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Geosciences Column

Geosciences Column: Taking a Breath of the Wild – are geoscientists more effective than non-geoscientists in determining whether video game world landscapes are realistic?

Geosciences Column: Taking a Breath of the Wild – are geoscientists more effective than non-geoscientists in determining whether video game world landscapes are realistic?

For years, geoscientists have been both fascinated and perplexed by the beautiful (yet often inaccurate) landscapes present in several video games. But are people with a geoscientific education better at telling ‘fake’ natural features from real ones? Rolf Hut, an assistant professor at Delft University of Technology in the Netherlands, and his colleagues sought to answer this question in a new study published in EGU’s open access journal Geoscience Communication

“Oh wow, that is a gorgeous volcano… which could never exist in the real world.” As a hydrologist I’m not an expert on volcanoes compared to some other EGU members I know. Yet, while walking through the fictional world of Hyrule in Nintendo’s latest installment of The Legend of Zelda game series: Breath of the Wild my emotions tend to constantly switch between excitement at the beauty of the landscape and puzzlement at the geoscientific… wrongness of it.

“That mountain could never generate enough runoff to feed a waterfall this big.”

“Ice capped mountains in the background of a sweltering dessert looks amazing. But it only takes me five minutes to get up that mountain, so there could never be snow there…” 

I know: it is just a game. First and foremost game designers had to make this game interesting to play and it wouldn’t have been much fun if you had to walk up a mountain for three days, (Edmund Hillary style) only to find a single piece of in-game equipment . So they condensed the game world. They made decisions that might hurt the sensitivities of geoscientists, but which ultimately made the game more enjoyable (and beautiful) for the majority of those people  whose wallets Nintendo is targeting. 

This whole process got me wondering: if I hadn’t been trained as a geoscientist, would I have had the same “this cannot exist in the real world” feelings that I now have? Would non-geoscientists interpret this fake world as something that potentially could exist? Given how many people play video games, versus how many are trained as geoscientists, this is an important research question. If people do ‘learn’ from games like The Legend of Zelda: Breath of the Wild, they might get a wrong impression of how the (geoscientific) world works.

Curiosity sparked, we set out to test this. And I say ‘we’ because this type of research requires the expertise of a statistician: Casper Albers, an expert of games for geoscience: Chris Skinner, an expert on science communication: Sam Illingworth, and finally someone who has spent more hours in the fictional world of Hyrule (where the The Legend of Zelda: Breath of the Wild is set) than is in any way reasonable: me. 

We picked screenshots from across Hyrule with geoscientifically interesting features such as volcanoes, glaciers, etc. Through a reverse image search (on Google) we then looked for real world photos with matching features. We wanted to ask both geoscientists and those without a geoscientific education to rate those pictures on “how likely they think that the features in the picture can exist in the real world?”. We wanted people to focus on the geo-features, and yet we assumed that normal photos would likely be instantly recognisable compared to the rendered images from the game world; so in order to account for this we applied an artistic ‘van Gogh’ filter to all images.

Two images used in the survey. Panels (a) and (b) are original and (c) and (d) are processed through the “van Gogh” filter. The left two images are from the video game The Legend of Zelda: Breath of the Wild and the right two images are from the real world. The bottom two figures were presented in the survey with the question “Knowing that this picture has gone through a “van Gogh”-filter, how likely do you think it is that the features depicted in the artistic renderings could exist in the real world?”. A 10-point scale was used, where 1 = completely unlikely to 10 = completely likely. (Credit: Rolf Hut et al. 2019)

We distributed our survey among geoscientists and non-geoscientists through social media channels and at the EGU General Assembly 2018. We found two very interesting results. Firstly, it (luckily) transpires that geoscientists are better than non-geoscientists at recognising what is a ‘fake’ landscape from a game; the difference between geoscientists and non-geoscientists is statistically significant. However, the effect is very small and both groups are fairly good in recognising which landscapes are and which aren’t from the game. 

What this research therefore highlights is that everyone, including myself, can continue to explore the beautiful countryside of Hyrule, without fearing that we will pick up erroneous knowledge about geoscience. 

