http://www.youtube.com/watch?v=GWAY0rl3lag
solid waste
HIGH SCHOOL: ENVIRONMENTAL SCIENCE
THE DYNAMIC EARTH
THE GEOSPHERE
The earth consists of rock, air, water, and living things that all
interact with each other. The four parts are the geosphere
(rock), the atmosphere (air), the hydrosphere (water), and the
biosphere (living things).
The geosphere consists of the solid part of the Earth that
consists of all rock, and the soils and sediments on Earth’s
surface.
The atmosphere is the mixture of gases that makes up the air
we breathe.
The hydrosphere makes up all of the water on or near the
Earth’s surface.
The biosphere is the part of the Earth where life exists.
Discovering Earth’s interior
Scientists can use seismic waves to learn about Earth’s
interior. Seismic waves are the waves that travel through
Earth’s interior during an earthquake. A seismic wave is
altered by the nature of the material through which it travels.
Seismologists measure changes in the speed and direction of
seismic waves that penetrate the interior of the planet.
In this way seismologists have learned that Earth is made up
of different layers and have learnt what substances make up
each layer.
http://science.howstuffworks.com/earthquake4.htm
Extra information on seismic waves
http://www.youtube.com/watch?v=yOGoKCK17a4&feature=r
elated
video on seismic waves and its impact
The composition of the Earth
Scientists divide the Earth into three layers – the crust, the
mantle, and the core – based on the composition of each
layer.
The crust is Earth’s thin outer layer is the crust. It is made
almost entirely of light elements. The crust is Earth’s thinnest
layer.
The mantle, which is the layer beneath the crust is made of
ricks of medium density. (iron-rich minerals)
Earth’s innermost layer is the core. The core is composed of
the densest elements. (nickel and iron)
http://www.youtube.com/watch?v=0AAITe0MImY
layers of earth (a person teaching students)
http://www.youtube.com/watch?v=6PDvjhELGdE&feature=re
lated
layers of earth (earthquake)shown
The structure of the Earth
The Earth can be divided into five layers based on the physical
properties of each layer.
Earth’s outer layer is the lithosphere. It is 15 Km to 300 Km
thick. It consists of the crust and the rigid, uppermost part of
the mantle. It is divided into huge pieces called tectonic
plates. It can have both continental and oceanic crust.
The layer beneath the lithosphere is the asthenosphere. It is
the solid plastic layer of the mantle between the mesosphere
and the lithosphere. It is made of mantle rock that flows very
slowly, which allows tectonic plates to move on top of it.
Beneath the asthenosphere is the mesosphere, the lower part
of the mantle.
The Earth’s outer core is a dense liquid layer. At the center of
the Earth is the dense, solid inner core, which is made up
mostly of the metals iron and nickel.
The temperature of the inner core is estimated to be between
4,0000C to 5,0000C. Even though the inner core is so hot, it is
solid because it is under enormous pressure. Earth’s outer and
inner core together make up about one third of Earth’s mass.
Plate tectonics
http://www.odsn.de/odsn/services/paleomap/animation.ht
ml
Plate tectonics Pangaea
The lithosphere – the rigid outermost layer of the Earth- is
divided into pieces called tectonic plates. These plates glide
across the underlying asthenosphere. The continents are
located on tectonic plates and move around with them. The
major tectonic plates include the Pacific, North American,
South American, African, Eurasian, and Antarctic plates.
Much of the geologic activity at the surface of the Earth takes
place at the boundaries between tectonic plates. Plates may
separate from one another, collide with one another, or slip
past one another. Enormous forces are generated at tectonic
plate boundaries, where the crust is pulled apart, is squeezed
together, or is constantly slipping.
The forces produced at the boundaries of tectonic plates can
cause mountains to form, earthquakes to shake the crust, and
volcanoes to erupt.
http://video.yahoo.com/watch/1595682/5390276
Plate tectonics (*)
Tectonic plates are continually moving around the Earth’s
surface. When tectonic plates collide, slip by one another, or
pull apart, enormous forces cause rock to break and buckle.
Where plates collide, the crust becomes thicker and
eventually forms mountain ranges. The Himalaya Mountains,
began to form when the tectonic plate containing Asia and the
tectonic plate containing India began to collide 50 million
years ago.
http://www.learner.org/interactives/dynamicearth/slip2.htm
l
formation of mountain animation
Earthquakes
http://www.weatherwizkids.com/earthquake1.htm
information regarding earthquakes
A fault is a break in the Earth’s crust along which blocks of the
crust slide relative to one another. When rocks that are under
stress suddenly break along a fault, a series of ground
vibrations is set off. These vibrations of the Earth’s crust
caused by slippage along a fault are known as earthquakes.
