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Geodynamics

Weathering the storm from a research vessel

Weathering the storm from a research vessel

Fieldwork can take geoscientists to some of the most remote corners of the Earth in some of the harshest conditions imaginable, but stories from the field hardly make it into a published paper. In this blog post, Raffaele Bonadio, a PhD student in seismology at the Dublin Institute for Advanced Studies in Ireland, shares a particularly formidable experience in the field while aboard a research vessel in the North Atlantic Ocean.  

We knew it would be stormy that night. At the previous evening’s briefing, the captain of the ship, composed and collected, notified us that we needed to make a diversion from the planned route to avoid getting too close to the eye of the storm, “We’ll slow down the vessel…” “kind of five metres swell expected”. He was calm and comfortable. The crew members were calm and comfortable. We, the guest scientists, were not.

Why were we in the middle of the ocean?

I was part of a team of researchers from the Dublin Institute for Advanced Studies working on the project SEA-SEIS (Structure, Evolution and Seismicity of the Irish offshore). Our task was to deploy a suite of seismometers on the bottom of the North Atlantic Ocean from our research vessel, the RV Celtic Explorer, to investigate the geological evolution of the Irish offshore.

A map of the North Atlantic Ocean, showing the locations of seismometers deployed by the team’s research vessel, the RV Celtic Explorer. Credit: Raffaele Bonadio

Why study the Irish offshore?

The tectonic plate that Ireland sits on was deformed and stretched to form the deep basins offshore. The plate then broke, and its parts drifted away from each other, as the northern Atlantic Ocean opened. Hot currents in the convecting mantle of the Earth caused volcanic eruptions and rocks to melt 50-100 km below the Earth’s surface. These hot currents may have come from a spectacular hot plume rising all the way from the Earth’s core-mantle boundary (at 2891 km depth) to just beneath Iceland.

What do ocean bottom seismometers do?

Ocean bottom seismometers record the tiny vibrations of the Earth caused by seismic waves, generated by earthquakes and ocean waves. As the waves propagate through the Earth’s interior on their way to the seismic stations, they accumulate information on the structure of the Earth that they encounter. Seismologists know how to decode the wiggles on the seismograms to obtain this information. With this data, they can do a 3D scan (tomography) of what’s inside the Earth.

One of the research team’s seismometers being dropped into the North Atlantic Ocean. The instruments sink to the bottom of the ocean, where they measure the Earth’s movement. Credit: SEA-SEIS Team

In this project, we want to better understand how the structure of the tectonic plate varies from across the North Atlantic and what happens beneath the plates. And is there an enormous hot plume beneath Iceland, responsible for the country’s volcanoes today and the formation of Giant’s Causeway in Ireland? This is what we hope we will find out!

Experiencing an ocean storm

We were aboard the ship about 9 days and had just deployed “Ligea”, the 14th seismometer before the captain had notified us that a storm was heading our way.

While we were told in advance of the approaching storm, there was no way we could have imagined what it would be like to be in the middle of a stormy ocean. I had only heard some stories and I didn’t fully believe them…

I was awakened by the sound of my table lamp smashing on the ground, even the 15 cm protection edge around the table couldn’t help. The closet door opened and hit the wall. I managed not to fall off the bed, pointing my legs and make a crack with my back. I heard one of my colleagues laughing in the next cabin after a loud thud. “Did he just fall off the bed?” I thought to myself – his laugh did sound a bit of hysterical.

I realized a big wave had crashed on the side of the ship. I couldn’t believe that water and metal crashing together could make such a harsh bang. The previous evening was a continuation of bangs, splashes, sprinkles, bloops, clangs, and creaks … but even with all these noises and disturbances, I managed to sleep, exhausted from dizziness and sea-sickness.