Of course we have to be careful with interpreting our results: it is only a first study into this new field of science and we encourage anyone to build on our work by studying different games, different screenshots and people across more dimensions than only geoscientists versus non-geoscientist. Our paper is available for free via the open access EGU journal Geoscience Communication, and any questions can be directed to the corresponding author: me. Although please allow some time before I answer: chances are I am not continuously looking at my inbox because I’m spending my time wandering through the beautiful, but recognisably fake, plains, mountains and volcanoes of Hyrule.

By dr. ir. Rolf Hut, researcher at Delft University of Technology, the Netherlands

[This article is cross-posted on Rolf Hut’s personal site]

Geosciences Column: How erupting African volcanoes impact the Amazon’s atmosphere

Geosciences Column: How erupting African volcanoes impact the Amazon’s atmosphere

When volcanoes erupt, they can release into the atmosphere a number of different gases initially stored in their magma, such as carbon dioxide, hydrogen sulfide, and sulfur dioxide. These kinds of gases can have a big influence on Earth’s atmosphere, even at distances hundreds to thousands of kilometres away.

A team of researchers have found evidence that sulfur emissions from volcanic eruptions in Africa can be observed as far as South America, even creating an impact on the Amazon rainforest’s atmosphere. The results of their study were published last year in the EGU journal Atmospheric Chemistry and Physics.

Amazon Tall Tower Observatory based in the Amazon rainforest of Brazil (Credit: Jsaturno via Wikimedia Commons)

In September 2014, the Amazon rainforest’s atmosphere experienced an unusually sharp spike in the concentration of sulfate aerosols. During this period, the Amazon Tall Tower Observatory (ATTO) based in Brazil reported levels of sulfate never recorded before in the Amazon Basin.

Sulfate aerosols are particles that take form naturally from sulfur dioxide compounds in the atmosphere. When sulfate aerosols spread throughout the atmosphere, the particles often get in the way of the sun’s rays, reflecting the sunlight’s energy back to space. These aerosols can also help clouds take shape. Through these processes, the particles can create a cooling effect on Earth’s climate. Sulfate aerosols can also facilitate chemical reactions that degrade Earth’s ozone layer.

Fossil fuel and biomass burning have been known cause an increase in atmospheric sulfate, but researchers involved in the study found that neither human activity increased the level of sulfate in the atmosphere significantly. Instead, they examined whether a volcanic eruption could be responsible.

Scientists have suggested for some time that sulfur emissions in the Amazon could come from African volcanoes, but until now they’ve lacked proof to properly justify this idea.

Edited Landsat 8 image of the volcanoes Nyamuragira and Nyiragongo in Congo near the city of Goma. (Credit: Stuart Rankin via flickr, NASA Earth Observatory images by Jesse Allen, using Landsat data from the U.S. Geological Survey.

However, in this study the research team involved caught volcanic pair in the act. By analysing satellite images and aerosol measurements, the researchers found evidence that in 2014, emissions from the neighboring Nyiragongo-Nyamuragira volcano complex in the Democratic Republic of the Congo, central Africa, increased the level of sulfate particles in the Amazon rainforest’s atmosphere.

Satellite observations revealed that volcanoes experienced two explosive events in September 2014, releasing sulfur emissions into the atmosphere. During that year, the volcanic complex was reportedly subject to frequent eruptive events, sending on average 14,400 tonnes of sulfur dioxide into the atmosphere a day during such occasions. This amount of gas would weigh more than London’s supertall Shard skyscraper.

Map of SO2 plumes with VCD > 2.5 × 1014 molecules cm−2 color-coded by date of observation. The 15-day forward trajectories started at 4 km (above mean sea level, a.m.s.l.) at four locations within the plume detected on 13 September 2014 (light blue) are indicated by black lines with markers at 24 h intervals. (Credit: Jorge Saturno et al.)

The images further show that these emissions were transported across the South Atlantic Ocean to South America. The sulfate particles created from the emissions were then eventually picked up by an airborne atmospheric survey campaign and the ATTO in the Amazon.

