Download Tropical Cyclone Classification

IB Geography – Option D: Hazards and disasters – risk assessment and response
Part I. Characteristics of Hazards (and background terms and info)
Important Terms
Avoid using the term “natural disaster” as it oversimplifies the many ways in which people are exposed to risk and
create the preconditions necessary for a disaster to occur.
Hazard:
Hazard event:
Disaster:
Risk:
Vulnerability:
The “Spheres” - GLAHB
Geosphere:
Lithosphere:
The Earth’s Interior
Lithosphere and Geosphere
The geosphere would include the mountains and all
1
landforms as well as all layers of the interior
Note: Sometimes the term "lithosphere" is used instead of geosphere, however the lithosphere only refers
to the uppermost layers of the solid Earth (crust and upper mantle)
Hydrosphere:
Biosphere:
Atmosphere:
All four spheres can be and often are present in a single location. For example, a piece of soil…
 Geosphere:
 Hydrosphere:
 Biosphere:
2
 Atmosphere:
Interactions of the spheres
http://www.classzone.com/books/earth_science/terc/content/investigations/es0103/es0103page01.
cfm
What are some of the interactions at work here?
What sphere interactions can you infer from this photograph?


3

Atmospheric Levels
Atmospheric Levels - Images
4
Troposphere
Stratosphere
Mesosphere
Thermosphere
Ionosphere
5
Exosphere
Cloud characteristics which impact and influence climatic hazards
6
Cumulus clouds
Cirrus clouds:
Cumulonimbus clouds:
Nimbostratus clouds
What are Hazards? What are the different types? How are they classified?
There is a wide range of natural hazards or geophysical processes. They operate in the following spheres:
Lithosphere, geosphere, hydrosphere, atmosphere, biosphere
In an interpretive sketch- outline the different spheres (Atmosphere, Biosphere, Geosphere, Hydrosphere)
7
We will be looking at two areas where hazards occur: Climatic and Lithospheric
Hazard classification is difficult because where hazards originate and impact are not mutually exclusive. Some
classification categories follow…
Classification: Geophysical Origins
Please note that a similar table is in your Hazards and Responses text, page 8
1. Geomorphological –
Examples:
2. Tectonic (Lithospheric)-
Examples:
3. Biological-
Examples:
8
4. Atmospheric-
Examples:
Classification: Characteristics
Beneath are a few examples of hazards. This is not intended to be a comprehensive list.
1. Tropical cyclones: hurricanes, cyclones, typhoon
Three types of tropical cyclones are…