Earthquakes are occurring all the time, but many are so small
that we cannot feel them. Other earthquakes are enormous
movements of the Earth’s crust that cause widespread
damage.
The Richter scale is used by scientists to quantify the amount
of energy released by an earthquake. The smallest magnitude
that can be felt is approximately 2.0, and the largest that has
ever been recorded is 9.5.
Each increase of magnitude by one whole number indicates
the release of 31.7 times more energy than the whole number
below it.
Earthquakes that cause widespread damage have magnitudes
of 7.0 and greater.
The majority of earthquakes takes place at or near tectonic
plate boundaries because of the enormous stresses that are
generated when tectonic plates separate, collide, or slip past
each other. Over the past 15 million to 20 million years, large
numbers of earthquakes have occurred along the San Andreas
fault, which runs almost the entire length of California. The
San Andreas fault is the line where parts of the North
American plate and the Pacific plate are slipping past one
another.
Earthquake hazard
http://www.geo.mtu.edu/UPSeis/hazards.html
The Effect of Ground Shaking
The first main earthquake hazard (danger) is the effect
of ground shaking. Buildings can be damaged by the
shaking itself or by the ground beneath them settling to
a different level than it was before the earthquake
(subsidence).
FIGURE 1 - THESE
MEN
BARELY
ESCAPED
WHEN
THE FRONT OF
THE ANCHORAGE
J.C.
PENNY'S
COLLAPSED
DURING THE 1964
GOOD
FRIDAY
EARTHQUAKE.
Buildings can even sink into the ground if soil liquefaction
occurs. Liquefaction is the mixing of sand or soil and
groundwater (water underground) during the shaking of
a moderate or strong earthquake. When the water and
soil are mixed, the ground becomes very soft and acts
similar to quicksand. If liquefaction occurs under a
building, it may start to lean, tip over, or sink several feet.
The ground firms up again after the earthquake has past
and the water has settled back down to its usual place
deeper in the ground. Liquefaction is a hazard in areas
that have groundwater near the surface and sandy soil.
Buildings can also be damaged by strong surface waves
making the ground heave and lurch. Any buildings in the path
of these surface waves can lean or tip over from all the
movement. The ground shaking may also cause landslides,
mudslides, and avalanches on steeper hills or mountains, all of
which can damage buildings and hurt people.
The second main earthquake hazard is ground
displacement (ground movement) along a fault. If a
structure (a building, road, etc.) is built across a fault,
the ground displacement during an earthquake could
seriously damage or rip apart that structure.
From Figure 4 you can tell that the San Andreas Fault
is a right-lateral transverse (strike-slip) fault because
the other side of the road (on the opposite side of the
fault) has moved to the right, relative to the
photographer's position.
FIGURE 4 - THIS ROAD, WHICH CROSSES THE
SAN ANDREAS FAULT, WAS CUT IN HALF BY THE
1906 EARTHQUAKE. ONE END OF THE ROAD SLID
20 FEET (6.5 METERS) PAST THE OTHER DURING
THE QUAKE.
Flooding
The third main hazard is flooding. An earthquake can
rupture (break) dams or levees along a river. The water
from the river or the reservoir would then flood the
area, damaging buildings and maybe sweeping away or
drowning people.
Tsunamis and seiches can also cause a great deal of
damage. A tsunami is what most people call a tidal wave,
but it has nothing to do with the tides on the ocean. It is a
huge wave caused by an earthquake under the ocean.
Tsunamis can be tens of feet high when they hit the shore
and can do enormous damage to the coastline. Seiches are
like small tsunamis. They occur on lakes that are shaken
by the earthquake and are usually only a few feet high,
but they can still flood or knock down houses, and tip over
trees.
Fire
The fourth main earthquake hazard is fire. These fires can be
started by broken gas lines and power lines, or tipped over
wood or coal stoves. They can be a serious problem, especially
if the water lines that feed the fire hydrants are broken, too.
For example, after the Great San Francisco Earthquake in
1906, the city burned for three days. Most of the city was
destroyed and 250,000 people were left homeless
FIGURE 6 - SAN FRANCISCO BURNING AFTER THE
1906 EARTHQUAKE.
Most of the hazards to people come from man-made
structures themselves and the shaking they receive from the
earthquake. The real dangers to people are being crushed in a
collapsing building, drowning in a flood caused by a broken
dam or levee, getting buried under a landslide, or being
burned in a fire.
http://www.authorstream.com/presentation/Dr_Dave113874-hazards-sichuan-earthquake-landslide-china-disasterhazard-conference-07-11-philip-allen-1-entertainment-pptpowerpoint/
Hazards of earthquake powerpoint
Earthquakes are not restricted to high-risk areas. In 1886, an
earthquake shook Charleston, South Carolina, which is
considered to be in a medium-risk area. Because the soil
beneath the city is sandy, this earthquake caused extensive
damage. During shaking from a strong earthquake, sand acts
like a liquid and causes buildings to sink.
