Sulphur breath: tracking the emissions of volcanoes

The sulphur fumes of Mount Ijen in East Java, Indonesia The sulphur fumes of Mount Ijen in East Java, Indonesia Shutterstock
12 Apr
2017
In a new report, researchers have calculated the global emissions of sulphur dioxide caused by volcanic activity

Sulphur dioxide (SO2) is an aerosol that cools the atmosphere, can cause acid rain, and, at low altitudes, causes respiratory problems in humans. Volcanoes are natural sources of the gas and often we associate these emissions with dramatic eruptions. In reality, however, most of the gas is emitted when they are not erupting – through their everyday puffing and steaming.

‘Daily volcanic emissions are a constant input to the Earth’s atmosphere,’ says Simon Carn, lead author of a new report on global volcano emissions and associate professor at Michigan Tech in Houghton, Michigan. ‘These can impact climate in more subtle ways than a big eruption.’

Mount Erebus in AntarcticaMount Erebus in Antarctica was monitored from space for the first time (Image: Pagnanelli)

In order to get a good idea of how much SO2 is being regularly released, Carn and his team have used satellite data look at the respiration of 91 active volcanoes across the globe from 2005 to 2016.

They found that 20 to 25 million tons of SO2 are being emitted annually, considerably higher than a previous estimate of made in the 1990s of 13.4 million tons. However, Carn believes that this doesn’t mean that volcanoes are emitting more, only that measurements are becoming more accurate:

‘The satellite measurements we used cover the entire globe, and so we were able to measure emissions from many more volcanoes than any previous study.’

The global range of the satellite data also brought some surprises. Strong SO2 pulses were detected from volcanoes that had been completely off the radar to most volcanogists. ‘Many volcanoes were known to be strong emitters of gas,’ he says, ‘but a few in remote parts of countries like Indonesia and Tonga were new discoveries.’

newnewgifThe wax and wane of volcano emissions on the coast of Central America (Image: Carn et al)

While the collective SO2 has stayed the same, changes can be seen at an individual level. This is because emissions of SO2 are mainly related to the supply of fresh magma. ‘A volcano’s variable magma supply would cause its emissions to wax and wane over time,’ says Carn. ‘Meanwhile, volcanoes with a continuous supply of magma have roughly constant emissions.’ Because of the gas and magma relationship, changes in SO2 can also be used to forecast potential eruptions.

AsoMount Aso, Japan showed an increase in SO2 emissions before eruptions in 2014 and 2016 (Image: Shutterstock)

Human activity produces twice the amount of SO2 as volcano emissions, mostly by the burning of fossil fuels – particularly solid fuels such as coal. Over the past few decades, however, stricter policies and changes to industry have brought about a steady decline of human emissions of the gas. As this continues, volcano monitoring will continue to demonstrate the natural background levels of SO2.

Share this story...

Submit to FacebookSubmit to Google PlusSubmit to Twitter

Related items

Geographical Week

Get the best of Geographical delivered straight to your inbox every Friday.

Subscribe Today

EDUCATION PARTNERS

Aberystwyth UniversityUniversity of GreenwichThe University of Winchester

TRAVEL PARTNERS

Ponant

Silversea

Travel the Unknown

DOSSIERS

Like longer reads? Try our in-depth dossiers that provide a comprehensive view of each topic

  • The Air That We Breathe
    Cities the world over are struggling to improve air quality as scandals surrounding diesel car emissions come to light and the huge health costs of po...
    Diabetes: The World at Risk
    Diabetes is often thought of as a ‘western’ problem, one linked to the developed world’s overindulgence in fatty foods and chronic lack of physi...
    National Clean Air Day
    For National Clean Air Day, Geographical brings together stories about air pollution and the kind of solutions needed to tackle it ...
    The Nuclear Power Struggle
    The UK appears to be embracing nuclear, a huge U-turn on government policy from just two years ago. Yet this seems to be going against the grain globa...
    REDD+ or Dead?
    The UN-backed REDD+ (Reducing Emissions from Deforestation and Forest Degradation) scheme, under which developing nations would be paid not to cut dow...

MORE DOSSIERS

NEVER MISS A STORY - follow Geographical

Want to stay up to date with breaking Geographical stories? Join the thousands following us on Twitter, Facebook and Instagram and stay informed about the world.

More articles in NATURE...

Energy

Could human waste one day be fuelling our homes and…

Geophoto

Every year, the LPOTY awards celebrate the best in Britain’s…

Climate

At the 23rd Convention of the Parties (COP) climate change…

Oceans

Knowing where past coral reefs existed is a crucial component…

Oceans

Numerous low-lying Pacific islands have disappeared under rising seas

Oceans

In this exclusive film for Geographical, see how an unusually…

Climate

Marco Magrini considers why the recent devastation caused by hurricanes…

Geophoto

Country borders are some of the most controlled environments on…

Wildlife

Nature reserves and protected areas in Germany have lost 76…

Oceans

An investigation into shark fins and ray gills sold in…

Climate

Geographical’s regular look at the world of climate change. This…

Wildlife

The rapid spread of Asian hornets is likely to make…

Energy

Europe provides more than €112billion (£97billion) in subsidies to fossil…

Oceans

A study of various fish populations has found dramatic reductions…

Geophoto

The seasonal changes of September promise much photographic potential for…

Oceans

Shipping traffic can increase lightning strikes, according to a pioneering…

Polar

New documentary travels to remote Antarctica to unpack the complex…

Oceans

The deaths of these majestic creatures had remained an unsolved…

Wildlife

Over a two-year period, a new species of plant or…

Wildlife

As part of New Zealand’s plan to cull millions of…