A new study suggests that climate change could cause a sudden increase in volcanic eruptions. Scientists say global warming that’s occurring due to human activities is melting ice fast in some parts of the world with volcanic activity. They believe this could result in a rapidly growing number of volcanic eruptions.
Melting ice could cause more volcanic eruptions
University of Leeds researchers led the study and published their findings in the journal Geology. Dr. Graeme Swindles from the university’s School of Geology explained to R&D Magazine that volcanic activity in Iceland was less when glaciers covered the country more extensively. However, as the glaciers melted, they observed a rising number of volcanic eruptions because of pressure changes on the surface.
To conduct the study, the researchers analyzed volcanic ash that had been preserved in peat deposits and lake sediment in Iceland. Based on their examination of the preserved ash and sediment, the researchers believe that about 4,500 to 5,500 years ago, volcanic activity in Iceland was greatly reduced.
Temperatures dropped before volcanic eruptions declined
They correlated this timeframe with temperatures in the region and found that temperatures around the globe had declined significantly before this period of reduced volcanic activity. The main result of those lower temperatures was glacier growth in Iceland, they added.
The researchers estimate that about 600 years passed between the global temperature drop and the significant decline in the number of volcanic eruptions. They theorize that a similar time lag can be expected between the global warming trend of the modern era and, possibly, a time of increased volcanic eruptions at some point in the future.
According to R&D, the volcanic system in Iceland is currently undergoing a recovery from what scientists refer to as the “Little Ice Age,” which occurred between 1500 and 1850 and was marked by significantly lower temperatures. Since the end of that era, global warming — caused by humans and also from natural causes — has resulted in Iceland’s glaciers melting again.
How humans impact climate
According to Dr. Swindles, the fact that some of the global warming is caused by humans makes it even harder to predict how long the time lag will be between the climate change and probably uptick in volcanic eruptions. However, he said that understanding the impact humans are having on climate change is important because it helps us see how today’s actions might have an impact on generations to come.
The volcanic system in Iceland is greatly affected by any change in surface pressure because it changes stress levels on underground chambers where magma can build up. Rifts in the boundaries between the continental plates interact with build-up in magma and gases underground. All of these effects also interact with pressure on the surface of the volcano caused by the ice and glaciers in Iceland, which also has an impact on the surface pressure.
Study co-author Dr. Ivan Savov explained that as ice melts and glaciers in Iceland retreat, the amount of pressure that’s exerted on the surface of the Earth is reduced, which can cause mantle melt to increase and also have an impact on magma flow and also on the amount of magma the Earth’s crust can hold. Thus, he said that even “small” surface pressure changes can change the probability of volcanic eruptions in areas that are covered by ice, such as Iceland.