Researchers believe that the shrinking glacier cover over Iceland's volcanoes could lead to more volcanic activity. Climate change is seen as a primary driver of the ice melt.
'Little Ice Age'
A study led by researchers from the University of Leeds reveals that there was less volcanic activity in the volcanically active regions of Iceland when there was more glacier covering. Researchers examined the volcanic ash preserved in lake sediments and peat deposits in Iceland and found that between 4,500 and 5,500 ago, there was a period of significantly reduced volcanic activity.
Interestingly, this period came after a significant temperature decrease which led to glacier growth in Iceland. In fact, Iceland's volcanic system experienced what is called the "Little Ice Age," a period that was marked by colder climates which happened between the years of 1500 and 1820.
Increased Volcanic Activity
After the "Little Ice Age," both natural and human-caused climate change has been causing the Icelandic glaciers to melt, thereby changing the volcanic surface pressure.
"This can increase the amount of mantle melt as well as affect magma flow and how much magma the crust can hold," explains Dr. Ivan Savov, co-author of the study.
As it happens, researchers found that there was a 600-year lag between the temperature drop and the significant decrease in volcanic activity. They surmise that the same lag could be expected between the current temperature increase and the volcanic activity increase.
Despite this, researchers state that the human contributions to climate change make it much more difficult to predict how long the lag will be. As such, they believe that this is why climate summits are even more important because it allows people to understand just how current actions can affect future generations.
Volcanic Activity In Iceland
On average, Iceland experiences one major volcanic event every five years, and parts of Iceland frequently experience earthquakes as a result. Since the Middle Ages, it is estimated that a third of all the lava on the Earth's surface erupted in Iceland, and that's still not counting submarine eruptions which are more extensive than land eruptions.
In fact, just these past months, Bárðarbunga volcano, the largest volcano in Iceland which also happens to be sitting partly under Europe's largest ice cap, had been exhibiting some volcanic activity. If it erupts, it could wreak havoc on air travel worldwide just like what happened when Eyjafjallajökull volcano erupted in 2010.
Based on the study, the warming climate could result in these volcanic activities to become more frequent. There are over a hundred volcanoes on Iceland's central plateau which have not erupted in thousands of years, but there are 30 to 40 active volcanoes.
The study is published in the journal Geology.