Transcript File - Down the Rabbit Hole

Major Concept:
• Earth is a dynamic planet
• How do physical events in the environment affect our
health
Although we cannot prevent most natural disasters,
there are steps that scientists, engineers,
governments, and citizens can take to resist damage
and deal with the aftermath.
A landslide caused by the Great
Sichuan Earthquake in Sichuan
Province, China
 Earth’s crust is broken
into large pieces called
tectonic plates, which
float on a layer of
molten rock.
 The plates move in
different directions
 Earthquakes tend to
occur along active plate
boundaries.
 Earthquakes can
damage
structures and trigger
landslides and
tsunamis.
Plates move
at the rate of
a few
centimeters
per year –
about the
same rate as
your
fingernails
grow.
There are three types of plate boundaries.
This is when the plates collide
This is when the plates separate
When plates slide by each other
 The Pacific Plate
(left) west side
moves north
 The North American
Plate (right) east
side moves south
WEST
EAST
 A continent-continent
collision is like a train
wreck - both sides end
up taking severe
damage. Neither side
wants to subduct.
 The entire AlpineHimalayan mountain
system from Spain to
Thailand is behaving
this way.
 The last major
earthquake in
Southern California
occurred almost
twenty years ago
 Openings in Earth’s
crust that eject molten
lava and other materials
 Ash and gases from
volcanic eruptions can
block sunlight, causing
temperatures to drop.
 Eruptions can trigger
landslides and
mudflows.
Did You Know? In 1991, Mount Pinatubo
erupted in the Philippines, covering the area
around the volcano with a layer of volcanic
materials up to 180 m (600 ft) thick.
 Molten lava can cover
and destroy surrounding
land.
Most of the Earth’s active volcanoes on
land are located around the Pacific Rim
 A storm is a violent disturbance in the
atmosphere
 4 major types of storms:

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
Thunderstorms
Tornadoes
Hurricanes
Winter Storms
 A meteorologist is a scientist who studies
weather and tries to predict it
 Tornadoes: Rotating
funnels of air that can
travel over 400 km (250 mi)
per hr
 Hurricanes: Storms that
form over tropical oceans,
with winds over 119 km
(74 mi) per hour
 Thunderstorms: Produce
lightning and thunder,
usually with heavy rain
Did You Know? Hurricane Katrina, which struck
New Orleans in 2005, caused more than $80 billion
in damage and killed 1800 people.
 A thunderstorm is a small storm often
accompanied by heavy precipitation and
frequent thunder and lightning.
 Form in large cumulonimbus clouds (also
called thunderheads) on hot, humid
afternoons
 Warm, humid air rises
rapidly and the air
cools, forming dense
thunderhead clouds
 Heavy rain falls,
sometimes along with
hail
 Within the thunderhead
cloud there are strong
updrafts and downdrafts
 Lightning heats the air to 30,000oC
 Thunder is the sound of the rapidly heated air
expanding suddenly and explosively
 Light travels faster than sound so you see
lightning before you hear thunder
 Lightning is a sudden spark, or electrical
discharge
 Positive and negative charges jump between
parts of a cloud, or between nearby clouds,
or between a cloud and the ground
 Watch the sky for a flash of lightning.
 Count the number of seconds until you
hear thunder.
 Divide the number of seconds by 5 to
calculate the distance the storm is away
from your location in miles (or divide by 3
for kilometers).
 A tornado is a rapidly whirling, funnel-shaped
cloud that reaches down from a storm cloud
to touch Earth’s surface
 Warm, moist air flows in at the bottom of a
cumulonimbus cloud and moves upward
 A low pressure area forms inside the cloud
 Warm air rotates as it meets winds blowing in
different directions at different altitudes
 Tornado Alley is an area of the United States
that has a high frequency of tornadoes
because cold, dry air moves south from
Canada to meet warm, humid air from the
Gulf of Mexico
 5 states that cross Tornado Alley are:

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

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Texas
Oklahoma
Kansas
Nebraska
Iowa
 Tornadoes are ranked on the Fujita scale by the
amount of damage they cause
 A tornado watch is an announcement that
tornadoes are possible in your area. Stay
tuned to the radio or television news.
 A tornado warning is an announcement that
a tornado has been sighted. Take shelter
immediately!
 The safest place to be during a tornado is in
a storm shelter or the basement of a wellbuilt building
 A hurricane is a tropical cyclone that has winds of 119 km/h or higher
 Hurricanes form in the Atlantic, Pacific, and Indian Oceans
 In the western Pacific Ocean, hurricanes are called typhoons
 A hurricane begins over warm ocean water as a low-pressure area,
or tropical disturbance.
 A hurricane draws its energy from the warm, humid air at the ocean’s
surface
 As the air rises and forms clouds, more air is drawn into the system
 Inside the storm are bands of very high winds and heavy rains
 Winds spiral inward toward the area of lowest pressure at the center
 Hurricanes last longer than other storms, usually a
week or more
 After a hurricane passes over land, it no longer has
warm, moist air to draw energy from so it loses strength
 A storm surge is a “dome” of water that sweeps across
the coast where a hurricane lands
 For safety during a hurricane, people are told to
evacuate
 Evacuate means to leave the area immediately
 All year round, most precipitation begins in
clouds as snow
 A large amount of humid air that cools below 0oC
can produce a winter storm
 Blizzard = Blowing snow and reduced visibility
 Main Hazards

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Vehicle accidents
Hypothermia
Exertion
Immobility
Masses of snow that slide down a slope
Conditions favoring avalanches:
Slope greater than 30 degrees
Unstable snowpack
Heavy snowfall
Warm temperatures
Did You Know? A big North
American avalanche can contain
230,000 m3 of snow—about the
equivalent of 20 football fields filled
with snow 3 m (10 ft) deep.
 Main direct impacts
are deaths, injuries,
and economic losses
to communities
affected.
 Indirect impacts
include wider
economic losses to
tourism industry,
transport delays, and
wider spatial
economic losses.
 Heavy rainfall on snow
(more likely in Scotland
than the Alps!)
 Deforestation - reducing
slope stability
 Vibrations – skiers or
more dangerous earth
movements
 Long cold winters then
heavy snow falls in
spring. i.e. slip plane
created.
 Snow lying on a slope is subject to stress :
 gravity is pulling it downwards
 adhesion and weight is keeping it “stuck” to the slope.
 Often these stresses are delicately balanced, and a slight
change can bring about failure, particularly where the
snow-pack is under tension.
 No warning.
 Up to 200mph
 Up to 50 tons/m 2
force
 Occur at any time
in season.
 Example :Galtur,
Austria.
 Usually late in
season.
 Slow moving (515mph).
 Considerable
weight of wet
snow (up a million
tonnes).
 Example : Odda,
Norway.
 Slab avalanches
are most common
occurrence.
 Often started by
human error.
 Most frequent
cause of death
amongst skiers,
snowboarders, and
power-skiers.
 Speeds up to
100mph.