexico city in 70
years. Mexico city is located 45 miles from the volcano.
On August 26, 1997 Popocatapetl erupted ash to about 2500 ft. into the air. They were not
considered dangerous eruptions.
Popocatepetl, Hawaii
Photo by the U.S. Department of Interior, U.S. Geological Survey
Structure and
Formation
At the top of most volcanic
mountains is a crater, which marks the
upper end of the vent. A large crater, or
caldera, may be formed by the collapse of
the mountain top after the withdrawal of
magma. Crater Lake in Oregon occupies 20
sq mi of a caldera left by the collapse of
Mounth Mazama, an ancient extict volcano.
Underwater eruptions are common,
especially in the seas near island arcs. In
Japan in 1952, a underwater eruption of
Myozin-San sunk a ship with all on board.
Most new volcanoes start on
the flanks of older ones, forming adventive
cones. Paricutin was born on Feb. 20 1943
in the state of Michoacan, Mexico. Gases
and hot ashes began to emerge from a
fissure in a cornfield, and soon later a cone
30 ft high had been built around the vent.
In a week it had grown to 450 ft and the
roar of the eruption was heard 200 mi
away. When its activity ceased nine years
later, the volcano had built a cone 1,300 ft
high and its lava had buried two towns.
To Index
TORNADOS
Tornadoes are one of weathers most deadly and fascinating forces. Even though
they are often limited by size (not being more than one kilometer wide at most) they leave
vast areas of destruction and death behind them. They are also called twisters or cyclones.
Tornadoes are characterized by violent winds that swirl in a counter clockwise direction
north of the equator and clockwise south of the equator. Most people recognize them as a
towering black funnel extending downward from the base of a large cumulonimbus cloud. It
rotates at speeds up to three hundred miles per hour (480 km) or in some rare cases, even
faster. In the center of the tornado, the air pressure is very low in comparison to surrounding
air pressure.
The speed of the wind is the primary cause of deaths and destruction of property.
Many people are killed by flying objects and debris (missiles). The funnel shaped cloud
travels in a skip like movement, and usually never lasts for more than a couple of minutes in
any one given place. It is because of this skip movement that the tornado leaves some
areas wrecked while others a few yards away almost untouched.
Certain parts of the world (ie. Australia, the Midwestern and Southern US) are
more prone to have tornadoes. They also occur more frequently in the spring and summer
months. Tornadoes usually occur as part of a severe thunderstorm and often come in
advance of cold fronts, however, they can also occur (although less frequently) ahead of
warm fronts, and even behind cold fronts.
The greatest killer tornado in the United States occurred during the year 1925 in
Indiana, Illinois, and Missouri. It was the fastest and largest one ever recorded, with a
destructive path two hundred and twenty miles long and one mile wide, and traveled at a
speed of sixty miles per hour. It killed six hundred ninety five people and injured over two
thousand.
To Index
At this point in time, formation of tornadoes
are not fully understood by scientists. They usually form
in a giant rotating thunderstorm called a supercell.
Supercells form when cold polar air meets warm tropical
air. The result is a great instability caused by the rising
warm air. A squall line, or narrow zone of cumulonimbus
clouds forms, giving life to the tornadoes. Lightning
flashes, and heavy rains and hail begin to fall. Soon
after, the easiest recognizable part of the tornado, the
funnel, seems to descend from the base of the cloud. In
actuality, it does not, but rather the pressure within the
cloud drops due to the increasing wind speeds. This is
known as Bernoulli's principle. As the pressure drops, it
causes moisture in the air to condense. This action
continues down the spiral, giving the impression that the
funnel is descending from the cloud base. In addition to
the visible funnel, there is also a hissing sound, which
turns into a loud roar when the tornado touches the
earth.
Many people believe that there is no tornado
unless there is a visible funnel cloud. However this is
not true, for 'invisible' tornadoes can exist. Its the same
thing as a normal tornado, but the funnel cloud does not
descend to the ground. The latter situation is extremely
rare. This is a simulation of how a tornado forms:
Once the tornado reaches the ground, it
starts to up debris around it. This can actually change
the color of the tornado, because some dirt in the
southern states is actually a deep shade of red.
How Tornadoes are
Formed
Classification of Tornadoes
Tornadoes are classified in the United States on a scale called the Fujita-Pearson Scale, named after Professor Fujita
of the University of Chicago and Dr. Allen Pearson, director of the National Severe Storm Forecast Center. There are seven levels on
the Fujita Scale, from zero to six (six being the strongest). Remember that the size of the tornado does not necessarily show how
destructive it is. Small tornadoes can be more destructive than large ones.
The Fujita Scale
Number
0
Wind Speeds (mph) Intensity Description
40 – 72
Gale Tornado
1
73 – 112
2
113-157
3
158 – 206
4
207 – 260
5
261 – 318
6
319 – 379
Type of Damage Capable
Minor structural damage. Tree branches break off, and
small trees are uprooted. Damages large signs also
Moderate Tornado
Hurricane wind speed. Roof surface ripped off houses,
and mobile homes are overturned. Cars are pushed off
the road and attached garages might be destroyed.
Significant Tornado
Extensive damage. Roofs torn off frame houses. Mobile
homes destroyed. Trains, box cars turned over. Large
trees torn from the ground and snapped. Light objects
become deadly missiles.
Severe Tornado
Roofs of well built houses are ripped off. Numerous
trees ripped out of the earth. Trains are overturned.
Devastating Tornado Well build houses are totally destroyed. Newly build
houses are thrown considerable distances. Cars thrown
and other large objects become missiles.
Incredible Tornado
Well built houses are torn out of the ground and thrown
great distances. Trees become debarked, and car size
missiles fly up to one hundred meters. Steel reinforced
concrete structures are badly damaged.
Inconceivable Tornado Winds at these speeds are highly unlikely, but if a
tornado this big did occur, the wreckage would be so
great it would be unidentifiable. Everything would e
destroyed.
Safety Tips
There are a number of ways to protect yourself from the deadly effects of tornadoes. If you ever find yourself in
the vicinity surrounding a tornado, the best thing to do is to get into a shelter that is equipped with a storm cellar. If you don't
have a shelter designed to withstand tornadoes, then go into your basement. Do not stand near any windows, as they are prone
to blow out due to the drastic drop in pressure. If you cannot reach the basement in time, find a closet or bathroom on the
lowest floor possible. Toilets and bathtubs are usually anchored into the ground, and thus are usually the only things left intact
after a tornado hits.
If you are inside a school or any other large building, do not stand under an area with a very large roof such as a
gymnasium, because they are the most likely to crumble first due to the high wind speeds. Try to avoid hallways that have
doorways leading outside the building.
If you are outside, find cover under an overpass. A ditch is also a good choice if it is not raining. If there is rain, then you need to
watch out for flash floods and drowning. Always crouch down and make yourself a small "target". If you are in a car, do not try to
drive away from the tornado, because you might actually be driving toward it. Numerous people have died in cars because
tornadoes have thrown the cars or toppled them over.
If you live in a mobile home, you should vacate it immediately, for it offers virtually no protection at all. The tornado
can pick it up like a toy and hurl it miles from its original space.
Of course, there are the usual chores you can do when any large storm is approaching, such as stocking up on canned food,
fresh water, and batteries for radios and flashlights.
