GeoLog

field work

Imaggeo on Mondays: In the belly of the beast

In the belly of the beast . Credit: Alexandra Kushnir (distributed via imaggeo.egu.eu)

Conducting research inside a volcanic crater is a pretty amazing scientific opportunity, but calling that crater home for a week might just be a volcanologist’s dream come true, as Alexandra postdoctoral researcher at the Institut de Physique du Globe de Strasbourg, describes in this week’s Imaggeo on Mondays.

This picture was taken from inside the crater of Mount St Helens, a stratovolcano in Washington State (USA). This particular volcano was made famous by its devastating explosive eruption in 1980, which was triggered by a landslide that removed most of the volcano’s northern flank.

Between 2004 and 2008 Mount St Helens experienced another type of eruption – this time effusive (where lava flowed out of the volcano without any accompanying explosions). Effusive eruptions produce lava flows that can be runny (low-viscosity) like the flows at Kilauea (Hawaii) or much thicker (high viscosity) like at Mount St Helens. Typically, high viscosity lavas can’t travel very far, so they begin to clump up in and around the volcano’s crater forming dome-like structures.  Sometimes, however, the erupting lava can be so rigid that it juts out of the volcano as a column of rock, known as a spine.

The 2004 to 2008 eruption at Mount St Helens saw the extrusion of a series of seven of these spines. At the peak of the eruption, up to 11 meters of rock were extruded per day. As these columns were pushed up and out of the volcanic conduit – the vertical pipe up which magma moves from depth to the surface – they began to roll over, evoking images of whales surfacing for air.

‘Whaleback’ spines are striking examples of exhumed fault surfaces – as these cylinders of rock are pushed out of the volcano their sides grind against the inside of the volcanic conduit in much the same way two sides of a fault zone move and grind past each other. These ground surfaces can provide scientists with a wealth of information about how lava is extruded during eruption. However, spines are generally unstable and tend to collapse after eruption making it difficult to characterize their outer surfaces in detail and, most importantly, safely.

Luckily, Mount St Helens provided an opportunity for a group of researchers to go into a volcanic crater and characterise these fault surfaces. While not all of the spines survived, portions of at least three spines were left intact and could be safely accessed for detailed structural analysis. These spines were encased in fault gouge – an unconsolidated layer of rock that forms when two sides of a fault zone move against one another – that was imprinted with striations running parallel to the direction of extrusion, known as slickensides. These features can give researchers information about how strain is accommodated in the volcanic conduit. The geologist in the photo (Betsy Friedlander, MSc) is measuring the dimensions and orientations of slickensides on the outer carapace of one of the spines; the southern portion of the crater wall can be seen in the background.

Volcanic craters are inherently changeable places and conducting a multi-day field campaign inside one requires a significant amount of planning and the implementation of rigorous safety protocols. But above all else, this type of research campaign requires an acquiescent mountain.

Because a large part of Mount St Helens had been excavated during the 1980 eruption, finding a safe field base inside the crater was possible. Since the 2004-2008 deposits were relatively unstable, the science team set up camp on the more stable 1980-1986 dome away from areas susceptible to rock falls and made the daily trek up the eastern lobe of the Crater Glacier to the 2004-2008 deposits.

Besides being convenient, this route also provides a spectacular tableau of the volcano’s inner structure with its oxidized reds and sulfurous yellows. The punctual peal of rock fall is a reminder of the inherent instability of a volcanic edifice, and the peculiar mix of cold glacier, razor sharp volcanic rock, and hot magmatic steam is otherworldly. That is, until an errant bee shows up to check out your dinner.

By Alexandra Kushnir, postdoctoral researcher at the Institut de Physique du Globe de Strasbourg, France.

This photo was taken in 2010 while A. Kushnir was a Masters student at the University of British Columbia and acting as a field assistant on the Mount St Helens project.

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: How are clouds born?

GeoTalk: How are clouds born?

Geotalk is a regular feature highlighting early career researchers and their work. In this interview we speak to Federico Bianchi, a researcher based at University of Helsinki, working on understanding how clouds are born. Federico’s quest to find out has taken him from laboratory experiments at CERN, through to the high peaks of the Alps and to the clean air of the Himalayan mountains. His innovative experimental approach and impressive publication record, only three years out of his PhD, have been recognised with one of four Arne Richter Awards for Outstanding Early Career Scientists in 2017.

