GeoLog

Geoscientific Methods

Imaggeo on Mondays: The calm before the storm

Imaggeo on Mondays: The calm before the storm

The picture was taken during the 2015 research cruise HE441 in the southern German Bight, North Sea. It features the research vessel Heincke, on a remarkably calm and warm spring day, forming a seemingly steady wake.

The roughly 55 metre long FS Heincke, owned by the German federal government and operated by the Alfred Wegener Institute, provides a great platform for local studies of the North Sea shelf. Eleven scientists and students from the University of Bremen, MARUM Research Faculty, University of Kiel, and Federal Waterways Engineering and Research Institute, along with the ship’s crew formed a great team under the supervision of chief scientist Christian Winter.

On deck, different autonomous underwater observatories were waiting to be deployed. Their purpose was to measure the seabed- and hydrodynamics in a targeted area of the German Bight. The investigation of the interaction between geomorphology, sedimentology and biogeochemistry is crucial to understand the processes acting on this unique and dynamic environment. In the German Bight various stakeholders with diverse interests come together. Profound knowledge, backed by cutting edge research, helps to resolve future conflicts between use and protection of the environment.

While this photo features a tranquil day at sea, some days later the weather and wave conditions got so bad that the cruise had to be abandoned. Storm Niklas, causing wave heights of more than three metres, made deployment and recovery of the observatories too dangerous for the crew, scientists, and delicate instruments.

Despite the severe weather, the research cruise was still able to gather important data with the time made available. Schedules on research vessels are tight and optimized to fit as much high-quality measurements as possible into time slots that are depending on convenient sea (tide) and weather conditions. State-of-the-art research equipment were prepared, deployed, recovered and assessed several times during the then only 8-day long cruise. Measurements were supported by ship based seabed mapping and water column profiling. Transit times, like the one depicted, were used to prepare the different sensors and instruments for the upcoming deployment.

The rare occasion of good weather combined with idle time was utilized to take this long exposure photo. A calm sea, a stable clamp temporarily attached to a handrail, and a neutral density filter were additionally required to increase the exposure time of the camera to 13 seconds, in order to capture this picture. The long exposure time smooths all movement relative to the ship, enhancing the effect of the wake behind the Heincke vessel.

Over the course of several years, regular Heincke research cruises and the collaboration between the different institutions has led to the successful completion of research projects, with findings being published in various journals, listed below.

By Markus Benninghoff, MARUM, University of Bremen, Germany

Further reading

Ahmerkamp, S, Winter, C, Janssen, F, Kuypers, MMM and Holtappels, M (2015) The impact of bedform migration on benthic oxygen fluxes. Journal of Geophysical Research: Biogeosciences, 120(11). 2229-2242. doi:10.1002/2015JG003106

Ahmerkamp, S, Winter, C, Krämer, K, de Beer, D, Janssen, F, Friedrich, J, Kuypers, MMM and Holtappels, M (2017) Regulation of benthic oxygen fluxes in permeable sediments of the coastal ocean. Limnology and Oceanography. doi:10.1002/lno.10544

Amirshahi, SM, Kwoll, E and Winter, C (2018) Near bed suspended sediment flux by single turbulent events. Continental Shelf Research, 152. 76-86. doi:10.1016/j.csr.2017.11.005

Krämer, K and Winter, C (2016) Predicted ripple dimensions in relation to the precision of in situ measurements in the southern North Sea. Ocean Science, 12(6). 1221-1235. doi:10.5194/os-12-1221-2016

Krämer, K, Holler, P, Herbst, G, Bratek, A, Ahmerkamp, S, Neumann, A, Bartholomä, A, van Beusekom, JEE, Holtappels, M and Winter, C (2017) Abrupt emergence of a large pockmark field in the German Bight, southeastern North Sea. Scientific Reports, 7(1). doi:10.1038/s41598-017-05536-1

Oehler, T, Martinez, R, Schückel, U, Winter, C, Kröncke, I and Schlüter, M (2015) Seasonal and spatial variations of benthic oxygen and nitrogen fluxes in the Helgoland Mud Area (southern North Sea). Continental Shelf Research, 106. 118-129. doi:10.1016/j.csr.2015.06.009

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: Crowned elephant seals do citizen science

Imaggeo on Mondays: Crowned elephant seals do citizen science

In the Southern Ocean and North Pacific lives a peculiar type of elephant seal. This group acts like any other marine mammal; they dive deep into the ocean, chow down on fish, and sunbathe on the beach. However, they do all this with scientific instruments attached to their heads. While the seals carry out their usual activities, the devices collect important oceanographic data that help scientists better understand our marine environment.