Hurricane

Typhoon

Cyclone
They are all the same type of storm system – the only distinction is the location
2. Tornado is a violent, dangerous, rotating column of air that is in contact with both
the surface of the earth and a cumulonimbus cloud or, in rare cases, the base of a
cumulus cloud.
3. Drought refers to a long, conintuous period with little or no precipitation. Drought is
not just a natural phenomenon but a conflict between natural water availability and
human demand.
4. Flood refers to a large flowing or overflowing of water, especially over land not usually
submerged.
5. Earthquake is the result of a sudden release of energy in the Earth’s crust that
creates seismic waves.
9
6. Tsunami is a very large ocean wave caused by an underwater earthquake or volcanic
eruption.
7. Volcano is an opening, or rupture, in a planet’s surface or crust, which allows hot
magma/lava, ash and gases to escape from below the surface.
8. mudslide is a slow moving and often destructive mass of mud flowing down a slope.
9. landslide is the usually rapid downward movement of a mass of rock, earth or
artificial fill on a slope
10. Dust storm- wind blowing top layer of geosphere
11. Acid rain is rain containing acids that form in the atmosphere when industrial gas
emissions (especially sulfur dioxide and nitrogen oxides) combine with water
12. Others…
Defining HAZARD and how measured
a. An event is considered a hazard in the sense that there has to be some impact on the anthrosphere or human life, i.e.
loss of life, costs to human activities, etc.
b. The impact of hazards is measured in terms of losses or gains
1 direct losses- measurable loss in numbers, either human or property
2 indirect losses- non measurable loss in regard to short and long term social consequences on a local or
global scale
3 direct gains – measurable improvements in (re)building of projects, property
4 indirect gains- non measurable short term and long term physical and social impacts
c. Impacts of hazards are evaluated on the following conditions
1 population impacts
2 financial impacts
10
a) often in terms of insurance pay outs
3 educational impacts
4 economic impacts, i.e. impact on GDP
5 infrastructure impacts
d. LEDCs tend to be most impacted by natural hazards
e. Primary vs. secondary hazards
1) primary
2) secondary-
Atmospheric pressure background/components
Water and heat
1. Water has one of the highest heat capacities of all known substances.
2. This means that it takes a lot of heat to raise the temperature of water by just one
degree.
3. Water absorbs and stores a tremendous amount of heat from solar radiation
4. Further energy is absorbed by water vapour as the latent heat of vaporization,
which is the heat required to evaporate water or change it from a liquid to a vapor.
5. This latent heat of vaporization is given up to the atmosphere when water
condenses to form precipitation
6. Both liquid water and water vapour are important in absorbing heat from solar
radiation and transporting this heat around the planet.
Air masses
1. Due to general atmospheric circulation patterns, air masses containing differing
amounts of heat and moisture move into and across continents.
11
2. Polar air masses, containing little moisture and low temperatures move downward
from the poles.
3. Air masses that form over water are generally moist
4. Those that form over the tropical oceans are both moist and warm.
5. Because of the differences in moisture and heat, the collision of these air masses
can cause instability in the atmosphere.
The Website - http://earthsci.org/Flooding/unit1/u1-02-00.html, breaks down
information regarding tropical storms extremely well.
Air pressure
1. a barometer measures air pressure, and can tell you something about what the
weather is going to be like. Rising air pressure means good weather is coming, and
dropping air pressure means that bad weather is on the way.
2. Air masses are constantly moving. In some places air is going up; in other places it
is falling. In between, air is moving parallel to the surface ... causing winds.
a drop in air pressure, or low pressure, usually means that air above you is
rising, and expanding.
This rising, expanding air will cool, forcing its water vapour to condense,
clouds to form, and maybe rain to fall.
12
high pressure, probably means that the air above is falling, and compressing.
a. As this air falls, it gets warmer.
b. This means it can hold more water vapour, so any clouds that exist will
evaporate, leaving a clear sky.
3. Once air has been set in motion it undergoes an apparent deflection from its path,
as seen by an observer on the earth. This apparent deflection is called the "Coriolis
force" and is a result of the earth's rotation.
The Coriolis force is zero right at the equator.
13
Warm and Cold Fronts
A front is the region where two air masses of different densities meet. The change in density is
usually caused by
14
Warm Front
Warm front: In this case we have a cold air mass moving from right to left on the left-hand side
of the image. On the right, we have a warm air mass that is also moving from right to left; the
difference is
When the warm air mass hits the cold one,
Precipitation is found on the cold air mass side of the front. Warm fronts are associated with
15
Cold Front
Cold front: In this example, we have a cold air mass moving from left to right on the left-hand
side of the image. On the right, we have a warm air mass that is relatively stationary.
When the cold air mass hits the cold one, it digs underneath the warm air mass because (1)
The digging motion of the cold air forces (2)
This rising motion causes the air to be cooled until (3)
Precipitation is found on the warm air mass side of the front. Cold fronts are associated with
(4)
However, the rain is generally confined to a small horizontal range. The vertical development
of clouds, often associated with warm fronts - may form (5)
16
Occluded Fronts
In an occluded front, a cold front catches up to a warm front. There are two types of
occluded fronts, cold-occluded and warm occluded.
In a cold-occluded front, the air behind the cold front is colder than that in front of the
warm front.
As the cold front approaches the warm front, its colder air not only pushes the warm air
upward as in a regular cold front, but it also pushes up the cold air in front of the warm
front. This is because it is more dense (colder).
The temperature will go from cold to very cold, with the pressure falling before passage,
reaching a minimum while the occlusion is passing and rise afterward.
In a warm-occluded front, the coldest airmass is below the warm front. The cold front
will catch up to the warm front. The cold front moves above the surface because the
coldest, most dense air is below the warm front.
Temperatures are going to be very cold before passage of a warm-occluded front, with
the temperature rising after passage, but still being cold. The pressure will fall until the
front passes, and then rise. Expect light-heavy showers before, during, and after the
passage of a warm-occluded front. The visibility is especially poor in a warm-occluded
front, but it begins to clear after the front moves out
17
Climatic Hazards: Tropical Storms
Before beginning, students should have read and responded to the article “Extreme
Weather” by Jeff Masters in The New Scientist
Notes from “Extreme Weather,” New Scientist (Jeff Masters)