But probably the best precaution to avoid getting hurt by a tornado is to be alert and follow instructions. Many people get hurt by
tornadoes because they are not informed about severe weather conditions in the area, so listening to weather forecasts are
important. You should have at least one battery operated radio because of the possibility of a power failure.
Satellites carry cameras which beams pictures back to earth about cloud and moisture formation above, and snow
and ice below to observation stations on the ground. The meteorologist collects this valuable information, analyses and maps it,
and uses it to inform the public about what type of weather to expect. Unfortunately, if a tornado is going to occur,
meteorologists usually can only alert us about eighteen to thirty six hours in advance (short range forecast). Radar is also used
to track severe storms. One type of radar, called doppler, is very helpful because it can indicate the location and possible path
the tornado will take as well at the wind speed.
Generally speaking, when weather forecasts are issued, they contain information on the type of weather (ie. is it
sunny, cold, or boating or farming conditions). However, when an advisory bulletin is issued their are two important terms used
that we should all be familiar with. These are "watch" and "warning" and are valuable in preparing us for a pending storm. A
watch, when it applies to a tornado, means that the conditions are right and the odds are good for one to form. A warning means
that a tornado is in progress, and that you must get into shelter immediately.
Tornado Over Land
Waterspout
Waterspouts are weak tornadoes that form over warm water.
Waterspouts are most common along the Gulf Coast and
southeastern states. In the western United States, they occur with
cold late fall or late winter storms, during a time when you least
expect tornado development.
Waterspouts occasionally move inland becoming tornadoes
causing damage and injuries.
Tornado Over
Water
How Do Tornadoes Form?
Before thunderstorms develop,
a change in wind direction and
an increase in wind speed with
increasing height creates an
invisible, horizontal spinning
effect in the lower atmosphere.
A lower cloud base in
the center of the
photograph identifies an
area of rotation known
as a rotating wall cloud.
This area is often nearly
rain-free. Note rain in
the background.
Rising air within the
thunderstorm updraft tilts
the rotating air from
horizontal to vertical.
An area of rotation, 2-6 miles
wide, now extends through
much of the storm. Most
strong and violent tornadoes
form within this area of strong
rotation.
Moments later a strong
tornado develops in this
area. Softball-size hail and
damaging "straight-line"
winds also occurred with this
storm.
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TSUNAMI
A tsunami (pronounced tsoo-nah-mee) is a chain of fast moving waves caused by sudden trauma
in the ocean. They can be generated by earthquakes, volcanic eruptions, or even the impact of meteorites.
Tsunami are also incorrectly known as tidal waves, but unlike tidal waves they are not caused by changes in
the tides.
They are most common around the edge of the Pacific, where more than half of the world's
volcanoes are found. These seismic surges can assault coastlines, often with little or no warning. Rocks
weighing as much as 20 metric tonnes have been plucked from sea walls and carried 180m inland.
"Tsunami" is the Japanese word meaning tidal wave. A tidal wave is a large sea wave caused by a
submarine earthquake or volcanic explosion. When the ocean floor is tilted or offset during an earthquake, a
set of waves is created. These waves are similar to the concentric waves generated by an object dropped into
the water.
Usually tsunamis move entirely across an ocean to the shore. A tsunami can have wavelengths of
60 to 120 mi and may reach speeds of 800 km/h. When the wave enters shallow waters, the wave, which
may have been half a meter high out at sea, grows rapidly. When the wave reaches the shore, it may be 50 ft.
high or more. Tsunamis have incredible energy because of the great volume of water affected. They bring
waves of destruction capable of killing thousands of residents along the coast. Towering walls of water have
struck populated coastlines with such fury that entire towns have been destroyed. In 1896 a population of
20,000 in Sanriku, Japan were wiped out. Tsunamis have resulted in waves as high as 135 ft. above normal
sea level.
When a tsunami strikes the shore, it creates a number of waves with troughs that are lower than
normal sea level. Each following wave is higher than the one before it. The period between waves is 10 to 30
minutes. This usually gives people ample time to escape to high ground after the first wave.
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Most tsunamis originate along the Ring of Fire. The Ring of Fire is a area of volcanoes
and seismic activity 24,000 mi long. It encircles the Pacific Ocean. Since the year 1819, more than
40 tsunamis have struck the Hawaiian Islands. A tsunami warning system has been developed in
areas such as Hawaii, where many devastating tidal waves occur. Hawaii, the highest risk area,
averages one tsunami every year with a damaging occurrence every 7 years. Alaska, also at high
risk, averages a tsunami every 1.75 years and a damaging event every 7 years. The warnings are
provided by seismograph records. Seismographs help determine the location of where a
submarine earthquake occurred. These earthquakes usually originate in one of the deep trenches
in the Pacific Ocean floor.
One of the largest and most destructive tsunamis ever recorded traveled at least half
way around the world in 1883 after the collapse of Krakatoa, a volcano in Indonesia. Waves up to
100 ft. high caused great damage along the coast of Sumatra.
In 1964, an Alaskan earthquake generated a tsunami with waves between 10 and 20
feet high along parts of the California, Oregon, and Washington coasts. This tsunami caused more
than $84 million in damage in Alaska and 123 fatalities in Alaska, Oregon, and California. Although
tsunamis are rare along the Atlantic coastline, a severe earthquake on November 18, 1929, in the
Grand Banks of Newfoundland generated a tsunami that caused considerable damage and loss of
lives at Placentia Bay, Newfoundland. In 1946, a tsunami with waves of 20 to 32 feet crashed into
Hilo, Hawaii, flooding the downtown area and killing 159 people.
The Tsunami Warning Centers in Honolulu, Hawaii, and Palmer, Alaska, monitor
disturbances that trigger tsunamis. When a tsunamis is recorded, it is tracked and a tsunami
warning is issued to the threatened area. Most deaths during a tsunami are a result of drowning.
Associated risks include flooding, polluted water supplies, and damaged gas lines. Since 1945,
more people have been killed as a result than as a direct result of an earthquake's groundshaking.
The slump area at Leworahang. In this area twenty-four people were reported
killed. Twelve houses were completely submerged and are no longer visible. The cliff was
formed when subsidence due to earth shaking occurred. A short time later a tsunami of
fourteen meters overran the cliff.
In the deep ocean, destructive tsunamis can be small--often only a few feet or
less in height--and cannot be seen nor can they be felt by ships. But, as the tsunami
reaches shallower coastal waters, wave height can increase rapidly. Sometimes, coastal
waters are drawn out into the ocean just before the tsunami strikes. When this occurs,
more shoreline may be exposed than even at the lowest tide. This major withdrawal of the
sea should be taken as a warning of the tsunami waves that will follow.
Wave power
Tsunamis aren't like wind-generated waves that rhythmically roll onto a beach. A tsunami
can have a wavelength (ie distance between wave crests) in excess of 100km (60 miles) and there
may be an hour between them. They travel at great speeds across an ocean with hardly any energy
losses and are barely noticeable out at sea.
Over the deep Pacific Ocean, a tsunami travels at about 800kph (500mph). If an earthquake
happened in Los Angeles, a tsunami could hit Tokyo quicker than you could fly between the cities by
jet. The tsunami caused by the earthquake off the coast of Indonesia in late 2004 travelled 4,500km
(2,800 miles) to Somalia in East Africa in just seven hours.