First, could you introduce yourself and tell us a little more about your career path so far?

I am an enthusiastic atmospheric chemist  with a passion for the mountains. My father introduced me to chemistry and my mother comes from the Alps. This mix is probably the reason why I ended up doing research at high altitude.

I studied chemistry at the University of Milan where I got my degree in 2009.  During my bachelor and master thesis I investigated atmospheric issues affecting the polluted Po’ Valley in Northern Italy and since then I have always  worked as an atmospheric chemist.

I did my PhD at the Paul Scherrer Institute in Switzerland where I mainly worked at the CLOUD experiment at CERN. After that, I used the acquired knowledge to study the same phenomena, first, at almost 4000 m in the heart of the Alps and later at the Everest Base Camp.

I did one year postdoc at the ETH in Zurich and now I have my own Fellowship paid by the Swiss National Science Foundation to conduct research at high altitude with the support of the University of Helsinki.

We are all intimately familiar with clouds. They come in all shapes and sizes and are bringers of shade, precipitation, and sometimes even extreme weather. But most of us are unlikely to have given much thought to how clouds are born. So, how does it actually happen?

We all know that the air is full of water vapor, however, this doesn’t mean that we have clouds all the time.

When air rises in the atmosphere it cools down and after reaching a certain humidity it will start to condense and form a cloud droplet. In order to form such a droplet the water vapor needs to condense on a cloud seed that is commonly known as a cloud condensation nuclei. Pure water droplets would require conditions that are not present in our atmosphere. Therefore, it is a good assumption to say that each cloud droplet contains a little seed.

At the upcoming General Assembly you’ll be giving a presentation highlighting your work on understanding how clouds form in the free troposphere. What is the free troposphere and how is your research different from other studies which also aim to understand how clouds form?

The troposphere, the lower part of the atmosphere, is subdivided in two different regions. The first is in contact with the Earth’s surface and is most affected by human activity. This one is called the planetary boundary layer, while the upper part is the so called free troposphere.

From several studies we know that a big fraction of the cloud seeds formed in the free troposphere are produced by a gas-to-particles conversion (homogeneous nucleation), where different molecules of unknown substances get together to form tiny particles. When the conditions are favourable they can grow into bigger sizes and potentially become cloud condensation nuclei.

In our research, we are the first ones to take state of the art instrumentation, that previously, had only been used in laboratory experiments or within the planetary boundary layer, to remote sites at high altitude.

Federico has taken state of the art instrumentation, that previously, had only been used in laboratory experiments or within the planetary boundary layer, to remote sites at high altitude. Credit: Federico Bianchi

At the General Assembly you plan on talking about how some of the processes you’ve identified in your research are potentially very interesting in order to understand the aerosol conditions in the pre-industrial era (a time period for when information is very scarce). Could you tell us a little more about that?

Aerosols are defined as solid or liquid particles suspended in a gas. They are very important because they can have an influence on the Earth’s climate, mainly by interacting with the solar radiation and cooling temperatures.

The human influence on the global warming estimated by the Intergovernmental Panel for Climate Change (known as the IPCC) is calculated based on a difference between the pre-industrial era climate indicators and the present day conditions. While we are starting to understand the aerosols present currently, in the atmosphere, we still know very little about the conditions before the industrial revolution.

For many years it has been thought that the atmosphere is able to produce new particles/aerosol only if sulphur dioxide (SO2) is present. This molecule is a vapor mainly emitted by combustion processes; which, prior to the industrial revolution was only present in the atmosphere at low concentrations.

For the first time, results from our CLOUD experiments, published last year,  proved that organic vapours emitted by trees, such as alpha-pinene, can also nucleate and form new particles, without the presence of SO2. In a parallel study, we also observed that pure organic nucleation can take place in the free troposphere.

We therefore have evidence that the presence of sulphur dioxide isn’t necessary to make such a mechanism possible. Finally, with all this new information, we are able to say that indeed, in the pre-industrial era the atmosphere was able to produce new particles (clouds seeds) by oxidation of vapors emitted by the vegetation.

