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volcanoes

Imaggeo on Mondays: Hints of an eruption

Imaggeo on Mondays: Hints of an eruption

The photograph shows water that accumulated in a depression on the ice surface of Vatnajökull glacier in southeastern Iceland. This 700m wide and 30m deep depression [1], scientifically called an ‘ice cauldron’, is surrounded by circular crevasses on the ice surface and is located on the glacier tongue Dyngjujökull, an outlet glacier of Vatnajökull.

The photo was taken on 4 June 2016, less than 22 months after the Holuhraun eruption, which started on 29 August 2014 in the flood plain north of the Dyngjujökull glacier and this depression. The lava flow field that formed in the eruption was the largest Iceland has seen in 200 years, covering 84km2 [2] equal to the total size of Manhattan .

A number of geologic processes occurred leading up the Holuhraun eruption. For example, preceding the volcanic event, a kilometre-wide area surrounding the Bárðarbunga volcano, the source of the eruption, experienced deformation. Additionally, elevated and migrating seismicity at three to eight km beneath the glacier was observed for nearly two weeks before the eruption [3]. At the same time, seven cauldrons, like the one in this photo, were detected on the ice surface (a second water filled depression is visible in the upper right corner of the photo). They are interpreted as indicators for subglacial eruptions, since these cauldrons usually form when geothermal or volcanic activity induces ice melt at the bottom of a glacier [4].

Fracturing of the Earth’s crust led up to a small subglacial eruption at the base of the ice beneath the photographed depression on 3 September 2014. This fracturing was further suggested as the source of long-lasting ground vibrations (called volcanic tremor) [5].

My colleagues and I studied the signals that preceded and accompanied the Holuhraun eruption using GPS instruments, satellites and seismic ground vibrations recorded by an array of seismometers [2, 5]. The research was conducted through a collaboration between University College Dublin and Dublin Institute for Advanced Studies in Ireland, the Icelandic Meteorological Office and University of Iceland in Iceland, and the GeoForschungsZentrum in Germany.

The FP7-funded FutureVolc project financed the above mentioned research and further research on early-warning of eruptions and other natural hazards such as sub-glacial floods.

By Eva Eibl, researcher at the GeoForschungsZentrum

Thanks go to www.volcanoheli.is who organised this trip.

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/.

Imaggeo on Mondays: “Vancouver! Vancouver! This is it!”

Mount St Helen's, Washington, seen from Johnston Ridge.

On May 18th 1980 Mount St Helens (an active stratovolcano of the Cascades located in the North West US), erupted explosively following a magnitude 5.1 earthquake. The quake triggered a devastating landslide which swept away the volcano’s northern flank – in what is the largest debris avalanche recorded on Earth to date. Removal of a section of the edifice depressurised the volcano’s magmatic system triggering powerful lateral eruptions, which removed the top 300 m of the volcano.

In total, 57 people lost their lives, 250 homes were destroyed and the local infrastructure, including bridges, highways and railways, were badly damaged. Prior to the eruption, the flanks Mount St Helens and its surrounding areas were covered in a dense forest. Following the lateral blasts, all trees within a 10 km radius of the volcano were obliterated, while those further afield were badly scorched.

Andy Smedley, an atmospheric scientist, visited Mount St Helens recently, as part of a road trip around Washington and Oregon states.

“What I can tell you is that the scale is still fairly awe-inspiring, as is the devastation still evident on the ground,” he says of his visit to this extraordinary mountain. “The image in question was taken from the Johnston Ridge, which is named after David Alexander Johnston,” goes on to say Andy.

At the time of the eruption, Johnston was a volcanologist with the United States Geological Survey, in charge of volcanic-gas studies and spent long hours working on the flanks of the volcano. On the morning of the eruption he was one of the first geologists on the mountain. Observing the volcano from what he though was a safe distance (10 km from the vent), upon a ridge know at the time as Coldwater II, Johnston was one of the first to report the eruption: “Vancouver, Vancouver! This is it!” He was swept away by the lateral blast shortly after.