Heat naturally moves from hotter to colder areas

Atmosphere and oceans transport hear from the equator to the poles

Instability occurs where air is less dense than its surroundings

Instability is greatest when there is cold, dense air aloft and warm, moist air at
lower levels (moist air less dense than dry air)

As air moves upwards, it expands further

Expansion causes cooling (because as the molecules of air move farther apart, the
amount of kinetic energy in a given volume falls)

At some point the air becomes too cool for water vapour to remain in the gas
phase (called the dew-point temperature)

Water vapour begins condensing, forming clouds and precipitation
Two main ingredients are needed to create precipitation
1.
2.
18
The three main ways in which air gets lifted are
1.
2.
3.
Thermal Column
A thermal column is a column of rising air in lower altitudes of the atmosphere.
Thermal columns are created by uneven heating patterns of the Earth’s surface from
solar radiation. The sun warms the ground, and the air directly above the ground begins
to warm.
As the warm air expands, it becomes less dense than the air around it and rises.
As the warmer air rises, it cools due to its expansion in lower high-altitude pressures.
When it cools to the same temperature as the surrounding air, it stops rising. Downward
flow surrounds a thermal column. The downward flow is caused by colder air being
displaced at the top of the thermal column. Thermal columns are also known simply as
thermals.
Thermal columns are often indicated by the presence of visible cumulus clouds. A steady
wind causes thermals and the respective cumulus clouds to align in rows oriented with
wind direction. As the cumulus clouds form by the riding thermal air, water vapour
begins to condense into water droplets. The droplets release latent heat energy which
19
allows the air to rise higher. As the air mass becomes unstable and condenses even
more water vapour, showers or even thunderstorms can form.
Thermal columns are one of many sources of lift that soaring birds use to climb higher
into the air.
Draw and annotate your diagram
20
Tropical Cyclones
This is a very good site to explain conditions of tropical storms
http://www.srh.noaa.gov/jetstream/tropics/tc.htm
Tropical Cyclone Classification
A tropical cyclone is a storm system characterized by…
Tropical cyclones with an organized system of clouds and thunderstorms with a defined
circulation, and maximum sustained winds of 38 mph (61 kph) or less are called
"tropical depressions". Once the tropical cyclone reaches winds of at least 39 mph (63
kph) they are typically called a "tropical storm" and assigned a name.
If maximum sustained winds reach 74 mph (119 kph), the cyclone is called:

A hurricane in the North Atlantic Ocean, the Northeast Pacific Ocean east of the
dateline, and the South Pacific Ocean east of 160°E,

A typhoon in the Northwest Pacific Ocean west of the dateline (super typhoon if
the maximum sustained winds are at least 150 mph / 241 kph),

A severe tropical cyclone in the Southwest Pacific Ocean west of 160°E or
Southeast Indian Ocean east of 90°E,

