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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

The Geology of Skyrim: An unexpected journey

Back in January I did a talk at an event called Science Showoff, a comedy night based in London where scientists stand up in front of an audience in a pub and talk about funny stuff to do with their work. I talked about video games. Not any video game however, I talked about The Elder Scrolls V: Skyrim.

For those of you who don’t know what this is, it’s a fantasy role playing video game. It is a great game with some beautiful graphics, especially the scenery; including flora, fauna and rocks. So I did what any other geologist would do. I mapped Skyrim. This means I used all the internet resources I could to find out the locations of every major ore deposit in the region of Skyrim, colour coded them and placed them on a map. My aim was to find out a possible story for the geological evolution of Skyrim.

Like any scientific investigation, you start off with a theory and you commence your investigations to try to prove it wrong. In some cases it is very difficult to prove the theory wrong and so it remains valid, but in most others you do manage to prove it wrong somehow. However, this does not mean that the time and investigations were wasted; instead this process brings up new answers, and questions that scientists investigate further. In the case of mapping the geology of Skyrim, I came up with an initial theory that I presented at Science Showoff, and have since found that my initial theory was probably wrong. This doesn’t dishearten me though, it has proved an interesting journey – if unexpected – that I am sure has engaged and enthused many people.

First, I will introduce you to my map of all the major ore deposits in Skyrim. I am by no means claiming that this is accurate and I am certainly not claiming that the final interpretation is accurate either (forgetting for a moment we are discussing a fantasy location). My main reason for taking on this little project was to introduce geology to an audience that may not normally engage with the sciences and so the results of this investigation are not meant to be 100% accurate, but they are meant to be inspiring.

My initial map of Skyrim with ore locations indicated as coloured blobs over the coloured topographic map. Red = iron, blue = corundum, purple = orichalcum, white = quicksilver, grey = silver, yellow = moonstone. (Base map modified from one produced by Tim Cook)

My initial map of Skyrim with ore locations indicated as coloured blobs over the coloured topographic map. Red = iron, blue = corundum, purple = orichalcum, white = quicksilver, grey = silver, yellow = moonstone (click for larger). (Base map modified from one produced by Tim Cook)

For a geologist it is not enough to just have a map of where lots of rocks are. What we need is an understanding of the nature of the earth beneath our feet. In finding out how the rocks got where they are today, we can then build up a history of the evolution of the area – including different environments that one area of land went through over millions of years.

The most common types of rocks we find in Skyrim are iron ore and corundum. In this world, corundum isn’t actually a rock – but it is a rock forming mineral. Rocks are simply amalgamations of other minerals in the form of crystals or grains. In igneous and metamorphic rocks, formed from cooling magma or changed through heat and pressure deep in the crust respectively, the minerals are crystalline in form. In sedimentary rocks the minerals are generally granular – from other rocks that have been ground down as sediments into their individual minerals. Corundum most commonly occurs as a mineral in metamorphic rocks, so we are going to assume that our ‘corundum ore’ is a metamorphic rock of some kind.

It is really important to know in what order the rocks got where they are – which is the oldest and which is the youngest. The map above gives us some clues to the order in which the rocks were laid down. Near the top left there is an area of low topography, and inside this is a red blob with a blue blob in the middle of it. The most likely way for these rocks to be in this formation is that the iron (red) is older than the corundum (blue), so the corundum was deposited after the iron ore. Quicksilver is another name for mercury in our world, the most common ore of which is cinnabar. Cinnabar formation is associated with volcanic activity and hot springs. On the map you can generally see quicksilver (white) associated spatially with corundum and iron ore. If you look closely it appears that quicksilver is usually found on the higher topography, so from this it could be inferred that quicksilver was formed later than both the iron ore and corundum.