The practice of tagging elephant seals to obtain data started in 2004, and today equipped seals are the largest contributors of temperature and salinity profiles below of the 60th parallel south. You can find all sorts of data that has been collected by instrumented sea creatures through the Marine Mammals Exploring the Oceans Pole to Pole database online.

The female elephant seal, pictured here at Point Suzanne on the eastern end of the Kerguelen Islands in the Southern Ocean, is a member of this unusual headgear-wearing cohort. This particular seal had been roaming the sea for several months with the device (also known as a miniature Conductivity-Temperature-Depth sensor) on her head. As the seal dove hundreds of metres below the sea surface, the instrument captured the vertical profile of the area, recording the ocean’s temperature and salinity, as well as chlorophyll a fluorescence and concentrations. When the seal resurfaced, the sensor sent the data it had accrued to scientists by satellite.

Etienne Pauthenet, a PhD student at Stockholm University who was involved in a seal tagging campaign, had a chance to snap this photo before tranquilising the seal and retrieving the tag.

Using elephant seals and other marine mammals to collect data gives scientists the opportunity to analyse remote regions of the ocean that aren’t very accessible by vehicles. Studying these parts of the world are important for gaining insight on how oceans and their inhabitants are responding to climate change, for example. With the help of data-gathering elephant seals, researchers are able to amass in situ measurements from regions that previously had been hard to reach, apply this data to oceanographic models, and make predictions on ocean climate processes.

While gathering data via elephant seals are crucial to oceanographic research, Pauthenet explains that the practice is sometimes quite difficult. “It can be complicated to find back the seal, because of the Argo satellite signal precision. The quality of the signal depends on the position of the seal, if she is lying on her back for example, or if she is still in the water.”

While on the research campaign, Pauthenet and his colleagues were stationed at a small cabin on the shore of Point Suzanne and they walked the shore every day in search of the seal, relying on location points transmitted from a VHF radio. After seven days they finally located her and removed her valuable crown. The seal was then free to go about her business, having given her contribution to the hundreds of thousands of vertical profiles collected by marine mammal citizen scientists.

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: The best of imaggeo in 2018

Imaggeo on Mondays: The best of imaggeo in 2018

Imaggeo, our open access image repository, is packed with beautiful images showcasing the best of the Earth, space and planetary sciences. Throughout the year we use the photographs submitted to the repository to illustrate our social media and blog posts.

For the past few years we’ve celebrated the end of the year by rounding-up some of the best Imaggeo images. But it’s no easy task to pick which of the featured images are the best! Instead, we turned the job over to you!  We compiled a Facebook album which included all the images we’ve used  as header images across our social media channels and on Imaggeo on Mondays blog post in 2018 an asked you to vote for your favourites.

Today’s blog post rounds-up the best 12 images of Imaggeo in 2018, as chosen by you, our readers.

Of course, these are only a few of the very special images we highlighted in 2018, but take a look at our image repository, Imaggeo, for many other spectacular geo-themed pictures, including the winning images of the 2018 Photo Contest. The competition will be running again this year, so if you’ve got a flair for photography or have managed to capture a unique field work moment, consider uploading your images to Imaggeo and entering the 2019 Photo Competition.

A view of the southern edge of the Ladebakte mountain in the Sarek national park in north Sweden. At this place the rivers Rahpajaka and Sarvesjaka meet to form the biggest river of the Sarek national park, the Rahpaädno. The rivers are fed by glaciers and carry a lot of rock material which lead to a distinct sedimentation and a fascinating river delta for which the Sarek park laying west of the Kungsleden hiking trail is famous.

