GeoLog

GeoLog

Imaggeo on Mondays: Fairy chimneys in Love Valley

Imaggeo on Mondays: Fairy chimneys in Love Valley

Every year tourists from around the world flock to Love Valley in Göreme National Park in the Cappadocia region of central Turkey to marvel at the region’s peculiarly pointy geological features. These cone-shaped formations, known as ‘fairy chimneys’ or hoodoos, dominate the park’s skyline, with some rocky spires extending up to 40 metres towards the sky.

While the name ‘fairy chimney’ suggests mythical origins, these rocks began to take shape millions of years ago, when many active volcanoes dominated the region. “The deposits of [volcanic] ash, lava and basalt laid the foundations for today’s landscape,’ commented Alessandro Demarchi in the photo’s description, who captured the stunning photograph featured today. The volcanic material consolidated into a soft rock known as ‘tuff.’ Then over the years, natural weathering forces like wind and water eroded weaker parts of the rock away, leaving behind the pinnacles we see now.

Around the 4th century, during the reign of the Roman empire, many Christian pilgrims traveled to Cappodocia to flee persecution. They built their new life into the region’s rocks, carving out a network of homes and churches from the towers of tuff. If you look closely at background of the image, you can even spot remnants of their handiwork.

The region was named a UNESCO World Heritage Site in 1985, and today you can enjoy the extraordinary geological formations, as well as their cultural history, either from the ground or up in the air through hot air balloon tours.

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at http://imaggeo.egu.eu/upload/.

GeoTalk: To understand how ice sheets flow, look at the bedrock below

GeoTalk: To understand how ice sheets flow, look at the bedrock below

Geotalk is a regular feature highlighting early career researchers and their work. In this interview we speak to Mathieu Morlighem, an associate professor of Earth System Science at the University of California, Irvine who uses models to better understand ongoing changes in the Cryosphere. At the General Assembly he was the recipient of a 2018 Arne Richter Award for Outstanding Early Career Scientists.  

Could you start by introducing yourself and telling us a little more about your career path so far?

Mathieu Morlighem (Credit: Mathieu Morlighem)

I am an associate professor at the University of California Irvine (UCI), in the department of Earth System Science. My current research focuses on better understanding and explaining ongoing changes in Greenland and Antarctica using numerical modelling.

I actually started glaciology by accident… I was trained as an engineer, at Ecole Centrale Paris in France, and was interested in aeronautics and space research. I contacted someone at the NASA Jet Propulsion Laboratory (JPL) in the US to do a six-month internship at the end of my master’s degree, thinking that I would be designing spacecrafts. This person was actually a famous glaciologist (Eric Rignot), which I did not know. He explained that I was knocking on the wrong door, but that he was looking for students to build a new generation ice sheet model. I decided to accept this offer and worked on developing a new ice sheet model (ISSM) from scratch.

Even though this was not what I was anticipating as a career path, I truly loved this experience. My initial six-month internship became a PhD, and I then moved to UCI as a project scientist, before getting a faculty position two years later. Looking back, I feel incredibly lucky to have seized that opportunity. I came to the right place, at the right time, surrounded by wonderful people.

This year you received an Arne Richter Award for Outstanding Early Career Scientists for your innovative research in ice-sheet modelling. Could you give us a quick summary of your work in this area?

The Earth’s ice sheets are losing mass at an increasing rate, causing sea levels to rise, and we still don’t know how quickly they could change over the coming centuries. It is a big uncertainty in sea level rise projections and the only way to reduce this uncertainty is to improve ice flow models, which would help policy makers in terms of coastal planning or choosing mitigation strategies.

I am interested in understanding the interactions of ice and climate by combining state-of-the-art numerical modelling with data collected by satellite and airplanes (remote sensing) or directly on-site (in situ).  Modelling ice sheet flow at the scale of Greenland and Antarctica remains scientifically and technically challenging. Important processes are still poorly understood or missing in models so we have a lot to do.

I have been developing the UCI/JPL Ice Sheet System Model, a new generation, open source, high-resolution, higher-order physics ice sheet model with two colleagues at the Jet Propulsion Laboratory over the past 10 years. I am still actively developing ISSM and it is the primary tool of my research.

More specifically, I am working on improving our understanding of ice sheet dynamics and the interactions between the ice and the other components of the Earth system, as well as improving current data assimilation capability to correctly initialize ice sheet models and capture current trends. My work also involves improving our knowledge of the topography of Greenland and Antarctica’s bedrock (through the development of new algorithms and datasets). Knowing the shape of the ground beneath the two ice sheets is key for understanding how an ice sheet’s grounding line (the point where floating ice meets bedrock) changes and how quickly chunks of ice will break from the sheet, also known as calving.