Often, field work can be a very rewarding part of the research process, but traditional research papers have little room for relaying those experiences. What were the highlights of your time in the Himalayas and how does the experience compare to your time spent carrying out laboratory experiments?

Doing experiments in the heart of the Himalayas is rewarding. But life at such altitude is tough. Breathing, walking and thinking is made difficult by the lack of oxygen at high altitudes.

I have always been a scientists who enjoys spending time in the laboratory. For this reason I very much liked  the time I spent in CERN, although, sometimes it was quite stressful. Being part of such a large international collaboration and being able to actively do science was a major achievement for me. However, when I realized I could also do what I love in the mountains, I just couldn’t  stop myself from giving it a go.

The first experiment in the Alps was the appetizer for the amazing Himalayan experience. During this trip, we first travelled to Kathmandu, in Nepal. Then, we flew to Luckla (hailed as one of the scariest airport in the world) and we started our hiking experience, walking from Luckla (2800 m) up to the Everest Base Camp (5300 m). We reached the measurement site after a 6 days hike through Tibetan bridges, beautiful sherpa villages, freezing nights and sweaty days. For the whole time we were surrounded by the most beautiful mountains I have ever seen. The cultural element was even more interesting. Meeting new people from a totally different culture was the cherry on the cake.

However I have to admit that it was not always as easy as it sounds now. Life at such altitude is tough. It is difficult to breath, difficult to walk and to install the heavy instrumentation. In addition to that, the temperature in your room during nights goes well below zero degrees. The low oxygen doesn’t really help your thinking, especially we you need to troubleshoot your instrumentation. It happens often that after such journey, the instruments are not functioning properly.

I can say that, as a mountain and science lover, this was just amazing. Going on a field campaign is definitely the  best part of this beautiful job.

To finish the interview I wanted to talk about your career. Your undergraduate degree was in chemistry. Many early career scientists are faced with the option (or need) to change discipline at sometime throughout their studies or early stages of their career. How did you find the transition and what advice would you have for other considering the same?

As I said before, I studied chemistry and by the end of my degree my favourite subject moved to atmospheric chemistry. The atmosphere is a very complex system and in order to study it, we need a multidisciplinary approach. This forced me to learn several other aspects that I had never been in touch with before. Nowadays, I still define myself as a chemist, although my knowledge base is very varied.

I believe that for a young scientist it is very important to understand which are his or her strengths and being able to take advantage of them. For example, in my case, I have used my knowledge in chemistry and mass spectrometry to try to understand the complex atmospheric system.

Geotalk is a regular feature highlighting early career researchers and their work.

What is in your field rucksack? Backpacking in the wilderness

When hiking to altitudes above 2000 m packing light is crucial! Credit: Alexa Van Eaton

When hiking to altitudes above 2000 m packing light is crucial! Credit: Alexa Van Eaton

Inspired by a post on Lifehacker on what your average geologist carries in their rucksack/backpack, we’ve put together a few blog posts showcasing what a range of our EGU members carry in their bags whilst in the field!

This bag belongs to: Alexa Van Eaton

Field Work location: Glacier Peak volcano, Washington, USA

Duration of field work: 12 days

What was the aim of the research?: Glacier Peak is an ice-clad stratovolcano in Washington State, USA. Even though it is the second most explosive volcano in the Cascade Range (behind Mount St. Helens), it is so remote that most people haven’t even heard of it. Unlike Mount St. Helens, Hood or Rainier, the volcano can’t be seen from any of the major cities in the Pacific Northwest. This summer, we spent 12 days backpacking through the Glacier Peak Wilderness area to investigate the volcano’s eruptive history.

Fuel is important during field work too! Credit: Alexa Van Eaton (click to enlarge)

Fuel is important during field work too! Credit: Alexa Van Eaton

One specific aim was to document the deposits from two large, explosive eruptions that occurred about 13.5 thousand years ago. These eruptions transported volcanic ash all the way out to the east coast of the USA, and likely beyond. But the detailed story of what really happened during those eruptions—and why they occurred in the first place—is best recorded in the thick deposits close to the volcano. Getting to these sites high on Glacier Peak meant backpacking to about 7,000 ft [over 2000 m ] elevation through dense forest.