Alongside his USGS colleagues, Johnston was pivotal in ensuring the area around Mount St Helens remained closed to the public after unrest at the volcano was detected in early 1980. The data Johnston collected in the run-up to the devastating blast was crucial to unravelling the processes which governed the eruption.

Coldwater II has since been renamed to Johnston Ridge in memory of the dedicated geologist. There is also a visitor centre, with the same name, from which Andy took this impressive photo of Mount St. Helens.

“The peak is about 6 miles away from the camera and there’s very little vegetation that’s returned in the intervening 36 years [since the eruption],” describes Andy “you get some sense of the size of the eruption from the debris flows down the front flanks of the mountain, but it’s also worth pointing out the new lava dome building and Crater Glacier, one of the youngest glaciers on Earth, both within the 1980 crater.”

“Though it can’t be seen in the image, another thing that struck me was the extent of the blast – it can still be clearly seen by the ranks of toppled tree trunks pointing away from Mount St Helens that surround the nearby hills and extend for some miles on the drive up.”

As volcanic eruptions go, Mount St Helen’s wasn’t particularly large (VEI 5), but Andy thinks it’s relative proximity to centres of population in Washington State and Oregon made it stand out in the public’s consciousness.

“It’s not often that the contiguous USA experiences such a full on eruption (I think the nearby Lassen Peak was the last in 1915), and to have it right there on people’s doorsteps, with the ash column eventually blowing across several states, seemed to make its mark.”

By Laura Roberts, EGU Communications Officer

 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/.

 

Imaggeo on Mondays: Moving images – Photo Contest 2016

Since 2010, the European Geosciences Union (EGU) has been holding an annual photo competition and exhibit in association with its General Assembly and with Imaggeo – the EGU’s open access image repository.

In addition to the still photographs, imaggeo also accepts moving images – short videos – which are also a part of the annual photo contest. However, 20 or more images have to be submitted to the moving image competition for an award to be granted by the judges.

This year saw seven interesting, beautiful and informative moving images entered into the competition. Despite the entries not meeting the required number of submissions for the best moving image prize to be awarded, three were highly ranked by the photo contest judges. We showcase them in today’s imaggeo on Mondays post and hope they serves as inspiration to encourage you to take short clips for submission to the imaggeo database in the future!


Aerial footage of an explosion at Santiaguito volcano, Guatemala. Credit: Felix von Aulock (distributed via imaggeo.egu.eu)

During a flight over the Caliente dome of Santiaguito volcano to collect images for photogrammetry, this explosion happened. At this distance, you can clearly see the faults along which the explosion initiates, although the little unmanned aerial vehicle is shaken quite a bit by the blast.


Undulatus asperitus clouds over Disko Bay, West Greenland. Credit: Laurence Dyke(distributed via imaggeo.egu.eu)

Timelapse video of Undulatus asperitus clouds over Disko Bay, West Greenland. This rare formation appeared in mid-August at the tail end of a large storm system that brought strong winds and exceptional rainfall. The texture of the cloud base is caused by turbulence as the storm passed over the Greenland Ice Sheet. The status of Undulatus asperitus is currently being reviewed by the World Meteorological Organisation. If accepted, it will be the first new cloud type since 1951. Camera and settings: Sony PMW-EX1, interval recording mode, 1 fps, 1080p. Music: Tycho – A Walk.

Lahar front at Semeru volcano, Indonesia. Credit: Franck Lavigne (distributed via imaggeo.egu.eu)

Progression of the 19 January 2002 lahar front in the Curah Lengkong river, Semeru volcano, Indonesia. Channel is 25 m across. For further information, please contact me (franck.lavigne@univ-paris1.fr)

 

GeoTalk: Friction in volcanic environments by Jackie Kendrick

GeoTalk: Friction in volcanic environments by Jackie Kendrick

Geotalk is a regular feature highlighting early career researchers and their work. In this interview we speak to Jackie Kendrick, a volcanologist at the University of Liverpool, and winner of the 2016 GMPV Outstanding Young Scientist Award. The occasion will be marked during the upcoming General Assembly, where you’ll be able to listen to Jackie speak in session GMPV 1.1 on the topic of friction in volcanic environments.