Steensby Glacier flows around a sharp bend in a deep canyon. (Credit: NASA/ Michael Studinger)

At the General Assembly, you presented a new, comprehensive map of Greenland’s bedrock topography beneath its ice and the surrounding ocean’s depths. What is the importance of this kind of information for scientists?

I ended up working on developing this new map because we could not make any reliable simulations with the bedrock maps that were available a few years ago: they were missing key features, such as deep fjords that extend 10s of km under the ice sheet, ridges that stabilize the retreat, underwater sills (that act as sea floor barriers) that may block warm ocean waters at depth from interacting with the ice, etc.

Subglacial bed topography is probably the most important input parameter in an ice sheet model and remains challenging to measure. The bed controls the flow of ice and its discharge into the ocean through a set of narrow valleys occupied by outlet glaciers. I am hoping that the new product that I developed, called BedMachine, will help reduce the uncertainty in numerical models, and help explain current trends.

3D view of the bed topography and ocean bathymetry of the Greenland Ice Sheet from BedMachine v3 (Credit: Peter Fretwell, BAS)

How did you and your colleagues create this map, and how does it compare to previous models?

The key ingredient in this map, is that a lot of it is based on physics instead of a simple “blind” interpolation. Bedrock elevation is measured by airborne radars, which send electromagnetic pulses into the Earth’s immediate sub-surface and collect information on how this energy is reflected back. By analyzing the echo of the electromagnetic wave, we can determine the ice thickness along the radar’s flight lines. Unfortunately, we cannot determine the topography away from these lines and the bed needs to be interpolated between these flight lines in order to provide complete maps.

During my PhD, I developed a new method to infer the bed topography beneath the ice sheets at high resolution based on the conservation of mass and optimization algorithms. Instead of relying solely on bedrock measurements, I combine them with data on ice flow speed that we get from satellite observations, how much snow falls onto the ice sheet and how much melts, as well as how quickly the ice is thinning or thickening. I then use the principle of conservation of mass to map the bed between flight lines. This method is not free of error, of course! But it does capture features that could not be detected with other existing mapping techniques.

3D view of the ocean bathymetry and ice sheet speed (yellow/red) of Greenland’s Northwest coast (Credit: Mathieu Morlighem, UCI)

What are some of the largest discoveries that have been made with this model? 

Looking at the bed topography alone, we found that many fjords beneath the ice, all around Greenland, extend for 10s and 100s of kilometers in some cases and remain below sea level. Scientists had previously thought some years ago that the glaciers would not have to retreat much to reach higher ground, subsequently avoiding additional ice melt from exposure to warmer ocean currents. However, with this new description of the bed under the ice sheet, we see that this is not true. Many glaciers will not detach from the ocean any time soon, and so the ice sheet is more vulnerable to ice melt than we thought.

More recently, a team of geologists in Denmark discovered a meteorite impact crater hidden underneath the ice sheet! I initially thought that it was an artifact of the map, but it is actually a very real feature.

More importantly maybe, this map has been developed by an ice sheet modeller, for ice sheet modellers, in order to improve the reliability of numerical simulations. There are still many places where it has to be improved, but the models are now really starting to look promising: we not only understand the variability in changes in ice dynamics and retreat all around the ice sheet thanks to this map, we are now able to model it! We still have a long way to go, but it is an exciting time to be in this field.

Interview by Olivia Trani, EGU Communications Officer

An overnight train view of China’s Anthropocene – Part 1

An overnight train view of China’s Anthropocene – Part 1

The nighttrain from Shanghai to Beijing is a comfortable affair. The train is new and clean. My travel partner and I can charge our phones and relax on soft beds. The railway is almost frictionless, and overall the experience is similar to any ride in the West. But outside, as the vehicle roars through the early night, things become increasingly hazy. As we reach further out from the Shanghai metropolis there is a slow realisation that the urban air-polluted luminous glow would not be left behind.

For those who have yet to visit China, it’s hard to truly convey the extent of the air pollution problem. During our time in Shanghai the smog was all encompassing; we could feel it settle on our skin and invade our lungs with every breath. Outdoors there was no escaping it. The Chinese air pollution forecast designated the risk level ‘moderate,’ and we wondered what ‘high’ would entail.

