Surtsey
Birth of an Island
Written by Deborah T. Sycamore
Contents Birth of Surtsey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 Volcanic Formations . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . .5 A Living Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 A Shrinking Island . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . .11 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Birth of Surtsey
What would it be like to witness the birth of an island? In November of 1963, an underwater volcano erupted off the
coast of Iceland. It gave scientists a rare opportunity to observe what happens when new land is formed. On and off,
the eruption lasted for nearly four years, with fiery lava flows, explosions, massive clouds of steam, and black smoke
seen for miles. Scientists from all over the world traveled to Iceland to observe the birth of this new landmass. The
new island was named Surtsey (SUHRT-see)— after Surtur, a Norse god of fire in Icelandic mythology. Surtsey
offers the world an opportunity to see the forces of nature at work.
Early on the morning of November 14, 1963, local fishermen observed black smoke and steam clouds rising from the
ocean, about 20 miles off the southern coast of Iceland. The captain of the boat thought, at first, that another boat
was on fire. He drew closer to help. However, it was not a boat that was on fire; it was the ocean itself. An
underwater volcano had been gradually building almost 400 feet below the ocean waves. All the smoke, fire, and
boiling water announced the arrival of the volcano’s rim as it broke through the ocean’s surface.✱
As Surtsey erupted, seawater spilled into the main vent. The eruption became more violent as the seawater came into
contact with the molten rock, or magma. The captain of the fishing ship reported lava bombs, some the size of small
cars, being tossed thousands of feet into the air. Some landed in the water near his boat. Towering clouds full of rock,
cinder, ash, and steam were seen for miles. These airborne volcanic materials are called tephra (TEHF-ruh). Within
approximately two hours of Surtsey’s eruption, dark columns of ash and smoke rose to 11,500 feet at a rate of 330 feet
per second. At one point, the tephra columns skyrocketed nearly 4 miles into the sky!
Columns of tephra, or volcanic ash, rocketed almost 4 miles into the sky.
Where Is Surtsey?
Iceland
Surtsey
Greenland
AlaskaAlas
ka
Canada
N
Glossary
adverse
difficult or harmful
barren
having few or no plants
cinder
partly burned material
At night, the ongoing eruption lit up the sky and could be seen for miles. Villagers reported a strong sulfuric odor,
similar to the smell of rotten eggs, as well as volcanic ash falling like rain onto their homes. It was often difficult to
see exactly what was happening due to the thick fog, smoke, and steam surrounding the volcano. Nine days after
Surtsey first erupted, a large explosion created a 130-foot-high mountain that blocked the seawater from rushing into
the magma vent. Lava flowed from the cinder cone without any interference from the sea and covered the surface
with a hard crust as it cooled. Surtsey the volcano soon became Surtsey the island.
Within a year of the first eruption, a second eruption on Surtsey formed another cinder cone. All eruptions came to a
halt in 1967. Finally, Surtur 1 and Surtur 2, the two major vents on Surtsey, ceased to erupt and slowly became coneshaped craters. Surtsey rose to more than 950 feet above the ocean floor (about the height of a 60-story building).
Nearly 560 feet of the volcano now rises above the surface of the water. This additional height above the ocean allows
Surtsey to survive as an island because the volcano has built up a cone that is large enough to keep the seawater out
of its crater. Over the course of four years, Surtsey grew to about 2 square miles in size.
An aerial view captures the two major vents on Surtsey: Surtur 1 and Surtur 2.
Volcanic Formations
Surtsey and the main island of Iceland have much in common. Both were created by geologic processes involving
plate tectonics. The theory is that the outermost section of Earth’s shifting crust is made up of plates that move in
relation to one another to form new ocean crusts and to stimulate volcanic eruptions. Earth is a sphere made up of
many layers. The lithosphere (LITH-uh-sfeer) is the rigid outermost layer of Earth. It includes the crust and the
uppermost part of the mantle. It is made up of multiple floating plates. These plates are constantly in motion. Some
move apart, others move over or under one another, and some plates collide against one another. The asthenosphere
(as-THEN-uh-sfeer) is the thin part of Earth right below the lithosphere. It includes part of the lower mantle. Here’s
where the lithosphere plates float like puzzle pieces.