The researchers of the study suggest that these observations indicate that African volcanoes can have an effect on the Amazon Basin’s atmosphere, though more research is needed to understand the full extent of this impact.

By Olivia Trani, EGU Communications Officer

References and further reading

Volcanic gases can be harmful to health, vegetation and infrastructure. Volcano Hazards Program. USGS.

Aerosols and Incoming Sunlight (Direct Effects). NASA Earth Observatory

Saturno, J., Ditas, F., Penning de Vries, M., Holanda, B. A., Pöhlker, M. L., Carbone, S., Walter, D., Bobrowski, N., Brito, J., Chi, X., Gutmann, A., Hrabe de Angelis, I., Machado, L. A. T., Moran-Zuloaga, D., Rüdiger, J., Schneider, J., Schulz, C., Wang, Q., Wendisch, M., Artaxo, P., Wagner, T., Pöschl, U., Andreae, M. O. and Pöhlker, C.: African volcanic emissions influencing atmospheric aerosols over the Amazon rain forest, Atmospheric Chemistry and Physics, 18(14), 10391–10405, doi:10.5194/acp-18-10391-2018, 2018.

Geosciences Column: climate modelling the world of Game of Thrones

Geosciences Column: climate modelling the world of Game of Thrones

Disclaimer: This article contains minor spoilers for Season 8 of “Game of Thrones.” A basic understanding of the world of Game of Thrones is assumed in this post.

The Game of Thrones world of ice and fire is an unpredictable place both politically and environmentally. While the fate of the Iron Throne is yet to be confirmed, a humble steward has been working diligently to make some sense of the planet’s peculiar climate. The results could help scholars assess when future winters will be coming or how wind patterns may influence where eastern attacks on Westeros from invading dragons and ships would occur.  

It is known that the realms of Westeros and Essos are subject to long-living seasons, with many extending over several years, but Samwell Tarly, the former heir of House Tarly and current steward of the Night’s Watch, has developed a new theory to explain this long seasonal cycle.

His research suggests that the seasons’ extended lifespans could be due to periodic changes in the planet’s tilt as it orbits around the Sun. The results were published in the Philosophical Transactions of the Royal Society of King’s Landing in the Common Tongue, with translations available in Dothraki and High Valyrian.

Tarly carried out his analysis while on sabbatical at the Citadel in Oldtown, Westeros. In the published article he notes that his study was “inspired by the terrible weather on the way here to Oldtown”.

Uncovering climate observations and models

Tarly’s first developed his theory after studying observational climate records stored in the Citadel library’s collections. Many of these manuscripts contain useful information on a number of climate conditions present within the Game of Thrones world, including the multiyear length of seasons.

Seasons occur when regions of a planet receive different levels of sunlight exposure throughout a year. The southern and northern hemispheres experience opposite degrees of sunlight exposure due to the natural tilt of the planet’s axis as it orbits around the Sun. For example, when the southern hemisphere is tilted closer to the Sun it experiences a warmer season; at the same time the northern hemisphere is tilted away from the Sun, so it experiences a colder season.

When a planet is consistently tilted on one side as it orbits around the Sun, the world experiences four seasons during one year. Tarly proposed that seasons could last over several years if the tilt of a planet changes during its orbit: “so that the Earth ‘tumbles’ on its spin axis, a bit like a spinning top”, he explains. If a planet were to only change the side of its tilt once a year, it would experience permanent seasons.

Caption: an example of Earth’s orbit in which (a) the angle of tilt of the spinning axis of the Earth stays constant through the year (Credit: Dan Lunt, University of Bristol)

Caption: an example of Earth’s orbit in which (b) the tilt “tumbles” as the planet rotates round the Sun, such that the angle of tilt changes, so that the same Hemisphere always faces the Sun, giving a permanent season (Credit: Dan Lunt, University of Bristol)

Tarly put this theory to the test with the help of a climate model that he discovered on a computing machine stored in the Citadel cellars. “Luckily I learned how to code when I was back in Horn Hill avoiding sword practice,” Tarly explains in the text.

