Download Volcanoes: Powerful Forces of Nature

National Aeronautics and Space Administration
THE STAR WITNESS
A
P U B L I C A T I O N
O F
N A S A’S
“A M A Z I N G
S P A C E”
E D U C A T I O N
P R O G R A M
Special Feature
Volcanoes: Powerful Forces of Nature
By NASA’s Amazing Space reporters
August 2016
O
N JUNE 15, 1991,
a slumbering giant
awakened. Mount
Pinatubo, a volcano on the
Philippines island of Luzon, erupted
after lying dormant for 500 years.
The mammoth eruption was the
second largest volcanic outburst of
the twentieth century. A series of
huge explosions darkened the skies
that day and created a column of ash
that rose 21 miles (34 kilometers) in
the atmosphere. On the way down,
the ash mixed with rain from a
typhoon and fell across 2,500 square
miles (6,475 square kilometers).
Although hundreds of people died,
thousands of islanders living near
the volcano were evacuated.
Mount Pinatubo is just one of about
600 volcanoes throughout the world
that have had known eruptions
during recorded history. About 50 to
70 volcanoes erupt each year, making
these giant powerhouses one of the
most destructive forces on Earth. Not
IMAGE: U.S. Geological Survey
The eruption of the Mount Pinatubo volcano in the Philippines unleashed
a giant plume of material hundreds of miles across. The volcanic outburst on
June 15, 1991, was the second largest in the 20th century.
all of them reside in tropical climates
such as the Philippines. The largest
volcanic outburst of the twentieth
century occurred in Alaska, near the
Arctic Circle. The powerful blast from
Novarupta sent 3 cubic miles (12.5
cubic kilometers) of hot, liquefied
rock and ash into the air. Falling
ash measured more than a foot (0.3
meters) deep in a 3,000-squaremile (7,770-square-kilometer) area,
roughly the size of Delaware.
Continued, page 2…
www.nasa.gov
Continued from page 1…
The blast felt
around the world
Volcanic eruptions have
consequences beyond the regions
around them. They can also affect
the entire planet. The Mount
Pinatubo blast sent millions of
tons of pollutants into the air. Air
currents spread the particles around
the world, causing average global
temperatures to drop by roughly
1 degree Fahrenheit (0.56 degrees
Celsius) for about three years. The
dip in temperature was caused by
the layers of volcanic particles in
the atmosphere, which blocked
sunlight and cooled the planet.
Sulfur dioxide from the eruption
also enlarged the hole in Earth’s
ozone layer in the Antarctic.
Some volcanic eruptions have
caused crops to fail, creating
famines. Volcanic blasts also can
disrupt air travel. The outburst
from Iceland’s Eyjafjalkjokull
volcano in 2010 grounded airplanes
for several days as ash from the
eruption swept across Europe.
The volcano sits directly under the
jet stream, which carried the ash
into European airspace. The air
travel disruption was the largest
since the Second World War.
Io: The volcano capital of the
solar system
These violent outbursts are not
just confined to Earth. Scientists
have observed volcanic eruptions
on Jupiter’s moon Io.
Imagine living on a world roughly
the size of Earth’s moon where
volcanic eruptions are almost a
daily part of life. Welcome to Io, the
volcano capital of the solar system.
More active volcanoes reside on Io
2
Devastation
after Pinatubo
This town in the Philippines
was badly damaged by a
combination of the volcanic
eruption of Mount Pinatubo
and flooding from Typhoon
Yunya. Heavy rainfalls,
coupled with falling ash,
caused large mudflows,
which destroyed many
bridges and made travel
dangerous.
IMAGE: U.S. Geological Survey
Global effects of Mount Pinatubo eruption
IMAGE: NASA/Goddard Space Flight Center Scientific Visualization Studio
The map above represents the global distribution of sulfur dioxide and dust
particles from the Mount Pinatubo eruption. A computer model tracked particles
from the blast and found that it took less than three months to spread throughout
Earth’s atmosphere. The colors in the graphic represent the atmospheric height
of the particles. The blue dots are particles closer to Earth’s surface, while the red
dots represent the highest particles in the atmosphere.
than on any other world in the solar
system. Io’s surface is pockmarked
with active volcanic craters called
calderas. These hot craters thrive in
a world where the average surface
temperature is a frigid minus 202
degrees Fahrenheit (minus 130
degrees Celsius). The heat near the
volcanoes, however, can reach 3,000
degrees Fahrenheit (1,649 degrees
Celsius), hot enough to keep liquid
lava flowing. But once hot sulfur
dioxide ash from volcanic blasts hits
the moon’s surface, it turns to snow.
