Energy, Resources and the Environment

Words on Wednesday

Understanding groundwater – students’ pre-conceptions and conceptual change by a theory-guided multimedia learning program

Words on Wednesday aims at promoting interesting/fun/exciting publications on topics related to Energy, Resources and the Environment. If you would like to be featured on WoW, please send us a link of the paper, or your own post,


Citation: Unterbruner, U., Hilberg, S. and Schiffl, I. Understanding groundwater – students’ pre-conceptions and conceptual change by a theory-guided multimedia learning program. Hydrol. Earth Syst. Sci. Discuss., 12, 11689-11737, 2015

Blog by Sylke Hilberg

Groundwater is a crucial topic in education for sustainable development. Knowledge about groundwater is an indisputable prerequisite for a sustainable use of water as a valuable natural resource. But international studies with students of different ages have shown that the basic hydrogeological concept of groundwater defined as water within porous and permeable rocks is not an established everyday notion. Most popular, however, is the idea of groundwater as a subterranean river or lake. This is what we aimed to change with the help of our interactive multimedia learning program “Zwischen Regenwolke und Wasserhahn” (Between the raincloud and the tap, Unterbruner & Hilberg, 2012) that we developed in an academic cooperation between the faculties of Geology and Science Education/Biology Didactics at the University of Salzburg.

We designed the multimedia learning program on the basis of hydrogeology, conceptual change research and multimedia research. In order to ascertain the effectiveness of the learning program two studies were conducted with Austrian pupils (7th grade) and teacher training students from the fields of biology and geography. Using a quasi-experimental research design, the participants’ conceptions and knowledge regarding groundwater were determined in a pre- and post-test. The results show that groundwater education can be significantly improved by using our multimedia learning program. Both pupils and students, achieved a significant increase in correct groundwater conceptions and knowledge achieved during a one-off session with the multimedia program. The two drawings of a 12-year old boy show the conceptual change by learning with the program.

Left, pre-test: Groundwater as a huge subterranean lake. Right, post-test : Correct drawing of groundwater

Left, pre-test: Groundwater as a huge subterranean lake. Right, post-test: Correct drawing of groundwater

The complete program consists of four chapters (Water in the Ground, Water in the Mountains, Water in Pipes, Interesting facts about Water, language: german) and is available free on the internet at


Oil in Kenya: Blessing or Fuel for Fights

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Citation: J. Schilling, R. Locham, T. Weinzierl, J. Vivekananda, and J. Scheffran. The nexus of oil, conflict, and climate change vulnerability of pastoral communities in northwest Kenya. Earth Syst. Dynam. Discuss., 6, 1163-1200, 2015

Blog by Janpeter Schilling

“Now, we will all be rich”, I was told by Eduang, a Turkana pastoralist in northwest Kenya. That was in 2011, when people first heard about oil located under their feet. A year later, the company Tullow Oil actually struck oil in Turkana, announced its commercial viability and estimated the reserves to be in the neighborhood of 600 million barrels. Everybody was excited. Local community members like Eduang expected wealth and jobs. The former president of Kenya, Kibaki, called the oil discovery “very good news” in anticipation of significant revenues. So has oil been a blessing for Turkana?

To answer this question, one has to understand the situation in Turkana before oil was found. Turkana is the poorest and least developed county in Kenya. The pastoralists living in Turkana are well adapted to the harsh and dry climate but increasingly unpredictable rainfall and a higher drought frequency pose a significant challenge for the local communities. On top of the climate uncertainty come the violent conflicts between different pastoral groups. The Turkana fight particularly with the Pokot over land, pasture, water and livestock. In this very conflict hotspot the oil has been found.

Coming back to our initial question, yes, a few Turkana have gotten a casual jobs with Tullow as a security guard or road assistant. And, yes, the water situation for the Turkana communities has somewhat improved as Tullow has given some water to the communities. However, no, the high expectations of the communities for employment and development have not been met. In addition, the communities feel that land has been taken from them and pollution associated with the oil exploration is likely to become another source of community frustration. Community road blocks and an attack on an oil site show the level of frustration.


