Archive | February, 2012

Imaggeo on Mondays: Seeing double

27 Feb

Double rainbow over a Tibetan Plateau lake by Janneke IJmker, distributed by EGU under a Creative Commons licence.

On 6 September 2009, monsoon clouds had built up throughout the day over the Donggi Cona lake in central China. Janneke IJmker, now a researcher at Deltares in the Netherlands, was doing fieldwork there as part of her PhD at RWTH Aachen University in Germany. By dinner time, the sun shone on raindrops from the clouds producing a magnificent double rainbow over the lake, which IJmker captured with her camera.

“The photograph was taken during a fieldwork study of Holocene climate variations in the Donggi Cona lake catchment on the north-eastern Tibetan Plateau. Monsoon clouds and intense solar radiation resulted in this double rainbow, nicely demonstrating the reversal of colours in the secondary rainbow,” IJmker noted.

Secondary rainbows are the result of a double reflection of sunlight inside the water droplets. This second reflection causes the colours of the secondary rainbow to be inverted, with blue on the outside and red on the inside, compared to the primary.

Imaggeo is the online open access geosciences image repository of the European Geosciences Union. Every geoscientist who is an amateur photographer (but also other people) can submit their images to this repository. Being open access, it can be used by scientists for their presentations or publications as well as by the press. If you submit your images to imaggeo, you retain full rights of use, since they are licenced and distributed by EGU under a Creative Commons licence.

Photo competition at the EGU 2012 General Assembly

22 Feb

If you are pre-registered for the 2012 General Assembly (Vienna, April 22-27), we invite you to submit photos to our annual photo competition. Winners receive a free registration to next year’s General Assembly!

The third edition of the EGU photo competition is now open. Until 10 March, every pre-registered participant of the General Assembly can submit up to two photos on any broad theme related to the earth, planetary, and space sciences. Short-listed photos will be exhibited at the conference, with the winner voted by General Assembly participants.

If you submit your images to the photo competition, you agree to also submit them to the EGU photo database, Imaggeo. (You will also have to register on the website so that the organisers can  appropriately process your photos.) Being open access, it can be used by scientists for their presentations or publications, as well as by the press. If you submit your images to the database, you retain full rights of use, since they are licensed and distributed by EGU under a Creative Commons license. If a short-listed entry, you also agree for the photo to be exhibited at the General Assembly.

For more information, please check the photo competition page on Imaggeo. Previous winning photographs can be seen on the 2010 and 2011 winners’ pages.

Last year’s winning photo: Geysir by James Levine, distributed by EGU under a Creative Commons licence.

Happy Carnival from the EGU Executive Office in Munich!

21 Feb

With everyone at the office busy with General Assembly preparations and other activities, a typical Bavarian breakfast on Carnival day is a most welcome break. Germany loves Carnival and Munich, while lagging behind Cologne, Düsseldorf, and Mainz in Fasching parties, is no exception. At the office, we decided to celebrate the date with a Weißwurst Frühstückaccompanied by… Bavarian beer, of course! Good thing we, as other German workers, have the afternoon free to watch the Carnival parades.

EGU staff ready for a Weißwurst Frühstück. From left to right: Edvard Glücksman (Science Communications Fellow), Karen Resenberger (Secretary), Philippe Courtial (Executive Secretary), Robert Barsch (Webmaster & System Admin), and Bárbara Ferreira (Media and Communications Officer).

Imaggeo on Mondays: Serene landscape, active volcano

20 Feb

Osorno Volcano — Chile by Lilli Freda, distributed by EGU under a Creative Commons licence.

This image, captured in Chile by Lilli Freda from Italy’s Istituto Nazionale di Geofisica e Vulcanologia, depicts a cloudless sky, a calm blue lake (Llanquihué), and a picture-perfect mountain with a snow-covered top. But the serenity of the landscape is only apparent: the triangular structure in the background is in fact the very active and explosive Osorno volcano.

“Osorno is a 2652-m-high stratovolcano, one of the most active volcanoes of the southern Chilean Andes. During the past 14,000 years, explosive eruptions occurred frequently and produced pyroclastic flows and surges. Recorded historical eruptions have originated from both summit and flank vents producing basaltic and andesitic lava flows that have entered both Llanquihué and Todos los Santos lakes,” Freda explained.