As a tsunami leaves the deep water of the open ocean and travels into the shallower water near the
coast, it behaves like a normal wave - only with more muscle.
Shallow water slows the tsunami and its height grows. Tsunamis batter the coast with
tremendous amounts of energy. They can strip sand from beaches, tearing up trees, and even
obliterating whole towns. Some have been known to reach as much as 30m above sea level.
Preparing for the arrival of a Tsunami
1) Find out if your home is in a danger area.
Know the height of your street above sea level and the distance of your street from the coast.
Be familiar with the tsunami warning signs.
People living along the coast should take earthquakes under consideration as a warning signal of a coming
tsunami. A rise or fall in coastal waters is a sign that a tsunami is approaching the coast.
2) Make evacuation plans.
Pick an inland location that is elevated to a high level. After a natural disaster strikes, roads may be blocked
off. It is essential to pick more than one evacuation route.
Teach family members how and when to turn off gas, electricity, and water.
Teach children how and when to call 9-1-1 and which radio station to listen for information.
3) Have disaster supplies on hand.
Flashlight
Portable, battery-operated radio
First aid kit
Emergency food and water
Essential medicines
Develop an emergency communication plan.
4) In case family members are separated from one another during a tsunami have a plan for getting
back together. Ask a relative or friend to be the "family contact" in case of emergency. After a
disaster, often it's easier to call long distance. Make sure everyone knows about the contact person.
What to do after a tsunami strikes
1) Help injured or trapped persons.
Give first aid where appropriate. Do not move seriously injured persons unless they are in immediate danger
of further injury.
2) Stay out of damaged buildings. Return home only when the authorities are absolutley sure it is safe.
Use a flashlight when entering damaged buildings. Check for electrical shorts and live wires.
Open windows and doors and shovel mud to give walls and doors an opportunity to dry.
3) Check food supplies and test drinking water.
Fresh food that has come in contact with flood waters may be contaminated and should be thrown out.
4) Inspecting Utilities in a damaged home
If you smell gas or hear a blowing or hissing noise, open a window and quickly leave the building. Turn off the
gas at the outside main valve if you can and call the gas company.
If you see sparks or broken wires turn off the electricity at the main fuse box.
If you suspect sewage lines are damaged, avoid using toilets or water and call a plumber.
To Index
EARTHQUAKES
Causes
Earthquakes are caused by stresses below the earth's outer surface. These stresses usually build
up until the rocks fracture along a "fault plane." This causes vibrations, also known as seismic waves. Seismic
waves will then travel in all directions from the area of fracture. In large earthquakes seismic waves may be
detected over the entire earth.
Earthquake Glossary
Effects
Earthquakes produce various damaging effects to the areas they act upon. This includes damage
to buildings and in worst cases the loss of human life. The effects of the rumbling produced by earthquakes
usually leads to the destruction of structures such as buildings, bridges, and dams. They can also trigger
landslides. An example of how an earthquake can lead to even more destruction is the 1959 earthquake near
Hebgen, Montana. It caused a land slide that killed several people and blocked the Madison River. Due to the
fact that the Madison River was blocked, a lake was created which later flooded the nearby town of Ennis.
Besides producing floods and destroying buildings, earthquakes that take place under the ocean
can sometimes cause tsunamis, or tidal waves. Tsunamis are high and long walls of water which travel at a
very rapid rate. They are notorious for destroying entire populations and cities near coastlines. In 1896
Sanriku, Japan, with a population of 20,000, suffered such a fate.
To Index
Intensity of Earthquakes
The intensity of an earthquake becomes weaker outward from the epicenter. However, various types of ground
respond differently to earthquake vibrations. Buildings on filled ground are damaged more than structures built on solid rock
even though both may be at the same distance from the epicenter.
The magnitude of a particular earthquake is a single number which does not vary from place to place. Magnitude
is the total energy released by an earthquake at its focus. Earthquakes of large magnitude are stronger and generally more
destructive than those of small magnitude. The amount of destruction depends not only on the magnitude but on the kind of
ground and types of buildings thereon, and on the location of the focus in relation to heavily populated areas.
Large earthquakes are preceded by many aftershocks, which may persist for days or weeks. The first shock is the
most damaging. However, sometimes an aftershock may be even more powerful than the original shock.
The intensity of an earthquake is measured in terms of its geological effects and the overall damage it brings.
There are two major scales in which earthquakes are measured. These two scales are the Mercalli Scale and the Richter Scale.
Richter Scale
the Richter scale was named after the American seismologist Charles Francis Richter. This scale measures the
motion of the land surface 60 mi from the epicenter, or focus, of the earthquake. An estimated 800 quakes of magnitudes 5 to 6
occur worldwide each year. About 50,000 quakes of magnitudes 3 to 4 occur each year, and only about one of magnitude 8 to 9
each year.
Mercalli Scale
The Mercalli scale was introduced at the turn of the 20th century by the Italian seismologist Giuseppe Mercalli.
This scale measures the intensity of shaking with numbers from I to XII. Intensity I on this scale is defined as an event felt by
very few people, whereas intensity XII is assigned to a catastrophic event that causes total destruction. Events of intensities II to
III are roughly equivalent to quakes of magnitude 3 to 4 on the Richter scale, and XI to XII on the Mercalli scale correspond with
magnitudes 8 to 9 on the Richter scale.
Mercali Scale
I. Hardly felt
II. Felt only by a few persons at rest, especially on upper floors
of buildings.
III. Can be felt by persons indoors, especially on upper floors
of buildings. Many people do not recognize it as an
earthquake.
IV. Felt indoors by many, outdoors by few during the day. At
night, some awakened. Dishes, windows, doors disturbed.
Standing motor cars rocked noticeably.
V. Felt by nearly everyone; many awakened. Some dishes,
windows broken. Unstable objects overturned.
VI. Felt by all
VII. Considerable damage in poorly built or badly designed
structures.
VIII. Damage slight in specially designed structures. Damage
great in poorly built structures. Heavy furniture overturned.
IX. Damage considerable in specially designed structures.
Damage great in substantial buildings, with partial collapse.
Buildings shifted off foundations.
X. Many objects destroyed, buildings collapse.
XI. Few structures remain standing. Bridges destroyed. Rails
bent greatly.
XII. Total Damage.
Richter Scale
Between to 0-4.3 on the Richter scale,
People at rest upstairs notice shaking.
Shaking felt indoors; hanging objects swing.
Between 4.3-4.8
Sleeping people are awakened.
Dishes, doors and trees shake and rock.
Between 4.8-6.2
Difficult to stand; people walk unsteadily.
Windows break; plaster,bricks, and tiles fall.
Between 6.2-7.3
General panic.
Damage to foundations; buildings destoyed.
Water thrown out of river.
Between 7.3-8.9
Total destruction; roads break up, rocks fall.
Large cracks appear in ground.
How to protect yourself during an earthquake
1.) If an earthquake is occurring the most important thing to do is to DROP and COVER. Drop and cover
means to fall on to the floor and get under something for protection. During an earthquake, if you are indoors, it
is very important to stay calm and take cover under a heavy object.
2.) If you are outdoors, stay as far away from buildings as possible.
3.) Stay away from glass or anything that could fall.
4.) If you are in a crowded area, do not even consider running for the nearest exit. Everyone will be doing that,
and crowding will lead to even more injuries. Take cover under something heavy and stay away from things
that could fall on you. It is also very important to remain as calm as possible.