The Voyager 1 spacecraft was the
first observatory to discover active
volcanoes on the volatile moon in
1979. Since then, astronomers have
been using satellites, including
NASA’s Galileo spacecraft and
Hubble Space Telescope, and groundContinued, page 3…
The 2010 eruption of Icelandic
volcano, Eyjafjalkjokull
ICELAND
Eyjafjalkjokull
Atlantic
Ocean
Plume from
eruption
IMAGE: David Karnå
Eruption in progress: This view, taken from
Þórolfsfell mountain, shows the dramatic fireworks
of lava and ash produced by the eruption of the
Eyjafjalkjokull volcano in Iceland, on May 10, 2010.
Continued from page 2…
based observatories to monitor
Io’s turbulent, chaotic activity. The
satellites spotted about 150 active
volcanoes on Io. Astronomers,
however, think the moon may have
as many as 400 active volcanoes.
IMAGE: Jeff Schmaltz, MODIS Rapid Response Team
Plume from Eyjafjalkjokull eruption: This image, taken by
NASA’s Aqua satellite, was made only days after the eruption of
Iceland’s Eyjafjalkjokull volcano. Ash and a plume of material from
the blast are sweeping across the Atlantic Ocean and moving
into Europe. The wave of volcanic material impacted air travel in
Iceland for more than a month and in Europe for several days.
Voyager finds active volcanoes on
Jupiter’s moon, Io
Astronomers hit the jackpot
In 2013 astronomers struck a gold
mine when they witnessed three
volcanoes on Io blasting material
into space during a two-week
period. Astronomers observed two
of them on the same day in Io’s
southern hemisphere. Using the
W. M. Keck Observatory in Hawaii,
astronomers calculated that the
brightest outburst produced a lava
flow that was 30 feet (9 meters) thick
and spanned 50 square miles (130
square kilometers) — enough to
LOKI PATERA
Lava
Caldera
Lava
lake
This image of
Jupiter’s moon Io
from the Voyager
1 satellite shows
several lava flows and
calderas on Jupiter’s
moon Io. Calderas
are the centers of
volcanic activity.
The large black
region below the
center of the image
is the active lava
lake in Loki Patera,
the largest volcanic
depression on Io.
IMAGE: NASA/JPL/USGS
Continued, page 4…
3
Continued from page 3…
cover Manhattan Island, the heart of
New York City. The other eruption
produced flows covering 120 square
miles (311 square kilometers). Both
eruptions generated what looked
like “curtains of fire” as lava blasted
from long gashes in Io’s crust.
However, the third eruption two
weeks later from yet another volcano
was the most dramatic. The event,
captured by the Gemini North
telescope and NASA’s Infrared
Telescope Facility, both in Hawaii,
was brighter than the previous
two eruptions and hotter than any
volcanic eruption seen today on
Earth. Astronomers compared the
outburst to the destructive eruptions
on our planet when it was young.
A violent past
In fact, the rocky planets — those
planets closest to the sun — and
many moons in our solar system
show evidence of past volcanic
activity. Mercury contains ash
deposits. Mars is home to many
extinct volcanoes, including Olympus
Mons, the largest volcano in our
solar system. These features formed
millions of years ago when our
solar system was much younger
and its objects were much hotter.
Many recipes for
volcanic eruptions
Although volcanoes are plentiful
in the solar system, the forces
that produce them vary.
On Earth, the continents that make
up our planet are part of massive
“tectonic plates” located beneath
our planet’s surface. These plates
are always in motion, and volcanoes
typically form where they collide
or spread apart. Volcanoes can also
Continued, page 5…
Observations of volcanic activity on Jupiter’s volatile moon, Io
Two plumes of material rising from separate volcanic eruptions
appear in this image of Io, taken by the Galileo Orbiter. The first plume
from the erupting caldera, Pillan Patera, appears to have a blue color,
as it extends off the left edge of the moon. The second plume, from the
Prometheus caldera, is colored red and is near the center of the image.
The Prometheus caldera is marked by bright and dark rings. Two other
volcanoes, Surya Patera and Culann Patera, are also shown.
From the
Galileo
Orbiter
From the Gemini North Telescope, Hawaii
Surya
Patera
Prometheus
Reddish
plume
Culann
Patera
Plume
from
erupting
Pillan
Patera
IMAGE: NSF/NASA/JPL-Caltech/
UC Berkeley/Gemini Observatory
Simultaneous eruptions: This image, taken
in near-infrared light by the Gemini North
Telescope, reveals two of the three volcanic
outbursts that astronomers witnessed during
a two-week period on Io. The largest and
brightest blast appears at upper right; the
fainter outburst can be seen at the bottom
edge of the moon. A lava lake named Loki
is the bright spot in the middle of Io. The
outburst at upper right represented one of the
largest observed eruptions on Io, the most
volcanically active body in the solar system.
