By Susan Huff
Turbulent seas and severe storms made it unsafe for fishing, so almost the entire fishing fleet of 60-70 fishing ships lay in the harbor at Vestmannaeyjar. The occupants of the island of Heimaey slumbered away in a deep winter's sleep when they were awakened in the early morning of 23 January 1973 around 2:00 a.m. by fire engines' sirens sounding their alarms. A volcanic eruption had begun on the island without warning. This was the beginning of Iceland's largest natural disaster in recent history--the eruption of the Eldfell (Hill of Fire) volcano.
Volcanic activity is integral to Iceland. Iceland lies astride the Mid-Atlantic Ridge, where the North American and Eurasian Plates are moving apart. The Vestmannaeyjar archipelago, or island chain, lies off the south coast of Iceland, consisting of 15 islands and 30 skerries (small rocky islands) and sea stacks--all formed by eruptions. Heimaey (Home Island) is the only settlement on Vestmannaeyjar (also known as the Westman Islands) that is inhabited year-round. Because there are few good harbors along the southern coast of Iceland and because the waters in the south are rich fishing grounds, the harbor at Vestmannaeyjar has consistently been the center of Iceland's fishing industry. Vestmannaeyjar is important to the economy of Iceland.
Within six hours of the eruption's onset, almost all of the island's 5,300 inhabitants had been evacuated to the mainland by boat. Some people remained behind to try to save belongings from threatened houses and to perform essential functions. A few people who were unable to travel by boat--mostly the elderly and hospital patients--were evacuated by air. Planes were sent from Reykjavik and Keflavik to assist. By the end of the day, all evacuees were spread around the mainland--housed by family, friends, and strangers.
Back at Heimaey, the eruption continued. A fissure 300 meters in length had opened up at about 1:55 a.m. on January 23 on the eastern side of the island, about a kilometer from the center of town. The fissure rapidly expanded to the length of 2 kilometers, crossing the island from one shore to the other. Spectacular lava fountaining (curtains of fire) 50 to 150 meters high occurred all along the fissure for the first few hours of the eruption, but then the eruption became concentrated in one vent about half a mile from the old volcanic cone of Helgafell, just outside the eastern edge of the town.
Within two days, the lava flow had built a cinder cone over 100 meters (330 feet) high. The thick lava flow moved slowly and relentlessly toward the north, northeast, and east of the island.
In addition to the lava flow, the island was threatened by tephra fall (small rock fragments ejected from the volcano). Houses close to the rift were soon destroyed by lava flows and tephra fall. Lava bombs and advancing lava destroyed some houses as they set fire and burned the houses. Many houses were destroyed by the weight of the ash fall, but crews of volunteers worked to clear ash from roofs and board up windows, which saved many houses. By the end of January, tephra covered most of the island, reaching depths of 16 feet in some places.
By early February, the tephra fall had stopped, but lava flows continued and caused serious damage. The greatest threat was the lava flow toward the harbor. Losing this harbor would not only have a significant impact on the fishing industry at Vestmannaeyjar but on the economy of Iceland as a whole. Previous attempts to slow lava flow with sprayed water had been tried in Hawaii and Mt. Etna on a much smaller scale and with limited success. However, Þorbjörn Sigurgeirsson, professor of physics at the University of Iceland's Science Institute, had conducted his own experiments as the new volcanic island of Surtsey, Vestmannaeyjar was formed between 1963-1967. Water was sprayed onto the lava flow that was advancing into the lagoon near the scientific observation hut.
Professor Sigurgeirsson proved that advancing lava flow could be impeded by cooling with seawater and prematurely solidifying the advancing lava-flow front. He became a strong proponent of spraying seawater on the lava flow at Eldfell to prematurely cool the lava flow, with the idea that the congealed lava would create a barrier to the upstream lavas, thus sparing the harbor and preventing further damage to the structures in the town. His persuasive efforts resulted in a lava-cooling operation that began on 7 February 1973 and ended on 10 July 1973 when lava stopped flowing from Eldfell.
The first attempt to slow the lava flow was made by firemen from the fire department at
Vestmannaeyjar two weeks after the volcano started erupting. They began spraying seawater on the headwall of the creeping lava, and this seemed to have some effect. More powerful pumps and increasing numbers of pumps were ordered from the mainland of Iceland. These pumps were not powerful enough to reach the top of the lava edge. It was not possible to get the hoses closer because the lava edge was steep, hot, and constantly moving.
Photo - U.S. Geological Survey.
On March 1, the dredging boat Sandey arrived and began spraying seawater on the
lava flow. This was perfect timing because at this same time, a large chunk of the new
mountain wall broke loose and was being carried by the lava flow toward the harbor.
The Sandey did its job and the lava tongue was cooled which prevented the large
chunk from continuing toward the harbor. But it was determined if the lava flow was
to be stopped, more powerful pumps were needed. A formal request for assistance was made and two weeks later, on March 26, the first delivery of pumping equipment came by air from the United States. In total, 32 pumps arrived from the United States with the necessary pumping capacity to stop the lava flow. The volcanic eruption produced a new mountain 220 meters (720 feet) high.
During and after the Eldfell eruption, a massive cleanup and restoration effort was necessary to remove ash and tephra. But there were some benefits from the volcano:
-One square mile of new land was added to the island, increasing its size by 20%.
-The harbor entrance was considerably narrowed by the lava flow but was not closed off. The narrowing of the harbor entrance by the new lava flow actually improved the shelter provided by the harbor and provided a breakwater.
-After the eruption halted and residents began returning to Vestmannaeyjar, they used the heat from the cooling lava flows to provide hot water and to generate electricity.
-Some of the tephra was used to extend the island's small airport runway and as landfill upon which 200 new houses were built.
-The cooling and hardening of lava flow by spraying the advancing lava flow with seawater became the most ambitious program ever attempted by man to control volcanic activity and minimize damage. This experiment was of significant importance to other communities that may be threatened by damage from volcanoes.
Only about 2,000 residents initially returned to Vestmannaeyjar after the Eldfell eruption. Even after 50 years since the evacuation of the island, the current population of 4,135 has not reached the 1973 population of 5,300. According to the city's website, about 400 current inhabitants are foreigners and about half of those are from Poland.
Vestmannaeyjar has returned to a thriving fishing community that requires a much smaller labor force. Now ships are larger and more technologically advanced, and production has moved from land-based freezing installations to factory ships. Vestmannaeyjar is a laboratory for geologists and a major tourist attraction.
On this 50th anniversary of the volcanic eruption at Vestmannaeyjar, it is a good time to reflect on the perseverance, courage, fortitude, and ingenuity of Icelanders as they responded to this natural disaster, with help from foreign friends.
Jónsson, Valdimar Kr. & Matthíasson, Matthías (1973). Lava-Cooling Operations During the 1973 Eruption of Eldfell Volcano, Heimaey, Vestmannaeyjar, Iceland. U.S. Geological Survey. Retrieved 3 December 2022.
Trønnes, Reidar G., "Geology and geodynamics of Iceland" Nordic Volcanological Institute, University of Iceland. Retrieved 3 December 2022.
Williams, Richard S., Jr. & Moore, James G. (1983). "Man Against Volcano: The Eruption on Heimaey, Vestmannaeyjar, Iceland (2nd Edition)" U.S. Geological Survey. Retrieved 3 December 2022.