The government of Kenya, currently undergoing the process of devolution, has not used the opportunity of oil to improve the situation in Turkana in terms of education, economy, health and infrastructure. Currently, Nachoo, another pastoralist who I recently interviewed in Turkana seems to be right. Nachoo told me “where there is oil, there is conflict”.

Drilling into magma: the future of electricity production from volcanic geothermal systems?

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Citation: Scott, S., Driesner, T. & Weis, P. Geologic controls on supercritical geothermal resources above magmatic intrusions. Nature Communications. 6:7837 doi: 10.1038/ncomms8837 (2015)

Blog by Samuel Scott

Electricity production from high-enthalpy geothermal systems typically involves drilling boreholes into permeable reservoirs at depths of 1-2 km and temperatures between 250-300 °C. The fluid that comes up the wellbore consists of a mixture of liquid and vapor, from which the vapor is separated and passed through a steam turbine to generate on average 3-5 MW per well. The Iceland Deep Drilling Project (IDDP) was founded by a group of international scientists who sought to drill to deeper, hotter conditions where water is a single-phase, intermediate density, supercritical fluid. Basic thermodynamic considerations suggest that wells drilled into supercritical geothermal resources could potentially provide an order of magnitude more electricity than a conventional geothermal well. A plan was developed to drill a borehole to 4-5 km depth in the Krafla geothermal system, with the aim of discovering a reservoir at supercritical temperatures (>374 °C) and pressures (>220 bars).

Transparent, opalescent steam discharges from the IDDP-1 borehole at the Krafla volcano in Iceland. (Image: Kristján Einarsson/IDDP)

Transparent, opalescent steam discharges from the IDDP-1 borehole at the Krafla volcano in Iceland. (Image: Kristján Einarsson/IDDP)

Drilling was difficult and did not go as expected. After chunks of quenched glass began to come up the wellbore, they knew that they had drilled into a magmatic intrusion located around 2 km depth. Studies of the glass showed that it was rhyolitic in composition. Temperature measurements suggested a fluid temperature as high as 450 °C, but since the intrusion was encountered at a relatively shallow depth, the fluid pressure was less than the supercritical pressure, and the fluid was categorized as ‘superheated steam’. The big surprise was the fact that the fluid reservoir was nonetheless much more powerful than typical wells drilled to 2 km depth. As can be seen in videos taken during the well testing (, the well discharged large volumes of translucent and opalescent fluid – classic indicators of a supercritical fluid. Well tests indicated that the well could potentially generate 35 MWe of electric power, roughly an order of magnitude greater than a typical geothermal well. However, there were many questions that surrounded this discovery. How did this fluid reservoir form? How could it form at such a shallow depth? It was unclear whether the IDDP reservoir was an anomaly, or whether similar resources could exist in other high-enthalpy systems.

This led myself and a group of collaborators at ETH Zurich to use numerical models to understand the hydrology of the IDDP reservoir. The computer code had already been successfully applied to understand high-temperature fluid flow in other settings, such as mid-ocean ridges and the formation of copper-rich porphyry deposits. We set-up the model such that only a few key parameters were needed, aimed at capturing the main sources of geologic variability between different geothermal settings. The key data that go into the model are the depth of the intrusion, the host rock permeability (a measure of how fractured the system is as a result of tectonic activity) and the brittle-ductile transition temperature (which determines the temperature where rock becomes impermeable due to plastic deformation closing connecting fluid flow pathways).

These models show how these primary geologic controls determine the extent and thermal conditions of supercritical reservoirs. For example, our study identified a brittle-ductile transition temperature greater than 450 °C as a key control on reservoir formation. Since basalt has a brittle-ductile transition temperature >450 °C, while granite becomes impermeable around 360 °C, we expect that the best resources will be found in basaltic rocks. Additionally, if the rock surrounding the intrusion is very permeable, we expect the supercritical resources to be close to the intrusion, relatively limited in spatial extent, and at temperatures near 400 °C. If the rock surrounding the intrusion is moderately permeable, the reservoirs will be larger and at higher temperatures. However, the fluid production rate for a well drilled into a supercritical reservoir will be higher when rock permeability is higher. Thus, there is a trade-off between fluid temperature and well productivity that is governed primarily by rock permeability. These basic concepts can inform future efforts to discover and exploit these resources.