From the Hubble Space Telescope
IMAGE: NASA/JPL/University of Arizona
Pele volcano erupting: In 1996, the Hubble
Space Telescope observed a large plume
of material erupting from Pele, one of Io’s
most powerful volcanoes. The plume is
the wispy, red material extending from the
moon’s lower left edge.
IMAGE: John Spencer (Lowell
Observatory) and NASA
4
Continued from page 4…
occur at a “hot spot” in the middle
of a plate. Volcanoes form when
liquid rock, called magma, from
within the Earth travels up to the
surface. At the surface, the liquid
rock erupts to form lava flows
and ash deposits. The volcano
continues to grow, getting bigger
over time, as it continues to erupt.
Mercury’s varied surface
Io: The big squeeze
On Io, the volcanic activity is
driven by Jupiter’s powerful tidal
forces of gravity, which squeeze
the moon’s interior and heat it up.
Like Earth’s volcanoes, molten rock
is then forced through Io’s surface,
erupting as volcanoes. In fact, Io is
the only place in the solar system,
other than Earth, where active
volcanoes have been observed
ejecting extremely hot lava.
Io, however, has a lower surface
gravity than Earth. So material
can leave Io’s surface more easily
and travel far into space. For that
reason, many Io eruptions can
blast debris high above the moon.
One such eruption shot plumes
of material more than 300 miles
(483 kilometers) high, forming a
huge umbrella of hot material.
Mars: Land of the
giant volcanoes
The volcanoes on Mars were active
long ago and are now extinct.
These dead volcanoes, however,
are much larger than any volcano
on Earth. For example, Mars’
Olympus Mons, the largest volcano
in the solar system, is up to 100
times larger than Mauna Loa,
Earth’s biggest active volcano. In
fact, the entire chain of Hawaiian
Islands (from Kauai to Hawaii)
would fit inside Olympus Mons.
IMAGE: NASA/Johns Hopkins University Applied Physics
Laboratory/Carnegie Institution of Washington
This colorful view of Mercury, created with data taken by NASA’s
Messenger spacecraft, is not the gray appearance that the planet
presents to the human eye. Astronomers assigned the colors to show
the chemical, mineralogical, and physical differences between the
rocks that make up Mercury’s surface.
One reason for the Martian
volcanoes’ monstrous size is that
Mars does not have tectonic plates
beneath its surface that move the
way they do on Earth. On our planet,
as a plate drifts over a hot spot of
magma, a new volcano forms. As
the plate moves away, the volcano
is separated from the magma, stops
growing, and becomes extinct. The
hot magma, however, finds another
place in the surface to break through,
and another volcano is formed. This
process continues, creating a chain of
volcanoes, like those that formed the
Hawaiian Islands. Instead of building
one large volcano, the erupting lava
forms many smaller volcanoes.
The surface on Mars, however,
remains stationary over a hot spot
of magma, and the erupting lava
piles up in one place, making one
giant volcano. Olympus Mons
spans 374 miles (602 kilometers)
across at its base and reaches an
elevation of 16 miles (26 kilometers),
more than twice as tall as Mauna
Kea, a dormant volcano in Hawaii
that is Earth’s tallest mountain as
measured from its base, deep in
the Pacific Ocean, to its peak.
Like Io, Mars also has a lower surface
gravity than Earth, which helped
Continued, page 6…
5
Continued from page 5…
to produce tremendous eruptions
long ago. The lava flows on Mars
also lasted longer — many weeks
— and were more widespread, than
those on our planet. Observations
have captured a vast lava flow the
size of the state of Oregon on Mars’
surface. In fact, volcanic features
cover most of the planet’s surface.
The Martian volcanoes are extinct
because the planet’s core has
cooled. The volcanoes, therefore,
have no heat to power them.
Olympus Mons,
our solar system’s largest volcano
This Hubble Space
Telescope image of Mars
shows the largest volcano in
the solar system, Olympus
Mons. The giant extinct
volcano is the irregular circular
feature just above the center
of the image. Olympus Mons
is 374 miles (602 kilometers)
wide, as large as Arizona.
Its summit is about 16 miles
(26 kilometers) above the
surrounding plains. It is three
times higher than Mt. Everest
(see close-up, below).