5.) Be prepared for aftershocks after the initial earthquake has ended. Aftershocks are follow-up earthquakes.
They are smaller than the first one, but still are very dangerous.
To Index
LIGHTNING
Even today the phenomenon of lightning is still not fully
understood. It is awesome and frightening to many and because of the
mystery that surrounds it, several cultures have developed different
beliefs about it. Some African cultures believe that when someone is hit
by lightning that he/she was cursed even before the event. The
Romans and Greeks believed that the gods were fighting and this was
one of their weapons. Lightning kills and injures many people, starts
thousands of forest fires, and causes millions of dollars in property
damage every year.
Lightning is characterized by the discharge of electricity
between rain clouds or between a rain cloud and the earth. It is usually
seen as an arc of extremely bright light which can be many kilometers
in length, however, there are other forms as well. Accompanying the
lightning is the giant roar of thunder. The thunder is caused by the
expansion of air that has been heated by the lightning which then
collides with cooler air, creating the sound of an explosion.
Thunderstorms are the most common types of storms, and
thunder itself, although frightening, is not dangerous. It is the lightning
that causes the problems. Lightning and thunder occur together,
however we hear the thunder after we see the lightning. Sound waves
travel about one mile in five seconds, while light travels at more than
186,000 miles per second. Therefore, lightning is seen immediately
when it occurs, and thunder is heard a little later.
The different sounds of thunder (deep roar/loud crash) is
caused by the different types of lightning, for example, the thunder that
has the sharp crackle like sound is caused when the large trunk of
lightning forks into many branches.
To Index
How Lightning is Formed
Before lightning is formed, the cumulonimbus cloud of
thunderstorms must become electrically charged. In most rain clouds, the
bottom of the cloud is negatively charged and the top is positively charged. It is
not known how the cloud becomes charged, but scientists have formed
numerous theories to try to explain this phenomenon. These theories have
been divided into two main categories: those that require ice and those that do
not. However, meteorologists are leaning toward the theory that requires ice
because lightning is not often seen unless ice has formed in the upper layers
of the rain cloud.
Theories
The first theory describes how ice gains a negative charge while
frozen and unfrozen water keeps its positive charge. Another theory shows
how when large droplets fall swiftly, they gain a negative charge, while slowly
falling water gains a positive charge.
Theories that do not require ice gives the explanation that the cloud gets its
charge by attracting negative charges from the ionosphere. These negative
charges are pushed to the base of the cloud by strong downdrafts, while the
positive particles are pushed upwards by warm air within the rain cloud.
Strokes
Eventually the negative charge of the base of the cloud gives the
earth a positive charge. When the electrical potential reaches approximately
ten thousand volts per centimeter, ionization occurs along a narrow path and
the result is a flash of lightning. The negative particles descend from the base
of the cloud to the ground.
However, most lightning flashes are not a single event, but rather numerous
strokes followed by a leader stroke. There can be up to 42 strokes to a
lightning bolt. The time between successive strokes is 0.02 seconds. The
average bolt lasts only one fourth of a second.
Safety Tips
Since lightning can be very dangerous and it has killed and maimed many people, it is important for
us to follow safety measures and protect ourselves and property.
During a storm stay indoors, however if you are caught outside in a severe storm, never stand under any tall
objects such as trees. It is better to lay down in an open field away from any surrounding tall objects. Avoid any
large bodies of water and if you are swimming, leave the water immediately.
Stay away from metal objects such as bicycles and tractors. Never play golf or go fishing during a
storm. If your are outside playing any games with metal gear, be sure to take it off if a storm starts. If you are
driving a car during a thunderstorm stay in the car as this is though to be a safe place, however avoid touching
any metal in the car. Do not use the telephone since lightning might strike the tall telephone poles. Avoid using
any electrical equipment such as hair driers, electric razors, microwave ovens, or washers et cetera.
Today, most tall buildings are protected by lightning rods. This concept was first introduced by
Benjamin Franklin in 1749. These are metal rods which are placed on top of the highest, most exposed part of
the building. A wire leads from the rod and is buried underground away from the building. This attracts the
lightning and conducts its discharge away from the building and into the ground.
Aerials and power lines are protected by using lightning arrestors. These have a space between the line and
ground wire which is filled with gas. The lightning discharge causes the gas to ionize, which in turn offers a
low-resistant exit for the electricity.
Common Misconceptions about Lightning
There are many myths and misconceptions about lightning and some of them are very dangerous. The old
expression that lightning never strikes twice in the same place is not true. Indeed it has been shown that
some very tall buildings have been struck several times in the same storm. Also, many people, especially
children, think that during a thunderstorm it is better to seek shelter under tall trees. This in fact is very
dangerous, for tall trees are more likely to get struck by lightning. Yet another erroneous belief is that a clap
of thunder always occurs after a bolt of lightning. In fact, many thunderclaps are never heard due to their
distance from the observer.
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DROUGHT
Drought is a period or condition of unusually dry weather within a geographic area where rainfall is normally
present. During a drought there is a lack of precipitation. Droughts occur in all climatic zones. However, its characteristics
vary significantly from one region to another.
Drought usually results in a water shortage that seriously interferes with human activity. Water-supply
reservoirs empty, wells dry up, and crop damage ensues. Its seriousness depends on the degree of the water shortage, size
of area affected, and the duration and warmth of the dry period. In many underdeveloped countries, such as India, people
place a great demand on water supply. During a drought period there is a lack of water, and thus many of the poor die.
Most precipitation depends on water vapor carried by winds from an ocean or other source of moisture. If
these moisture-carrying winds are replaced by winds from a dry region, or if they are modified by downward motion, as in
the center of an anticyclone, the weather is abnormally dry and often persistently cloudless. If the drought period is short, it
is known as a dry spell. A dry spell is usually more than 14 days without precipitation, whereas a severe drought may last for
years.
Statistics indicate that every 22 years a major drought occurs in the United States, most seriously affecting the
midwestern states. The drought of 1933-35, during which large areas of the Great Plains became known as the Dust Bowl,
is an example of a disastrous drought that took place in the United Staes. The effect of the drought was brought about by
overcropping, overpopulation, and lack of relief measures.
Although drought cannot be reliably predicted, certain precautions can be taken in drought-risk areas. These
include construction of reservoirs to hold emergency water supplies, education to avoid overcropping and overgrazing, and
programs to limit settlement in drought-prone areas. The Southern Africa Development Community monitors the crop and
food situation in the region and alerts the people during periods of crisis.
When there is a dry spell, grass begins to turn brown. Flowers need to be watered more frequently. Dirt
patches dry up. Cracks form across the surface of the ground. After many weeks of such weather, plants die out. The roots
of the plants, which previously anchored soil down, can no longer keep the soil from eroding. The dirt is then blown up by
the wind, causing huge clouds known as dust storms. Because they can turn the sky dark, they are sometimes known as
black blizzards.
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Effects of Drought
Drought produces a large number of impacts that affects the social, enviornmental, and economical standard of living. Its
affects spread far beyond the physical effects of drought itself. Water is integral to produce goods and provide certain
services.Some direct impacts of drought are reduced crop, rangeland, and forest productivity; reduced water leves; increased
fire hazard; increased livestock and wildlife death rates; and damage to wildlife and fish habitat. A reduction in crop
productivity usually results in less income for farmers, increased prices for food, unemployment, and migration.
