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Imaggeo

Imaggeo on Mondays: Monitoring Antarctica’s ocean current

Imaggeo on Mondays: Monitoring Antarctica’s ocean current

This week’s featured image depicts a quiet and still oceanic landscape in Antarctica, but polar scientists are studying how energetic and variable the ocean currents in this part of the world can be.

In this picture, the marine research vessel RRS James Clark Ross is making its way through the Lemaire Channel, a small passage off the coast of the Antarctic Peninsula, south of the southernmost tip of Chile. This channel is about 11 kilometres long and just 1,600 metres wide at its narrowest point, bordered by a spectacular range of steep cliffs.

At the time this photo was taken, the ship was headed to the Rothera Research Station, a British Antarctic Survey base on the white continent’s peninsula. The scientists aboard the vessel are part of a decades-long research campaign surveying the ocean current surrounding Antarctica, known as the Antarctic Circumpolar Current (ACC). The ACC is the world’s strongest and most influential current, transporting 165 million to 182 million cubic metres of water every second and connecting most of Earth’s major oceans. As such, any changes to the ACC have the potential to impact other marine environments around the world.

For more than 25 years, scientists from the UK’s National Oceanography Centre (NOC) have ventured south each Antarctic summer to measure the ocean’s physical features in one region of the Southern Ocean, called the Drake Passage. Spanning just 800 kilometres between the Falkland Islands and the Antarctic Peninsula, the Drake Passage is the shortest crossing from Antarctica to any other landmass. This makes it a prime spot to survey the ocean’s currents, as the flow is constricted to a narrow geographical region.

So far, researchers have completed 24 survey trips across the passage. The data collected during these trips have been used to assess how physical features of the ACC change, both throughout a single year and over the course of several years. Yvonne Firing at NOC leads the latest expeditions as part of the UK funded ORCHESTRA project. The continuation of this monitoring is helping scientists study how the ocean stores excess heat and carbon. No other ocean basin has been monitored so consistently, making the Drake Passage the most comprehensively studied part of the Southern Ocean.

By Olivia Trani, EGU Communications Officer

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: Loch Coruisk – home of the wild Kelpie

Imaggeo on Mondays: Loch Coruisk – home of the wild Kelpie

On the south-western coast of the Isle of Skye, Scotland, lies Loch Coruisk, supposedly home of a water horse. At the southern end of this freshwater Loch, the Scavaig River discharges into a sea Loch, Loch na Cuilce. Loch Coruisk snuggles close to the center of the Cuillin Hills complex, younger than both the northern and southern formations of the Isle. At present, the neighbouring hills are dominated by Paleogene intrusive bytownite gabbros that are responsible for the jagged outline of the topography. Cuillin Hills forms the remains of an eroded magmatic chamber.

Description by Cedric Gillmann, as it first appeared on imaggeo.egu.eu.

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: The surprising beauty of the Arctic tundra

Imaggeo on Mondays: The surprising beauty of the Arctic tundra

Close your eyes and try to imagine first thing which comes to your mind, when somebody says “Tundra”. What would you imagine?

Being a master student, I imagined cold, flat and a dead field. In fact, Tundra turn out to be completely different, at least in September 2010, when I and my colleagues were lucky to visit it.

As it is well known from textbooks no big trees grows in Tundra, however, the local mosses were full of colour and various berries.
Those hills (on the photo), called “sopkas”, build up the amazing landscape of tundra. Those hills are not originated volcanically or as debris. Those are conglomerations of stones pushed up from the ground by permafrost during melting-freezing cycle. So, each sopka should grow a little every winter, representing a magnificent power of permafrost.

Description by Alexandra Loginova, as it first appeared on imaggeo.egu.eu.

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: Recreating monster waves in art and science

Imaggeo on Mondays: Recreating monster waves in art and science

Featured in this blog post is a collection of images that gives a picture-perfect example of life imitating art.