If the rock (white) surrounding an impermeable body of magma (grey) is only highly permeable, supercritical water (red) is restricted to a thin layer around the magma (left panel). However, if the rock is moderately permeable, a large area can be heated to supercritical conditions (right panel). (Illustration: from Scott et al. 2015, Nature Comm.)

Our models were able to reproduce measured data from the IDDP well when the geologic controls are set to appropriate values for the Krafla system. This supports the model set-up, as well as the conclusion that supercritical geothermal resource properties depend on geologic controls. Moreover, the models show that conventional geothermal resources result simply from the mixing of supercritical fluids ascending from the intrusion and cooler fluids circulating near the intrusion but not heated to supercritical conditions. This is a new way to look at conventional high-enthalpy geothermal reservoirs.

In future studies, we will seek to better understand the role of supercritical water in controlling the thermal structure and temporal evolution of high-enthalpy geothermal systems. As our understanding progresses, we will move towards modeling specific geologic settings, including the Reykjanes geothermal system where the next IDDP well will be drilled. Since the Reykjanes geothermal field contains groundwater that is known to have a large seawater component, fluid salinity is likely to play a key role on supercritical resource formation and properties. Salt changes the thermodynamic properties of water such as density and viscosity and allows boiling to occur at higher temperatures and pressures than for pure water. This may affect the formation of similar supercritical reservoirs in unexpected ways.

Although this was not the outcome the IDDP expected, the fact that such a reservoir was encountered on the first intentional effort suggests they may be a common feature that we have been passing up by targeting reservoirs at shallower depths. It also means that targeting supercritical geothermal resources may be even more economically attractive than expected by the IDDP, since wells do not need to be drilled as deep as expected. Exploiting supercritical water resources has the potential to massively improve the economics of power production from magma-driven geothermal systems. Time will tell whether or not they can be found in systems all over the world, but we anticipate that the search for these fluid reservoirs will continue.

Data4Sustain – a new webGIS renewable energy feasibility tool

Words on Wednesday aims at promoting interesting/fun/exciting publications on topics related to Energy, Resources and the Environment. If you would like to be featured on WoW, please send us a link of the paper, or your own post, at


Blog by Darren Beriro, British Geological Survey

British Geological Survey (BGS) and consortium members Land Quality Management, Nottingham Energy Partnership, Nottingham Geospatial Institute, Positive Homes and University of Nottingham Estates Office are working on a new project called Data4Sustain. The project is being led by LQM and has attracted prestigious funding from UK’s Innovation agency, Innovate UK[1] (Solving Urban Challenges with Data – Feasibility Studies[2]) and the Natural Environment Research Council (NERC). Over the next 12 months, Data4Sutain will produce a prototype web-based geographical information system (webGIS) for landowners, developers, community groups, local authorities, and their advisors to conduct renewable energy feasibility studies.

The prototype webGIS will display information about when a renewable energy technology (e.g. geothermal, hydro, wind, solar) is expected to be viable at a given site or building. The webGIS will utilise urban datasets and combine these with technology specific ‘operating windows’ to identify the most attractive location for new installations. As the renewable energy sector matures there is increasing expectation (i.e. removal of FITs, etc) for efficient decision-making and investment. Data4Sustain aims is to facilitate this process in both the short and long-term siting of such technologies.


If you are interested in contacting the project team please email or call LQM on 0115 7484080. To register your interest in Data4Sustain and keep up to date with the latest developments please sign-up to the Data4Sustain mailing list.

[1] Innovate UK is the new name for the Technology Strategy Board – the UK’s innovation agency. Taking a new idea to market is a challenge. Innovate UK funds, supports and connects innovative businesses through a unique mix of people and programmes to accelerate sustainable economic growth. For further information visit

[2] Feasibility Studies is a single-company or collaborative R&D grant scheme run by Innovate UK that allows businesses the opportunity to test an innovative idea and its feasibility to be developed and eventually taken to market. Feasibility studies are a way for companies to carry out exploratory studies which could lead to the development of new products, processes, models, experiences or services. The study could involve for instance investigating the technical feasibility of a new idea.