The many effects of drought can be listed as economic, environmental, or social. Please click here to see the list of its many
negative effects. However, not all impacts of drought are negative. Fortunate agricultural producers located outside the
drought area benefit by selling their goods at higher prices.
Drought is also associated with increases in insect infestations, plant disease, and wind erosion. Droughts may cause
problems with insects and diseases to forests. Forest fires increase dramatically during periods of droughts
Farmers are not the only ones who suffer from droughts. Retailers who provide goods and services to farmers must deal with
reduced business. This later leads to unemployment and loss of tax revenue for the government. The recreational and tourism
industries are seriously damaged because tourists do not want to travel to a country that is suffering from a severe water
shortage. Shortages of certain goods results in the costly importation of necessary goods from outside the affected area.
Environmental losses are caused by damages to plant and animal species. Wildlife habitat, and air and water quality are
usually damaged due to a lack of water and an increase in forest and range fires. Most of the effects of drought are shortterm, and as the drought comes to an end many problems are solved. However, many other environmental effects hinder the
area for long periods after the drought is over. For example, wildlife habitat may be ruined through the loss of wetlands, lakes,
and vegetation. Some species of animals may be wiped out from the area as well.
Other drought-related impacts include social impacts. Social impacts include health, public safety, conflicts between water
users, and reduced quality of life. During droughts many people migrate to areas outside the drought-affected location. When
this happens, the area loses a great deal of its population, and thus the area has less financial support. Between 1950 and
1980 the drought of Brazil had a loss of 5.5 million people. This continues to be a significant problem in the economic
development of Brazil.
Desertification
In many underdeveloped countries where a desert is present, such as Africa, severe
drought and lack of sufficient rainfall may lead to desertification. Desertification can be defined
as the expansion of the desert. This is usually caused by overgrazing of cattle and wind.
During a drought, the land can become starved of nourishment or contaminated with
mineral salts and even when it does rain, often the ground cannot support growth.The basic
cause of all drought is insufficient rainfall. This can be due to global patterns of air circulation,
like the Sahara - or, it can be created by man.
Dried-out land
The effects of dams and irrigation in hot climates can have a dramatic effect on the
environment. The dams and water irrigation preventing rivers from running their natural course
can dry the land. This prevents water vapour from rising to create rain clouds.
In a natural desert like the Sahara, dry air descends over the region bringing clear skies and hot
sunshine. These hot deserts get little rain at any season. The problem often lasts for many
years with rainy seasons failing to show.
Short term droughts can also be caused when high pressure systems persist over an area of
land for several weeks. This blocks the passage of low pressure systems that bring rain.
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HURRICANES
Hurricanes are one of natures many destructive forces. The word comes from West Indian;
huracan ("big wind"). Hurricanes are seasonal storms and are most prevalent in August and September.
They develop from easterly waves, which can later develop into a tropical depression with winds up to 31
miles per hour. Later, it might develop into a tropical storm with winds up to 73 miles per hour, and eventually
a hurricane. Thunderstorms often form with hurricanes and then produce waterspouts.
Hurricanes are huge tropical cyclones that originate over oceans near the equator, such as the Caribbean
Sea and the Gulf of Mexico. Usually they follow a parabola shaped path and sometimes do not reach any
land at all. However, if they do reach land, destruction of property is imminent. Winds whirl in a counter
clockwise direction in the northern hemisphere and clockwise in the southern hemisphere. Wind speeds of a
hurricane range from seventy to one hundred fifty miles per hour. These winds blow circularly around a lowpressure center known as the eye of the storm. Hurricanes cause numerous deaths in addition to the millions
of dollars of property damage each year due to the intense winds and huge tidal surges.
One of the most destructive elements of a hurricane is the huge waves that are formed because
of the strong winds and heavy rains. These waves called a storm surge can rise several feet above water
levels, especially during high tide. The worst hurricane in the United States was the one during the year of
1900 in Galveston Texas, where a hurricane swept a fifteen foot wall of water out of the Gulf of Mexico and
into the city, washing away and killing six thousand people. About 90 percent of deaths during a hurricane
are caused by drowning. Another devastating outcome of a hurricane is the mudslides that can follow. These
are caused by the heavy rains and extensive deforestation in some areas. A good example of this was during
the month of July 1998, when a huge mudslide that followed a storm in a little Himalayan village in India,
killed hundreds of people
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How Hurricanes are Formed
Hurricanes develop from belts of low pressure
called easterly waves. These regions of low pressure occur in
ocean winds called trade winds. On certain occasions, the
easterly waves form into tropical depressions, which are
characterized by a group of thunderstorms with cyclonic winds of
up to thirty one miles per hour. The next stage in development is
a tropical storm, with winds of up to seventy three miles per hour.
Any wind speed higher than that and it is a hurricane.
The fuel that powers hurricanes is derived from
latent heat from the condensing of water vapor. Thunderstorms
can produce up to ten inches of rain per day, and thus produce
an incredible amount of energy, up to 24 x 10¹¹ kilowatt hours per
day on average. This is the equivalent of how much power most
industrialized nations use in one year (such as the United
States).
Winds swirl around the eye, the calm center of the
hurricane. The eye has a diameter of about twenty miles across
and has very few winds or clouds. Surrounding the eye are
storm clouds called wall clouds. It is within these clouds that the
heaviest rains and strongest winds occur. These wind speeds
are kept up by the differences in horizontal pressure between the
eye and outer regions of the storm.
Initially, when a hurricane forms, its forward
movement is very slow (fifteen miles per hour), but as it gets
farther away from the equator, its speed increases up to sixty
miles per hour in middle latitudes. But in addition to gaining
speed as is moves away from the equator, it also begins to die.
Eventually it looses its source of power as it passes over land
and gets ripped apart by friction. Hurricanes usually only last
between five and ten days.
Safety Tips
If you are ever living where hurricanes are likely to strike, you must prepare yourself for the worst, for they
cause death and widespread property damage to most coastal towns and cities. Hurricane winds can tear
down houses, and torrential rains and tidal surges can flood the land. The months when hurricanes occur
(hurricane season) are from the early summer to late fall. During these months you should:
Find a local shelter and plan a safe route to get there if a hurricane warning is issued.
If you have a boat, make sure you find a safe place for it.
Learn the storm surge history of your area.
Discard all dead tree limbs.
Secure all rain gutters.
A hurricane watch means that the storm is not an immediate threat to life or property, but may possibly turn
into one later.
Always be prepared with ways to get information about the storm, such as a radio, television, or an reliable
internet site. Also, have a battery power radio in case power is cut off in your area. If a hurricane watch is
issued for your town, be sure to do the following:
Stock up on canned food and fresh water.
Put fuel in your car.
Get batteries for the radio and some flashlights.
Replenish all supplies of necessary medicine.
Secure all outdoor objects.
Board up all windows and bring in all pets.
Put your boat in a safe place or moor it.
A hurricane warning will be announce by the National Hurricane Center if a hurricane will strike your area
within the vicinity of twenty four hours. If this happens, you must monitor your local broadcasts and if
directed to, evacuate.
If and when your are allowed back into your home, be sure to watch out for downed power lines, and never
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touch them or trees that are in contact with them.
