What lies beneath
Mention volcanoes and most people think of spectacular eruptions, lava flowing down hillsides and great plumes of smoke rising into the atmosphere and covering the landscape in ash - or perhaps the grounding of all air travel for weeks. However, major eruptions such as these are not the only type of volcanic activity, and many volcanoes worldwide are known to be persistently active.These volcanoes constantly emit gases including carbon dioxide and sulphur dioxide, and deposit heavy metals in the surrouding area such as lead, copper and zinc. The dangers of spectacular volcanic eruptions are well known; landslides and earthquakes can be devastating. But damage caused by these persistently active volcanoes is less well researched.
The Earthwatch project is evaluating long-term trends.
Professor Hazel Rymer of the Open University (OU), UK, has been working with Earthwatch since 1987, and currently runs the Volcanology and Ecology in Nicaragua project studying the activity of the Masaya volcano in the Masaya National Park, on the west coast of Nicaragua. The aim of this research is to establish how damaging these persistently active volcanoes are in terms of restricting biodiversity and impeding economic development and poverty reduction over long periods. Professor Rymer has been working in the field of volcanology and geosciences for 20 years. Based at the OU since 1985, this year she was granted her Professorship in Environmental Volcanology.
The Volcanology and Ecology in Nicaragua project is about understanding how natural variations in persistent activity affect the local environment. The idea is to characterise the interactions between key volcano-derived elements (heavy metals such as lead, copper and zinc) and the environment, and identify the risks they pose. Heavy metals may enter the food chain as a result of their uptake by edible plants, so factors controlling the total concentrations of heavy metals in soils are of great importance for human toxicology and agricultural productivity. High concentration of gases at persistently active volcanic sites can cause heavy metal pollution of soil, water and the atmosphere.
Volunteers collect data at a number of sites.
Professor Rymer uses a range of methods to monitor the Masaya volcano. In 2009, sulphur detection plates1 were deployed, high resolution gravity (microgravity2) mapping was carried out, and Bougar gravity3 was measured, low frequency radio (VLF) and magnetic surveys4 were established, sulphur dioxide profiles5 were measured, and butterflies and trees were identified. All of these activities ran with high precision GPS (Global Positioning Systems) surveys throughout to ensure accuracy of data collection; by knowing the exact position of a certain reading it is possible to accurately replicate the reading at a later date.
Earthwatch volunteers
Volunteers collect data at a number of sites, and they identify butterflies and plants. Species such as the Tradescanthia (spiderwort), Pernettya (prickly heath), and the affectionately named ‘Tourist Tree' provide important insights into the cycling of heavy metal deposits throughout the ecosystem.
In the last year the project has begun to produce some exciting results that have the potential to have a dramatic impact on the present theories surrounding persistently active volcanoes and their impact on the environment.
Since 2009 important trends have been emerging in the microgravity readings suggesting a shift in the sub-crater magma levels at Masaya. These, along with some previously unrecognised fractures, may indicate the build-up of stress within the volcano, and could be an indication of a potential eruption. The Bouguer gravity surveys have allowed the full extent of the lava tunnel system beneath the park to be identified. This information will be vital if there is an eruption as it will allow the scientists and park officials to monitor areas of weakness.
Pollution from volcanoes has implications for local communities.
In 2009 survey efforts were extended to evaluate long term trends and correlate changes in gas output from the volcano with changes seen in the soil and plants. To assess absorption of pollutants in plants, samples of locally grown plant material (leaves, stems, flowers and fruits) were collected in areas surrounding the volcano. Uptake of heavy metal pollutants including cadmium, copper, lead and zinc were recorded in the plant material analysed.
Helping local communities
Implications for local people include a build-up of pollutants in their agricultural crops. To mitigate against this, operational guidelines for monitoring and responding to changes in volcanic degassing6 were put in place in 2009. These will be a great help when it comes to establishing short-term responses to gas-related health emergencies, as well as medium-term land management policies to reduce the effect of degassing on human and agricultural activity - both will be of direct economic benefit to vulnerable communities.
By mapping the distribution of air plants7 within and around the park, it was found that the location of these plants mirrored results from the sulphur detection plates in indicating levels of gas deposition, potentially identifying a new way to monitor gas flux from the volcano.
Professor Rymer and her team work closely with the Nicaraguan government body tasked with volcano and environmental monitoring, and share all of the research results with them. Educational material is provided from this project to the National Park Office and used in its visitor centre to inform the public about volcanic risk and environmental impact. In the past year work has begun with local farmers to investigate water quality with a view to advising on safety for agriculture.
This has all had a positive effect on the wardens within the National Park, who are educated on which species of flora and fauna to monitor, as well as providing help to develop a more systematic recording system of volcanic activity.
Earthwatch and the Open University
Following the success of Earthwatch's work with Professor Rymer and other OU scientists, in 2009 an official collaboration was set up between Earthwatch and the OU, to enable Earthwatch volunteers to gain OU credits by using their Earthwatch experience as their practical element of the new BSc Natural Sciences degree. This means that volunteers worldwide can gain credit for participating in Earthwatch expeditions. This degree is available globally online so is accessible to a large number of students who are unable to study conventionally.
Damage caused by persistently active volcanoes is less well researched.
There is no need for volunteers on this inspiring project to have any background in geophysics - just a passion for learning and a strong commitment to accurate data collection. Find out more about the mysterious world of the volcano.
Dr Hazel Rymer's research is made possible by the support of people like you. Please help us to continue to support vital environmental research by donating today.
Report by Helen Walters.
1 Petri dishes coated with lead that detect the amount of sulphur dioxide in the air based on the reaction of the lead.
2 Microgravity, also called weightlessness or zero gravity, is the absence of gravity.
3 The gravity field obtained after latitude, elevation and terrain corrections have been applied to the measured gravity data.
4 Magnetic geophysical surveys measure small, localised variations in the Earth's magnetic field.
5 The amount of sulphur dioxide measured within the environment.
6 Degassing is the process by which magma loses its volatiles to the atmosphere.
7 Air plants grow in trees or on rocks. They are not parasitic, and they absorb the nutrients and moisture they need from the air or crevices on the surface of the host.