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

My name is Jackie Kendrick, and I’m a post-doc in volcanology at the University of Liverpool. I studied for an MSci in Geology at University College London, where I conducted my research project in the Rock and Ice Physics Laboratory. This was an insightful experience for me, I had always been passionate about volcanoes, but having the opportunity to work hands-on in a research environment taught me that I wanted to focus on a career an academia.

I then went on to an Internship at the USGS Cascades Volcano Observatory in Washington State (USA), where I worked on processing of seismic data and had the chance to do a huge amount of fieldwork in incredibly varied settings – for example I installed seismometers at Crater Lake, deployed rapid-response monitoring systems (termed spiders!) at Mount St. Helens and performed landslide simulations at a debris flow flume.

I then moved to Munich, where I undertook my PhD in the Department of Earth and Environmental Sciences at Ludwig Maximilian University. During my PhD I was fortunate enough to largely choose the direction of my studies, as such my research focused on lava dome eruptions from an integrated field, monitoring and experimental approach. Lava dome eruptions have always held a huge fascination for me, and their unpredictable behaviour, with rapid changes from effusive to explosive eruptions, continues to enthral the volcanological community. My PhD opened up possibilities I could not have imagined, and I visited breath-taking volcanic landscapes and state-of-the-art laboratories, where I met so many inspirational scientists – I knew the research community was something I could not turn my back on.

Upon completing my PhD in early 2013 I secured a post-doctoral position at University of Liverpool, funded by the European Research Council. During this position I have worked on a great variety of topics, including experimental studies of magma rheology, rock deformation and friction experiments as well as learning new volcano monitoring strategies like infrasound. Importantly, I have also helped design and develop bespoke high-temperature equipment for the rapidly growing Experimental Volcanology Laboratory, which has allowed me to target specific conditions not previously explored, and once again focus my attention toward the behaviour of dome-building volcanoes, which I find so dynamic in both activity and dormancy.

My primary goal in my research is to strive for the integration of multiple strategies, be it geophysics, geochemistry or geodynamics to try to better understand volcanological processes, and that’s something I hope to continue to pursue throughout my career.

During EGU 2016, you will receive the Outstanding Young Scientist Award from the GMPV Division for your work on understanding what role friction plays in volcanic eruptions. For instance, you’ve carried research out which tries to decipher what role the frictional properties of volcanic rocks and ash play in controlling the run-out distances, and associated risk, of pyroclastic density currents. Could you tell us a bit more about your research in this area and its importance?

This is something that I have really just started working on in the last year – it’s a new direction for me and that’s really exciting! To be recognised by the community, in receiving this award, is a great honour, and I do hope that I can continue to push frontiers with the research I undertake in the future.

This new endeavour into pyroclastic flows  developed naturally, logically from work I was doing on sector collapse at volcanoes – where a volcano becomes unable to support its own weight and fails and collapses. We have just recently acquired the capability to study the frictional properties of rocks at high temperature, something which has been really lacking in volcanology previously, and so this opened up a whole realm of possible applications – one of which is looking at the dynamics of pyroclastic flows. Supported by colleagues at University of Liverpool, our approach is to constrain the frictional properties of a range of volcanic materials at realistic temperatures, for example, pyroclastic flows can reach several hundreds of degrees, even as high as 1000oC. The accurately constrained material properties that we get through laboratory experiments can then be integrated into models using accurate topography, which can predict for example, run-out distance, i.e. how far a flow will travel away from the volcano.