A severe cyclonic storm in the North Indian Ocean, and

Just a tropical cyclone in the Southwest Indian Ocean.
Tropical cyclones in the northern hemisphere rotate counterclockwise, while those in the southern hemisphere rotate clockwise
On the map, label where you would locate the three types of tropical cyclones
21
CNorthern hemisphere simplified sketch showing subtending arc of wind and waves towards the eye of the storm.
North of the Equator the cyclone air mass revolves in an anti-clockwise direction.
South of the Equator the cyclone air mass revolves in a clockwise direction.
Cyclone Direction
Northern Hemisphere- counter clockwise
Southern Hemisphere- clockwise
An anticyclone (that is, opposite to a cyclone) is
22
Conditions needed for a tropical cyclone/hurricane
1.
2.
3.
4.
5.
6.
7.
8.
For tropical cyclonic storms to occur, the Coriolis force must be present.
Remember that the Coriolis effect is zero near the equator and increases to the
north and south of the equator.
23
Without the Coriolis force, the low pressure of the disturbance cannot be maintained.
Vertical wind shear is…
Or, if a tropical cyclone has already formed, large vertical shear…
Draw and annotate the conditions needed for the development of a Tropical Cyclone
24
Tropical Storm Development/Stages
Although tropical storms may rapidly intensify into tropical cyclones, there are different stages of
development. Very few tropical disturbances actually become tropical cyclones.
1) Tropical Wave – an area of low pressure moving westward. It is usually associated with
showers and clouds
2) Tropical Disturbance - an organized area of showers and thunderstorms that forms.
Typically, they…
3) Tropical Depression –
4) Tropical Storm - a tropical cyclone with maximum sustained wind speeds that range from
5) Hurricane (or typhoon or cyclone) -
25
***Annotate the above diagram for cyclone/hurricane conditions
http://earthsci.org/Flooding/unit1/u1-05-01b.html Surface convergence or movement
(indicated by the small horizontal arrows in the diagram) causes rising motion around a
surface cyclone (labelled as "L").
** As long as favorable conditions exist, this process continues to build upon itself. Note
that all tropical waves, disturbances, or storms do not necessarily develop into
hurricanes.
26
http://www.youtube.com/watch?v=HJydFJORWf4
27
Tropical Cyclone Formation Basins
Tropical Cyclone Formation Basin
Given that sea surface temperatures need to be at least 80°F (27°C) for tropical cyclones
form, it is natural they form near the equator.
Of course, the Coriolis Force prohibits development on the equator

Cyclones can often live for a long period of time -- as much as two to three weeks.

Once a disturbance has become a tropical depression, the amount of time it takes
to achieve the next stage, tropical storm, can take as little as half a day up to a
couple of days. It may not happen at all.

The same may occur for the amount of time a tropical storm needs to intensify
into a cyclone.