There are 11 historical explosions recorded for Osorno between 1575 and 1869, when the last known eruption occurred.

Freda took this photo in 2004 during a field trip that followed the General Assembly of the International Association of Volcanology and Chemistry of the Earth’s Interior, held in Pucón, Chile, that year.

Imaggeo is the online open access geosciences image repository of the European Geosciences Union. Every geoscientist who is an amateur photographer (but also other people) can submit their images to this repository. Being open access, it can be used by scientists for their presentations or publications as well as by the press. If you submit your images to imaggeo, you retain full rights of use, since they are licenced and distributed by EGU under a Creative Commons licence.

Imaggeo on Mondays: Orange anvils

13 Feb

Orange anvils by Katja Weigel, distributed by EGU under a Creative Commons licence.

The anvils in this picture are not heavy steel or iron blocks but rather soft clouds coloured orange by the setting sun. The term is used to describe the upper part of a cumulonimbus or thunderstorm cloud that tends to spread out in an anvil shape as warm air bumps up against the bottom of the stratosphere (the atmospheric layer between 15-50 kilometres height).

Katja Weigel, a researcher at the Institute of Environmental Physics, University of Bremen, Germany took this picture at Mindil Beach in Darwin, Australia, shortly after sunset on 11 November 2005. She travelled there for the SCOUT-O3 (Stratospheric-Climate Interactions with Emphasis on the Upper Troposphere and Lower Stratosphere) campaign.

“The aim of the campaign was to observe and investigate transport into the stratosphere by strong tropical convection. The 11 November 2005 was the day before the research aircraft M55-Geophysika arrived in Darwin. Therefore, we did not take measurements in the clouds shown here but in and around similar clouds during the following weeks,” Weigel said.

More information about the SCOUT-O3 can be found in the campaign’s flyer, or in the special issue ‘SCOUT-O3 Tropics’ of the EGU journal Atmospheric Chemistry and Physics.

Imaggeo is the online open access geosciences image repository of the European Geosciences Union. Every geoscientist who is an amateur photographer (but also other people) can submit their images to this repository. Being open access, it can be used by scientists for their presentations or publications as well as by the press. If you submit your images to imaggeo, you retain full rights of use, since they are licenced and distributed by EGU under a Creative Commons licence.

Geosciences column: Life in the aftermath of hydrothermal vents

8 Feb

Pioneering new study explores the structure and function of microbial communities at expired hydrothermal vent sites

Undiscovered lifeforms abound in Earth’s most seemingly inhospitable environments, as demonstrated by the recent discovery of bacteria living deep underneath the seafloor. An equally extreme environment can be found in the vicinity of hydrothermal vents, where water is expelled from the Earth’s crust at temperatures exceeding 400°C, after it percolates down through cracks formed at the intersection of tectonic plates. We now know that active vents teem with life, yet little is known about these habitats after venting eventually stops.

A study recently published in the Open Access journal mBio explored the inactive mineral deposits left behind by expired vents along the floor of the deep sea, showing they serve as long-term microhabitats for a succession of unique bacterial communities with potentially important roles within the broader marine food chain. This work is the first to demonstrate that life continues even as vent activity drops off.

Active hydrothermal vents and their distinctive chimneys (source: Wikipedia)

Searching for life at inactive vent sites: a genetic approach

The study, co-authored by researchers at the University of Southern California and the University of Minnesota, characterised microbial communities using advanced genetic sequencing techniques. The scientists obtained samples from expired vent chimneys on the East Pacific Rise, a tectonic plate boundary that runs along the Pacific Ocean, using the US Navy deep-sea submersible, Alvin — famous for its use in the exploration of the Titanic in 1986.

The genetic sequences provide a snapshot of the bacterial community at each sampling location. These data include the type of species present and, based on similarities with described species, their potential role within the local microbial food chain; in other words, what contribution their uptake of nutrients could make to the wider marine ecosystem. By obtaining similar data from active vents, the researchers could predict how relative counts of bacterial species change as venting ceases and the environment cools.

Microbes vital for marine ecosystems

The chimneys are formed by minerals carried by the vent emissions as they emerge from deep within the hot crust and collide with seawater. In the context of the study now published, they are of particular interest as long-term habitats for microbes because they are both widespread and resilient, remaining for up to 20,000 years following the expiry of a vent.