 

Melt ponds. Credit: Michael Tjernström (distributed via imaggeo.egu.eu)

The February 2018 header image used across our social media channels. The photos features ponds of melted snow on top of sea ice in summer. The photo was taken from the Swedish icebreaker Oden during the “Arctic Summer Cloud Ocean Study” in 2008 as part of the International Polar Year.

 

Karstification in Chabahar Beach, IRAN. Credit: Reza Derakhshani (distributed via imaggeo.egu.eu)

The June 2018 header image used for our social media channels. The photo was taken on the Northern coast of the Oman Sea, where the subduction of Oman’s oceanic plate under the continental plate of Iran is taking place.

 

River in a Charoite Schist. Credit: Bernardo Cesare (distributed via imaggeo.egu.eu)

A polarized light photomicrograph of a thin section of a charoite-bearing schist. Charoite is a rare silicate found only at one location in Yakutia, Russia. For its beautiful and uncommon purple color it is used as a semi-precious stone in jewelry.

Under the microscope charoite-bearing rocks give an overall feeling of movement, with charoite forming fibrous mats that swirl and fold as a result of deformation during metamorphism. It may be difficult to conceive, but these microstructures tell us that solid rocks can flow!

 

Refuge in a cloudscape. Credit: Julien Seguinot (distributed via imaggeo.egu.eu)

The action of glaciers combined with the structure of the rock to form this little platform, probably once a small lake enclosed between a moraine at the mountain side and the ice in the valley.

Now it has become a green haven in the mountain landscape, a perfect place for an alp. In the Alps, stratus clouds opening up on autumn mornings often create gorgeous light display.

 

Antarctic Fur Seal and columnar basalt Credit: Etienne Pauthenet (distributed via imaggeo.egu.eu).

This female fur seal is sitting on hexagonal columns of basalt rock, that can be found in Pointe Suzanne at the extreme East of the Kerguelen Islands, near Antarctica. This photo was the November 2018 header image for our social media channels.

 

Silent swamp predator. Credit: Nikita Churilin (distributed via imaggeo.egu.eu).

A macro shot of a Drosera rotundifolia modified sundew leaf waiting for an insect at swamp Krugloe. This photo was the January 2018 header image and one of the finalists in the 2017 Imaggeo Photo Competition.

 

Once there was a road…the clay wall. Credit: Chiara Arrighi (distributed via imaggeo.egu.eu)

The badlands valley of Civita di Bagnoregio is a hidden natural gem in the province of Viterbo, Italy, just 100 kilometres from Rome. Pictured here is the ‘wall,’ one of the valley’s most peculiar features, where you can even find the wooden structural remains of a trail used for agricultural purposes in the 19th and 20th centuries.

 

New life on ancient rock. Credit: Gerrit de Rooij (distributed via imaggeo.egu.eu).

“After two days of canooing in the rain on lake Juvuln in the westen part of the middle of Sweden, the weather finally improved in the evening, just before we reached the small, unnamed, uninhabited but blueberry-rich island on which this picture was taken. The wind was nearly gone, and the ragged clouds were the remainder of the heavier daytime cloud cover,” said Gerrit de Rooij, who took this photograph and provided some information about the picture, which features some of the oldest rocks in the world but is bursting with new life, in this blog post.

 

Cordillera de la Sal. Credit: Martin Mergili (distributed via imaggeo.egu.eu)

The photograph shows the Valle de la Luna, part of the amazing Cordillera de la Sal mountain range in northern Chile. Rising only 200 metres above the basin of the Salar de Atacama salt flat, the ridges of the Cordillera de la Sal represent a strongly folded sequence of clastic sediments and evapourites (salt can be seen in the left portion of the image), with interspersed volcanic material.

 

Robberg Peninsula – a home of seals. Credit: Elizaveta Kovaleva (distributed via imaggeo.egu.eu).

“This picture is taken from the Robberg Peninsula, one of the most beautiful places, and definitely one of my favorite places in South Africa. The Peninsula forms the Robberg Nature Reserve and is situated close to the Plettenberg Bay on the picturesque Garden Route. “Rob” in Dutch means “seal”, so the name of the Peninsula is translated as “the seal mountain”. This name was given to the landmark by the early Dutch mariners, who observed large colonies of these noisy and restless animals on the rocky cliffs of the Peninsula,” said Elizaveta Kovaleva in this blog post.