In areas that are prone to earthquakes, it is worth the extra
investment to build bridges and buildings that are at least
partially earthquake resistant. Earthquake-resistant buildings
are slightly flexible so that they can sway with the ground
motion.
VOLCANOES
A volcano is a mountain built from magma-melted rock-that
rises from the Earth’s interior to the surface. Volcanoes are
often located near tectonic plate boundaries where plates are
either colliding or separating from one another.
Volcanoes may occur on land or under the sea, where they
eventually break the ocean surface as islands.
The majority of the world’s active volcanoes on land are
located along tectonic plate boundaries that surround the
Pacific Ocean.
http://www.youtube.com/watch?v=y4KbyB2UnTM
volcanic eruption (song)
http://www.youtube.com/watch?v=bYYgx8Wo6UQ&feature=
related
Mount Etna volcanic eruption (*)
http://www.youtube.com/watch?v=GwLYFwjhgaw
Video on Mount St. Helens
Local effects of volcanic eruptions
http://library.thinkquest.org/17457/volcanoes/effects.php
 Volcanic eruptions can be devastating to local economies
and cause great human loss.
 Clouds of hot ash, dust, and gases can flow down the
slope of a volcano at great speed and cause great damage
to everything in their path.
 During an eruption, volcanic ash can mix with water and
produce a mudflow. In 1985, Nevado del Ruiz in Columbia
erupted, melting ice at the volcano’s summit. A mudflow
raced downhill and engulfed the town of Armero.
 The ash that falls to the ground can cause buildings to
collapse under its weight, bury crops, and damage the
engines of vehicles.
 Volcanic ash may also cause breathing difficulties
Global effects of volcanic eruptions
Major volcanic eruptions, such as the eruption of Mount St.
Helens can change Earth’s climate for several years. In large
eruptions, clouds of volcanic ash and sulfur-rich gases may
reach the upper atmosphere. As the ash and gases spread
across the planet, they can reduce the amount of sunlight that
reaches the Earth’s surface. This reduction in sunlight can
cause a drop in the average global surface temperature.
In the 1991 eruption of Mount Pinatubo in the Philippines,
large clouds of ash and gases entered the Earth’s atmosphere.
The amount of sunlight that reached the Earth’s surface was
estimated to have decreased by 2 to 4 percent. As a result, the
average global temperature dropped by several tenths of a
degree Celsius over a period of several years.
Erosion
The removal and transport of surface material is called
erosion. Erosion wears down rocks and makes them smoother
as time passes. The older a mountain range is, the longer the
forces of erosion have acted on it. the round-topped
Appalachian mountains in the eastern United States are older
than the jagged Rocky Mountains in the west.
Water erosion
Erosion by both rivers and oceans can produce dramatic
changes on Earth’s surface. Waves from ocean storms can
erode coastlines to give rise to a variety of spectacular
landforms.
Over time, rivers can carve deep gorges into the landscape.
Wind erosion
Wind can change the landscape of our planet. In places where
plants grow, their roots hold soil in place. But in places where
there are few plants, wind can blow soil away very quickly.
Beaches and deserts which have loose, sandy soil, are
examples of places where few plants grow. Soft rocks, such as
sandstone, erode more easily than hard rocks, such as granite,
do.
Explosive volcanic eruptions pose both short-term and long-term hazards. Lava flows and
lahars can wipe out the flanks of mountainsides. Volcanic ash can blanket the landscape for
miles, and ash clouds can disrupt aircraft travel, such as the incident in 1989 when ash from
Alaska's Redoubt volcano temporarily disabled a passenger airplane. On longer time scales,
eruptions can inject massive quantities of ash into the atmosphere, greatly reducing the
solar heating of the Earth and potentially interrupting the global food supply for several
years.
In 1991, mount Pinatubo in the Philippines erupted, and strong winds spread the aerosol
particles from the plume around the globe. The result was a measurable cooling of the
Earth's surface for a period of almost two years. The role of natural hazards research and
developing applications to mitigate the effects of disasters has global implications for
reducing loss and saving lives.
Expected Accomplishments: