Eyjafjallajokull is a relatively small volcano in a chain of Icelandic volcanos near the Arctic Circle. There is evidence that, since at least the seventh century, the more than mile high volcano has erupted periodically to spew ice, ash, toxic gasses, and boiling water over the surrounding territory and emit a plum of gasses and solid particles into the upper atmosphere.
As the plum travels around the world , and is subjected to temperature and other atmospheric changes, contents are released in varying amounts upon the general population. Reports of reactions to the fall-out have always been present, but as science has advanced, reports have become more specific and descriptive.
Historically, the disturbance of Eyjafjallajokull signals an eruption of its larger and more violent neighbor, Katla (The Dragon). The last time Eyjafjallajokull spoke, prognosticators were not disappointed.
Prior to 2010, Eyjafjallajokull last erupted in March, 1821, and the volcanic activity continued until 1823, when Katla blew up.
This series of Eyjafjallajokull eruptions began with a minor episode in 1821. Ash containing a large fraction of fluoride was released.
Additionally, relatively small glacier runs and light flooding of nearby rivers developed. Before the eruptions ended in 1823, flooding had become extreme and destructive.
A second series of explosive eruptions began near the end of December, 1821, and lasted several days. Deposits of the dark gray ash, containing from 28-40% silicon dioxide, can still be found in many regions of the southern portion of Iceland.
Silicosis is a possible result of long-term exposure to this substance. A specific relationship between silicosis and the 1821 eruptions is unclear, but there is no doubt that respiratory distress and all the hazards characteristic of a heavy ash fall were present.
Relative quiet ensued until the beginning of August, 1822, when explosive eruptions intensified with significant ash fall to the far north and southwest areas of Iceland.
From August to December, volcanic activity subsided, but local farmers began to attribute the death of cattle and sheep in the area to poisoning from the eruption. Modern analysis has identified the cause of these deaths as fluoride poisoning.
When the craters of Eyjafjallajokull were explored in early 1823, a fissure vent near the summit caldera was discovered. It was not long thereafter that Katla erupted and columns of steam were seen on the summit of Eyjafjallajokull.
From afar, Eyjafjallajokull and Katla are two of a chain of gracefully beautiful mountains at the base of the Arctic Circle. It is believed that the two volcanoes exploded at the same time in 1823, but, mainly because they are remote and capped by glaciers, there is much to be learned about their activity, chemistry, and emissions.