AVALANCHES AND
LANDSLIDES
An is any swift movement of snow, ice, mud, or rock down a mountainside or slope. Avalanches, which are
natural forms of erosion and often seasonal, can reach speeds of more than 200 miles per hour. They are
triggered by such events as earthquake tremors, human-made disturbances, or excessive rainfall.
Destruction from avalanches results both from the avalanche wind (the air pushed ahead of the mass) and
from the actual impact of the avalanche material.
Where: Italian Alps
When: 218
When Hannibal, the Carthaginian general, crossed the Alps to conquer Rome, 18,000 soldiers, 2,000
horses, and many elephants died. Most of the deaths were caused by Alpine avalanches.
Where: United States
When: 1910
The worst snowslide in U.S. history occurred in the Cascade Mountains in Wellington, Washington,
when 96 people were trapped when their train became snowbound. An avalanche then swept them
to their deaths in a gorge 150 feet below the tracks.
Where: Peru
When: 1962
When tons of ice and snow slid down Huascaran Peak in the Andes Mountains, nearly 4,000 people
were killed. Some 30 years later, it is still considered the world's worst avalanche.
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What Causes An Avalanche
No two snowflakes are the same, right? Snow falls in
many different shapes - as crystals, pellets, or granules. The flakes
are always six-pointed stars in enchantingly different patterns.
Granules and pellets can fall as needles, pyramids, plates, or bullets.
However, these flakes change after falling. Because of changing air
temperature and pressure from additional snow, the points of each
crystal get smaller. The center then grows larger until a rounded grain
of snow has formed. The six-pointed crystals are pushed together as
they lose their points, in a process known as settling. A foot of fresh
snow can settle down to four inches in twenty-four hours. These
changes occur slowly at low temperatures, and all metamorphosis
stops at -40 degrees Fahrenheit.
The shape of the snowflake goes on to determine how
stable the snow cover is. Snow that is stable and solidly packed does
not slide easily and usually doesn’t cause avalanches. Crystals make
the most stable snow because the six points of each flake interlocks
with other crystals. When both granules and pellets fall from the sky,
they roll over each other, making snow loose and unstable. This is the
kind of snow most likely to cause an avalanche because it consists of
different kinds of flakes or different layers of snow. A layer of loose
snow can slide over a layer or more solid snow.
Another, very dangerous snow condition is a layer of snow
known as a depth hoar, which is also known as sugar snow. Large,
round and cup-shaped snow crystals act like ball bearings, causing
any snow on top to slide right off. It would be like trying to walk across
a floor covered with marbles. The slightest disturbance, from a person
or an animal, can trigger an avalanche.
Rock Avalanches
All earth and material on a slope has an “angle of repose,” or an angle at which that material will remain
stable. Loose dry rock remains in place at angles up to 30 degrees, but wet clay will start to slip at more than
1 or 2 degree inclinations. Landslides are the sudden downhill movements of earth or other solid material, and
are usually caused by rain, thaws, or forces either increasing the top material weight, lubricating the material
layers, or making the slope too steep. They can be triggered by earthquakes, saturation with heavy rain, or
crashing waves.
History’s largest and most destructive landslides have been caused by earthquakes that started
the material moving. Excessive rainfall or snowmelt, however, is also known to saturate and lubricate soil on
steep angles. Rapid temperature changes can also cause land to slide by alternately shrinking and expanding
soil formations, or by forming ice heaves between layers of rock. Forest fires are indirectly responsible for
landslides because they take away slope vegetation, making erosion easier. Man can also cause slides by
mining the earth, underground excavation, pumping and draining groundwater levels, or overdeveloping
hillsides.
Types of Avalanches
Hard-Slab Avalanche
Slab avalanches are caused by build-ups of old snow that has been packed down and settled for a long time.
Hard-slab avalanches start when the top layer of snow breaks up, causing car-sized chunks of ice to come
down a mountain at 30 to 50 miles an hour.
Sometimes, hard deposits of snow are carved into waves or cornices by the wind, forming a sort of wave as
thick as 30 feet that hangs up to 20 feet out over the edge of a cliff. These can be deadly to skiers, who think
they are on safe, firm snow. However, the weight of just one person can trigger an avalanche. With a loud
crack, the slab can break loose and bury a person in seconds.
Wet-Slab Avalanche
Wet-slab avalanches occur commonly on bright, cloudless days in spring when snow is softened by rain. As
the bonds between water molecules in the snow weaken, an entire slope can begin to slide. Wet-slab
avalanches move much slower, creeping along at 5 to 10 miles per hour, picking up boulders, trees, and
earth along the way. These accumulate into a dirty wall of debris where the mass stops.
Rock avalanches
Rock avalanches are often caused by earthquakes or by sudden drops in temperature. In a rock slide,
fragments break away from the face of a steep slope and fall down its side. Rock slides are different from
rock falls in that they occur on lower slopes, and usually closer to inhabited areas. The worst such event in
North America occurred on April 28, 1903. 90 million tons of rock were sent down Turtle Mountain in Alberta,
Canada. After a period of warm weather, there was a quick cold spell. Water that had collected in cracks of
rock froze, expanded, and shattered rocks. People 25 miles away were able to hear the sound of rock
hurtling downhill at 60 miles per hour. Chunks of rock, carried in a huge slide of earth, plowing under the
Oldman River. The rock avalanche carried water and parts of the river bottom 400 feet to the opposite side of
the valley. When it was all over, the rocks (some the size of railroad cars) were scattered 65 feet deep over
one square mile. The rockslide killed 70 people.
A landslide is a sudden collapse of a large mass of hillside. There are many different types of landslides,
where not only earth, but rock, mud, and debris flow down the side of a slope. A mudflow occurs when a
slope is so heavily saturated with water that it rushes downhill as a muddy river, carrying down debris and
spreading out at the base of the slope. They are faster than soil creeps but slower than landslides, but the
wetter the material, the faster it moves. Mudflows are the fastest, wettest flows, while the slowest, driest ones
are earthflows. Earthflows occur on clay, silt, or sand slopes, when the wet ground breaks up and falls down
a mountainside, making a rounded, tongue-like shape. Another type of earth movement is the soil creep.
Even on very shallow slopes, the loose, weathered material, or regolith, will eventually move downhill. It
absorbs water and swells up, and when the water evaporates, the soil shrinks and moves downill a little
more. Soil creeps are also known as heaves. You can tell that soil is creeping if you see tilted structures like
fences, walls, power lines, and tree trunks.
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FLASH FLOODS
How do flash floods occur?
Several factors contribute to flash flooding. The two key elements are rainfall intensity and duration. Intensity is the rate of
rainfall, and duration is how long the rain lasts. Topography, soil conditions, and ground cover also play an important role.
Flash floods occur within a few minutes or hours of excessive rainfall, a dam or levee failure, or a sudden release of water
held by an ice jam. Flash floods can roll boulders, tear out trees, destroy buildings and bridges, and scour out new channels.
Rapidly rising water can reach heights of 30 feet or more. Furthermore, flash flood-producing rains can also trigger
catastrophic mud slides. You will not always have a warning that these deadly, sudden floods are coming. Most flood deaths
are due to FLASH FLOODS.
Most flash flooding is caused by slow-moving thunderstorms, thunderstorms repeatedly moving over the same area, or
heavy rains from hurricanes and tropical storms.
