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Geodynamics

Imaggeo on Mondays: Three coloured pools

Imaggeo on Mondays: Three coloured pools

With the Imaggeo Photo Contest opening last week, what better than feature one of the 2015 competition finalists as this week’s Imaggeo on Mondays image. In this post, Irene Angeluccetti, author of the photograph, writes about the threatened ecosystem of Mono Lake. If you’ve been inspired by Irene’s photograph, why not entre the photo contest for your chance to win a free registration to the General Assembly in 2017? You can find out more by reading this blog post.

On a brief stop on the road from the Yosemite park to Las Vegas, we got hooked by some postcards depicting the nearby Mono Lake. We decided immediately to make a quick detour to visit the Natural Reserve surrounding the lake. Although noon wouldn’t provide the best light over the lake, we spent an hour wandering among the towers of the South Tufa area.

The alkaline Mono Lake waters, with a pH of 10 and far more salty than the ocean, are home to crowds of alkali flies and brine shrimps. These in turn are food for dozens of different waterbird species.

Mono Lake’s unique ecosystem has long been threatened by a constant decrease in water level due to water diversion. A dramatic water level drop has been observed since its tributaries started being diverted to meet the need of the Los Angeles growing water demand since 1941 on. By 1978 the lake water levels had dropped by almost half of its original volume, spurring the creation ofcitizens committee which started to take care of the future of the lake. The effort of the committee, in protecting Mono Lake, has led to the partial restoration of the original water volume. However periods of extreme drought still threaten this fragile ecosystem.

Western USA is facing one of the most severe droughts on record. In particular, California is entering the fourth year of a drought that is creating an extremely parched landscape. An effective drought monitoring is essential to plan response and recovery actions. This is especially true in the case of low-income countries prone to agricultural droughts and subsequent famine crisis.

By Irene Angeluccetti, researcher at ITHACA – Information Technology for Humanitarian Assistance, Cooperation and Action

If you pre-register for the 2016 General Assembly (Vienna, 17 – 22 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/.

Imaggeo on Mondays: A hidden waterfall

Imaggeo on Mondays: A hidden waterfall

It’s fascinating how a relatively small outcrop, carved out by rivers and ancient ice, can reveal much about the geological history of an area. Today’s Imaggeo on Mondays post is one such example. Antonio Girona, a researcher at the University of Zaragoza, gives us a whirlwind tour of the geological history of the rocks revealed by the Sorrosal Waterfall, in Spain.

The visit to the Sorrosal Waterfall is an obligatory stop in your way to the Ordesa National Park, located in the Aragonese Pyrenees (NE-Spain). In the northern area of Huesca province, after a short walk from the town of Broto, this hidden waterfall can be found showing the geomorphological and geological history of the valley.

The Sorrosal Waterfall is located in the confluence of two valleys: Broto Valley, run by the Ara River (nowadays the longest river in the Pyrenees with 67 km) and Sorrosal Valley, a hanging valley 125 m above the position from which this photograph was taken. This waterfall was generated by the combined action of a glacier and the river. During the Ice Age, this site was covered by a 30 km long, 370 m deep glacier that shaped the valley that we nowadays call Broto Valley. At the same time Sorrosal river, fed by a small glacier in its headwaters, carved this valley transversely resulting in the Sorrosal Waterfall.

As a consequence of the slope between the two valleys, an interesting outcrop of geological interest can be observed. The rocks were originated from deep-marine sediments (turbidites) from the Eocene, which suffered a series of stepping folds as a result of the Pyrenees Alpine orogeny, becoming the wavy structure than can be appreciated nowadays.

 

By Antonio Girona Garcia, University of Zaragoza.

 

If you pre-register for the 2016 General Assembly (Vienna, 17 – 22 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/.

 

 

The best of Imaggeo in 2015: in pictures

The best of Imaggeo in 2015: in pictures

Last year we prepared a round-up blog post of our favourite Imaggeo pictures, including header images from across our social media channels and Immageo on Mondays blog posts of 2014. This year, we want YOU to pick the best Imaggeo pictures of 2015, so we compiled an album on our Facebook page, which you can still see here, and asked you to cast your votes and pick your top images of 2015.

From the causes of colourful hydrovolcanism, to the stunning sedimentary layers of the Grand Canyon, through to the icy worlds of Svaalbard and southern Argentina, images from Imaggeo, the EGU’s open access geosciences image repository, have given us some stunning views of the geoscience of Planet Earth and beyond. In this post, we highlight the best images of 2015 as voted by our Facebook followers.

