GeoLog

“Crater lake” by Michelle Salmon, distributed by the European Geosciences Union under a Creative Commons licence

At the border between the Pacific and Australian plates, crossed by the Pacific Ring of Fire, New Zealand is one of the most geologically active countries in the world. Volcanoes abound in this island-country, which contains the “world’s strongest concentration of youthful rhyolotic volcanoes“, and earthquakes are a frequent presence. Mount Ruapehu, a stratovolcano located in the middle of the North Island, is the largest active volcano in New Zealand, and is also one of the world’s most active. Being the highest point of the North Island, Ruapehu also sees frequent snowfall and hosts the country’s largest ski fields.

It was on a ski trip that Michelle Salmon, from The Australian National University, captured the stunning Crater Lake of Mount Reapehu. “This image was taken near the summit of Mount Ruapehu looking down on the volcanic crater,” she says. “The volcano’s active vent is filled by Crater Lake which varies in temperature from 10 to 50 degrees Celsius. This vent last erupted in 2007. There are three ski fields on this active volcano and this photo was taken on a ski trip a couple of weeks after a small eruption that sent waves from the lake crashing into the wall of the crater. The crack in the snow on the far side of the crater is a result of this eruption.”

New Zealand is home to some of the most beautiful landscapes in the world, many of which were captured on film by director Peter Jackson in his The Lord of the Rings movies. Mount Ruapehu featured in the trilogy: it was one of two volcanoes used to represent Mount Doom, a volcano in Middle Earth, the fictional setting of The Lord of the Rings.

Imaggeo is the online open access geosciences image repository of the European Geosciences Union. Every geoscientist who is an amateur photographer (but also other people) can submit their images to this repository. Being open access, it can be used by scientists for their presentations or publications as well as by the press. If you submit your images to imaggeo, you retain full rights of use, since they are licenced and distributed by EGU under a Creative Commons licence.

In this month’s Geosciences Column, Amanda Gläser-Bligh writes about SAR (synthetic aperture radar) satellites and how they can be used to map glacier lakes and mitigate related flood hazards.

Glaciers are a natural storage system and provide a perennial source of fresh water to the surrounding low-lying areas, which can be used for drinking water, irrigation, or even hydroelectricity. But when glaciers melt rapidly and form lakes before unstable moraines, the possibility of glacial lake outburst floods increases, causing concern for nearby population centers.

Due to the ever-changing nature of glacial lakes, Dr Tazio Strozzi and his team have developed a method to monitor these changes as they happen to limit the catastrophic potential from the lake outbursts. Their ideas are presented in the paper, “Glacial lake mapping with very high resolution satellite SAR data” recently published in the EGU open-access journal, Natural Hazards and Earth System Sciences.

Most glacial lakes are located in areas that are difficult to monitor terrestrially. An easier approach is to monitor changing surface conditions from space. To get the level of detail needed for developing lakes in remote regions, synthetic aperture radar (SAR) satellites are employed. These satellites can produce images at a 2-m interval – enough to determine the boundaries of a lake when a trained person examines the pictures. And SAR is not dependent on the weather, whereas other optical methods have trouble creating images through cloud cover or at night.

The orbit of a single SAR satellite moves in a coil-like motion, longitudinally around the planet and can take anywhere between 11 and 46 days to come back to a specific location, depending on the satellite. But since there are a good number of available operating SAR satellites, their efforts can be combined so that more frequent observation of an area can occur; image data on a single lake-forming region can therefore be gathered within hours. Such areas could be potentially dangerous, time-consuming, and expensive for a geological team to approach, showing the advantages of using satellite imagery.

There are some limitations, though. Smaller lakes are difficult to map with SAR. Computers are also not able to analyze the data alone, as backscattering and noise often makes it difficult to determine if an area is composed of water, ice, or wet snow cover. Specialized software is employed to analyze the images, which are often combined with digital elevation models (3D representations of terrains) to add geocoding information, but a human eye is necessary to make the final judgment call about the details of the lake border on the map.

Photograph of the Weingarten glacier lake in Switzerland with GPS path in red. (From: Strozzi et al., 2012)

Dr. Strozzi and his team looked at three glacial areas (in Switzerland, Tajikistan, and Nepal) to determine the changing nature of glacial lakes and to test the SAR technology. In Switzerland and Nepal, teams travelled to the lake sites to make on-the-ground comparisons to the SAR satellite images. The results show that the SAR imaging is of high enough quality to make assessments in changes in lake shapes. And when used in conjunction with other optical and land-based information sources, can be used as a hazard predictor in glacial regions.