Towards the bottom left of the province of Skyrim, in the west, you can see a distinct area where there is a quicksilver blob inside an iron ore blob. This would imply that here the quicksilver is directly on top of the iron – but we know that there should be corundum between these two. This is what geologists call an unconformity. An unconformity represents a missing chunk of time in the geological record. When rocks get laid down – by volcanoes or rivers – it takes millions of years. If we are expecting a rock to be somewhere and see that it is missing, we know we are missing a period of geological time in this area and it presents an interesting puzzle: why has this happened? It could be because of tectonic movements of the crust: raising mountains, eroding them then redepositing other sediments on the eroded mountains, but all we see is a road cutting with some different looking rocks and some missing in the middle. This is one of the most important principles in geology, and for many other subjects. It was through identifying an unconformity that James Hutton discovered the concept of ‘deep time’ in 1788 – that the Earth is thousands of millions of years old.

Orichalcum is a bit of an enigma. Many historical texts in the real world refer to orichalcum and yet there is a lot of dispute over what kind of metallic material it was – was it an ore, an alloy or something else entirely? From around 428 BC in Ancient Greek texts began implying that orichalcum was chalcopyrite, a copper ore that can be formed in a number of ways, but always associated with hydrothermal circulation and precipitation in either a sedimentary or volcanic environment. Orichalcum can be seen on the map adjacent to quicksilver on high topography, indicating this may be the most recent rock to be formed in Skyrim’s history.

A cartoon of the four main rocks and the order in which they were laid down (oldest at the bottom). (Credit: Jane Robb)

A cartoon of the four main rocks and the order in which they were laid down (oldest at the bottom). (Credit: Jane Robb)

Iron ore in our world is most commonly derived from banded iron formations. These are at least 2,400 million years old! They represent the point from which organisms started photosynthesising and producing oxygen. As these rocks are so old, many of them have been deformed through metamorphism.

Knowing how individual rock types form doesn’t tell us the whole story about Skyrim’s evolution though. The crust of the Earth is mobile – in some places it pushes together (compresses) and in others it pulls apart (extension or rifting), destroying and forming new crust in those areas respectively like a large conveyor belt around the Earth. When different rocks that should be on top of another (like in the diagram above) can be seen next to each other on the same topographic level, we can infer that some tectonic movement has happened. In the east of Skyrim, we see an area of higher topography and several of the different rocks aligned next to each other.

A topographic base map of Skyrim with my annotations of a compressional fault (line with triangles on it, compressing approximately north-south) and extensional faults (lines with little lines on them). The yellow line A-B is showing the location of a cross section cartoon (below). (Map modified from one produced by Tim Cook)

A topographic base map of Skyrim with my annotations of a compressional fault (line with triangles on it, compressing approximately north-south) and extensional faults (lines with little lines on them). The yellow line A-B is showing the location of a cross section cartoon (below). (Map modified from one produced by Tim Cook)

A topographic base map of Skyrim with my annotations of a compressional fault (line with triangles on it, compressing approximately north-south) and extensional faults (lines with little lines on them). The yellow line A-B is showing the location of a cross section cartoon (below). (Map modified from one produced by Tim Cook)

Cross section cartoon A-B of the rocks as they might be underground, showing extensional faulting and erosion. The black ‘ticks’ on the diagram indicate the direction of movement of the land relative to the areas around it. (Credit: Jane Robb)

Skyrim is surrounded to the south and west by mountains, the largest being the Throat of the World. Mountains usually form through landmasses compressing together and bunching up. As this happens the rocks around the area of compression undergo an intense amount of pressure and heat that changes the rocks from their original state – forming metamorphosed rocks. Two of our most abundant rock types are metamorphic – iron ore and corundum. These rocks are also the oldest we see in Skyrim, indicating that for the first part of Skyrim’s history (spanning at least 2 billion years) it was under the sea forming iron ore sediments. A rock, we cannot be sure what it was originally, was deposited on top of the iron ore several millions of years later and then both were squeezed and pushed into mountains and the rest of Skyrim.

Millions of years later, the land started to pull itself apart in the east of Skyrim. Extension is a common trigger for volcanic activity, and combined with what could either have been a warm and wet or marine environment quicksilver and orichalcum deposits began to form above the previously metamorphosed rocks.

In modern day Skyrim, we still see some hot springs and nearby volcanic activity in Solstheim as well as the east being aptly named The Rift.

By Jane Robb, EGU Educational Fellow