Of course, these are only a few of the very special images we highlighted in 2015, but take a look at our image repository, Imaggeo, for many other spectacular geo-themed pictures, including the winning images of the 2015 Photo Contest. The competition will be running again this year, so if you’ve got a flare for photography or have managed to capture a unique field work moment, consider uploading your images to Imaggeo and entering the 2016 Photo Contest.

Different degrees of oxidation during hydrovolcanism, followed by varying erosion rates on Lanzarote produce brilliant colour contrasts in the partially eroded cinder cone at El Golfo. Algae in the lagoon add their own colour contrast, whilst volcanic bedding and different degrees of welding in the cliff create interesting patterns.

 Grand Canyon . Credit: Credit: Paulina Cwik (distributed via imaggeo.egu.eu)

Grand Canyon . Credit: Credit: Paulina Cwik (distributed via imaggeo.egu.eu)

The Grand Canyon is 446 km long, up to 29 km wide and attains a depth of over a mile 1,800 meters. Nearly two billion years of Earth’s geological history have been exposed as the Colorado River and its tributaries cut their channels through layer after layer of rock while the Colorado Plateau was uplifted. This image was submitted to imaggeo as part of the 2015 photo competition and theme of the EGU 2015 General Assembly, A Voyage Through Scales.

Water reflection in Svalbard. Credit: Fabien Darrouzet (distributed via imaggeo.egu.eu)

Water reflection in Svalbard. Credit: Fabien Darrouzet (distributed via imaggeo.egu.eu)

Svalbard is dominated by glaciers (60% of all the surface), which are important indicators of global warming and can reveal possible answers as to what the climate was like up to several hundred thousand years ago. The glaciers are studied and analysed by scientists in order to better observe and understand the consequences of the global warming on Earth.

Waved rocks of Antelope slot canyon - Page, Arizona by Frederik Tack (distributed via imaggeo.egu.eu).

Waved rocks of Antelope slot canyon – Page, Arizona by Frederik Tack (distributed via imaggeo.egu.eu).

Antelope slot canyon is located on Navajo land east of Page, Arizona. The Navajo name for Upper Antelope Canyon is Tsé bighánílíní, which means “the place where water runs through rocks.”
Antelope Canyon was formed by erosion of Navajo Sandstone, primarily due to flash flooding and secondarily due to other sub-aerial processes. Rainwater runs into the extensive basin above the slot canyon sections, picking up speed and sand as it rushes into the narrow passageways. Over time the passageways eroded away, making the corridors deeper and smoothing hard edges in such a way as to form characteristic ‘flowing’ shapes in the rock.

 Just passing Just passing. Credit: Camille Clerc (distributed via imaggeo.egu.eu)

Just passing. Credit: Camille Clerc (distributed via imaggeo.egu.eu)

An archeological site near Illulissat, Western Greenland On the back ground 10 000 years old frozen water floats aside precambrian gneisses.

Sarez lake, born from an earthquake. Credit: Alexander Osadchiev (distributed via imaggeo.egu.eu)

Sarez lake, born from an earthquake. Credit: Alexander Osadchiev (distributed via imaggeo.egu.eu)

Beautiful Sarez lake was born in 1911 in Pamir Mountains. A landslide dam blocked the river valley after an earthquake and a blue-water lake appeared at more than 3000 m over sea level. However this beauty is dangerous: local seismicity can destroy the unstable dam and the following flood will be catastrophic for thousands Tajik, Afghan, and Uzbek people living near Mugrab, Panj and Amu Darya rivers below the lake.

Badlands national park, South Dakota, USA. Credit: Iain Willis (distributed via imaggeo.egu.eu)

Badlands national park, South Dakota, USA. Credit: Iain Willis (distributed via imaggeo.egu.eu)

Layer upon layer of sand, clay and silt, cemented together over time to form the sedimentary units of the Badlands National Park in South Dakota, USA. The sediments, delivered by rivers and streams that criss-crossed the landscape, accumulated over a period of millions of years, ranging from the late Cretaceous Period (67 to 75 million years ago) throughout to the Oligocene Epoch (26 to 34 million years ago). Interbedded greyish volcanic ash layers, sandstones deposited in ancient river channels, red fossil soils (palaeosols), and black muds deposited in shallow prehistoric seas are testament to an ever changing landscape.