This type of study is hugely important at lava dome volcanoes especially, where pyroclastic flows can be triggered by even small collapse events on the lava dome or at lava flow fronts – events that may have no warning at all. Never has this been more apparent than standing on the lava dome at the summit of Mount Unzen (Japan), observing the precipitous drop to the small, vulnerable suburbs of Shimabara town, where tragically, 44 people lost their lives in a pyroclastic flow in 1991.  Hopefully, via our efforts to accurately predict flow dynamics, as well as actively tackling real-time monitoring targeted directly at pyroclastic flows (currently underway at Santiaguito volcano, Guatemala), such tragedies can be avoided in future.

The view down over Mount St. Helens crater from the summit, in the centre the lava dome has grown in the collapse scar from the 1980 eruption. The collapse devastated the proximal land and vegetation, dead trees still float like matchsticks in the calm waters of Spirit Lake and the event left the inner workings of the volcano open to scrutiny. In the background, the glacier-capped Mount Rainier lies dormant. (Credit: Jackie Kendrick)

The view down over Mount St. Helens crater from the summit, in the centre the lava dome has grown in the collapse scar from the 1980 eruption. The collapse devastated the proximal land and vegetation, dead trees still float like matchsticks in the calm waters of Spirit Lake and the event left the inner workings of the volcano open to scrutiny. In the background, the glacier-capped Mount Rainier lies dormant. (Credit: Jackie Kendrick)

These approaches are also pertinent in understanding landslides and sector collapse events too – an interest of mine that was sparked during fieldwork at Mount St. Helens, which suffered one of the most infamous and catastrophic sector collapses ever documented in 1980.

It seems like Mount St. Helens has been a pretty inspirational place for you over the years! Can you tell us more about the work it’s stimulated?

Absolutely- I’ve been lucky enough to visit this spectacular volcano on numerous occasions, sometimes for work and always for pleasure!

My MSci research looked at the strength of rocks that make up the volcanic edifice rocks (usually layered lava flows that give volcanoes their familiar cone-shape), but the real defining moment in my career path was during fieldwork in 2010. During a visit organised between Ludwig Maximilian University of Munich, University College London, University of British Columbia and with the USGS we had the chance to study the crater lava domes up close for almost a week, to conduct thorough structural investigation of the internal lava dome characteristics. The domes, formed during eruptions in 1980-86 and 2004-08 are surrounded by the so-called Crater Glacier, which forms a ring around the domes, and which prevents access by foot – instead, we had to fly in by helicopter and camp in the crater!

There I began to appreciate lava domes for what they are, huge, rigid masses of near-solidified rock that are forced through the crust by buoyant magma below. This is especially true of Mount St. Helens, where the magma during the 2004-08 eruption was already crystallised at a depth of about 1 km and the dome is formed of a series of solid magma spines that rose up during the eruption, like arching whalebacks from the crater floor. These whalebacks are mantled by the products of friction, shear zones with powdery gouge, complex fracture networks and distorted crystals. It became suddenly apparent to me how important frictional processes were during these types of eruption, and how exciting it could be to push my research in a new direction endeavouring to understand it!

So since your career defining visit to Mount St. Helens in 2010, it’s  been your goal to understand how frictional properties come into play in different volcanic scenarios, including the conduit?

Exactly, I’ve always had a passion for new and exciting research directions – and looking at the frictional properties of volcanic rocks in the context of erupting magma was something only touched upon experimentally before.

During an eruption, magma (called lava after it reaches the surface) is carried from the subterranean magma chamber to the surface in a conduit. Some conduit models have proposed a friction criteria to explain certain seismic signals, but parameters were derived theoretically or from friction experiments on other rocks. I started performing friction experiments in 2011. In these experiments 2 cylindrical rock cores are placed end-on, while a load (force) is applied from one end, and the other end is rotated at a desired velocity to create a simulated fault. I’ve looked at the frictional behaviour of volcanic glass, of ash, and of crystalline lavas – and I always try to integrate these studies with geophysical observations of real processes. You can  watch one of these experiments in this video:

Another important aspect is examining microstructures and performing geochemical analysis, to make sure that the experiments recreate elements of natural examples. So far these investigations have led to a number of important findings:

