In 2010, a large volcanic eruption made headlines all across Europe. As the explosive eruption
continued, millions of tons of ash was ejected high into the atmosphere, and spread out over
millions of square kilometers to the east. This made it unsafe to fly aircraft. As a result,
more than 100,000 flights were cancelled, and about $5 billion in revenue was lost across
the continent. The volcano which caused this severe economic disruption was the
Eyjafjallajökull volcano in southern Iceland. This video will discuss this volcano,
its 2010 eruption, and mention what its future hazards are.
The Eyjafjallajökull volcano can be found in the south central portion of Iceland. Specifically,
it is 120 kilometers east-southeast of the national's capital, Reykjavik.
The reason why this volcano exists, along with others in Iceland is quite unusual.
You see, Iceland is split right down the middle by what is called a mid ocean ridge. Mid ocean ridges
are responsible for about 75% of the world's volcanic activity. They represent two plates
spreading apart, where new lava is erupted in the middle thus forming new crust. Normally, mid
ocean ridges are at great depth. However, there is also a mantle hotspot in the area. Since the mid
ocean ridge represents the thinnest part of the nearby crust, lava erupts in excess from around
the ridge thus forming Iceland and its volcanoes. The Eyjafjallajökull volcano began forming 800,000
years ago, when a series of basaltic eruptions began. These early eruptions resembled the
volcanic activity which you see in the Hawaiian islands today. Over the next several hundred
thousand years, numerous eruptions produced 4 different rock types. These different rock
types represent a magma chamber with areas of different compositions which produce both effusive
and explosive eruptions. As an example, trachyte represents the most explosive eruptions witnessed
at this volcano, such as what occurred in 2010. At some point during this mountain's geologic
history, one or more caldera collapses occurred. This resulted in a 2.5 kilometer
wide caldera in the summit, which is typically covered by a glacier.
The first eruption to be witnessed from this volcano occurred in 920 AD.
This explosive eruption occurred on the northwest flank of the mountain and formed the Skerin ridge.
A subsequent eruption from 1821 to 1823 was an order of magnitude smaller, and took
place at the central caldera. The ash from this eruption contained a high amount of the
element fluorine, which in high doses harms the bone structure of livestock.
The volcano then became dormant for 187 years. Then, after several earthquake swarms and an
uplift in a portion of the mountain, the volcano erupted. On March 20th of 2010, an eruption began
8 kilometers to the east of the main crater. A fountain of lava rose from a fissure vent,
causing nearby snow to turn into steam. Over the next three weeks, this eruption continued
with strombolian style volcanic activity. On April 12th, this part of the eruption ended.
Two days later, the main phase of the eruption began as several large craters opened at the main
summit. These vents ejected millions of tons ash into the air, causing an eruption plume to reach
10 kilometers into the atmosphere. This ash cloud slowly drifted southeast and soon covered much
of Europe and Russia. All across Europe, 107,000 flights were cancelled. As the eruption continued,
areas around the summit were overlaid by up to a meter of fresh black ash. During this phase,
a large volume of erupted lava near the summit crater flowed northwards and caused a significant
amount of the glacier overlying the mountain to melt, creating a large flood downslope.
Over time, the volume erupted from the volcano slowly decreased, until the eruption
ended on Jun 23rd. This eruption was rated as Cataclysmic, as a 4 on the 0 to 8 volcanic
explosivity index. In what represented the largest eruption on the planet of the last several years,
about 250 million cubic meters of ash was ejected. Since then, the volcano has been quiet.
If the volcano was to erupt again in the future, it would pose similar hazards to what occurred
in 2010, although a smaller eruption is more likely. Future eruptions could open a new vent
on the main summit, or up to 12 kilometers from its center. The main hazard during an eruption
to the population of Iceland is large lahars resulting from a partial melting of the glacier.
Even a small eruption could endanger a number of nearby towns which lie on the southern flanks of
the mountain. This poses a much greater danger than the risk of long-distance
lava flows. Other hazards include the ash clouds which can disrupt air travel,
short distance pyroclastic flows, and ashfall which can damage drinking water and kill
crops. This stratovolcano erupts about once every 400 years, so it will likely be
a long time until the next eruption. I hope that you enjoyed this video.
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