Olympus Mons
Shaping our solar system
Volcanic activity has helped shape
the landscape of Io and our other
solar system neighbors. Spacecraft
that have flown by Io since 1979
have observed numerous surface
changes as a result of Io’s volcanic
activity. Material launched by
eruptions create large lava flows and
paint the surrounding surface of Io
in shades of yellow, red, white, black,
and green. The volcanic material also
is found in Io’s patchy atmosphere.
The smooth plains are dotted with
tall mountains, some rising higher
than Mount Everest in Nepal, one
of the tallest mountains on Earth.
Unlike other solar system worlds,
Io does not have any craters from
asteroid impacts. Scientists think that
new impact craters are buried by the
frequent flow of volcanic material.
Keeping watch
IMAGE: NASA, J. Bell (Cornell U.) and M. Wolff (SSI)
Close-up of Olympus Mons
Side view
Olympus Mons
Mt. Everest
Viking Orbiter 1’s view of Olympus Mons
Outline
of
Arizona,
to scale
Olympus Mons
Volcanoes are a tremendous force of
nature, but thanks to ground-based
observatories, space telescopes, and
Earth-observing satellites, scientists
have a better understanding of the
impact of volcanoes on Earth and
on our solar system neighbors.
Continued, page 7…
6
IMAGE: NASA/JPL-Caltech
This image of Olympus Mons was taken
in 1978 from the Viking 1 Orbiter satellite.
Continued from page 6…
Scientists use satellite observations
to keep vigil on volcanoes all over
our world. With their perspective
from space, satellites have a unique
view of changes to Earth’s surface
and atmosphere. Their heat-sensitive
detectors, for example, reveal when
and where lava appears, and help
scientists predict where the lava will
flow — alerting people to evacuate
when a volcano awakens near
towns and cities. Using satellites to
track the ash spewed by Iceland’s
Eyjafjalkjokull volcano in 2010,
scientists mapped the location of
the ash in the sky, keeping planes
and passengers out of harm’s way.
Satellite data also have helped
researchers develop new techniques
for monitoring eruptions. Scientists,
One month after the Pinatubo eruption
IMAGE: U.S. Geological Survey, July 1, 1991, by Willie Scott
Devastation: This desolate wasteland resembles a prehistoric landscape.
The image was taken of an area around the Mount Pinatubo volcano about
one month after the devastating eruption in 1991. A mixture of hot gas,
rock, and ash from the volcanic blast blankets the landscape, covering and
charring vegetation. The environmental impacts of this natural disaster lasted
for many years.
Continued, page 8…
Twenty-five years after Pinatubo eruption
Renewal: This view of
Lake Pinatubo in the
Philippines may look
like paradise, but 25
years ago this area
was far from serene.
Back then Lake
Pinatubo was actually
a crater where hot lava
erupted from under
the surface, exploding
as a volcano. The
devastating eruption
of Mount Pinatubo
was the second
largest in the 20th
century. Since
the 1991 blast,
the mountain and
surrounding area have
slowly sprung back
to life. Many tourists
visit the area, enjoying
the flourishing green
mountains and lake.
IMAGE: Chris Tomnong
7
Continued from page 7…
for example, used instruments and
techniques developed by studying
the eruptions of Mount St. Helens
in Washington and other volcanoes
in the 1980s to accurately predict
the Mount Pinatubo outburst. By
forecasting the impending eruption,
scientists warned people living in the
volcano’s shadow to move to safety,
which saved thousands of lives.
Although our solar system neighbors
are far away, astronomers are using
space-based and ground-based
observatories to monitor geologic
activity produced by active volcanoes
on these nearby worlds.
From death to life
The saying “time heals all wounds”
is certainly true regarding the
destructive power of volcanic
eruptions on Earth. Falling ash,
flowing lava, mudslides, and deadly
gases create a wasteland around
the erupting volcano, wiping out
towns, tearing apart highways, and
killing wildlife and vegetation. In
time, however, life begins to take
hold again. Mount Pinatubo, for
example, is green again 25 years
after the huge eruption, and its
volcanic crater has become a lake.
More than 3,000 tourists a year
climb the volcano and enjoy the
beautiful view or swim in the
lake. In Hawaii, coffee plantations
thrive in the rich soil produced by
lava flows from Mauna Loa, the
world’s largest active volcano.
SEE MORE Hubble images and read more
Star Witness news stories at Amazing Space,
NASA’s award-winning educational website for
K­­­–12 students and teachers.
http://amazingspace.org/news
www.nasa.gov