GeoLog

Natural Hazards

Imaggeo on Mondays: The retreating glaciers of the Svaneti Range, Georgia

Imaggeo on Mondays: The retreating glaciers of the Svaneti Range, Georgia

Today’s Imaggeo on Mondays picture shows the central section of the Svaneti Range, located in the Svaneti Region – a historic province of northwestern Georgia. The range is the second biggest range formed by the modern glaciation on the southern slopes of the Georgian Caucasus Mountains. In today’s post, Levan Tielidze, a researcher at Ivane Javakhishvili Tbilisi State University, writes about the ice capped peaks of these high mountains and highlights the precarious balance of this cryospheric system.

Svaneti range is approximately 100 km long and is distinguished by the height of its relief, as well as by the fact that the area covered by glaciers in the region exceeds that covered elsewhere in the southern slopes of the Georgian Caucasus.These features define the range and lead it to be divided into three sections: eastern, central (shown in this picture) and western. The eastern and western sections are lower in altitude than the central region and modern ice cover cannot be found there, with the exception of Mount Dadiashi which stands at 3535 m asl.

However, glaciers do cap the peaks in the central areas of the range, and can be found between the sections of Lasili and Leshnuri. Here is where you’ll find the highest peak of the mountain range: Laila (Laila-Lehli) -4009 m asl.

The glaciers in this region are retreating and losing volume. Data from the 1960s indicated that glaciers in the range numbered up to 48 and covered an area of approximately 27.76 km2 , equivalent to the size of just over 2500 football pitches. By 2014 the area covered by the glaciers in the region had shrunk by 27.5% and now only covers approximately 20.13 km2.

Some of the largest glaciers of the northern slopes of the range are formed on Laila peak, which itself is covered by a glacier cap. Among these glaciers the largest is Eastern Laila, located in the Khumpreri River basin. The glacier is formed of two ice streams which flow from separate valleys. In 1960 the glacier area was  close to 5.96 km2; its terminus ended at a height of 2300 meters asl. By 2014 the eastern Laila’s area decreased to 3.55 km2 and has retreated to an altitude of 2640 m asl. The total glacier length is now approximately 4.52 kilometers.

The glaciers are an important source of water for agricultural production in Georgia, and runoff in large glacially-fed rivers (Kodori, Enguri, Rioni, Tskhenistskali, Nenskra) supplies several hydroelectric power stations. In addition, glacier outburst floods and related debris flows are a significant hazard in Georgia and in the Caucasus. Future trends in glacier change are thus a topic of considerable interest to the region.

By Levan Tielidze, Institute of Geography, Tbilisi State University, Georgia

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/.

Looking back at the EGU Blogs in 2015: welcoming new additions

Looking back at the EGU Blogs in 2015: welcoming new additions

It’s a little over 12 months since we launched the new look EGU blogs and with the holidays and new year approaching, what better time to take stock of 2015 as featured in the EGU Blogs? The past year has been full of exciting, insightful and informative blog posts. At the same time, we’ve welcomed new additions to the network and division blogs.

The network blogs

A recent highlight of the year has to be the addition of a new blog to the network: please welcome our new blogger Professor David Pyle, author of VolcanicDegassing – a blog about volcanoes and volcanic activity. In 2016 you can look forward to posts about David’s ongoing research in Latin America, the Caribbean, Ethiopia and Europe, as well as historical and contemporary descriptions or other representations of volcanic activity across the globe.

Vesuvius in eruption, April 26, 1872. Original caption ‘from a photograph taken in the neighbourhood of Naples”. (Palmieri and Mallet, 1873). Published in the Decemeber 15th post:  'The first volcanic eruption to be photographed?'

Vesuvius in eruption, April 26, 1872. Original caption ‘from a photograph taken in the neighbourhood of Naples”. (Palmieri and Mallet, 1873). Published in the Decemeber 15th post: ‘The first volcanic eruption to be photographed?