Atmospheric and oceanic conditions play the major role in determining these
events
28
Tropical Cyclone/Hurricane/Typhoon Structure
The main parts of a tropical cyclone are the
1) rainbands,
a)
b) These bands are capable
c)
**In fact, if one were to travel between the outer edge of a hurricane to its center, one
would normally progress from light rain and wind, to dry and weak breeze, then back to
increasingly heavier rainfall and stronger wind, over and over again with each period of
rainfall and wind being more intense and lasting longer
2) the eye,
a) The hurricane's centre is…
An eye will usually develop when the maximum sustained wind speeds go above 74 mph
(119 km/h) and is the calmest part of the storm.
3) the eyewall.
29
a)
b)
** Changes in the structure of the eye and eyewall can cause changes in the wind speed,
which is an indicator of the storm's intensity. The eye can grow or shrink in size, and
double (concentric) eyewalls can form
Air spirals in toward the center in a counter-clockwise pattern in the northern
hemisphere (clockwise in the southern hemisphere), and out the top in the opposite
direction. In the very center of the storm, air sinks, forming an "eye" that is mostly
cloud-free.
4) Cirrus cloud cover
a)
b)
Hurricanes – The warning process
 Meteorological stations use track mapping to follow the movement and changes in
the development of a tropical storm and tropical cyclone
o a hurricane watch declared when a tropical storm intensifies and likely that
a tropical cyclone will develop within 24-36 hours.
 A hurricane warning is issued when hurricane conditions are expected in 24
hours or less.
 Each region has a separate rating system for the classification of the tropical
cyclone. The severity of a hurricane in terms of its intensity is measured by the
Saffir-Simpson Scale, on a scale of 1-5, with 5 being the most severe.
o the hurricane is ranked by its wind speed. The scale helps to estimate the
amount and type of damage expected from the storm.
30
Saffir- Simpson Scale
Category 1.
Some damage is expected, with most of it limited to
shrubbery, unanchored houses and items. Some minor flooding will cause pier damage.
Category 2.
Considerable damage can be expected to shrubbery and
some trees may be blown down; there will be damage to mobile homes, signs, roofs, windows
and doors. Small craft may be torn from moorings and marinas will probably flood. Some lowlying areas and shoreline residences should be evacuated.
Category 3.
Large trees and most signs may be blown down; there may
be structural damage to small buildings; mobile homes will be destroyed. Serious flooding will
occur at the coast, with severe damage to shoreline structures and flooding up to eight miles (13
km) inland at elevations of five feet (1.5 m) or less.
Category 4.
Expect trees, signs and traffic lights to be blown down, and
extensive damage done to roofs, windows and doors. Mobile homes will be completely destroyed.
Beaches will be eroded and there will be flooding as far as 6 miles (9.5 km) inland for anything
under 10 feet (3 m) above sea level. Anyone staying within 500 yards (457 m) of shore will be
evacuated, as will all single-story residences within 2 miles (4 km) of shore.
Category 5.
Trees, signs, traffic lights will be blown down. There will be
extensive damage to buildings and major damage to lower floors of structures less than 15 feet
(4.5 m) above sea level within 500 yards (457 m) of shore. Massive evacuation of residential
areas 5-10 miles (8-16 km) from shore will be required.
31
*** Case study- hurricane/cyclone: where, when, why, details: length,
amount of precipitation, strength of wind, deaths, damage,
preparation, reaction, government/NGO/personal involvement
32
► Engineering Nature: Engineering Hurricanes (43 minutes)
(hurricane basics, impact of global warming, predicting and preparing for hurricanes)
Documentaries on Discovery Streaming
► Raging Planet: Hurricanes
Hurricane Scale (3.5 min)
Hurricane formation (3.25 min)
Hurricane glass (9.14 min)
Hurricane Katrina (7 min)
Hurricane Ike (9+ min)
33
Climatic Hazards: Drought
Drought
* only a natural hazard “…to people if water-supply systems can not meet the
demands of agriculture, industry and public.” (pg 113)
Drought prone areas
Hill, Michael. ARID and SEMI-ARID
ENVIRONMENTS. London : Hodder
&Stoughton, 2002, pg.7.
34
What is drought? Where does it occur?
Main Areas:
Sub-Saharan Belt and Horn of
Africa
Southern and Central Africa
and Madagascar
Southern Spain and Portugal
Brazil (Northeast)
Australia
Northwest India
Central Asia
Northeast China
Southeast Asia, Indonesia
