Life on a Hotspot: Eruption on Heimaey, January 23, 1973
Iceland's
Existence is a Result of it's Unique Geologic Setting and the Active
Tectonics that Continue to Shape it .
This setting also contributes to the islands violent nature. One of
the most destructive volcanic eruptions in the history of Iceland
began in the early morning of January 23, 1973, near the Nation's
premier fishing port, the town of Vestmannaeyjar, on the island of
Heimaey.
The 1973
eruption began just before 1 a.m., January 23, on the eastern side of
Heimaey, approximately 1,100 yards from the center of town. A
north-northeast-trending fissure rapidly opened to a length of about
1.25 miles, traversing the island from one shore to the other. Spectacular continuous lava fountains played in the initial phase of
the eruption, but the activity soon consolidated to a small area along
the fissure about one-half mile northeast of Helgafell. Also during
the first 3 days, submarine volcanic activity occurred just offshore
at the north and south ends of the fissure vent. Within 2 days a
cinder-spatter cone rose more than 110 yards above sea level and was
later named Eldfell or "fire mountain" by the official Icelandic place
name committee. The output of lava and tephra was estimated to
be about 130 cubic yards per second. Within a few days after the
eruption, strong easterly winds resulted in a major fall of tephra on
the town of Vestmannaeyjar, completely burying homes close to Eldfell.
By early February the tephra fall slackened markedly, but a massive
lava flow approached the eastern edge of the town and threatened to fill
in the harbor of Iceland's most important fishing port. This was
averted due to
lava-cooling operations on the island. Also in early
February submarine activity just north of the
fissure severed an electric power cable and a water pipeline which
supplied electrical power and water from the Icelandic mainland.
See Figure. (Modified from Williams and Moore, 1976 a, b and
1983, and the National Land Survey of Iceland, 1979.)
The
eruption stopped in early July 1973; flowing lava was no longer
visible, although hidden subsurface flow may have continued for a
while. ... According to preliminary estimates about 300 million cubic
yards of tephra were deposited on and adjacent to Heimaey.
The
prolonged destruction related to the course of the eruption was
twofold: the highly visible destruction of homes, public buildings and
installations, commercial properties, and partial infilling of the
harbor by tephra falls and lava flows; and the economic and social
impact on the residents of Vestmannaeyjar, local commerce, and the
national and international economy of Iceland.
From: Williams, Jr., and Moore,
Man Against Volcano: The Eruption on Heimaey, Vestmannaeyjar, Iceland:
USGS General Interest Publication, 32p.
The 1973
eruption began just before 1 a.m., January 23, on the eastern side of
Heimaey, approximately 1,100 yards from the center of town. A
north-northeast-trending fissure rapidly opened to a length of about
1.25 miles, traversing the island from one shore to the other. Spectacular continuous lava fountains played in the initial phase of
the eruption, but the activity soon consolidated to a small area along
the fissure about one-half mile northeast of Helgafell. Also during
the first 3 days, submarine volcanic activity occurred just offshore
at the north and south ends of the fissure vent. Within 2 days a
cinder-spatter cone rose more than 110 yards above sea level and was
later named Eldfell or "fire mountain" by the official Icelandic place
name committee. The output of lava and tephra was estimated to
be about 130 cubic yards per second. Within a few days after the
eruption, strong easterly winds resulted in a major fall of tephra on
the town of Vestmannaeyjar, completely burying homes close to Eldfell.
By early February the tephra fall slackened markedly, but a massive
lava flow approached the eastern edge of the town and threatened to fill
in the harbor of Iceland's most important fishing port. This was
averted due to
The
prolonged destruction related to the course of the eruption was
twofold: the highly visible destruction of homes, public buildings and
installations, commercial properties, and partial infilling of the
harbor by tephra falls and lava flows; and the economic and social
impact on the residents of Vestmannaeyjar, local commerce, and the
national and international economy of Iceland. 