By running climate simulations with the proposed parameters of his theory, Tarly found that his model was consistent with much of the observational data present within the Citadel library. The models also estimated many climatic features of the world of Game of Thrones, including the seasonal change in temperature, precipitation and wind direction across Westeros.

In the published article, Tarly notes that his theory doesn’t explain how the planet transitions between summer and winter. He guesses that the tumbling pattern of the planet’s tilt persists for a few years, but then flips at one point so that the hemispheres experience new seasons. “The reasons for this flip are unclear, but may be a passing comet, or just the magic of the Seven (or magic of the red Lord of Light if your name is Melisandre),” Tarly writes.

Caption: The Northern Hemisphere winter (top row (a,b,c)) and summer (bottom row (d,e,f)) modelled climate, in terms of surface temperature (◦C; left column (a,d)) precipitation (mm/day; middle column; (b,e)) and surface pressure and winds (mbar; right column (c,f)). (Credit: Dan Lunt, University of Bristol)

The world of Game of Thrones compared to ‘real’ Earth

Tarly then compared the climate of the world of the Game of Thrones to that of a fictional planet called the ‘real’ Earth; Gilly, his partner and research associate, had found records of this planet’s climate in the Citadel library. The analysis revealed that in winter, The Wall, the northern border of the Seven Kingdoms, was similar in climate to many areas of the ‘real’ Earth, including parts of Alaska in the US, Canada, western Greenland, Russia, and the Lapland region in Sweden and Finland. “I always suspected that Maester St. Nicholas was a member of the Night’s Watch,” Tarly noted.

Caption: High-resolution (0.5◦ longitude ×0.5◦ latitude) mountain height for the whole planet. (b) Model-resolution (3.75◦ longitude ×2.5◦ latitude) mountain height for the region of Westeros and western Essos. (Credit: Dan Lunt, University of Bristol)

On the other hand, the models showed that the climate of Casterly Rock, the southern home of House Lannister, was similar to that of the Sahel region in Africa, eastern China, and a small region nearby Houston, Texas in the US.

Climate sensitivity in a world of ice and fire

Finally, Tarly used the climate models to investigate how climate change might impact the world of Game of Thrones. The simulations were done in response to some “worrying reports from monitoring stations on the island of Lys”; the stations have recently observed increasing concentrations of methane and carbon dioxide in the world’s atmosphere. It is suggested that this spike in greenhouse gas emissions could be due to the rising dragon population in Essos, deforestation from global shipbuilding, and excessive wildfire.

Tarly found that, by doubling the level of atmospheric carbon dioxide in his models, the world would warm on average by 2.1°C over 100 years. The results showed that the greatest warming would occur in the polar regions, since warming-induced sea ice and snow melt can trigger additional warming as a positive feedback.

By comparing this level of warming to the Pliocene period of the ‘real’ Earth 3 million years ago, Tarly predicted that the sea level of the world of Game of Thrones could rise by 10 metres in the long term. This degree of sea level rise is sufficient to flood several coastal cities, including King’s Landing.

In the paper, Tarly stresses that climate action from all the Kingdoms is needed to prevent even more social instability and unrest from climate change. He suggests that all governing bodies should work on reducing their greenhouse gas emissions and invest in renewable energy, such as windmills.

If he survives the war for Westeros, Tarly expects that improving his climate analysis will keep him busy for years to come.

By Olivia Trani, EGU Communications Officer

This unfunded work was carried out by Dan Lunt, from the University of Bristol School of Geographical Sciences and Cabot Institute, Carrie Lear from Cardiff University and Gavin Foster from the University of Southampton during their spare time, using supercomputers from the Advanced Centre for Research Computing at the University of Bristol. You can learn more about the climate models online here.

Geosciences Column: Flooded by jargon

Geosciences Column: Flooded by jargon

When hydrologists and people of the general public use simple water-related words, are they actually saying the same thing? While many don’t consider words like flood, river and groundwater to be very technical terms, also known as jargon, water scientists and the general public can actually have pretty different definitions. This is what a team of researchers have discovered in recent study, and their results were published in EGU’s open access journal Hydrology and Earth System Sciences. In this post, Rolf Hut, an assistant professor at Delft University of Technology in the Netherlands and co-author of the study, blogs about his team’s findings.