In total,
35
General characteristics - drought
1)
* precipitation, evaporation, transpiration, condensation,
2)
a) slowly “creeping hazards” (drought prone)
b) has greatest effect on geographical location compared to any other natural hazard
3)
a) lack of rainfall
b) ground water used up and disrupts hydrologic cycle (limits stream flow)
4)
a) can occur in only a few weeks
b) seasonal rainfall doesn’t let drought develop as easily
5)
a) human & non-human locale
b) 15-20 degrees north and south of the equator
6)
a)
b) result of “secondary natural hazards”
i. dust storms
ii. malnutrition of land
iii. pests- locusts, grasshoppers (eat all vegetation to the roots, plants can’t
hold moisture for the soil.
iv. wild fires
36
7 Drought classification
a. meteorological-
b. agricultural-
c. hydrological-
d. socio-economic-
37
drought frequency:
http://mapscroll.blogspot.com/2009/05/natural-disasters.html
Physical causes - drought
► Global circulation (high pressure) –
► Rain shadow effect –
Rain Shadow Effect
38
EX: Morocco – dry on other side of Atlas mountains = Sahara
► Continentality
vs. Alps causing MORE precipitation to drop on Italian side, but some still dropped on
French side (near Chamonix)
EX: US. Has two rainshadow effects (Coastal Mtns & Rocky Mtns) before last of water
vapour gets to central U.S. & continentality results (limited moisture)
 Cold Ocean currents – the steady flow of cold ocean currents in a given direction,
when ocean temperature changes, air temperature changes, changing flow of air
with water vapour to miss certain land masses completely
 Location: Between 20’ and 30’ N and S – area on earth that gets the least
moisture. Air flow does not move easily, sun doesn’t shine directly, causing less
air flow, movement or precipitation. Dry soil, little or now water to evaporate for
future precipitation
39
Human Causes for Drought
 Deforestation:
 Overgrazing/over farming -
EX- Argentina – too many crops, or not rotated – top soil nutrients are consumed
and not replenished by new crops or fertilizers, so top soil is blown away
Ex: Sahel, bordering the Sahara desert
 land mismanagement:
EX: Australia- Eastern coast of Australia- Sydney, Melbourne
Case study of Drought- in Niger, years, environmental/climatic causes, human causes,
consequences, government/NGO/TNC attempts to prepare or react to hazard and disaster
40
Tectonic Hazards: Earthquakes
Plate tectonics is a scientific theory which describes the large scale motions of Earth's
lithosphere.
Lithosphere: together the crust and upper mantle are called the lithosphere and they
extend about 80 km deep.
The lithosphere is broken into giant plates like puzzle pieces
The crust of the earth is
Thin
Less dense than the mantle
Mobile
oceanic crust is more dense than continental crust (key for subduction)
41
Four Types of zones of earthquake or seismic activity
1. Constructive (diverging) Boundaries along oceanic ridges
Earthquakes result from volcanic activity as magma rises and tensional forces in the crust
2a. Destructive (converging) boundaries – oceanic crust subducted under a continental plate or two
oceanic plates collide in island arc zones
Compressional force causes crustal stresses
Intermediate and deep earthquakes occur in a narrow zone indicating the subducting plate called a
Benioff zone.
2b. Collision boundary- Destructive (converging) boundaries of continental crust with continental crust
(Himalayas)
Shallow earthquakes
3. Lateral crust movement (also known as transform boundaries) – continental crust (San Andreas fault
example)
Dip-slip fault (normal)
Reverse dip-slip fault
42
Strike-slip fault
Measuring Earthquake (vibration)
Richter Scale:
Richter scale no.
No. of earthquakes
per year
Typical effects of this magnitude
< 3.4
800 000
3.5 - 4.2
30 000
4.3 - 4.8
4 800
Most people notice them, windows rattle.
4.9 - 5.4
1400
Everyone notices them, dishes may break, open
doors swing.
5.5 - 6.1
500
Slight damage to buildings, plaster cracks, bricks
fall.
6.2 6.9
100
Much damage to buildings: chimneys fall, houses
move on foundations.
7.0 - 7.3
15
7.4 - 7.9
4
> 8.0
One every 5 to 10 years
Detected only by seismometers
Just about noticeable indoors
Serious damage: bridges twist, walls fracture,
buildings may collapse.
Great damage, most buildings collapse.
Total damage, surface waves seen, objects thrown
43
in the air.
Depth of earthquakes
http://earthquake.usgs.gov/learn/topics/seismology/determining_depth.php
U.S. Geological Survey
Earthquakes can occur anywhere between the Earth's surface and about 700 kilometers below the surface.
