Transcript Iceland: Fire and Ice

Iceland: Land of Fire and Ice
Sitting Astride the Mid-Atlantic Ridge
The only place where the Mid-Atlantic
Ridge rises above sea level.
The Mid-Atlantic Ridge (Divergent
tectonic plate boundary) attracts
tourists.
Volcanic Activity
• Volcanic eruptions are far more frequent on
convergent tectonic plate boundaries
(Cascade Mountain Range & the Andes) than
on divergent tectonic place boundaries
(Iceland); however, eruptions do occur along
divergent boundaries. Recently and eruption
broke through the icecap in Iceland.
Iceland’s Eruptions
• Ash and roughly thirty-story-tall lava fountains shoot
from a half-mile-long (0.8-kilometer-long) rupture in
the icy cap of southern Iceland's Eyjafjallajokull
(pronounced AY-uh-full-ay-ho-kul) volcano early
Sunday.
• The geology of Iceland, though, is anything but
normal. The volcanic island lies just south of the
Arctic Circle atop the Mid-Atlantic Ridge, where two
tectonic plates are forever pulling apart. Magma
from deep inside Earth rushes upward, filling the
gaps and fueling Iceland's volcanic eruptions, which
occur about once every five years.
• From a different angle, Eyjafjallajökull's
"lavafall" appears unobstructed by billowing
steam, revealing the glowing yellow ribbon
cascading down the rocky gorge on March 26,
2010.
• Lava spraying high into the air draws crowds of tourists to
Iceland's Eyjafjallajökull volcano on March 27, 2010.
When the eruption started on March 21, hundreds of
people were evacuated from their homes, due to fears of
flooding, which could have occurred, had the volcano's
heat melted too much surrounding glacial ice.
Cooling lava flows
Tourists check out the cooling lava
Comparison
• These eruptions tend to be much less violent
and destructive than those of strato-volcanoes
that form near convergent boundaries.
• 1980 when Mt. St. Helen erupted in the
Cascade Mountains, nearly half of the
mountain was blown away.
• In Iceland the magma comes up to fill in a gap
created by the separating of the two tectonic
plates.
• Not far from Eyjafjallajokull glacier, the much
larger Mýrdalsjökull glacier (check the map on
the next slide) hides the fiery, gently sloping
Katla volcano that lies under the ice.
Eruptions on Iceland
Krafla Volcano - Iceland
An incandescent basaltic lava flow winds its way downslope from a vent at Krafla
volcano in Iceland in 1984. The flow originated from an 8.5-km-long fissure that
was initially active along its entire length. The fissure was produced by rifting along
the mostly submarine Mid-Atlantic Ridge where it rises above sea level and cuts
across the island of Iceland, forming an accessible natural laboratory for studies of
episodic eruptions at this oceanic spreading ridge.
Iceland Info.
• Area: 103,000 sq km
• Coastline: 4,970 km
• Terrain: mostly plateau interspersed with
mountain peaks, icefields; coast deeply
indented by bays and fiords
• Land use:
– arable land: 0.07%
– permanent crops: 0%
– other: 99.93% (2005)
• Natural resources: fish, hydropower,
geothermal power, diatomite
Demographic s
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Population: 306,694 (July 2009 est.)
Age Structure: 0-14 years: 20.7%
Population growth rate: 0.741% (2009 est.)
Urban population: 92% (2008)
Infant mortality rate: 3.23 deaths/1,000 live
births
• Life expectancy at birth: 80.67 years
• Adult literacy: 99%
Economy
• GDP - per capita (PPP): $39,800 (2009 est.)
– $42,800 (2008 est.)
– $42,600 (2007 est.)
• GDP - real growth rate: -6.3% (2009 est.)
– 1.3% (2008 est.)
– 5.5% (2007 est.)
• GDP - composition by sector:
– agriculture: 5.2%
– industry: 24%
– services: 70.8% (2009 est.)
Reykjavik –Capital City
Reykjavik
Roundup of Icelandic horses
The Gullfoss (Golden Falls) Waterfall in
southern Iceland.
An eruption of the geyser Strokkur.
A river with volcanic black sand banks meanders to
the sea through farm fields near the southern coast of
Iceland.
Looking across the plate boundary from
the European Plate to the N. American