PLAN AHEAD:
Identify where to go if told to evacuate. Choose several places...a friend's home or a motel in another town, or a shelter.
GO TO HIGHER GROUND! Know your area's flood risk. For information, call your local National! Weather Service
office, Red Cross chapter, or local emergency management agency.
Check your homeowner's or renter's insurance. Homeowners' policies do not cover flooding. Contact your insurance agent
to find out how to get flood insurance.
FLOODING CAN OCCUR NATIONWIDE
Even 6 inches of fast-moving flood water can knock you off your feet, and a depth of 2 feet will float your car! NEVER
try to walk, swim, or drive through such swift water. If you come upon flood waters, go the other way.
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FLOODING TAKES MANY FORMS...
Flash flooding occurs within 6 hours of the rain event. Flooding is a longer term event and may last a week
or more.
River Flood
Flooding along rivers is a natural and inevitable part of life. Some floods occur seasonally when winter or
spring rains, coupled with melting snows fill river basins with too much water, too quickly. Torrential rains
from decaying hurricanes or tropical systems can also produce river floodlng.
Urban Flood
As land is converted from fields or woodlands to roads and 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, streets can become swift moving rivers, while basements can become death traps as they fill with
water.
Coastal flood
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 cut off and blocked by high water.
Coastal flooding can also be produced by sea waves called tsunamis (tsoo-na -mez), sometimes referred to
as tidal waves. These waves are produced by earthquakes or volcanic activity.
MANY FLASH FLOODS OCCUR AT NIGHT...BE
PREPARED TO TAKE QUICK ACTION.
How can a foot or two of water cost you your life?
Water weighs 62.4 Lbs. per cubic foot and typically flows downstream at 6 to 12 miles an hour.
When a vehicle stalls in the water, the water's momentum is transferred to the car. For each foot the water
rises, 500 lbs. of lateral force are applied to the car.
But the biggest factor is buoyancy. For each foot the water rises up the side of the car, the car displaces
1,500 Lbs. of water. In effect, the car weighs 1,500 Lbs. less for each foot the water rises.
TWO FEET OF WATER WILL CARRY MOST
AUTOMOBILES AWAY!
Before the flood What YOU can do:
- Know your flood risk and elevation above flood stage. - Do your local streams or rivers flood easily? If so,
be prepared to move to a place of safety. Know your evacuation routes.
- Keep your automobile fueled; if electric power is cut off, gas stations may not be able to operate pumps
for several days. Store drinking water in clean bathtubs and in various containers. Water service may be
interrupted.
- Keep a stock of food that requires little cooking and no refrigeration; electric power may be interrupted.
- Keep first aid supplies on hand.
- Keep a NOAA Weather Radio, a battery-powered portable radio, emergency cooking equipment, and
flashlights in working order.
- Install check valves in building sewer traps to prevent flood water from backing up into the drains of your
home.
- Assemble a disaster supplies kit containing: first aid kit, canned food and can opener, bottled water,
rubber boots, rubber gloves, NOAA Weather Radio, battery-powered radio, flashlight, and extra batteries.
Go to higher ground Climb to safety!
- Get out of areas subject to flooding. This includes dips, low spots, canyons, washes, etc.
- Avoid already flooded and high velocity flow areas. Do not attempt to cross flowing streams.
- If driving, be aware that the road bed may not be intact under flood waters. Turn around and go another
way. NEVER drive through flooded roadways!
- If the vehicle stalls, leave it immediately and seek higher ground. Rapidly rising water may engulf the
vehicle and its occupants and sweep them away. Remember, it's better to be wet than dead!
- Be especially cautious at night when it is harder to recognize flood dangers.
- Do not camp or park your vehicle along streams and washes, particularly during threatening conditions.
When you receive a FLOOD WARNING:
- If advised to evacuate, do so immediately.
- Move to a safe area before access is cut off by flood water.
- Continue monitoring NOAA Weather Radio, television, or - emergency broadcast station for information.
During the flood:
- If you come upon a flowing stream where water is above your ankles, STOP! Turn around and go
another way.
- Do not attempt to drive over a flooded road.
- Children should NEVER play around high water, storm drains, viaducts, or arroyos.
After the flood:
- If fresh food has come in contact with flood waters, throw it< out.
- Boil drinking water before using. Wells should be pumped out and the water tested for purity before
drinking. If in doubt, call your local public health authority.
- Seek necessary medical care at the nearest hospital. Food, clothing, shelter, and first aid are available
from the Red Cross.
- Do not visit disaster areas. Your presence might hamper rescue and other emergency operations.
- Electrical equipment should be checked and dried before being returned to service.
- Use flashlights, not lanterns, torches or matches, to examine buildings. Flammable may be inside.
- Report broken utility lines to appropriate authorities.
Consider the following:
When it comes to hurricanes, wind speeds do not tell the whole story. Hurricanes produce storm surges,
tornadoes, and often the most deadly of all -- inland flooding. While storm surge is always a potential
threat, more people have died from inland flooding in the last 30 years. Intense rainfall is not directly
related to the wind speed of tropical cyclones. In fact, some of the greatest rainfall amounts occur from
weaker storms that drift slowly or stall over an area.
Inland flooding can be a major threat to communities hundreds of miles from the coast as intense rain falls
from these huge tropical air masses.
The United States has a significant hurricane problem. More than 60% of our Nation¹s population live in
coastal states from Maine to Texas, Hawaii, and Puerto Rico.
Hurricane Floyd (1999) brought intense rains and record flooding to the Eastern U.S. Of the 56 people
who perished, 50 drowned due to inland flooding.
What can you do?
When you hear hurricane, think inland flooding.
Determine whether you live in a potential flood zone.
If advised to evacuate, do so immediately.
Keep abreast of road conditions through the news media.
Move to a safe area before access is cut off by flood water.
Do not attempt to cross flowing water. As little as six inches of water may cause you to lose control of your
vehicle...two feet of water will carry most cars away.
Develop a flood emergency action plan with your community leaders.
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SNOWSTORMS AND
BLIZZARDS
A snowstorm is when snow falls from the sky as precipitation. A blizzard is the worst kind of
snowstorm, in which strong winds blow snow into snowdrifts (huge piles) that can bury people and
possessions. Its official definition is a tempestuous, frigid snow storm with blustery, piercing winds of 35
miles per hour or more and a windchill factor as low as -20º Fahrenheit. Transportation is difficult and
dangerous during blizzards because air temperatures can be 10ºF or lower, with visibility less than 400-500
feet.
When there is no much snow that people and animals cannot tell the earth from the sky, it is
known as a whiteout. In this disoriented state, humans and livestock can lose their way and freeze to death.
Blizzards carry the risk of hypothermia, frost bite, suffocation, and being stranded. Sub-zero temperatures,
arctic conditions, and 100 mph winds in mountainous regions pose additional threats.
Freshly fallen snow may be beautiful to look at, but a mere 4 inches on the ground is enough to
disrupt everyday life. Snow can block roads, strand people in their homes, and bring down telephone and
electric lines.
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Snowstorms happen when a mass of very cold air moves away from the
polar regions. When it collides with a warm air mass, the warm air rises quickly and
the cold air cuts underneath it. This causes a huge cloud bank to form, leading to
heavy snowfall. Snow will only fall from the cloud if the temperature of the air
between the bottom of the cloud and the ground is below 40ºF. A higher
temperature will cause the snowflakes to melt as they fall through the air, turning
them into rain or sleet.