Inside the train we lay on opposite bunks. I fixed the window blind ajar to keep a sleepy eye on nighttime tree tops and apartment blocks as we dart by. We passed endless residential towers as we edged by cities we would never become familiar with, some of which appear desolate, almost entirely unlit, but I can’t imagine for long. Once we passed directly under a giant coal fired power station and by countless fields illuminated in the haze by nocturnal agriculture. There are trucks loading at 3 a.m. Along this 1200 km stretch – think Paris to Madrid – the foggy dim light rarely ceded.

This true-color image over eastern China was acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS), flying aboard NASA’s Aqua satellite, on Oct. 16, 2002. The scene reveals dozens of fires burning on the surface (red dots) and a thick pall of smoke and haze (greyish pixels) filling the skies overhead. Credit: NASA (via Wikimedia Commons)

My traveling companion is a children’s doctor. She raised her concerns: what chance do children born in these cities today have of living long healthy lives? Will they live full lives breathing in this industrial gunk? She explained to me that respiratory diseases kill because of chronic inflammation in the lungs, similar to that experienced from exposure to cigarette smoke. Such inflammation can in time lead to reduced lung function and, consequently, increased pressure on the heart due to less oxygen intake. Then, as the heart works harder to introduce the oxygen the body needs, it can fail, leading to premature death.

Estimates on health issues relating to long-term exposure to air pollution in China are hard to come by. It’s also hard to assess how dangerous such exposure is, but it’s likely China will experience an epidemic of respiratory related illnesses in the near future. One recent study reported that the Chinese population will suffer about 1.6 million premature deaths each year due to air pollution. As well as the human cost of lost loved ones, these air pollution related health risks will become a tremendous financial burden on the national health system. In 2007, The World Bank estimated that the annual health cost of outdoor urban air pollution in China for 2003 was between 157 and 520 billion Chinese yuan, around 1-3% of China’s gross domestic product.

However, this year China announced it would, for the first time, introduce a human health air pollution watchdog. According to Chinese officials, this is the first attempt by the national government to address how pollution affects public health. One day, scientists will be able to report on how generations born today can benefit from such endeavours. But for now, the future remains uncertain.

This is Part 1 of a two-part series on the impact of air pollution in China and the country’s steps to usher a clean era for the 21st century. Keep an eye out for Part 2, appearing next week on Geolog.

By Conor Purcell, a Science & Nature Writer with a PhD in Earth Science

Conor Purcell is a science journalist with a PhD in Earth Science. He is the founding editor of www.wideorbits.com and can be found on twitter @ConorPPurcell and some of his other articles at cppurcell.tumblr.com.

Editor’s note: This is a guest blog post that expresses the opinion of its author, whose views may differ from those of the European Geosciences Union. We hope the post can serve to generate discussion and a civilised debate amongst our readers.

Imaggeo on Mondays: Getting involved with EGU!

Imaggeo on Mondays: Getting involved with EGU!

Today’s featured photo comes from the 2017 General Assembly. Did you enjoy this year’s 666 unique scientific sessions, 68 short courses and 294 side events? Did you know that EGU members and conference attendees can play an active role in shaping the scientific programme of the conference? It’s super easy!

You can suggest a session (with conveners and description), and/or modifications to the existing skeleton programme sessions. So, if you’ve got a session in mind for the 2019 conference, be it oral, poster or PICO, be sure to submit it before 6 September. Have a great idea for a Union Symposium or Great Debate? Make sure to submit your proposal by this Wednesday, 15 August!

But helping us prepare the next General Assembly is not the only way you can have a say in EGU activities over the coming weeks. The EGU’s Autumn Elections are coming up too and we need your help to identify suitable candidates for EGU’s next Treasurer. Until 15 September you can nominate candidates for the position. Think you’ve got it takes to have a go at the role? Then you are also welcome to nominate yourself!

Do you need funding to organise a training school in the Earth, planetary or space sciences? EGU training schools offer early career scientists specialist training opportunities they do not normally have access to in their home institutions. But hurry and submit your application before the deadline this week, 15 August.

In addition, we welcome proposals for conferences on solar system and planetary processes, as well as on biochemical processes in the Earth system, in line with two new EGU conference series we are launching that are named in honour of two female scientists. The Angioletta Corradini and Mary Anning conferences are to be held every two years with their first editions in 2019 or 2020. The deadline to submit proposals is also 15 August.

For other EGU related news, why not visit our news pages, or catch up on the latest via our monthly newsletter?

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at http://imaggeo.egu.eu/upload/.