GeoLog

Imaggeo on Mondays

Imaggeo on Mondays: The changing landscape of Patagonia

Imaggeo on Mondays: The changing landscape of Patagonia

Pictured here is a snapshot of an environment in transition. Today’s featured photo was taken at the foot of Monte Fitz Roy, a jagged Patagonia mountain located in Los Glaciares National Park on the border between Argentina and Chile.

The Patagonia region in South America is the second biggest source of glaciers in the southern hemisphere, behind Antarctica, but the region is losing ice at a rapid rate.

Satellite imagery analysis over the last few years has suggested that the Patagonia region is losing ice more than any other part of South America, with some glaciers shedding ice faster than any place in the world.

A recent study reported that the northern and southern Patagonia ice fields in particular are losing roughly 17 billion tons of ice each year. Los Glaciares National Park alone is home to around 50 large glaciers, but because of warming temperatures, almost all of these large ice masses have been shrinking over the last 50 years.

This level of glacial ice loss can be hard to fully imagine, but in 2017, Shauna-Kay Rainford, a PhD student at Pennsylvania State University in the United States and photographer of this featured image, got a first-hand glimpse of Patagonia’s changing landscape.

“Ensconced between the granite boulders I felt like I was at a pivotal moment of continued change,” said Rainford. “While the peaks of Mt. Ritz Roy remain and will likely remain tall and majestic, with each passing year the glacier continues to retreat further towards the peak and the glacial lake continues to expand more and more.”

Rainford had reached this scenic yet tragically ephemeral view after a strenuous hike up the mountain. “It was very emotional to think about what this view will look like in the future if I should ever visit the mountain again,” Rainford recalls. “It is always striking to be confronted with the adverse consequences of human actions.”

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at http://imaggeo.egu.eu/upload/.

Imaggeo on Mondays: A slice of fossil life

Imaggeo on Mondays: A slice of fossil life

I am a petrographer at the University of Padova, Italy, studying the metamorphic rocks that form the deep Earth’s crust beneath our feet, and what happens when they get so hot to start to melt.

I’ve spent (enjoyed I should say) more than 30 years looking at rocks with an optical microscope. This simple, cheap tool, and more importantly, its skilled use, remain key ingredients for good research in petrology!

I’ve been taught by scientists, like Ron Vernon of Macquarie University in Australia, that a good micrograph is essential to document my research and strengthen my conclusions, and so I’ve always paid particular attention to the quality of photos. In the meanwhile, I have also developed a particular interest in photomicroscopy with an aesthetic purpose, realizing that the cocktail of rocks and polarized light has an extraordinary potential in the ‘sciart’ (Science-and-Art) field.

The digital revolution has marked a turning point in this activity, and 10 years ago I have started my micROCKScopica project to showcase to the public the beauty hidden in the small slices of rock that are thin sections.

When I find a photogenic rock I play with polarizers to get the desired combinations of color, and then I take a photograph. And people can enjoy the images, their colors and shapes, even without knowing the geological history behind them.

This is particularly true for this photograph: it is a thin section of a piece of dinosaur bone but I don’t know much about it (what bone, which dinosaur), only that it had been collected in Utah, in the United States. I received a small sample of the bone by Denise M. Harrison, a friend with whom I collaborated for a book on Lake Superior Agates. She is an award-winning lapidary (someone who cuts, polishes and engraves stones), and makes lovely cabochons with all sort of semiprecious, hard stones. I asked her for some leftovers to make some thin sections, because I wanted to see something new, possibly silicified (impregnated with silica during fossilization) because chalcedony – the very fine-grained variety of common quartz – may be extremely photogenic.

I had no idea of how a bone could look like under the microscope, and the first sight left me speechless! The porous structure, and the patterns of the radiating textures in the chalcedony fillings are extraordinary, and provide a wealth of possibilities for nice images.

In this shot, that I replicated in red and blue, a larger hole had been filled with a fine-grained quartz sand – the dark moon shape on top left – somehow interrupting the regular pattern of the bone tissue, that to someone may recall Australian Aboriginal artwork.

Curiously, this anatomically-related image made me quite popular among pathologists and other medical doctors, who find many analogies with their subjects of research. The ages of the specimens are some hundred million years apart, though…

By Bernardo Cesare, University of Padova, Italy

www.microckscopica.org

Editor’s note: The fossil sample featured in this photo was collected and distributed legally from Utah.

If you pre-register for the 2019 General Assembly (Vienna, 07–12 April), you can take part in our annual photo competition! From 15 January until 15 February, every participant pre-registered for the General Assembly can submit up three original photos and one moving image related to the Earth, planetary, and space sciences in competition for free registration to next year’s General Assembly!  These can include fantastic field photos, a stunning shot of your favourite thin section, what you’ve captured out on holiday or under the electron microscope – if it’s geoscientific, it fits the bill. Find out more about how to take part at http://imaggeo.egu.eu/photo-contest/information/.