In addition to flood prevention, the results can also be uploaded into Google Earth, which accepts changes to mapped features to keep information as actual as possible. This contributes to a genuine visual guide to the planet, while at the same time keeping people safe from the hazards lurking from above.

By Amanda Gläser-Bligh, geologist and member of ELEEP, Emerging Leaders in Environmental and Energy Policy Network 

Geotalk, featuring short interviews with geoscientists about their research, continues this month with a Q&A with Dr Giuliano Di Baldassarre (UNESCO-IHE Institute for Water Education) regarding his work on floods, population changes, and risk prevention. If you’d like to suggest a scientist for an interview, please contact Bárbara Ferreira.

Giuliano Di Baldassarre hard at work

First, could you introduce yourself and let us know a bit about your current research topic(s)?

I was born in L’Aquila, Italy, in 1978. I have been fascinated by hydrological processes since I was a child, when I used to measure the velocity of water in rivers using technology as rough as floating pieces of wood! A few years later, I also started to realize the actual importance of studying hydrological processes. This is why I ended up studying hydrology and, in 2006, I got a PhD in water engineering at the University of Bologna. After that, I was a post-doc at the University of Bristol, United Kingdom, where I could advance my research on hydraulic modelling of floods and remote sensing observations of inundation patterns. Lastly, I moved to Delft, The Netherlands, and started working as a senior lecturer at the UNESCO-IHE Institute for Water Education. In Delft, I kept on exploring the value of space-borne data to support flood hydrology and, along with that, had the opportunity to start developing unconventional approaches for analyzing both biophysical and social processes in African floodplains.

Earlier this year, your received the EGU Division Outstanding Young Scientist Award for your “remarkable contribution to understanding and communicating the impact of global changes on flood risk”. Could you summarise the work you have done in this area, emphasising its wider importance?

My research focuses on the study of floodplain processes. As a matter of fact, floodplains are among the most precious ecosystems for providing services to the environment and supporting biodiversity. At the same time, since the earliest recorded civilizations – such as those in Mesopotamia and Egypt that developed in the fertile riparian areas of the Tigris and Euphrates and Nile rivers – human societies tend to develop in floodplain regions. As a result, flooding is nowadays the most damaging natural hazard and causes about half of all deaths from climate-related disasters. Sadly, flood losses and fatalities are dramatically increasing in many parts of the world because of continuous population growth in floodplains  in addition to changes in land use and climate. In this context, my research work has focused on three major points: the need to understand flood processes and improve our prediction skills, the opportunity offered  by the growing availability of remote sensing data to monitor floodplain areas, and the challenge of estimating (and communicating) the uncertainty intrinsic to any floodplain modelling exercise.

One of your research topics is flood risk and population changes. In what ways are populations more at risk of suffering the impacts of floods today than 50 years ago?

Flood related fatalities as well as associated economic losses have increased dramatically in many regions of the world. To identify the causes for such increased flood damages, one of the research lines I have recently been developing aims at analyzing not only hydrological data but also human population dynamics, since natural flood events can turn into flood disasters only if they coincide with vulnerable societies. One of the most interesting outcomes from the analysis of a large dataset of floods in Africa was that intensive and unplanned urbanization in floodplain areas driven by population growth has been playing a major role in increasing flood losses and fatalities.

You also work on initiatives to prevent and mitigate the impacts of water-related natural hazards such as floods and landslides. What can be done to prevent risk and what role can scientists play in this area?

Yes, I am leading a research project, KULTURisk, which has been funded by the EU’s Seventh Framework Programme (FP7). The main goal of KULTURisk is to develop a culture of risk prevention in Europe and demonstrate its advantages over traditional post-disaster recovery approaches. Depending on the peculiarity of the problem at hand, there are different measures that can be implemented to prevent water-related disasters: flood forecasting and early warning systems, non-structural options such as flood mapping and land-use planning, risk transfer strategies (insurance policies), and more traditional structural measures, such as dikes or levees. An appropriate planning of these prevention measures requires an active dialogue with public and private stakeholders. Given that prevention is hardly ever awarded, I think that scientists should provide a clear demonstration that risk prevention is often a sensible investment since the costs of preventive measures are often many times less than those of post-event recovery.

