GeoLog

GeoLog

Imaggeo on Mondays: Wandering the frozen Svalbard shore

Imaggeo on Mondays: Wandering the frozen Svalbard shore

These ethereal, twisted ice sculptures litter the frozen shoreline of Tempelfjorden, Svalbard, giving the landscape an otherworldly feel and creating a contrast with the towering ice cliff of the glacier and the mountains behind. They are natural flotsam, the scoured remnants of icebergs calved from the Tunabreen glacier, washed up on the shoreline.

These icebergs were calved from the Tunabreen glacier, which flows into Tempelfjorden from its source at the Lomonosovfonna ice cap. Tunabreen is a surge-type glacier, which means that it periodically switches between long periods of slow, stable flow to short-lived periods of very fast flow during which it advances. Tunabreen has historically surged approximately every 35 to 40 years, and its calving front advanced more than 2 kilometres during a surge in 2004.

Tunabreen is one of the glaciers monitored by the Calving Rates and Impact on Sea Level (CRIOS) project, an international initiative that involves several institutions. The glacier tends to slow during the winter months when there is less meltwater available to lubricate the sliding of ice over bedrock. Glaciologists were caught by surprise, therefore, when in late 2016 the glacier was observed to accelerate to speeds in excess of 3 m/day from the more usual 0.4 m/day. This acceleration began at the glacier terminus and spread up to 7km upstream over the following months. Tunabreen appeared to be surging decades earlier than expected!

The causes of this change in the glacier’s behaviour are not certain. However, the onset of this acceleration followed an unusually warm and wet autumn. Sea ice, which usually acts to oppose the flow by applying a resistive pressure against the calving front, also failed to form in Tempelfjorden over the winter. Both of these factors likely contributed. As a result of the flow acceleration, the surface of the glacier has become heavily crevassed, posing a hazard to travellers and glaciologists hoping to cross it!

I was fortunate to be able to visit Tunabreen in March 2017, as part of a glaciology course taught at UNIS, the University Centre in Svalbard. The view of the glacier’s 100ft high calving front framed by the mountains in the background is spectacular, and the trip by snowmobile was a fantastic daytrip. The surge continued throughout 2017 and early 2018, with the calving front advancing by more than a kilometre during that period. Since the summer of 2018, flow velocities have been decreasing, so it appears that the surge may have come to an end. This episode illustrates that there is still much we have to learn about the dynamics of surge-type glaciers, and that they can still take us by surprise!

Matt Trevers, PhD Researcher, Centre for Polar Observation and Modelling, University of Bristol

Further reading

Glaciers On The Move

Tunabreen may be surging decades earlier than expected (The University Centre in Svalbard)

What is going on at Tunabreen? (Penny How)

The recent surge of Tunabreen, Svalbard (Adrian’s glacier gallery) 

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 ash cloud of Eyjafjallajökull approaches

Imaggeo on Mondays: The ash cloud of Eyjafjallajökull approaches

This photo depicts the famous ash cloud of the Icelandic volcano Eyjafjallajökull, which disrupted air traffic in Europe and over the North Atlantic Ocean for several days in spring 2010. The picture was taken during the initial phase of the eruption south of the town of Kirjubæjarklaustur, at the end of a long field work day. Visibility inside the ash cloud was within only a few metres.

The eruption was preceded by years of seismic unrest and repeated magma intrusions. A first effusive fissure opened outside the ice shield of the volcano at the end of March 2010, followed by an explosive eruption in the main crater of the volcano in April 2010.

Iceland was well prepared for the eruption – the rest of the world obviously was not. The region around Eyjafjallajökull is sparsely populated, residents were prepared days before the eruption and the evacuation went smoothly. However, the grain size of the ejected volcanic ash was fine enough so that the unfavourable and unusual wind direction during these days transported the ash all the way to Europe and led to air space closures almost all over the continent.

By Martin Hensch, Nordic Volcanological Center, University of Iceland (now at Geological Survey of Baden-Württemberg, Germany)

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/.

November GeoRoundUp: the best of the Earth sciences from around the web

November GeoRoundUp: the best of the Earth sciences from around the web

Drawing inspiration from popular stories on our social media channels, major geoscience headlines, as well as unique and quirky research, this monthly column aims to bring you the latest Earth and planetary science news from around the web.

Major stories

Earth’s red and rocky neighbor has been grabbing a significant amount of attention from the geoscience media this month. We’ll give you the rundown on the latest news of Mars.

The NASA-led InSight lander, short for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport, touched down on the Red Planet’s surface last week, causing the space agency’s Jet Propulsion Laboratory (JPL) control room to erupt in applause, fist pumps, and cool victory handshakes.