Earth’s Layers
Lithosphere Asthenospher
The area where the islands of Iceland and Surtsey are located is one of the most volcanically active places on Earth.
Both islands straddle the Mid-Atlantic Ridge—a volcanic underwater mountain range that stretches nearly to
Antarctica, where two plates meet and move in opposite directions. Volcanic activity is quite common in places where
the plates pull apart. Magma forces its way to the surface and flows from vents that open along an underwater tear
between the two plates. This process is known as seafloor spreading. The magma starts to cool on contact with the
cold seawater. Molten debris continues to rise from the ocean floor, slowly becoming a mass of new rock, on which
magma continues to pour from Earth’s mantle. This is how Iceland and Surtsey were formed.
On Surtsey, the primary rock type is basalt (buh-SAWLT), which is formed from runny lava. Typically, it’s a very
fine-grained rock, due to the rapid cooling process. Gas bubbles are often trapped in the basalt as it cools to form tiny
air pockets—just like a sponge. Pillow lava is commonly found on Surtsey. This type of rock develops when molten
lava separates into clumps and rolls around underwater on the ocean floor. As the lava cools, these clumps build on
one another and cool down from the outside to the inside, similar to a toasted marshmallow.
Unusual rock formations can be found on Surtsey as a result of all the volcanic activity there.
There are places throughout Surtsey where the ground is still very warm. Gas vapors and steam still rise from the
vents. Birds find the steam-warmed rocks good places to roost.
A Living Laboratory
Surtsey is an ideal place to observe and document how life develops and survives on a barren, new land. As a unique
living laboratory, the new island is off-limits to visitors. Scientists need special permission from the government of
Iceland to visit Surtsey. This restriction allows the island to evolve without any human interference. The first plants
were carried to Surtsey as seeds by wind, waves, and migrating birds.
Biologists observe and measure clusters of sea sandworts.
Surtsey’s steep lava cliffs are home to many species of birds.
Sea rockets were the first sprouting plants to be observed on the island. Another type of plant gaining ground on the
outer slopes of the island is the sea sandwort. This is a tough, flowering plant that produces seeds that can float in
salt water for long periods of time. It grows low to the ground and forms thick clumps that are able to withstand
gusty winds. Mosses are found in Surtsey’s craters, where there is protection from the wind, and sea grasses are
found at the base of the tall cliffs.
Flies were the first animal species recorded on the island, followed by seals and seabirds. The seals migrate every
spring to the rocky shoreline to feast on fish and to rest. Surtsey’s spectacular lava cliffs are habitats for many
species of birds, such as gulls, guillemots, fulmars, and puffins. These birds construct nests in the cliffs in order to
protect their young from strong winds and adverse weather conditions. It is not uncommon to observe thousands of
birds at one time. Over 60 species of birds have been recorded on the island. Some are just passing through on their
annual migration; others have chosen to make Surtsey their permanent home. Scientists wonder which birds and
animals will come next and which will stay for many years to come. Only time will tell.
A Shrinking Island
Today, Surtsey is a little more than one square mile in size. Powerful ocean waves and strong southwesterly winds
have eaten away, or eroded, the little island. Scientists believe that the weight of the volcano caused some of the land
to disappear under the waves. However, these natural forces add to Surtsey’s character— forming long stretches of
black, sandy beaches, rounded boulders, and dramatic cliffs. At this rate of erosion, scientists calculate that this new
island will be visible for another 100 years.
Unusual rock formations can be found on Surtsey as a result of all the volcanic activity there.
Where Is Surtsey?
Iceland
Surtsey
Greenland
AlaskaAlas
ka
Canada
N
Glossary
adverse
difficult or harmful
barren
having few or no plants
cinder
partly burned material
cinder cone
craters
a volcanic shape formed when dust, ash, and
rock blast out from a vent in the ground and
settle to form a cone-shaped volcano with steep
sides and a narrow base
hollow areas that are shaped like a bowl at the
mouth of a volcano
crust
the solid, rocky, outer layer of Earth
debris
the broken, scattered remains of something
geologic
lava bombs
mantle
having to do with Earth’s crust, layers, and
rocks
large fragments of molten rock that blast out
of a volcano during an eruption
the thick layer of Earth that lies below the