Last but not the least, can you tell us a bit about your future research plans?

Given the aforementioned relevance of floodplain systems, many hydrological studies have investigated the impact of human activities (e.g. land-use changes, urbanization, river training) on the frequency and magnitude of floods. Meanwhile, a number of social studies have examined how the frequency and severity of flooding often determine whether or not human developments in floodplains are desirable. However, while human activities significantly change the frequency and severity of flooding, the frequency and severity of flooding in turn affect human developments in floodplain regions. Yet, these dynamic interactions between floods and societies and the associated feedback mechanisms remain largely unexplored and poorly understood. In hydrology, for instance, humans are typically considered as external forcing (or boundary condition) without representing the relevant feedback mechanisms. Thus, our predictions of future trajectories are often inappropriate.

I think that innovative research efforts are needed to better understand the behaviour of floodplains as coupled human-water systems and explore the feedback loops, reciprocal effects, surprises, and threshold mechanisms, taking place in floodplain systems. This type of research would enable a better understanding of how (and to what extent) the occurrences of floods shape diverse human developments while, at the same time, human activities shape the magnitude and frequency of floods.

“Patagonian blues” by Agathe Lisé-Pronovost, distributed by the European Geosciences Union under a Creative Commons license.

If you are feeling the Monday blues, this peaceful photograph of a Patagonian lake might be just what you need to light up your day. Patagonia is known for its rich volcanic history and dramatic landscapes, and this scene is no exception. It shows a lake in the Pali-Aike volcanic field on the Argentina-Chile border, located north of the Strait of Magellan: the beautiful Laguna Potrok Aike.

Agathe Lisé-Pronovost was lucky enough to visit the site in the Austral spring of 2008. “As part of my PhD, I was participating in the scientific drilling operations of PASADO, the Potrok Aike maar lake sediment archive drilling project in the framework of ICDP, the International Continental Scientific Drilling Program,” she says.

Potrok Aike is a maar lake, a water-filled volcanic crater that originated from an eruption in which groundwater came into contact with hot lava or magma. “It has a maximum diameter of 3.5 km and, at 200 metres depth, is the deepest crater of the Pali Aike volcanic field,” Agathe explains.

“It is a key site for paleoenvironmental studies because the sediments accumulate rapidly and it is located at 52 degrees of latitude south, on one of the only landmasses in the path of the strong Southern Hemisphere westerly winds.” Being highly susceptible to paleoclimatic changes, the lake is important in understanding the natural phenomena that cause climatic variability.

Imaggeo is the online open access geosciences image repository of the European Geosciences Union. Every geoscientist who is an amateur photographer (but also other people) can submit their images to this repository. Being open access, it can be used by scientists for their presentations or publications as well as by the press. If you submit your images to imaggeo, you retain full rights of use, since they are licenced and distributed by EGU under a Creative Commons licence.

In this month’s Geosciences Column, Wayne Deeker tells us about a new game – first presented in EGU’s Hydrology and Earth System Sciences – that aims to teach how to best share water resources.

With shrinking glaciers, depleted groundwater stores, and rising populations, water resources have never been under such pressure, and worse is yet to come. The resulting conflicts can get ugly and bring high stakes across borders. Resource management professionals, and especially today’s resource management students, are the ones who will bear the brunt of solving these problems. Any aid to make the teaching of water management easier is welcome.

Computer simulations have a long heritage in resource management teaching. Games, in particular, can effectively help students engage with, and understand, the issues. However, many previous water-management teaching games, which aimed to be as realistic as possible, were complex and difficult to understand. The ideal would be a game that simplifies reality yet also hits the key teaching points.

A hydrologist and a programmer from the University of Zurich, Jan Seibert and Marc Vis,  have devised a solution. Their game, called Irrigania, is a web-based teaching resource that simulates irrigation conflict issues among farmers and villages. The researchers presented this new teaching tool in a paper published last month in Hydrology and Earth System Sciences, an Open Access journal of the European Geosciences Union.

Though Irrigania’s parameters are simplified compared to reality, they are well chosen and accurately modelled. Hence, the game authentically illustrates the issues typical in conflict situations in an understandable way.

Players take the role of farmers who aim to make the best profit. Each farmer must irrigate up to ten fields, and decide whether to use rain, river, or ground water. Each has different costs, revenues, and recharge parameters. For instance, use of river water leads to quick depletion, yet this source has no yearly memory; groundwater overuse will not be apparent for some time, but aquifers take several years to recharge. The winner is the player who can make the highest profit; to achieve it they must work cooperatively, as other farmers in the same village draw from common resources. The main teaching issue is achieving the collective optimum, and showing that this may be different from the preferred solution for any individual player.

