Our beleaguered climate is enough trouble without the effects of any other destabilizing factors; however, another huge volcano is predicted to erupt and unleash clouds of volcanic ash into the atmosphere in the very near future.
The volcano, one of the largest in Iceland, has been showing signs of awakening since August 16th since a spate of significant seismic activity – more than 3000 earthquakes in its locality – was detected by the Icelandic Meteorological Office.
Scientists cannot guarantee an eruption as volcanoes are notoriously temperamental, and the seismic activity could subside without incident. Experts from the GFZ Helmholtz Centre Potsdam advise that their statistics indicate that seismic activity caused by moving magma only results in a volcanic eruption in less than 10 percent of all cases. Volcanologist Dr. Dave McGarvie said it is also possible that the magma may not even break through the surface of the glacier, averting an eruption altogether.
"There is no way to predict when the eruption may happen, but we should get a few hours notice," McGarvie added.
There is very little previous data on Bárðarbunga as it is situated in a very isolated region of Iceland and has produced relatively few previous blasts. At 2009 meters above sea level, Bárðarbunga is the country’s second highest mountain. It forms part of the biggest volcanic system in Iceland, though is completely covered by the Vatna Glacier. There are several other volcanoes within the system, which runs for 190 kilometers (118 miles) across central Iceland.
Evidence suggests that, around 500 years ago, Bárðarbunga produced one of the most powerful volcanic blasts that the world had experienced for 10,000 years. Its last eruption in 1996 was less violent, but there is no indication how significant the next explosion would be. If it does erupt, the greatest immediate threat to the surrounding area would be flooding due to molten lava melting the glacier. Consequently, the surrounding areas have already been evacuated and the volcano alert has been upgraded to orange, the fourth level on the five level eruption risk scale intended to indicate the level of risk a volcano poses to air travel.
An orange alert indicates that a volcano is showing "escalating unrest with increased potential of eruption", or is erupting without any major volcanic ash emissions.A red alert means that an eruption is "imminent", or is under way with "significant emission of volcanic ash into the atmosphere".
The global consequences of such an eruption can be profound: when another Icelandic volcano, Eyjafjallajökull, erupted back in 2010, it produced a huge ash cloud that spread across the whole of Europe, grounding all flights and stranding thousands of people for weeks. Eyjafjallajökull is also situated on a glacier, and its ash cloud was formed due to the rapid evaporation of water which occurred when boiling magma encountered freezing ice.
Eyjafjallajökull is smaller than Bárðarbunga, however, so there is the potential for any ash cloud resulting from this latest volcanic threat to be much larger than its 2010 predecessor; however, volcanologist Dave McGarvie suggested that this eruption may be far less disruptive to flights than Eyjafjallajökull, due to different wind direction and relaxed aviation laws, though British forecasters are particularly concerned by the risk because winds are currently blowing towards the U.K. from Iceland.
Laura Young, of the Met Office, said last night: "There is a north-westerly airflow at the moment and it looks like it will stay that way until Sunday or Monday. Depending on the extent, type and timing of any eruption, there is a risk that any volcanic ash could be dispersed across the UK. We are keeping a very, very close eye on it."
In 2010, prevailing winds transported the clouds of volcanic dust from Iceland over to the European mainland where it hung in the atmosphere for several weeks. Ash particles constitute a serious danger to aircraft engines, as they can enter the burning chamber, melt and settle on the cooler blades, eventually causing total engine failure. Consequently, planes are not allowed to fly through ash clouds and in 2010, all planes in affected areas were grounded, resulting in a billion euro loss for the airline industry. Supplies of food were severely affected, and many passengers were forced to live in hotels and hostels for weeks until the cloud dispersed and flights resumed.
The social and economic impacts of such a blast are immediately obvious, but the climatic effects are just as profound. Volcanoes can affect climate change in various ways: volcanic gases such as sulfur dioxide can cause global cooling, whilst volcanic carbon dioxide, a greenhouse gas, has the potential to promote global warming. Some of the most significant effects on climate result from the conversion of sulfur dioxide to sulfuric acid, which condenses rapidly in the stratosphere to form fine sulfate aerosols. These aerosols increase the amount of reflection of radiation from the Sun back into space, cooling down the Earth’s lower atmosphere or troposphere.
Previous large volcanic blasts occurring during the past century have typically caused a drop in global temperatures of half a degree for periods of one to three years. One of the largest eruptions of the twentieth century, Mount Pinatubo on June 15, 1991, unleashed a 20-million ton (metric scale) sulfur dioxide cloud into the stratosphere at an altitude of more than 20 miles, resulting in global cooling of 1.3 degrees for over three years.
We can only hope, therefore, that the rumblings from beneath Bárðarbunga subside without incident but Professor Stephen Sparks, a volcanologist at Bristol University, said there is a one-in-two chance Bardarbunga will erupt. Wind direction could minimise its threat to aviation, but the eruption could place an additional strain on an already dysfunctional global climate.