Eldfell is an active stratovolcano that is located in Iceland on the island of Heimaey, in the Vestmannaeyjar archipelago. It reaches an elevation of 656 feet and was created during a volcanic eruption on the east side of the island in 1973. Its name means Mountain of Fire in the Icelandic language. Iceland is an area with a high frequency of volcanic activity because it is located on top of the Iceland hotspot and beside the Mid-Atlantic Ridge. So many eruptions occur here that it is thought that a third of all basaltic lava in the world has been produced in and around Iceland.

On the 21st of January in 1973 small tremors were recorded around the island, but these were not strong enough to be felt by inhabitants. Although over one hundred tremors were detected by the morning of the 22nd, they were not uncommon to the area, so an eruption was not thought to be threat. The eruption began with the opening of a fissure on the eastern side of Heimaey that quickly moved across the island and comprised an area of 1.2 miles. Lava fountains reaching 492 feet emitted from the fissure, but activity quickly moved to the vent of the emerging volcano. A cone reaching 330 feet in elevation was formed in the first two days of the eruption and the cone was completed by February 18th of 1973.

The entire island of Heimaey was evacuated the morning the eruption began due to lava flows that were already moving into a nearby city and the threat of ash-fall, which could cover the entire island. Those where not evacuated by boat were evacuated by plane and nearly six hours after the eruption began, almost all of the inhabitants were evacuated. All of the cattle, sheep, and horses were slaughtered to prevent their deaths by lava flows and other volcanic activity and those people who remained also gathered items from threatened homes and to preform essential functions.

Many structures were destroyed by lava flows while others were flattened by heavy ash fall or by explosive lava bombs. However, many homes were saved by crews working to clear the ash and board windows. The lava flows were moving on land and underwater by February and were quickly becoming a threat to the harbor, which held the boats that gathered fish as the island’s main source of income. This was the largest threat to the island, despite the destruction the eruption had already caused, and efforts to slow the lava were attempted.

The first attempt to slow or stop the lava consisted of spewing sea water onto the oncoming flow, which worked surprisingly well, although most of the water was turned into steam. This attempt showed that the process could be successful. The next attempt consisted of spraying more water onto the flows at a higher rate as well as building pipes over the flows to release as much water as possible over the largest possible area. These efforts ended on July 8th of 1973 and the eruption lasted for a total of five months.

After the eruption, scientists began experimenting with the possibility of using the geothermal heat from inside of the hardened lava to heat houses. Eventually, five plants were built to extract this energy, which was used to heat many structures and provided hot water to almost every house on the island.  The tephra left behind from the eruption was used to elongate the island’s airport runway and used as landfill where new homes were built. The eruption caused the cone of the volcano to rise above the ocean about 720 feet, but slumping, erosion, and other natural causes have caused it to decrease in elevation. The island is now popular among tourists who can travel to the volcano by ferry and hike trails along its slopes.

Image Caption: The volcanic mountain of Eldfell against a white sky. Credit: michael clarke stuff/Wikipedia (CC BY-SA 2.0)