Fernandina, Galapagos Islands
- Fernandina Profile
Chuck Wood took this picture in 1979 while sailing around Fernandina
island. The lava flows are clearly seen on the sides of the volcano
and along the shore.
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- The Jan-Feb, 1995 eruption:
On Jan 25, sailors reported a red glow over Fernandina, the most active
of The Galapagos volcanoes. A group of interested people immediately
set sail to Fernandina and discovered that lava was flowing from a crack
in the ground (such cracks are called fissures). The new lava flowed
about five kilometers and entered the sea. By the 28th of September,
small clots of lava thrown up around the fissure had built a spatter
cone 20-30 m high. A plume or cloud of steam and ash particles rose
3-4 km above the cone.
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- Observations of a red glow over the caldera
at the top of Fernandina during the first night, and later discovery
of other fissures and fresh lava between the spatter cone and the caldera
suggests a story for how the eruption developed. Perhaps the eruption
started inside the caldera (explaining the red glow seen early on).
Then a crack or fracture allowed lava to escape along the line of fissures.
Finally, the eruption concentrated at the lower fissure where a cone
was built. And lava continued to pour into the sea at least until mid-February.
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- Fernandina Island
This picture of Fernandina was taken by a Space Shuttle crew in the
1980s. Everything on the island is volcanic - the lava flows are shades
of blue. The X on the bottom left side shows the approximate location
of the 1995 eruption site.
- One of the sad things about the eruption
is that many birds and fish were killed. The heat from the lava entering
the sea killed fish, and then seabirds who dived into the water to eat
the fish were scalded to death.
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- Background on the Galapagos Islands
- A thousand kilometers west of Ecuador
is a volcanic chain called the Galapagos Islands. These Pacific Ocean
islands are famous because the British scientist Charles Darwin visited
them in the 1830s. It was Darwin's studies of the Galapagos finches
and other birds and animals that led him to his famous theory of evolution.
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- Although the Galapagos includes nearly
a dozen islands, most of the volcanic activity during the last few hundred
years has occurred on two islands, Isabela and Fernandina. Isabela is
shaped like a seahorse and contains five and a half large shield volcanoes.
The half volcano is Ecuador (the name of a volcano, not the country!),
whose western half has apparently collapsed into the ocean.
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- The Galapagos Islands have been built
entirely by volcanism, and about 60 previous eruptions have been recorded
over the last 200 years, so it is not surprising that another eruption
has occurred. But the surprise is where the eruption happened. Although
many Galapagos eruptions have been in and around the large calderas
on top of the shield volcanoes, the activity that started Jan 25 was
from a vent far down the flank of Fernandina, near the sea. The last
time this occurred at Fernandina, in 1968, there was a huge collapse
of the floor of the caldera - it fell more than 350 meters. The new
eruption has not caused another collapse, so far.
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