 

The great jump of the Tequendama. Credit: Maria Cristina Arenas Bautista (distributed via imaggeo.egu.eu)

Tequendama fall is a natural waterfall of Colombia. This blog post highlights a Colombian myth about the origins of the waterfall, which is tied to a real climate event.

 

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 up 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/.

How to forecast the future with climate models

How to forecast the future with climate models

Our climate is constantly changing, and with the help of simulation modelling, scientists are working hard to better understand just how these conditions will change and how it will affect society. Science journalist Conor Paul Purcell has worked on Earth System Models during his time as a PhD student and postdoctoral researcher; today he explains how scientists use these models as tools to forecast the future of our climate.

While we can’t predict everything about our future, climate scientists have a good understanding of how our environment will look and feel like in the coming years. Researchers and climate specialists predict that temperatures will increase dramatically in the 21st century, ranging between 1.5°C and 4°C above pre-industrial levels, depending on your location and the amount of carbon dioxide pumped into the atmosphere in the near future. Forecasts of future drought and flood risk, at both regional and global bases, are also provided by climate experts.

Understanding how such features of Earth’s changing climate may manifest, and ultimately impact on our society, takes considerable international collaboration – a collaboration which is largely based around the results of climate modelling. That’s because climate predictions for the future are made using sophisticated computer models, which are built around mathematical descriptions of the physical and biological processes that govern our planet.

These models have become so complex in recent years that they are now referred to as Earth System Models (ESMs). Using ESMs, climate modellers can create simulations of the planet at different times in the future and the past. ESMs are in fact the only tools we have for simulating the global future in this sense. For instance, if we want to know how our climate may look like one hundred years from now, how ocean acidification levels may change and how this might impact ocean life, or how plants will respond to increasing levels of atmospheric carbon dioxide, ESMs are the only tool available.

The models are built in components, each representing a separate part of the Earth system: the atmosphere, the ocean, the land surface and its vegetation, and the ice-sheets and sea-ice. These are constructed by coding each component with the mathematics that describes the environmental processes at work.

Climate models are systems of differential equations based on the basic laws of physics, fluid motion, chemistry, and biology. Pictured here is a schematic of a global atmospheric model. (Credit: NOAA, via Wikimedia Commons)

For example, the winds in the atmosphere are described by the mathematics of fluid motion. Model developers translate these mathematical equations into code that computers can understand, like giving them a set of instructions to follow. Supercomputers can then interpret the code to simulate how winds, for example, are expected to develop at each global location through time. The results are usually plotted on world maps.

As scientists have learned more about our Earth’s systems over time, the complexity of these individual models has been ramped up dramatically. For example, the land surface and vegetation model components become more sophisticated as plant biologists understand more and more about how plants transfer water and carbon between the land and atmosphere.

And it’s not just one giant solo project either: there are tens of ESMs and hundreds of subcomponent models developed and used at research centres around the globe. Collaboration between these facilities is a necessary part of progress, and information is shared at international conferences ever year, like the American Geophysical Union’s Fall Meeting in the United States and the European Geosciences Union’s General Assembly in Europe.

This means that developments are always been made towards increasing the realism of ESMs. On the horizon such developments will include increasing the resolution of the global models for improving accuracy at regional locations, and also incorporating the results from the latest research in atmospherics, oceanography and ice sheet dynamics. One example is research into plants, specifically how they interact with carbon dioxide and water in the atmosphere. Further understanding of this biological process is expected to increase the realism of models over the coming years and decades. In general, improvements to the accuracy of model simulations can help to help society in the future. For example, models will be able to help predict how climate change may impact, say, water scarcity in South Africa, wildfire risk in the western United States, or crop yields in Asia. Indeed, the ESMs of the future should boast incredibly accurate simulations and prediction capabilities unheard of today.

By Conor Purcell, a Science & Nature Writer with a PhD in Earth Science

Conor Purcell is a science journalist with a PhD in Earth Science. He is also founding-editor of www.wideorbits.com and is on twitter @ConorPPurcell and some of his other articles at cppurcell.tumblr.com.