  1. That the heat that can be generated by friction can be immense – just try rubbing your hands together for a few seconds and then imagine this process in magma(!)
  2. Volcanic rocks melt readily under friction – much more rapidly than most other rock types
  3. The heat generated by friction can make the magma degas – volatiles in magma are only stable under certain pressure-temperature conditions, and if rapidly changed the gas will try to escape – we term this thermal vesiculation, and cite it as the driving force of some explosive eruptions
  4. When some lavas melt due to friction, the viscosity (stickiness) of the melt is abnormally high – this melt “glues” the slip zone together (a phenomena called viscous braking) and it can actually control the rate of an eruption.

The list goes on, and there are many applications beyond the conduit, in terms of volcanoes, faults and even material sciences. But even after several years, nothing beats the excitement of seeing a molten magma form between volcanic rocks rubbed together for just a fraction of a second!

The product of our first successful friction experiment at University of Liverpool in 2014 – we created frictional melt in a pair of andesites from Volcán de Colima (Mexico). (Credit: Jackie Kendrick)

The product of our first successful friction experiment at University of Liverpool in 2014 – we created frictional melt in a pair of andesites from Volcán de Colima (Mexico). (Credit: Jackie Kendrick)

We can’t argue, volcanoes are possibly one of the coolest things in the Earth sciences, but what about them sparked your interest and the willingness to dedicate your research to them? In particular, why did you choose this interdisciplinary field at the crossroads between structural geology, seismology and volcanology?

For me, volcanoes hold such intrigue because of the power they possess – the unharnessed raw energy expelled during an eruption is something just fascinating to watch. The fact that they hold the potential to wreak havoc, and that we don’t yet really understand all the processes involved, just adds to my desire to study them, to know them inside and out.

There’s no doubt in my mind that this can be best achieved using an interdisciplinary approach, it’s all about monitoring, detailing and simulating the process. That is, we see something in real-time via geophysics, we simplify the system so that we can explore individual processes experimentally, and then we integrate our findings back into models to see if we can recreate a phenomena – there’s no point explaining one aspect if it can’t tie in all the others.

Fortunately I’ve had a pretty varied background, nonetheless it’s impossible to be an expert at everything – only highlighting the need to work together, to integrate knowledge from different fields in order to start deciphering complex earth processes.

This was the goal of the recent NSF-funded Workshop on Volcanoes 2016, held at Quetzaltenango (Guatemala), near the ever-active Santiaguito volcano, where we shared best practices and methodologies in monitoring and research – something I believe should be at the forefront of our minds moving forward.

To finish, what advice would you give students fascinated by volcanoes wanting to pursue a career in academia studying volcanology?

Well, first off, I’d say go for it! There are so many great post-graduate options nowadays, and you can really go down any route you choose – be it remote monitoring (like InSAR), proximal monitoring (including seismicity, gas measurements), laboratory experiments (such as friction described here) or you can approach volcanology from the social sciences, looking at influences on people and the environment. There are so many ways that you can get into volcanology, and what’s important is drive and passion, more than a specific academic prerequisite.

That said, I would certainly advise getting some experience before committing to post-graduate study, not least to find out exactly where your interests lie! You can get involved in monitoring by volunteering at volcano observatories, or in research by contacting professors and other academics for short internships and research opportunities. If you’re still doing your undergraduate studies, ask around, speak to graduate students to get advice and learn about the options open to you, and if you can, go to conferences, they are excellent for meeting influential people that can help shape your career!

An explosion at the dynamic Santiaguito volcano (Guatemala) in January 2016 – the volcano offers a unique monitoring opportunity as the ancestral Santa Maria volcano sits just a few km away and several hundred meters higher – the perfect vantage point. (Credit: Jackie Kendrick)

An explosion at the dynamic Santiaguito volcano (Guatemala) in January 2016 – the volcano offers a unique monitoring opportunity as the ancestral Santa Maria volcano sits just a few km away and several hundred meters higher – the perfect vantage point. (Credit: Jackie Kendrick)