Late Holocene Fever. Credit: Christian Massari (distributed via imaggeo.egu.eu)

Late Holocene Fever. Credit: Christian Massari (distributed via imaggeo.egu.eu)

Mountain glaciers are known for their high sensitivity to climate change. The ablation process depends directly on the energy balance at the surface where the processes of accumulation and ablation manifest the strict connection between glaciers and climate. In a recent interview in the Gaurdian, Bernard Francou, a famous French glaciologist, has explained that the glacier depletion in the Andes region has increased dramatically in the second half of the 20th century, especially after 1976 and in recent decades the glacier recession moved at a rate unprecedented for at least the last three centuries with a loss estimated between 35% and 50% of their area and volume. The picture shows a huge fall of an ice block of the Perito Moreno glacier, one of the most studied glaciers for its apparent insensitivity to the recent global warming.

 Nærøyfjord: The world’s most narrow fjord . Credit: Sarah Connors (distributed via imaggeo.egu.eu)

Nærøyfjord: The world’s most narrow fjord . Credit: Sarah Connors (distributed via imaggeo.egu.eu)

Feast your eyes on this Scandinavia scenic shot by Sarah Connors, the EGU Policy Fellow. While visiting Norway, Sarah, took a trip along the world famous fjords and was able to snap the epic beauty of this glacier shaped landscape. To find out more about how she captured the shot and the forces of nature which formed this region, be sure to delve into this Imaggeo on Mondays post.

The August 2015 header images was this stunning image by Kurt Stuewe, which shows the complex geology of the Helvetic Nappes of Switzerland. You can learn more about the tectonic history of The Alps by reading this blog post on the EGU Blogs.

 (A)Rising Stone. Credit: Marcus Herrmann (distributed via imaggeo.egu.eu)

(A)Rising Stone. Credit: Marcus Herrmann (distributed via imaggeo.egu.eu)

The September 2015 header images completes your picks of the best images of 2015. (A)Rising Stone by Marcus Herrmann,  pictures a chain of rocks that are part of the Schrammsteine—a long, rugged group of rocks in the Elbe Sandstone Mountains located in Saxon Switzerland, Germany.

If you pre-register for the 2016 General Assembly (Vienna, 17 – 22 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/.

Geoscience hot topics – The finale: Understanding planet Earth

Geoscience hot topics – The finale: Understanding planet Earth

What are the most interesting, cutting-edge and compelling research topics within the scientific areas represented in the EGU divisions? Ground-breaking and innovative research features yearly at our annual General Assembly, but what are the overarching ideas and big research questions that still remain unanswered? We spoke to some of our division presidents and canvased their thoughts on what the current Earth, ocean and planetary hot topics will be.

Because there are too many to fit in a single post we’ve brought some of them together in a series of posts which will tackle three main areas. The first post focused on the Earth’s past and its origin, while the second post focused on the Earth as it is now and what its future looks like. Today’s is the final post of the series and will explore where our understanding of the Earth and its structure is still lacking. We’d love to know what the opinions of the readers of GeoLog are on this topic too, so we welcome and encourage lively discussion in the comment section!

A new, modern, era for research

That we have great understanding of the Earth, its structure and the processes which govern how the environment works, is a given. At the same time, so much is still unknown, unclear and uncertain, that there are plenty of research avenues which can help build upon, and further, our current understanding of the Earth system.

By Camelia.boban (Own work) [CC BY-SA 3.0], via Wikimedia Commons

Big Data’s definition illustrated with text. Credit: Camelia.boban (Own work) [CC BY-SA 3.0], via Wikimedia Commons

As research advances, so do the technologies which allow scientist to collect, store and use data. Crucially, the amount of data which can be collected increases too, opening avenues not only for scientists to carry out research, but for the wider population to be involved in scientific research too: the age of Big Data and Citizen Science is born.

The structure of the Earth

Despite a long history of study, including geological maps, studies of the structure of the Alps, and the advent of analogue models some 200 years ago, there is much left to learn about how geological processes interact and shape our Earth.

Some important unanswered questions in the realm of Tectonics and Structural Geology (TS) include:

“Why do some passive margins have high surface topography (take Norway, or Southeastern Brazil as an example) even millions of years after continental break-up? How does subduction, the process by which a tectonic plate slides under another, begin? And how does the community adapt to new research methods and ever growing datasets?” highlights Susanne Buiter, TS Division.

One important problem is that of inheritance and what role it plays in how plate tectonics work. Scientists have known, since the theory was first proposed in the 1950s (although it only became broadly accepted in the 1970s), that our planet is active: its outer shell is divided into tectonic plates which slide, collide, pull away and sink past one another. During their life-time the tectonic plates interact with surface process and eventually flow into the mantle below. This implies that any new tectonic processes will take place in material that carries a history.

“It is increasingly recognised that tectonic events do not act on homogenous, pristine materials, but more likely on crust that is cross-cut by old shear zones, incorporates different lithologies and which may have inherited heat from previous deformation events (such as folding),” explains Susanne.

So the key is: what is the impact of historical inheritance on tectonic events? Can old structures be reactivated and if so, when are they reactivated and when not? Do the tectonic processes control the resulting structures or is it the other way around?

Seismology too can shed more light on how we understand Earth processes and the structure of the planet.

“An emerging field of research is seismic super-resolution: a promising technique which allows imaging of the fine-scale subsurface Earth structure in more detail than has been possible ever before,” explains Paul Martin Mai, President of the Seismology (SM) Division.

The methodology has applications not only for our understanding of the structure and process which take place on Earth, but also for the characterisation of fuel reservoirs and identification of potential underground storage facilities. That being said, the technique is still in its infancy and more research, particularly applied to ‘real’ geological settings is needed.

Understanding natural hazards

The reasons to pursue further understanding in this area are diverse and wide-ranging: amongst the most relevant to society is being able to better comprehend and predict the processes which lead to natural disasters.

Earthquake 1920 (?). Credit: Konstantinos Kourtidis (distributed via imaggeo.egu.eu)

Earthquake 1920 (?). Credit: Konstantinos Kourtidis (distributed via imaggeo.egu.eu)

It goes without saying that, due to their destructive nature, earthquakes are a topic of continued cross-disciplinary scientific research. Generating more detailed images of the Earth’s structure, using seismic super-resolution for instance, can also improve our understanding of how and why earthquakes occur, as well as helping to determine large-scale fault behaviour.

And what if we could crowd source data to help us understand earthquakes better too? LastQuake is an online tool, operated via Twitter and an app for smartphones which allows users to record real-time data regarding earthquakes. The results are uploaded to the European-Mediterranean Seismological Centre (EMSC) website where they offer up-to-data information about ongoing shake events. It was used by over 8000 people during the April 2015 Nepal earthquakes to collect eyewitness observation, including geo-located pictures, testimonies and comments, in the immediate aftermath of the earthquake.

In this setting, citizens become scientists too. They contribute data, by acquiring it themselves, which can be used to answer research questions. In the case of LastQuake, the use of the data is immediate and can contribute towards easing rescue operations and alerting citizens of dangerous areas (for instance where buildings are at risk of collapse) providing a two-way communication tool.

Global temperatures and climate change

It is not only earthquakes that threaten communities. Just as destructive can be extreme weather events, such as typhoons, cyclones, hurricanes, storm surges, severe rainfalls leading to flooding or droughts. With the increased frequency and destructiveness of these events being linked to climate change understanding global temperature fluctuations becomes more important than ever.

Flooded Mekong. Credit: Anna Lourantou (distributed via imaggeo.egu.eu)

Flooded Mekong. Credit: Anna Lourantou (distributed via imaggeo.egu.eu)

Over periods of months, years and decades global temperatures fluctuate.

“Up to decades, the natural tendency to return to a basic state is an expression of the atmosphere’s memory that is so strong that we are still feeling the effects of century-old fluctuations,” says Shaun Lovejoy, President of the Nonlinear Processes Division (NP).

Harnessing the record of past-temperature fluctuations, as recorded by the atmosphere, can provide a more accurate way to produce seasonal forecasts and long-term climate predictions than traditional climate models and should be explored further.

Geoscience hot topics

Be it studying the Earth’s history, how to sustainably develop our communities, or simply understanding the basic principles which govern how our planet – and others – operates, the scope for avenues of research in the geosciences is vast. Moreover, the advent of new technologies, data acquisition and processing techniques allow geoscientists to explore more complex problems in greater detail than was ever possible before. It’s an exciting time for geoscientific research.

By Laura Roberts Artal in collaboration with EGU Division Presidents

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