A screenshot of Irrigania (from Seibert & Vis, 2012)

Irrigania has two login modes, teacher and student. Teachers can obtain a teacher-login by registering with the authors; then teachers set up the game, specifying the game’s length, the number of villages and farmers, precipitation conditions, and whether farmers can see each other’s input values. Players obtain their login details from the teacher and make decisions on how to use their fields. When all players have entered their values, the server runs the calculations and the game steps forward one year. During the game, farmers can see their accumulated balance, current hydrological conditions, and the previous year’s input of other farmers. At the end, farmers can go to the results page, tabulating outcomes per farmer and per village.

The authors recommend running game sessions in a computer laboratory where a class of students can communicate. They also suggest playing several rounds, exploring the game’s settings and possibilities. Irrigania can be played with any number of players, but four to six per village yields the most interesting outcomes and discussions.

Specifically, the authors noted that farmers in cooperative villages did best on average, though selfish farmers could still win. In such cases, the other players punished the selfish player by overusing their own resources, decreasing the whole village’s income. While not strictly rational behaviour according to conventional game theory, this realism is one of the game’s strengths. Hence, when players play several rounds, the folly of selfish behaviour becomes more apparent, making the tactic less attractive next time. Furthermore, when students did not know who the other farmers were, the lack of social control led to greater overuse and less income on average. Thus greater overuse should occur when players can make their decisions in secret. Cooperation also makes students more aware of the importance of keeping groundwater stable. Finally, the game illustrates the increasing difficulty of decision-making given unpredictable rainfall. When the game is set to random rainfall, players operate with partial information and, just as in real life, this makes long-term decisions more difficult.

As a tool for teaching water management issues, especially the classic Tragedy of the Commons, Irrigania should benefit teachers and students alike.

By Wayne Deeker, freelance science writer

This week’s guest post introduces a book recently published by Cambridge University Press.

Written by William I. Newman, a Professor at the University of California, Los Angeles, Continuum Mechanics in the Earth Sciences provides an introduction to continuum mechanics and essential mathematical and physical approaches in the Earth sciences. It also contains problem sets and worked examples, altogether providing a valuable first step towards understanding continuum mechanics, related tensor notation, and mathematical-background concepts. Clearly structured and merging basic with advanced topics, this textbook will capture the attention of both expert researchers and beginners in the area.

Hardback; ISBN: 9780521562898; Publication date: March 2012; 194 pages; Price: £40 (~€50)

The text is divided into nine main chapters, with the first three covering geometrical definitions of the material body and the response of materials under different forces. These definitions start with a review of essential mathematics for continuum problems, with the purpose of their geometrical descriptions in addition to covering rotation, transformation, and kinematics. The text continues, mainly in Chapter 2, by covering the most important physical quantities in continuum mechanics, like temperature, force, and stress.

The fourth chapter is devoted to fundamental laws and equations. This part of the text starts by introducing new terminology and is followed by the derivation of conservation laws. The following subsections cover some well-known constitutive equations, describing the internal mechanical, thermal, and other properties, of the constitutive quantities of the continuum materials. These parts are followed by thermodynamic considerations, which play a key role in the geosciences, particularly in the context of flows in Earth materials where the temperature can undergo dramatic change.

Chapter 5 is dedicated to linear elastic solids. It defines a body of material as elastic if at each body point the strain is a one-to-one function of stress at that point regardless of its history of loading. This chapter continues with discussions on statics and dynamical equations of isotropic bodies, homogeneous deformation equations, and the role of temperature on body deformation. It ends with a quick review on microscopic structure of crystals and their behaviour.

The next two chapters, on classical fluids and geophysical fluid dynamics, discuss the motion of fluids and their behaviour under stationary and dynamic inertial environments. Examples include the interior of Earth as well as the motion of the oceans and atmospheres.

The book ends with two chapters covering computations in continuum mechanics and nonlinearity in the Earth. The first one deals with partial differential equations used in numerical methods with the purpose of solving complicated real-word problems of continuum bodies rather than using simplified and linearized solutions.

