Iceland's unique features
two dozen volcanoes erupting regularly, Iceland is the most
geologically active place on the planet. It's also home to the
original "geysir," and is the meeting place of two
of the Earth's major geological plates.This
map and the text below will give you a brief look at Iceland's
fascinating geology. You can also read more about Icelandic
volcanoes, or learn how to make your own geyser
is the only place on Earth where the meeting of two tectonic plates
occurs above sea level. This ridge is the source of the island's
volcanic activity. Magma from the Earth's core pushes up through
the area around the ridge, creating lava flows that continue to
add to Iceland's landscape.
Located near the small town of Haukadalur, the "Great Geyser"
used to regularly spout plumes of superheated water and steam as
high as 60 to 80 meters. The English word "geyser" is
derived from the Icelandic "geysir," which means "gusher."
Though the Great Geysir is now relatively dormant, it sits amidst
a geothermal park that resembles Yellowstone, with its hissing steam
vents, belching mud pots and burbling springs. For more on Geysir,
check out the South Iceland travel bureau's page at www.south.is/geysir.html.
In 1998, this volcano erupted, spewing ash up through Vatnajokull
glacier, miles into the sky. Grimsvotn is one of several unusual
volcanoes in Iceland: rather than a mountainous cone, this volcano
is actually a fissure hidden under a monstrous glacier. Other eruptions
under the glacier have melted massive amounts of ice and resulted
in floods and washed out roads and bridges.
The most prominent volcano in Iceland, Hekla is a large, elongated
mountain cut through the middle by a 5.5 kilometer fissure. Lava
and ash often flow along the entire length of the fissure during
eruption. Ash and lava from eruptions as far back as 1104 can be
found all across Iceland, which can be used to date eruptions around
the island. Hekla's 1104 eruption was one of the largest in Iceland's
Two of this century's most notable eruptions have come from this
chain of volcanic islands. In 1963, an eruption began from the ocean
floor. By the time it stopped in 1967, a new island, which was named
Surtsey, had formed off the southern coast of Iceland. Then, in
1973, a major eruption occured on the island of Heimaey. Spectacular
curtains of fire and continuous lava fountains flowed for the first
three days, and hundreds of homes were buried under ash and lava
bombs. Inhabitants of the island fended of total destruction of
Iceland's major port by dowsing the lava flows with cold water.
For more on this major event in Iceland's recent history, see the
USGS publication "Man