Snowflakes form when ice crystals collide in a cloud and stick together.
Every snowflake has six sides, and no two snowflakes that fall are exactly alike.
Their varying shapes are a result of the different weather conditions in which they
are produced. Needle and rod shapes are formed by cold air, while warmer air
results to more complicated patterns
Before
•Try to stay inside if possible, but if you have to go outdoors, prepare yourself against the cold.
•Check the insulation around exterior pipes.
•Wear lots of layers - a few lightweight layers give more warmth than a single heavy coat. Try thermal
underwear, a turtleneck, a medium sweater, and a jacket.
•Wear a hat or cap to prevent heat loss. Also cover your mouth to protect your lungs. Wear gloves.
•Find out the wind chill factor, because wind and cold can drive down your body temperature.
•Take care when walking on icy sidewalks and snow. Wear hiking or snow boots, golf shoes, or put duct take
on the outer soles. On slippery paths, sprinkle sand, rock salt, or kitty litter to provide more traction.
•Always tell someone where you are going, how you are getting there, and when you think you will arrive.
This way, someone will know where you might be if you are stranded.
•Try not to drive, but keep the tank full and the fuel line from freezing.
•Keep food, water, blankets, coats, gloves, hats, a shovel, sand, rope, tire chains, jumper cables, and a
bright signal cloth inside the trunk of your car, in case you are ever stranded while driving.
•Prepare your car for winter cold and snow - flush the radiator and buy antifreeze. Also check the overall
electrical system and car battery. Make sure the headlights are working properly.
•Check and refill your heating fuel supply. Stock up on firewood if necessary.
•Inside your house, store emergency, food, water, and other necessary supplies.
•Learn CPR and first aid.
•Check the insulation surrounding interior pipes.
•Wrap up your hot water heater.
•Clean out the chimney flue to prevent fire hazard.
•Conserve heat by closing doors or heating only certain rooms.
•Insulate your house, the attic, around doors, windows, and outlets.
•Stuff rolled blankets or towels under doors and cracks to block cold.
•Surround windows with plastic, shutters, and hang up blankets or curtains.
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During
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Keep listening to storm warnings and updates. A storm watch means that a storm is possible.
If you hear the words, “storm warning,” go to a shelter. A storm is coming to the indicated area.
If you hear news of a blizzard warning, find shelter as soon as possible.
If you are stuck in your car, stay with the vehicle:
Tie a bright cloth onto your car antenna as a signal to rescuers.
Keep the window open a crack for air.
Stay warm by moving your arms and legs, keeping the blood flowing.
Start the car engine once every hour and use the heater for ten minutes. When the engine is running, leave the dome
light on.
Keep the exhaust pipe clear so that fumes can escape.
Keep pets under control by leashing them or putting them in carriers.
Leave a warm water faucet dripping so pipes will not freeze.
Get blankets, dry warm clothing, and hot water ready.
Be ready to administer aid for frostbite and hypothermia.
Stay inside.
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After
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Check for injuries and help the wounded if necessary or possible.
Be cautious when handling pets and animals. Keep them under control and treat them for any injuries.
Replace or repair broken waterlines.
Repair chimneys or other structures if necessary.
Replace broken windows or glass.
Report fallen power lines to your utility company.
If you have an emergency on your hands, call 911.
Avoid areas damaged by the storm, for those areas may contain unstable structures or land.
Repair damaged fences or fallen objects before letting pets outside.
The Dangers of Winter Storms
1. Snow and heavy snow
Snow is dangerous to travelers since it causes the road to become slippery. One of the more
dangerous times during winter storms is when the road initially becomes snow covered. A thin layer of snow
offers less traction than an inch or more. When traveling during a falling snow, remember to be especially
careful when the road is first covered with snow. Snow often leads to other problems which will be described
below.
2. Rain or freezing rain
Freezing rain is extremely dangerous to travelers since it coats roadways with ice. This reduces
the friction or "grabbing ability" that tires normally need to keep a car attached to the road. When you drive on
ice, you are no longer on the road!
3. Sleet and snow pellets
Sleet and snow pellets often occur during major Winter storms when the atmosphere is near
freezing on the eastern edge of the storm. Usually this is a sign of a "large and dangerous" storm which will
have strong winds and colder weather following.
4. Wind and blowing snow
One of the major dangers of winter storms is wind. Wind transports moisture into the storm at the
surface and aloft which allows the storm to intensify and continue unabated.
Wind can also create life-threatening conditions. Wind driven snow can cause "white-out" conditions which
reduce visibility so much that motorists can not see the road or other vehicles traveling on the road. White-out
conditions occur most often with major storms that produce a drier, more powdery snow.
If you encounter white-out conditions, you should reduce your speed considerably until conditions
improve or find a safe place to pull off of the road and remain there until the storm ends. A safe place is one
that does not obstruct traffic, like a parking lot of a filling station.
Wind driven snow can also result in drifting snow. Snow drifts can close roads when large enough,
but there are other hidden dangers in snow drifts. While driving at normal speeds in a vehicle and suddenly
plowing through snowdrift, you may lose control of your vehicle. To avoid this, always reduce your speed
enough that you can make it through the snow while not losing control. This is not an easy task to master,
even for experienced drivers.
5. Dangerously cold temperatures:
It's a fact of winter that the weather is cold. Add
to that Arctic cold during or immediately following a
snowstorm and you have a recipe for "life-threatening"
conditions. Cold weather and wind combine during the
Winter months to "rob our bodies of heat and moisture".
It is important to monitor the conditions at hand
during a Winter storm, but even more important to know
well ahead of time what to expect once the storm has
passed. It is then that the extremely cold weather usually
sets into a region! If you become stuck in a Winter storm
because the weather is adverse, then you need to know
that the weather following it may be just as dangerous.
Blizzards: The worst winter storms
A blizzard is a storm which contains heavy snowfall, strong
winds, and cold temperatures. The combination of these
elements creates blinding snow with near zero visibility,
deep drifts, and life-threatening wind chill values.
Persons should never venture out in blizzards,
nor should they continue to travel if a storm is upgraded to
a blizzard. You should seek shelter, any safe shelter,
immediately. A safe shelter is a public place such as a
motel or restaurant if you are on the road, or your home,
school, or business if you are already there.
In a blizzard, winds are 35 mph or greater and visibility is
reduced to less than 1/4 mile by falling snow and blowing
snow.
To Index
Information Gathered From These
Web Sites
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http://www.nssl.noaa.gov/NWSTornado/
http://library.thinkquest.org/C003603/english/flooding/index.shtml (has
info on many other disasters as well)
library.thinkquest.org/16132/frames.html
http://www.answers.com/
http://en.wikipedia.org/wiki/Natural_disaster
http://www.bbc.co.uk/science/hottopics/naturaldisasters/
http://www.aoml.noaa.gov/general/lib/hurricbro.html
http://www.bt.cdc.gov/disasters/http://www.bt.cdc.gov/disasters/
http://www.foxnews.com/specialsections/naturaldisaster/index.html
http://www.fema.gov/hazard/types.shtm
http://www.fema.gov/kids/dizarea.htm
To Index