Finally, the last chapter starts with some comments on the role of nonlinearity and its manifestation in the Earth sciences and continues by reviewing both friction, as the oldest mechanical aspect, and fracture, as one of the most challenging aspects of continuum mechanics. The last subsections cover percolation models, used to demonstrate self-organization under specific conditions, as well as fractals, used for the generation of noticeably realistic details of the objects.

Although on the whole an informative volume, this book unfortunately does not provide sufficient rigorous examples to work with, as is common in other continuum mechanics books. In addition, more examples about applications of continuum mechanics into real life Earth science problems could have made the book a little more interesting for student readers even in other fields within engineering.

By Arash Maghsoudloo, Research Assistant at Middle East Technical University

“Flat in the mountains” by Olivier Galland, distributed by the European Geosciences Union under a Creative Commons license.

Electric cars require roughly 1,000 times more lithium than a standard laptop. It is therefore understandable that Bolivia’s Salar de Uyuni, a unique environment shown here under deep-blue skies, is widely regarded as the ‘Saudi Arabia of lithium’, because it contains over 40% of the planet’s lithium chloride (LiCl) reserves, or more than 5.4 million tons.

The Salar is part of the Altiplano plateau, which formed during the uplift of the Andes mountains roughly 14 million years ago. Tourists from around the world flock to see the parched, white landscape, located at 3,656 m above sea level and lacking in almost any life form. Its salt surface crust ranges in thickness, from tens of centimetres to a few metres, and sits atop mud interbedded with salt and saturated with brine. It is the brine that mining companies are lining up to extract, as it contains a saturated solution of sodium chloride, lithium chloride, and magnesium chloride in water.

Olivier Galland, a senior researcher at the University of Oslo, took this photo during an outreach project called the Andean Geotrail. He describes the salar’s environment, “It is the lowest point of an endorheic basin, meaning that all the rivers of the basin flow toward it and are not connected to the sea. Instead, the water from the rivers accumulates in the salar, which transforms to a lake during Austral Summers, before evaporating, leaving behind the salt, which precipitates and forms this continuous crust. I took this picture during an outreach project, which was based on a cycling adventure through the Andes, from Ushuaia in southern Argentina to Lima, Peru. The aim of this adventure was to visit spectacular geological localities, and share our observations with 600 pupils who followed us through a blog. You can find more information on the Andean Geotrail webpage, and on the blog.”

Galland sees the next few years as vital in shaping the future of the salar. He explains, “The Salar de Uyuni typically represents a fantastic geotouristic locality, as thousands of tourists visit it every year. Unfortunately, none of these tourist have any idea of how it formed. The aim of our outreach project was to give the relevant information to explain the origin of such a scenery, and give another dimension to this lunar landscape. In addition, the Salar de Uyuni has become an economical issue, as it hosts the largest lithium deposit on Earth. Since its discovery, the touristic and mining industry are fighting to decide the future of this unique geological environment.”

Imaggeo is the online open access geosciences image repository of the European Geosciences Union. Every geoscientist who is an amateur photographer (but also other people) can submit their images to this repository. Being open access, it can be used by scientists for their presentations or publications as well as by the press. If you submit your images to imaggeo, you retain full rights of use, since they are licenced and distributed by EGU under a Creative Commons licence.

“Sunset on the Black Sea coast” by Gerrit de Rooij, distributed by the European Geosciences Union under a Creative Commons license.

In the context of human history, few bodies of water are as storied as the Black Sea, located at the juncture of Europe, Asia, and the Middle East. Countless cargo ships and frigates have sailed its waters, over 1,100 km in length from east to west, daunting enough that the Ancient Greeks believed its eastern shores (now Georgia) marked the edge of the known world.

However, perhaps the Black Sea’s most unique quality is that it is strictly meromictic; that is, its water column is divided into two separate layers that do not intermix, as they would in most other (holomictic) lakes. While the sea’s upper layer receives oxygen from the atmosphere, over 90% of its total volume is permanently anoxic, or heavily depleted of all oxygen.

The Black Sea’s stratification is enforced by its physical features, including by the topography of its basin, a vast, low-lying valley caused by the uplift of the Caucasus, Pontides, and Balkan mountain ranges after the collision of the Eurasian and African tectonic plates 5-12 million years ago. Many rivers also feed into the sea’s upper layers, keeping them generally cooler, less dense, and less salty than the deeper layer, which is fed by the warmer, saltier waters of the Mediterranean. Agricultural runoff in these rivers feeds phytoplankton, whose growth and decay keeps available oxygen at a premium.