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at http://imaggeo.egu.eu/upload/.

Imaggeo on Mondays: An iceberg-sized issue

Imaggeo on Mondays: An iceberg-sized issue

This was taken during a study, undertaken by me and my colleagues, on the sea ice of McMurdo Sound, Antarctica. We designed the project to document how supercooled water carrying suspended ice crystals flows along its pathway towards the open ocean. Ultimately, this work aims to assess the Ross Ice Shelf’s contribution of local melt to the long-term trend of increased sea ice cover around Antarctica – a signal which has been dominated by expansion in the Ross Sea.

However, over the winter prior to the field season an iceberg, 12 kilometres long and 1 kilometre wide that had calved from the Ross Ice Shelf, grounded itself across the middle of our intended study region. This created a significant constriction to the flow, as the iceberg forced the approximately 30 km-wide plume to squeeze into half of that space.

We quickly modified the objectives for the field season to take advantage of this, adding an element focusing on the fluid dynamics of accelerated large-scale flow around the tip of the iceberg, and another on the thermodynamics of the supercooled plume interacting with a deep wall of ice. These adjustments to our study required drilling several holes through the sea ice along lines that approached the iceberg from two different directions to collect the necessary oceanographic data.

The iceberg towers about 40 m above the frozen sea surface, with our field support team providing scale as they scope a route of safe approach. However, hidden from sight by the sea ice, the iceberg stretches a further 170 m below the surface to the point where it is grounded on the seafloor.

Conducting field science in Antarctica requires being able to adapt to a dynamic environment. In this case, our flexibility was rewarded with a unique data set – essentially a laboratory study in fluid mechanics on a real-world scale.

By Natalie Robinson, New Zealand National Institute for Water and Atmospheric Research (NIWA)

If you pre-register for the 2019 General Assembly (Vienna, 07–12 April), you can take part in our annual photo competition! From 15 January until 15 February, every participant pre-registered for the General Assembly can submit up three original photos and one moving image related to the Earth, planetary, and space sciences in competition for free registration to next year’s General Assembly!  These can include fantastic field photos, a stunning shot of your favourite thin section, what you’ve captured out on holiday or under the electron microscope – if it’s geoscientific, it fits the bill. Find out more about how to take part at http://imaggeo.egu.eu/photo-contest/information/.

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at http://imaggeo.egu.eu/upload/.

Imaggeo on Mondays: A pink and blue evening

Imaggeo on Mondays: A pink and blue evening

At sunset, the light travels a longer path in the atmosphere to reach our eyes than when the sun is high in the sky. At this time of the day, the light is more subject to scattering, as it interacts with more air (molecules and particles) before reaching our eyes, which explains why the sun is much less luminous and can be observed directly without being dazzled.

The sun appears redder because among the visible colours it emits, the blue radiation has been scattered by air molecules before this blue light reaches the observer. Indeed, the Rayleigh scattering theory says that the blue light (wavelength near 400 nm) is 16 times more scattered than the red light (wavelength near 800 nm). So the blue light is deviated outside the sun direction and only the remaining red light reaches the observer looking in the sun direction. This phenomenon also gives the blue colour of the sky when we look elsewhere than the direction of the sun.

Clouds consist of particles of liquid or solid water that are much larger than air molecules. It is then the Mie scattering theory that applies. This scattering favors no colour, which explains the milky colour of the clouds during the day. The clouds have the same colour of the solar radiation that strikes them. They therefore take a red colour at sunset and sunrise.

The night I took this photo, the beauty of the show was tinged with sadness: I came to the Pic du Midi Observatory in the Pyrenees (2800 m altitude) to observe the stars, not the clouds! This night of stars observation was a very great birthday present from my lab colleagues.

Luckily, the ceiling of the cloud layer lowered a little and the night was clear enough. The next morning, at dawn, the sea of ​​clouds confined in the valleys also offered a grandiose spectacle.

By Claudine Vanbauce, Université de Lille, Laboratoire d’Optique Atmosphérique, France

If you pre-register for the 2019 General Assembly (Vienna, 07–12 April), you can take part in our annual photo competition! From 15 January until 15 February, every participant pre-registered for the General Assembly can submit up three original photos and one moving image related to the Earth, planetary, and space sciences in competition for free registration to next year’s General Assembly!  These can include fantastic field photos, a stunning shot of your favourite thin section, what you’ve captured out on holiday or under the electron microscope – if it’s geoscientific, it fits the bill. Find out more about how to take part at http://imaggeo.egu.eu/photo-contest/information/.

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at http://imaggeo.egu.eu/upload/.