The lander, equipped with a heat probe, a radio science instrument and a seismometer, will monitors the planet’s deep interior. Currently, no other planet besides our own has been analysed in this way.

While scientists know quite a bit about the atmosphere and soil level of Mars, their understanding of the planet’s innerworkings, figuratively and literally, only scratches the surface. “We don’t know very much about what goes on a mile below the surface, much less 2,000 miles below the surface down to the center,” explains Bruce Banerdt, a scientist at JPL, to the Atlantic.

By probing into Mars’ depths, researchers hope the mission gives insight into the evolution of our solar system’s rocky planets in their early stages and helps explain why Earth and Mars formed such different environments, despite originating from the same cloud of dust.

“Our measurements will help us turn back the clock and understand what produced a verdant Earth but a desolate Mars,” Banerdt said recently in a press release.

The InSight lander launched from Earth in May this year, making its way to Mars over the course of seven months. Once reaching the planet’s upper atmosphere, the spacecraft decelerated from about 5,500 to 2.4 metres per second, in just about six minutes. To safely slow down its descent, the lander had to use a heatshield, a parachute and retro rockets.

“Although we’ve done it before, landing on Mars is hard, and this mission is no different,” said Rob Manning, chief engineer at JPL, during a livestream. “It takes thousands of steps to go from the top of the atmosphere to the surface, and each one of them has to work perfectly to be a successful mission.”

This artist’s concept depicts NASA’s InSight lander after it has deployed its instruments on the Martian surface. Credit: NASA/JPL-Caltech

The InSight lander is currently situated on Elysium Planitia, a plane near the planet’s equator also known by the mission team as the “biggest parking lot on Mars.” Since landing, the robot has taken its first photos, opened its solar panels, and taken preliminary data. It will spend the next few weeks prepping and unpacking the instruments onboard.

The devices will be used to carry out three experiments. The seismometers will listen for ‘marsquakes,’ which can offer clues into the location and composition of Mars’ rocky layers. The thermal probe will reveal how much heat flows out of the planet’s interior and hopefully show how alike (or unalike) Mars is to Earth. And finally, radio transmissions will demonstrate how the planet wobbles on its axis.

In other news, NASA has also chosen a landing site for the next Mars rover, which is expected to launch in 2020. The space agency has announced that the rover will explore and take rock samples from Jezero crater, one of the three locations shortlisted by scientists. The crater is 45 kilometres wide and at one point had been filled with water to a depth of 250 metres. The sediment and carbonate rocks left behind could offers clues on whether Mars had sustained life.

What you might have missed

By analysing radar scans and sediment samples, a team of scientists have discovered a massive crater, hidden underneath more than 900 metres of ice in northwest Greenland. After surveying the site, scientists say it’s likely that a meteorite created the sometime between 3 million and 12,000 years ago.

The depression under Hiawatha Glacier is 31 kilometres wide, big enough to hold the city of Paris. At this size, the crater is one of the top 25 largest craters on Earth; it’s also the first to be found under ice. An impact of this size significant mark on the Earth’s environment. “Such an impact would have been felt hundreds of miles away, would have warmed up that area of Greenland and may have rained rocky debris down on North America and Europe,” said Jason Daley from Smithsonian Magazine.

Links we liked

The EGU Story

This month, we have announced changes to the EGU General Assembly 2019 schedule, which aim to give more time for all presentation types. Check our news announcement for more information. In other news, we have opened applications to the EGU General Assembly 2019 mentoring programme, and are advertising a job opportunity for geoscientists with science communication experience to work at the meeting.

Also this month, we opened the call for applications for EGU Public Engagement Grants, and have announced the creation of the EGU Working Group on Diversity and Equality. Finally, we’ve published a press release on a new study that looked into whether data on seabird behavior could be used to track the ocean’s currents.

And don’t forget! To stay abreast of all the EGU’s events and activities, from highlighting papers published in our open access journals to providing news relating to EGU’s scientific divisions and meetings, including the General Assembly, subscribe to receive our monthly newsletter.

Imaggeo on Mondays: Exploring ice in the deep

Imaggeo on Mondays: Exploring ice in the deep

The occurrence of sporadic permafrost in the Alps often needs challenging fieldwork in order to be investigated. Here in the high altitude karstic plateau of Mt. Canin-Kanin (2587 m asl) in the Julian Alps (southeastern European Alps) several permanent ice deposits have been recently investigated highlighting how also in such more resilient environments global warming is acting rapidly. Important portions of the underground cryosphere are actually rapidly melting, loosing valuable paleoarchives contained in the ice.

Description by Renato R. Colucci, 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/.