EGU Hydrological Sciences Division President Gerrit de Rooij took this picture in August 2008 at the Romanian village of 2 Mai. He describes the moment of its capture, “It was during my holiday (the kids in the picture are my girls). There is not much geosciences in there, but with the sun, the atmosphere (visible through the scattered sunlight and the wind ripples on the water surface), the water, vegetation, and earth/soil all present, the link to hydrology and geosciences is straightforward. But I just made the photograph to capture the light of that morning and the light in the girls’ hair. With the elegant curve of the hill, the positioning of the horizon, and the sun just above it aligned with the hill crest to the left and one of the girls below, connected by the reflection band on the sea surface, I liked the geometric composition of the image.”

The anoxic zone of the Black Sea is of great interest to marine archaeologists because it is rife with well preserved shipwrecks, lacking the common wood-devouring microorganisms that inhabit most other oceans and seas around the world.

Imaggeo is the online open access geosciences image repository of the European Geosciences Union. Every geoscientist who is an amateur photographer (but also other people) can submit their images to this repository. Being open access, it can be used by scientists for their presentations or publications as well as by the press. If you submit your images to imaggeo, you retain full rights of use, since they are licenced and distributed by EGU under a Creative Commons licence.

Water or new iridescent fluid? by Alessandro Arato, distributed by EGU under a Creative Commons licence.

At ambient conditions, water is an odourless, tasteless, transparent liquid. It’s a vital fluid yet it has very simple properties. Unlike soap bubbles, for example, water is not iridescent – it does not appear to change colour when we view it from different angles. Unless, of course, there is something colourful in the background that the water reflects giving it an apparent iridescence. This is what happened in this simple yet luminous scene captured by Alessandro Arato of the Polytechnic University of Turin in Italy.

He took this picture about a year ago in a small village in the Alps near Turin, known locally as the ‘village of the fountains’. “Fountains have traditionally been the place for people to get their water supply (from the water sources and after depuration processes) in remote Alpine villages, and also for social life. Even today, it is still common to hear villagers say ‘Hey folks, let’s meet at the fountain’,” explains Alessandro.

“After a whole year of working and studying, August 2011 was dedicated to relaxation.” he says. “I was sitting on a bench in front of the fountain. The village balconies were filled with flowers, and when I grabbed the camera and pointed at the water, I saw the amazing variety of colours that now are in the photo.”

Imaggeo is the online open access geosciences image repository of the European Geosciences Union. Every geoscientist who is an amateur photographer (but also other people) can submit their images to this repository. Being open access, it can be used by scientists for their presentations or publications as well as by the press. If you submit your images to imaggeo, you retain full rights of use, since they are licenced and distributed by EGU under a Creative Commons licence.

Cordillera del Paine by Martin Mergili, distributed by EGU under a Creative Commons licence.

Images such as the one above inspire scientists and nature lovers alike. This photograph, showing a Chilean landscape with elements representative of various Earth-science disciplines, is simply stunning. In a beautiful mix of shapes and colours, a quiet lake with floating icebergs appears tucked in between a roughed mountain in the background and a colourful double rainbow in the foreground.

The photographer, Martin Mergili of the University of Natural Resources and Life Sciences in Vienna, captured this inspiring scenery during a holiday trip a few years ago. The photo shows the eastern edge of the southern part of Cordillera del Paine, a “small but spectacular” mountain group in the Torres del Paine National Park, which is located in Chilean Patagonia almost 2,000 kilometres south of Santiago de Chile.

“The prominent peaks visible in the left portion of the image are the Cuernos del Paine,” Martin explains. “The rainbow in the foreground is not just decoration, it reflects the ever-changing weather patterns characteristic of that area. Even though it is located in the rainshade of the Cordillera at the edge of the semi-arid Patagonian lowlands, the westerlies bring a lot of moist air from the Pacific Ocean. The icebergs in the lake in the foreground (Lago Grey) originate from the large Glaciar Grey calving into the lake.”

More stunning images of this and other landscapes are available from Martin’s website.

Imaggeo is the online open access geosciences image repository of the European Geosciences Union. Every geoscientist who is an amateur photographer (but also other people) can submit their images to this repository. Being open access, it can be used by scientists for their presentations or publications as well as by the press. If you submit your images to imaggeo, you retain full rights of use, since they are licenced and distributed by EGU under a Creative Commons licence.