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research cruise

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: Sunset over the Labrador Sea

Ruby skies and calm waters are the backdrop for this week’s Imaggeo image – one of the ten finalist images in this year’s EGU Photo contest.

 Sunset over the Labrador Sea. Credit: Christof Pearce (distributed via  imaggeo.egu.eu)

Sunset over the Labrador Sea. Credit: Christof Pearce (distributed via imaggeo.egu.eu)

“I took the picture while on a scientific cruise in West Greenland in 2013,” explains Christof Pearce, a postdoctoral researcher at Stockholm University. “We spent most of the time inside the fjord systems around the Greenland capital, Nuuk, but this specific day we were outside on the shelf in the open Labrador Sea. The black dot on the horizon toward the right of the image is a massive iceberg floating in the distance.”

Pearce took part in a research cruise which aimed to obtain high-resolution marine sedimentary records, which would shed light on the geology and past climate of Greenland during the Holocene, the epoch which began 11,700 years ago and continues to the present day.

A total of 12 scientists and students took part in the Danish-Greenlandic-Canadian research cruise in the Godthåbsfjord complex and on the West Greenland shelf. By acquiring cores of the sediments at the bottom of the sea floor, the research team would be able to gather information such as sediment lithology, stable isotopes preserved in fossil foraminifera – sea fairing little creatures – which can yield information about past climates, amongst other data. One of the main research aims was to learn more about the rate at which the Greenland Ice Sheet melted during the Holocene and how this affected local climate conditions and the wider climate system.

“The picture was taken approximately 25 kilometres off the shore of west Greenland coast. In this region the water depth is ca. 500 meters,” describes Pearce. “At this location we deployed a so-called gravity corer and took a 6 meter long sediment core from the ocean floor. Based on radiocarbon measurements – by measuring how much carbon 14 is left in a sample, the age of the sampled units can be known – we now know that these 6 meters correspond to approximately 12000 years of sedimentation, and thus it captures a history of climate and oceanography from the last ice age all the way to present day.”

 

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: Fly away, weather balloon

Some aspects of Earth Science are truly interdisciplinary and this week’s Imaggeo on Mondays photograph is testament to that. The maiden voyage of the research cruise SA Agulhas II offered the perfect opportunity to combine oceanographic research, as well as climate science studies. Raissa Philibert, a biogeochemistry PhD student, took this picture of the daily release of a weather balloon by meteorologists from the South African Weather Services.

Fly away, weather balloon! Credit: Raissa Philibert (distributed via imaggeo.egu.eu)

Fly away, weather balloon! Credit: Raissa Philibert (distributed via imaggeo.egu.eu)

The highlights of Raissa trip aboard the ship include

“the multidisciplinary aspects of the cruise. It was fascinating talking to people doing such different things. Being on the first scientific cruise aboard the vessel was also extremely exciting as well as going to the southern ocean in winter as this provides such rare datasets.”

This cruise was an excellent opportunity for scientists ranging from physical oceanographers, biogeochemists, meteorologists, ornithologists and zoologists to collect data. The two main scientific programmes aboard the cruise aimed to understand 1) the seasonal changes in the carbon cycle of the Southern Ocean, and 2) gain a better understanding of the modifications in water composition caused by the meeting and mixing of the Indian and Atlantic Oceans in the Agulhas Cape region in South Africa.

Understanding both of these processes is important because they impact on the global thermohaline circulation (THC), which is strongly related to global climate change. Think of the THC as a giant conveyor belt of water within the Earth’s oceans: warm surface currents, rush from equatorial regions towards the poles, encouraged by the wind. They cool and become denser during the time it takes them to make the journey northwards and eventually sink into the deep oceans at high latitudes. They then find their way towards ocean basins and eventually rise up (upwell if you prefer the more technical terms), predominantly, in the Southern Ocean. En route, these huge water masses transport energy (in the form of heat), as well as solids, dissolved substances and gases and distribute these across the planets Oceans. So you can see why understanding the THC is crucial to researchers wanting to better understand climate change.

This map shows the pattern of thermohaline circulation. This collection of currents is responsible for the large-scale exchange of water masses in the ocean, including providing oxygen to the deep ocean. The entire circulation pattern takes ~2000 years. Credit: Nasa Earth Observatory.

This map shows the pattern of thermohaline circulation. This collection of currents is responsible for the large-scale exchange of water masses in the ocean, including providing oxygen to the deep ocean. The entire circulation pattern takes ~2000 years. Credit: Nasa Earth Observatory.

The THCs also plays a large part in the carbon cycle in the oceans. Microscopic organisms called phytoplankton drive the main biological processes through which the ocean takes up carbon. They photosynthesise like plants which mean that they use carbon dioxide and water along with other nutrients to make their organic matter and grow. After some time, the phytoplankton die and their organic matter sinks. Part of this organic matter and carbon will remain stored in the deep ocean under various forms until it is brought back up thousands of years later by the THC. Through this cycle, phytoplankton play a major role in controlling the amount of carbon dioxide in the atmosphere and hence, also the Earth’s climate.

 

By Laura Roberts, EGU Communications Officer, and Raissa Philibert, PhD Student.

If you pre-register for the 2015 General Assembly (Vienna, 12 – 17 April), you can take part in our annual photo competition! From 1 February up until 1 March, 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/.

Put it in a nutshell – or in this case a 21 ft container

In his final post from the Floating University, Jens Weiser shares what it’s like to be part of an oceanographic research cruise and sums up some of the best experiences he’s had on board…

I started this series asking whether anyone of you had ever thought about joining a research cruise. Now that this cruise is coming to an end, I can only strongly advise everyone who might have responded to that by shaking their head to think at least twice. The experiences I have had, the people I have met, and the things I have seen and learned cannot be valued high enough. The overall scientific outcome cannot be assessed yet, since we still have a lot of work ahead of us: far from all the samples have been counted, datasets have yet to be processed and there are still sediment cores to be opened. The practical work we’ve carried out during the cruise is not only interesting but also opens your eyes towards why datasets are rarely perfect and gapless, why a samples from certain depths can be missing or why a core is not as long as you might want it to be. And of course, it has shown what a remarkable amount of work is needed to get these raw data in the first place.

From a more personal point of view the new insights are just as valuable. Meeting people from another place is almost always a rewarding experience, but having a common (scientific) starting point for sharing your thoughts gives you a whole lot of other ideas and ways to think about whatever nut there is to crack.

But of course we did not only talk and discuss research, but spent the last days on board disassembling our gear and packing our lab equipment back into the boxes and containers we unloaded them from before we set off. The containers will be send back to Germany and arrive there in approximately 6 weeks, when the whole game of unloading and unpacking will start over again. Yet this time we can also unpack bits and pieces of two of the most interesting regions in the world: the Agulhas region and the Namibian upwelling system, both of which are fascinating from a biological, oceanographical and geoscientific points of view. Seeing them with your own eyes, as I and the other students aboard the FS Meteor have been able to do, is probably one of the most valuable experiences to take home from the cruise, helping to get a hold of the gigantic puzzle we are all trying to put together.

A jumping humpback whale – just one of the great sights we encountered on this cruise (Credits: Volker Mohrholz)

A jumping humpback whale – just one of the great sights we encountered on this cruise (Credits: Volker Mohrholz)

By Jens Weiser, University of Bremen 

Catch up on previous posts in the series here: