Transcript Notes - Rudds Classroom

Volcanoes
Andes, South America
Many of the mountains in the Andes mountain
range are actually volcanoes
Galeras
• In 1988 soldiers reported small
earthquakes and the smell of sulfur
• Scientists believed they understood
Galeras and that it was stable
• 3 hikers and 6 volcanologists died when it erupted
unexpectedly while they were studying it
Planet Earth
Earth’s inner core is made up of magma
• Magma is molten rock below the surface
• Core reaches temperatures of 12,000o F
• Magma rises to the
surface between the
more than 20 tectonic
plates
Planet Earth
Underwater
• 80% of all volcanic activity
occurs underwater
• Creates underwater hot
springs that are more
than 700o F
• Water around the
springs contain
enough heat and
sulfur to create
entire ecosystems
Hawaii
Hawaiian chain of islands was created by a volcano
• Kilauea has had continuous
eruptions since 1970
• Does not erupt violently like
many volcanoes
• Lava flows at about 2,000o F
• Lava also flows very slowly
Japan
Sakurajima – active since 1955
• Erupts up to 400 times a year
• Most ash collects harmlessly on the volcano's slope
• However, when it rains, it creates mud flows that
wash out roads and bridges
• Safety channels with sensors
and surveillance cameras
help contain the threat
Japan
• Mud flows can travel up to 40 mph and sweep
up boulders the size of car
• Erupted in 1914 causing
massive mud flows that
destroyed the city below
• Every year on the
anniversary of the
disaster they have an
evacuation drill
History
Mediterranean
• 3,500 years ago, the city of Atlantis was
washed away when the volcano erupted and
the sea flooded in
History
Mount Vesuvius
• In 79 AD Mt. Vesuvius
erupted and destroyed
the city of Pompeii
• The people died in showers of scalding ash
Mount Vesuvius
• Giuseppe Fiorelli excavated Pompeii in 1863.
• During early excavations, occasional voids in the ash
layer were found that contained human remains.
• Fiorelli realized these empty spaces were left by the
decomposed bodies
• He devised a technique of injecting plaster into the
voids to recreate the forms of Vesuvius's victims.
• This technique is still in
use today, with a clear
resin instead of plaster
because it is more
durable, and does not
destroy the bones,
allowing further analysis
Indonesia
In 1850 Mount Tambora erupts
• Launches 20 cubic miles of
debris into the air.
• Cloud of ash circles the globe for several years
blocking out the sun
• On the other side of the world, the ash cloud caused:
• Snow to fall in July
• Crops to fail
• 80,000 people to starve to death
• Most powerful eruption in the past 10,000 years
United States
In 1980 Mount St. Helen’s erupted
• Exploded with the power
of 500 atomic bombs.
• In 9 minutes it killed
everything within 230
square miles
• A volcanic eruption occurs when magma reaches
the surface of the earth
• Magma contains gases that expand violently
when they reach Earth's atmosphere
Pyroclastic Flows
Volcanoes do not have to explode to be deadly
• Lava, too thick to flow, can ooze up slowly forming a
teetering heap of hot rock.
• Collapse triggers a searing avalanche of pulverized
rock, gas, and ash called a pyroclastic flow
• Pyroclastic Flows:
• Fast-moving mass
of hot gas and rock
• Temperatures of
2000o F
• Travels at over 100
mph
Caribbean
In 1902 Mount Pelée erupted
• Pyroclastic flow
incinerated the town
of Saint Pierre.
• In 2 minutes, 30,000
people died
• The only person to
survive was a prisoner
The walls of his cell were
so thick that they
protected him
Southern Japan
In 1991 Mount Unzen generated more than 35
pyroclastic flows per day
• Nearby villagers were evacuated
• Journalists and volcanologist
went to study the flows
Katia and Maurice Kraft
French volcanologists who studied and filmed
active volcanoes around the world
• Italy - gases surrounding the
volcano were so acidic that it
burned holes in their
clothing.
Katia and Maurice Kraft
• Africa - Ol Doinyo Lengai in Tanzania
• Unique because it produces black carbonatite lava
instead of red silicate lava
• Carbonatite lava is thicker
and can have a temperature
as low as 500o F.
• Carbonate minerals are
unstable and susceptible to
rapid weathering, causing
them to quickly turn from
black to grey/white in color
Katia and Maurice Kraft
1991 Mt. Unzen
• Set up their camp inside the evacuation zone.
• Moved to within 2 miles of the summit
• Killed by pyroclastic flow
• 10 times bigger than any of the previous flows
• 41 other people
in the valley
also died
Columbia
In 1985 Nevado del Ruiz erupts at 9:00 PM
• Melts part of its summit glacier
• Water cascades down the side
stripping the land of soil, trees,
and boulders
• Soon the mud flow is 130 ft deep
• Just before midnight, the flow reaches the town of
Armero approximately 30 miles away and engulfs it
• 23,000 people were
killed when they were
buried alive
Columbia
• Just a couple weeks before the eruption, scientist
surveyed the volcano and determined that the town
was at risk
• Instead of creating a
simple evacuation
plan that could have
saved thousands of
lives, their report was
ignored
• As a result, in 1986 the United States Geological
Survey (USGS) created the Volcano Crisis Assistance
Team at the Cascades Volcano Observatory located
50 miles from Mount St. Helens
Philippines
• In 1991 the Volcano Crisis Assistance Team was sent to
study Mount Pinatubo
• June 5th – Swarms of
earthquakes prompt a
Level 3 alert
• Eruption possible
within 2 weeks
• 20,000 people living 6 miles of the mountain
evacuated
• But Clark air force base
was not evacuated
Philippines
• June 7th – Cloud of ash prompts Level 4 alert
• Eruption possible within
24 hours
• Scientists also notice a plug
of thick lava – kind that
generates pryoclastic flows
• Evacuate air force base
• June 12th – Pinatubo erupts sending
an ash column 12 miles into the sky
• Ash and sand fall from sky over
50 miles away
• Evacuation radius is enlarged
Philippines
• June 15th – Pinatubo's final eruption
• Many pryoclastic
flows
• 10:00 AM is as dark
as midnight
• When people returned
• Buildings had collapsed from weight of ash and rain
(concrete) falling from sky
• 300 people died in collapsed
buildings
• Days afterwards mud flows
killed hundreds of people
Philippines
• Each year more mud flows kill hundreds
• Scientists expect the effects of the eruption to
affect area for another 100 years
Volcanoes
Volcanoes are a vital and necessary part of the
environment
• Build mountains.
• Create new land.
• Recycle life
giving gases.
• Bring necessary
minerals to the
surface of earth.