For scientific purposes, this earthquake depth range of 0 - 700 km is divided into three zones: shallow,
intermediate, and deep.
Shallow earthquakes
intermediate earthquakes
deep earthquakes
In general, the term "deep-focus earthquakes" is applied to earthquakes deeper than 70 km. All earthquakes
deeper than 70 km are localized within great slabs of shallow lithosphere that are sinking into the Earth's
mantle
Secondary Hazards
- Tsunami
Other terms
Focus (hypocentre)
Epicentre
44
Thrust fault
Richter scale
Measures the magnitude of an earthquake and is based on the amplitude of the lines made on a seismogram using
the largest wave amplitude recorded
Moment magnitude
A more complex scale that combines the amount of movement on the fault, rock strength and the size of the rupture
area
Body waves
A body wave is a seismic wave that moves through the interior of the earth, as opposed to surface waves that travel
near the earth's surface.
Surface waves
A surface wave is a seismic seismic wave that is trapped near the surface of the earth.
45
Mercalli scale
Remember – Richter measures energy of the seismic wave or shock while Mercalli measures the intensity or effect
on the surface of the earth.
Comparing the Richter and Modified Mercalli Scales (from the government of Monterssart, Disaster
Management Coordination Agency)
46
Japan uses Shindo ratings… (essentially Mercalli type rating)
Aftershocks
Aftershocks are earthquakes that follow the largest shock of an earthquake sequence. They are smaller than the
mainshock and within 1-2 rupture lengths distance from the mainshock. Aftershocks can continue over a period of
weeks, months, or years. In general, the larger the mainshock, the larger and more numerous the aftershocks, and
the longer they will continue.
Benioff zone
A dipping planar (flat) zone of earthquakes that is produced by the interaction of a
downgoing oceanic crustal plate with a continental plate. These earthquakes can be
produced by slip along the subduction thrust fault or by slip on faults within the
downgoing plate as a result of bending and extension as the plate is pulled into the
mantle. Also known as the Wadati-Benioff zone.
2011 Tohoku earthquake or the Great East Japan
Earthquake
Japan Meteorological Agency (JMA) official name
2011 off the Pacific coast of Tohoku
Earthquake”
“The
47
48
49
Human Induced Hazards
Case study: - Nuclear reactor failure in
Japan 2011
From Wikipedia- The Fukushima Daiichi
nuclear disaster (福島第一原子力発電所事故
Fukushima Dai-ichi is a series of equipment
failures, nuclear meltdowns, and releases
of radioactive materials at the Fukushima
I Nuclear Power Plant, following the Tōhoku
earthquake and tsunami on 11 March 2011.
It is the largest nuclear disaster since the
Chernobyl disaster of 1986.
The plant comprises six separate boiling water reactors originally designed by General
Electric (GE), and maintained by the Tokyo Electric Power Company (TEPCO). At the time
of the quake, Reactor 4 had been de-fuelled while 5 and 6 were in cold shutdown for planned
maintenance. The remaining reactors shut down automatically after the earthquake, and
emergency generators came online to control electronics and coolant systems. The
tsunami broke the reactors' connection to the power grid, leading the reactors to begin to
overheat. The flooding and earthquake damage hindered external assistance.
Fukushima explosion
In the hours and days that followed, reactors 1,
2
and 3 experienced full meltdown. As workers
struggled to cool and shut down the reactors,
several hydrogen explosions occurred. The
government ordered that seawater be used to
attempt to cool the reactors—this had the effect of ruining the reactors entirely. As
the water levels in the fuel rods pools dropped, they began to overheat. Fears of
radioactivity releases led to a 20 km (12 mi)-radius evacuation around the plant, while
50
workers suffered radiation exposure and were temporarily evacuated at various times.
Electrical power was slowly restored for some of the reactors, allowing for automated
cooling.
Japanese officials initially assessed the accident as Level 4 on the International Nuclear
Event Scale (INES) despite the views of other international agencies that it should be
higher. The level was successively raised to 5 and eventually to 7, the maximum scale
value. The Japanese government and TEPCO have been criticized in the foreign press for
poor communication with the public and improvised cleanup efforts. On 20 March, the Chief
Cabinet Secretary Yukio Edano announced that the plant would be decommissioned once
the crisis was over. Japan's foreign minister criticized foreign media reports over the
accident as overdone and excessive.
The Japanese government estimates the total amount of radioactivity released into the
atmosphere was approximately one-tenth as much as was released during the Chernobyl
disaster (whose 25th anniversary was the 26th of April). Significant amounts of radioactive
material have also been released into ground and ocean waters. Measurements taken by
the Japanese government 30–50 km from the plant showed radioactive caesium levels
high enough to cause concern, leading the government to ban the sale of food grown in
the area. Tokyo officials temporarily recommended that tap water should not be used to
prepare food for infants.
A few of the plant's workers were severely injured or killed by the disaster conditions
resulting from the earthquake. There were no immediate deaths due to direct radiation
exposures, but at least six workers have exceeded lifetime legal limits for radiation and
more than 300 have received significant radiation doses. Future cancer deaths due to
accumulated radiation exposures in the population living near Fukushima have been estimated
to be between 100 and 1,000. Fear of ionizing radiation could have long-term psychological
effects on a large portion of the population in the contaminated areas. On 16 December 2011
Japanese authorities declared the plant to be stable, although it would take decades to
decontaminate the surrounding areas and to decommission the plant altogether
51
Excerpts from Global Research.ca. The Severity of the Fukushima Daiichi Nuclear Disaster: Comparing Chernobyl and Fukushima.
http://www.globalresearch.ca/index.php?context=va&aid=24949. 15 January 2012
On April 15, Kyodo, Japan’s major news service, ran an English language piece by Russian
scientist Alexey V. Yablokov.
The English only Kyodo piece ties Yablokov’s extensive Chernobyl research with the unfolding
Fukushima crisis. Under the headline “How to minimize consequences of the Fukushima
catastrophe” Yablokov observed that:
The analysis of the health impact of radioactive land contamination by the accident at the
Fukushima Daiichi nuclear power plant, made by Professor Chris Busby (the European Committee
of Radiation Risk) based on official Japanese Ministry of Education, Culture, Sports, Science and
Technology data, has shown that over the next 50 years it would be possible to have around
400,000 additional cancer patients within a 200-kilometer radius of the plant.
This number can be lower and can be even higher, depending on strategies to minimize the
consequences. Underestimation is more dangerous for the people and for the country than
overestimation.
Based on the Chernobyl experience, he made the following recommendations:
1. Enlarge the exclusion zone [from 20 kilometers] to at least about a 50-km radius of the plant;
2. Distribute detailed instructions on effective ways to protect the health of individuals while
avoiding the additional contamination of food. Organize regular measurements of all people by
individual dose counters (for overall radionuclides) at least once a week. Distribute radioprotectors
and decontaminants (substances which provide the body protection against harmful effects of
radiation) of radionuclides. . .
3. Develop recommendations for safe agriculture on the contaminated territories: reprocessing of
milk, decontamination of meat, turning agriculture into production of technical cultures (e.g.
biofuels etc.). Such ''radionuclide-resistant'' agriculture will be costly (it may be up to 30-40
percent compared with conventional agriculture) and needs to be subsidized;
4. It is necessary to urgently improve existing medical centers -- and possibly create new ones -to deal with the immediate and long-term consequences of the irradiated peoples (including
medical-genetic consultations on the basis of chromosome analysis etc.);
52
5. The most effective way to help organize post-Fukushima life in the contaminated territories
(from Chernobyl lessons) is to create a special powerful interagency state body (ministry or
committee) to handle the problems of contaminated territories during the first most complicated
years.
A joint survey conducted by the Japanese and
U.S. governments has produced a detailed map of
ground surface radioactive contamination within
an 80-kilometer radius of the Fukushima Daiichi
nuclear power plant.
53
54
From The Daily Mail
Journey: This graphic depicts the predicted location of the Japan debris field as it swirls towards the U.S.
West Coast. Scientists predict the first bits of rubbish will wash up in a year's time
Consequences of tsunami debris
55