On the television a scientist is interviewed, in a room with a massive collection of books:

“Due to climate change, the once in two years flood now reaches up to…”

“Flood?” interrupts my dad “We haven’t had a flood in fifteen years; how can they talk about a once in two years flood?”

The return period of floods is an often used example to illustrate how statistically illiterate ‘the general public’ is supposed to be. But maybe we shouldn’t focus on the phrase ‘once in two years’, but rather on the term ‘flood’. Because: does my dad know what that scientist, a colleague of mine, means when she says “flood”?

In water-science the words that experts use are the same words that people use in daily life. Words like ‘flood’, ‘dam’ or ‘river’. Because we have been using these words for our entire lives, we may not stop and think that, because of our training as water scientists, we may have a different definition than what people outside our field may have. When together with experts on science communication, I was writing a review paper about geoscience on television[1] when we got into the discussion “what is jargon?”. We quickly found out that within geoscience this is an open question.

Together with a team of Netherlands-based scientists, including part-time journalist and scientist Gemma Venhuizen and professor of science communication Ionica Smeets and assistant professor on soils Cathelijne Stoof and professor of statistics Casper Albers we decided to look for an answer to this question. We conducted a survey where we asked people what they thought words like ‘flood’ meant. People could pick from different definitions. Those definitions were not wrong per se, just different. One might be from Wikipedia and another from a policy document from EU officials. We did not want to test if people were correct, but rather if there was a difference in meaning attached to words between water scientists and lay people. For completeness, we also added picture questions where people had to pick the picture that best matched a certain word.

The results are in. We recently published our findings in the EGU journal Hydrology and Earth System Sciences[2] and will present them at the EGU General Assembly in April 2019 in Vienna. As it turns out: words like ‘groundwater’, ‘discharge’ and even ‘river’ have a large difference between the meaning lay-people have compared to water scientists. For the pictures however, people tend to agree more. The figure below shows the misfit distribution between lay people and water scientists: the bigger the misfit, the more people have different definitions. The numbers on the right are the Bayes factor: bigger than 10 indicates strong evidence that differences between lay people and water scientists are more likely than similarities. The words with an asterisk are the picture questions, showing that when communicating using pictures people are more likely to share the same definition.

Graph showing the posterior distribution of the misfit between laypeople and experts by using a Bayes factor (BF) for every term used in the survey. Pictorial questions are marked with an asterisk. A value of the BF <1∕10 is strong evidence towards H0: it is more likely that laypeople answer questions the same as experts than differently. A value of the BF >10 is strong evidence towards H1: differences are more likely than similarities. In addition to a Bayes factor for the significance of the difference, we also calculated the misfit: the strength of the difference. The misfit was calculated by a DIF score (differential item functioning), in which DIF =0 means perfect match, and DIF =1 means maximum difference. (Figure from https://doi.org/10.5194/hess-23-393-2019)

Maybe that scientist talking about floods on the television should have been filmed at a flood site, not in front of a pile of books.

Finally, the term ‘flood’ proved to be one of the words that we do tend to agree on, so maybe dad should take that class in basic statistics afterall…

By dr. ir. Rolf Hut, researcher at Delft University of Technology, the Netherlands

[This article is cross-posted on Rolf Hut’s personal site]

References

[1] Hut, R., Land-Zandstra, A. M., Smeets, I., and Stoof, C. R.: Geoscience on television: a review of science communication literature in the context of geosciences, Hydrol. Earth Syst. Sci., 20, 2507-2518, https://doi.org/10.5194/hess-20-2507-2016, 2016.

[2] Venhuizen, G. J., Hut, R., Albers, C., Stoof, C. R., and Smeets, I.: Flooded by jargon: how the interpretation of water-related terms differs between hydrology experts and the general audience, Hydrol. Earth Syst. Sci., 23, 393-403, https://doi.org/10.5194/hess-23-393-2019, 2019.