As venting ceases, the microbial community composition within chimneys changes drastically and the remaining bacterial biomass, the size of the community, grows by up to five times. Furthermore, the new community comprises several species that can take up and distribute essential elements back into their global cycles. In other words, not only does this study show that inactive vent sites contain unique communities of microbes, but the results also suggest these species are particularly important for the healthy functioning of the marine ecosystem.

Microbial communities serve as an important link in the global cycling of elements vital for life, such as carbon and nitrogen. Bacteria break down dead plant and animal matter, taking in carbon and thereby reintroducing it to the food chain when they are in turn consumed by larger organisms. Through a process known as nitrogen fixation, some bacteria also create – or ‘fix’ – nitrogen, an element necessary for the growth of plants.

Understanding these processes in the deep sea gives us unprecedented insight into how entire marine ecosystems function. “There are all these organisms down there making biomass, and that’s not at all accounted for in our carbon cycle,” commented senior author, Katrina Edwards, in an interview with OurAmazingPlanet.

Bacterial lifestyle shift

Apart from demonstrating the important ecological role of life at expired vents, this study also complements previous work by illustrating how the drastic environmental change that accompanies vent expiry favours organisms with an entirely different lifestyle. At active vent sites, bacteria get the energy they need to survive from the heat and content of the fluids coming from deep within the Earth. At inactive vents, the two most commonly found bacterial groups stay alive using a different mechanism, generating energy from the minerals freed up by the natural weathering of the chimneys. “Seeing the shift in the microbial population – seeing who actually came and left, was fairly illuminating for me,” said Edwards.

This exploratory study will be followed up by more work on the mechanisms of bacterial community succession, both at hydrothermal vent sites and also, as Edwards explains to AstroBio Magazine, in microbes existing beneath rock surfaces. The authors conclude by explaining that studies focusing on other microscopic species have yet to be undertaken, but may hold equally great potential in understanding the vital ecological contribution of deep-sea microorganisms.

By Edvard Glücksman, EGU Science Communications Fellow  

Our next door neighbours

7 Feb

The EGU Executive Office is housed in one of the buildings of the Department of Earth and Environmental Sciences of the Ludwig Maximilian University of Munich, Germany. The building also hosts the Palaeontological Museum Munich, the public part of the Bavarian State Collection for Palaeontology and Geology, which is dedicated to the history of life and the Earth, and displays fossils from all eras of the planet’s history.

Edvard Glücksman, the new EGU Science Communications Fellow, likes to access the building using the entry on Richard-Wagner-Straße, which gives direct access to the Museum. Yesterday, he decided to photograph what he sees every morning:

Dinosaurs at the Palaeontological Museum, Munich

Edvard took this picture using the Photosynth app on his iPhone, which allows you to stitch together various photos into a panorama. Check out the 3D interactive version on the app’s website!

Imaggeo on Mondays: Waves hitting Cycladic rocks

6 Feb

Rocks and Sea Waves in Andros Island, Greece by Ioannis Daglis, distributed by EGU under a Creative Commons licence.

When he is not researching in the space sciences, Ioannis Daglis, the director of the Institute for Space Applications and Remote Sensing at the National Observatory of Athens in Greece, is often out with his camera. This picture of sea waves slamming cliff rocks in the Aegean Sea is a beautiful example of his artistic work, and one that shows some science too.

“I took this photo at Vitali Bay in the island of Andros in the Greek Cyclades during a summer vacation in August 2007. It shows a cliff made irregular by wave erosion, tectonic activity or both. It consists mainly of metamorphic rocks such as schists, phyllites and marbles. These are typical geologic formations that constitute 75% of the total coastline of the island since Andros is mainly covered by metamorphic formations,” Daglis explained.

The Cyclades is a geologically rich group of some 220 islands. The dormant volcano of Milos, the famous Santorini caldera, and the hot springs in Kythnos are examples of geological sites worth a visit.

Daglis’ geosciences-related photographs, taken in Greece and elsewhere, are featured on imaggeo.

Imaggeo is the online open access geosciences image repository of the European Geosciences Union. Every geoscientist who is an amateur photographer (but also other people) can submit their images to this repository. Being open access, it can be used by scientists for their presentations or publications as well as by the press. If you submit your images to imaggeo, you retain full rights of use, since they are licenced and distributed by EGU under a Creative Commons licence.