Richly illustrated and referenced posts have featured across the network throughout the year, with topics ranging from the journey aerosol particles go on throughout their life time, through to the role peculiarities of geology and geomorphology play in deciding on big international governance.

The most popular post written in 2015 was brought to you by Jon Tennant and featured the ichthyosaurs, an unusual turtle-fish-dolphin like marine reptile which cruised the seas 250 million years ago. The post focuses on the discovery of an ichthyosaur fossil named David, or rather Cartorhynchus lenticarpu as it is formally known, and how the remarkable specimen sheds light on the origins of these unusual creatures.

Matt Herod’s post on Geosphere in early December 2014 featuring the story behind the legal battle of Italian geochemists who were sued after publishing results stating that they could not find above background levels of depleted uranium in former Italian military firing ranges, is the second most read post across the network in the past year. With a strong resemblance to the L’Aquila verdict against the Italian seismologists, which was resolved in 2014, Matt highlights there are lessons to be learnt from both cases in the post.

Natural hazards and the April 2015 Nepal earthquakes featured heavily across the network too. In the immediate aftermath of the earthquake, the Geology for Global Development blog compiled a comprehensive list of links and resources which readers could consult to find out up to date and reliable information about the events in Nepal. A list which is still a useful resource some 8 months after the tragedy and which is the third most popular post on the network this year. Simon Redfern, of Atom’s Eye View of the Planet, wrote a piece on how and why scientists have identified Kathmandu valley as one of the most dangerous places in the world, in terms of earthquake risk.

With many of the network bloggers being in the thick of PhD research or having recently submitted their thesis, tips and hints for a successful PhD completion also proved a focus of the content across the network. Despite being originally written in April 2013, Jon Tennant’s blog post on why and how masters students should publish their research was the most popular post of the year! The most read post from Geology Jenga advertised a new, and free, online course on how to survive the PhD journey.

The division blogs

Since their launch last December, the division blogs have gone from strength to strength. Keeping you updated with news and information relevant to each division, they have also featured accounts of field and laboratory work, as well as professional development opportunities and open vacancies.

Throughout the year the division blogs have been enhanced through the addition of the Atmospheric Sciences, Energy Resources and Environment blogs and, most recently, the Biogeosciences Division blog too.

Cross-section of the age of the Greenland Ice Sheet from radar data. Credit: NASA's Scientific Visualization Studio and MacGregor et al., 2015.

Cross-section of the age of the Greenland Ice Sheet from radar data. Credit: NASA’s Scientific Visualization Studio and MacGregor et al., 2015.

The most popular post of the year was shared by the Seismology Division and touched upon the controversial topic of whether cloud formations can be used to predict earthquakes, while the Cryosphere Division blog’s image of the week of late October featuring a cross section of the Greenland Ice Sheet was the second most popular post. Round-up posts about the 2015 General Assembly, tips for convening sessions at the conference, as shared by Geodesy Division, and some soul searching by the Geomorphology Division as to why a proposed session wasn’t included in the final conference programme also proved very popular.

Get involved

Are you a budding science writer, or want to try your hand at science communication? All the EGU Blogs, from GeoLog (the official EGU blog), through to the network and division blogs, welcome guest contributions from scientists, students and professionals in the Earth, planetary and space sciences.

It couldn’t be easier to get involved. Decide what you’d like to write about, find the blog that is the best fit for your post and contact the blog editor – you can find all editor details on the individual blog pages. If in doubt, you can submit your idea for a post via the Submit a Post page on GeoLog, or email the EGU Communications Officer, Laura Roberts, who can help with initial enquiries and introduce you to individual blog editors.

Don’t forget to a look at the blog pages for a flavour of the content you can expect from the new, and existing, blogs in 2016. The blogs are also a great place to learn about new opportunities, exciting fields of research and keep up to date with news relating to the upcoming 2016 General Assembly.

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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