Roughly half the time we would set up a base camp and coordinate day hikes for the mapping and stratigraphic work. Other times we would traverse with our gear to cover more ground. That made the backpack situation pretty crucial. During last year’s fieldwork my backpack was way too heavy (maybe ~40 pounds?), so this time I was committed to slimming it all down, without sacrificing the essentials (e.g., coffee and chocolate…). This year my base weight was ~8 pounds lighter, which made a huge difference.

The one item I couldn’t live without: Cold-weather down sleeping bag (rated to -16degC). A close runner-up would be my 1944 US Army entrenching shovel. It’s vintage and ridiculously heavy, but nothing does a better job of chopping climbing steps into steep tephra outcrops just when you need it.

USGS summer intern Kristin Beck enjoying the view of Glacier Peak volcano from 7,000 ft. elevation. Credit: Alexa Van Eaton

USGS summer intern Kristin Beck enjoying the view of Glacier Peak volcano from 7,000 ft. elevation. Credit: Alexa Van Eaton

 

If you’ve been on field work recently, or work in an industry that requires you to carry equipment, and would like the contents of your bag to feature on the blog, we’d love to hear from you. Please contact the EGU’s Communication Officer, Laura Roberts (networking@egu.eu)

What is in your field rucksack? Camping in Iceland

rebecca_withlabels

When you head out into the field, which is the one item you can’t do without? For Rebecca Williams, a volcanologist at the University of Hull, good footwear is essential!

Inspired by a post on Lifehacker on what your average geologist carries in their rucksack/backpack, we’ve put together a few blog posts showcasing what a range of our EGU members carry in their bags whilst in the field!

Beautiful, eyrie, the land where fire meets ice: Iceland. An Earth scientist’ dream, complete with lava, volcanoes, earthquakes, impossible landscapes, ice, snow, the ocean…Iceland, is a top destination for many scientist who want to better understand the processes which shape our planet. Among them, Rebecca Williams, a volcanologist at the University of Hull, who spent a few days camping on the volcanic island this summer.

This bag belongs to: Rebecca Williams, University of Hull.

Field Work location: Þórsmörk, Iceland

Duration of field work: 10 days

What was the aim of the research?: I was working with Dave McGarvie and Jonathan Moles, from the Open University. They are working on a volcano in the area and had come across the Þórsmörk Ignimbrite. Ignimbrites are the deposits from pyroclastic density currents. This unit is quite complicated and not well understood. It is best exposed in Þórsmörk, so we spent 4 days here doing a recce of the exposure in the Þórsmörk area, trying to understand its many facies and their relationship to each other. I then spent the remainder of the time with a field assistant (Steph Walker from Royal Holloway) doing some detailed work on the best exposures, collecting some samples and recording the details of the deposit. We also recce’d some new areas to try to determine the extent of the deposit and finding new localities for future work.

The one item I couldn’t live without:

Footwear! We covered over 10 miles of rough ground and varied terrain each day, so good footwear is essential. I was very thankful for the trekking sandals when fording the rivers. One fording point is on the famous Laugavegur trekking from the hot springs area of Landmannalaugar to the glacial valley of Þórsmörk. We would often see people trying to ford the river in trainers, crocs and even bare feet! It was clear that this wasn’t ideal, and from some of the screeches, very difficult! But in these trekking sandals, I was able to wade over in relative ease and comfort.

Rebecca in the field. Credit: Rebecca Williams

Rebecca in the field. Credit: Rebecca Williams

In the picture of me in the field, you can see what I actually carry when I’m out and about. The zip off trousers were great for fording rivers – I wasn’t expecting it to be hot enough in Iceland to wear them to work! Strapped to my bag are my sandals for fording rivers, and my hammer. The poles were great for getting around on slopes like the one in the background, and for helping out when fording rivers. Here I’m also carrying a spade – acquired once in Iceland. This is unusual for me, I’m used to working with much harder rocks like the welded ignimbrites in Pantelleria. The spade was very useful for digging through scree slopes and material broken up and crushed by glaciers.

 

If you’ve been on field work recently, or work in an industry that requires you to carry equipment, and would like the contents of your bag to feature on the blog, we’d love to hear from you. Please contact the EGU’s Communication Officer, Laura Roberts (networking@egu.eu)

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