The photos in the left column are three consecutive still frames of a breaking wave that scientists generated in a lab environment at the University of Edinburgh in the UK. The pictures in the centre and right columns show the same wave images, but now superimposed with the famous 19th century Japanese woodblock print, The Great Wave off Kanagawa.

While the images were produced on opposite sides of the Earth with a few hundreds of years between their creation, the curves and edges of the waves are very similarly positioned.

“Completely coincidentally, in a strange twist of fate, the wave we created bears striking resemblance to The Great Wave off Kanagawa, painted many years ago by the Japanese artist Katsushika Hokusai,” said Mark McAllister, a researcher at the University of Oxford in the UK. He is part of a team of scientists working to better understand the dynamics of freak waves – waves that are unexpectedly large in comparison to the waves that surround it.

The images also highlight the similarities between artists and scientists that often are overlooked: while art and science are different in many ways, both involve observing and trying to interpret their surroundings. The wave simulation photos and the woodblock print both visualise a common endeavor: recreating nature to better understand it.

Simulating monster waves

The photographs in the left column feature the recreation of a very particular wave that took form in 1995 in the North Sea, known as the Draupner freak wave. This particular surface wave was one of the first confirmed observations of a freak wave at sea. The Draupner Oil Platform had taken measurements of the event, reporting that the wave was 26 metres tall (more than twice as tall as the surrounding waves). Rogue waves as high as 30 metres had been reported by sailors and scientists for many years, but until the 20th century there was wide disbelief from the scientific community that such waves were more than myth.

“The measurement of the Draupner wave in 1995 was a seminal observation initiating many years of research into the physics of freak waves and shifting their standing from mere folklore to a credible real-world phenomenon,” said McAllister in a recent press release.

Such rogue waves are capable of causing heavy damage to large ships, and by recreating the Draupner freak wave, McAllister and his colleagues are trying to better understand how this marine phenomenon occurs.

Experiments were carried out in the FloWave Ocean Energy Research facility at the University of Edinburgh. The facility has a circular basin equipped with wavemakers around the entire circumference, allowing scientists to generate waves from any direction and recreate complex wave conditions.

The research team was able to simulate this wave on a smaller scale by crossing two different wave groups at a large angle. They found that when the two wave groups hit each other at 120 degrees, this allowed the freak wave to take shape.

Typically, wave breaking in the ocean limits the maximum height of waves. But when waves cross each other at large angles, wave breaking behaviour changes, removing typical height limitations.

Monster wave immortalised in print

The Great Wave off Kanagawa, one of Hokusai’s most famous prints, depicts three crewed boats at sea, seemingly seconds away from crashing into a monstrous wave, with Japan’s Mount Fugi sitting in the distance. The work is often interpreted to symbolize the eternity and formidable force of nature compared to the frailty of humans.

While the print is often considered to be an artistic representation of a tsunami, one study argues that the features and conditions are more similar to a freak wave event. By using the boats and the mountains as reference points, the researchers involved in the study estimate that the great wave is approximately 10-12 metres in height.

While many artists distort reality to enhance and highlight certain aspects of their work, the researchers point out that Hokusai’s work is likely to be representative of nature, noting that he strove for years to understand the structure of his surroundings and draw them accurately in his art. In the afterward of his 1834 collection of prints containing The Great Wave of Kanagawa, Hokusai writes:

“Since the age of six, I had a habit of sketching from life. From fifty onwards I began producing a fair amount of art work, but nothing I did before the age of seventy was worthy of attention. At seventy-three, I began to grasp the structures of birds and beasts, insects and fish, and of the way plants grow.

If only I go on trying, I will surely understand them still better by the time I am eighty, so that by ninety I will have penetrated to their essential nature. At one hundred, I hope I may have a divine understanding of them, while at one hundred and ten I may have reached the stage where every dot and every stroke I paint will be alive. May men of great age and virtue see that I am not hoping for too much!”

By Olivia Trani, EGU Communications Officer

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/.