I checked the clock on the wall: it was 3:20 in the morning. I looked at the porthole, due to the vertical movement my cabin was underwater half of the time. I walked through the cabin, trying to reach the toilet. “Oh, I wish they made the cabin smaller! I can’t reach both walls with my arms,” I said to myself. I opened the tap to refresh my face, the flowing water danced right and left across the basin. I then climbed up to the deck, I had to literally climb up the stairs. Up there I couldn’t see anything but darkness; I couldn’t see the boundary between the sky and the sea.

More than a week had passed since our departure, yet my body had still not adapted to this incessant movement. My eyes could not follow my body and my stomach did not react well, I couldn’t see anymore what was horizontal and what wasn’t. However, I wasn’t even scared, I believed nobody on the ship was (or is it only that I wanted to believe this?). It wasn’t fear, but rather an unceasing uncomfortable feeling: I knew I was more than 900 km from any dry land, in the middle of the North Atlantic Ocean, on a 66 m long vessel; I knew the captain and the crew were working hard to take us far from the storm. I was not scared…

In a few hours we were planning to deploy an ocean bottom seismometer, a very sophisticated device that is able to operate at huge pressures at the bottom of the ocean; released from the ship it would sink and install itself on the seafloor 4 km under the surface of the waves. In other words, a 200 kg ‘little orange elephant’, as the students who supported us from land every day liked to call it! “Will we be able to deploy? Will we be able not to crash the instrument on the sides? Will we instead be able to keep our balance and walk up to the deck?”

“Yes, we will.”

How did this look like? Find out more in this video:

 

So, what did we accomplish?

As part of the SEA-SEIS project, led by Dr. Sergei Lebedev, our research team successfully deployed 18 seismometers at the bottom of the North Atlantic Ocean. The network covers the entire Irish offshore, with a few sensors also in the UK and Iceland’s waters. The ocean-bottom seismometers were deployed between 17 September and 5 October, 2018, and will be retrieved in April of 2020.

To find out more about the SEA-SEIS Projects, have a look at SEA-SEIS or check out our introductory video.

By Raffaele Bonadio, Dublin Institute for Advanced Studies, Ireland

Winners of the EGU Best Blog Posts of 2018 Competition

Winners of the EGU Best Blog Posts of 2018 Competition

There is no doubt that 2018 was packed full of exciting, insightful and informative blog posts. An impressive 382 posts were published across the EGU’s official blog, GeoLog, as well as the network and division blogs!

In December, to celebrate the excellent display of science writing across the network and division blogs, we launched the EGU Blogs competition. From a list of posts selected by our blog editors, we invited you, the EGU Blogs readers, to vote for your favourite post of 2018. We also invited EGU division blog editors and office staff to take part in a panel vote. After more than two weeks of voting, the winners are finally in!

Without further ado, we’d like to extend a big congratulations to the Geodynamics (GD) Division Blog, winner of the public vote, and the Geology for Global Development (GfGD) Blog, winner of the panel vote!

The GD division blog was crowned winner of this year’s public vote for their post on the Global Young Scientists Summit (GYSS) in Singapore! Follow blog contributor Luca Dal Zilio’s experience attending this gathering of over 250 PhD and postdoctoral fellows!

The GfGD blog snagged first place in the panel vote with their post: The Case Against Fieldwork – How can we internalise the carbon cost of fieldwork, as scientists who investigate the earth system? Read blog contributor Robert Emberson’s analysis and personal experience with the carbon footprint of working in the field!

All the posts entered into the competition are worthy of a read too, so head over to the poll and click on the post titles to learn about a variety of topics: from social media responses to geomagnetic activity, to exploring what artificial intelligence can do for climate science and watching socio-hydrology on Broadway.

If the start of a new year, with its inevitable resolutions, along with the range and breadth of posts across the EGU Blogs have inspired you to try your hand at a little science writing then remember all the EGU Blogs welcome (and encourage!) guest posts. Indeed, it is the variety of guest posts, in addition to regular features, which makes the blogs a great read! If you would like to contribute to any of the network, division blogs or GeoLog, please send a short paragraph detailing your idea to the EGU Communications Officer, Olivia Trani at networking@egu.eu.

Imaggeo on Mondays: The best of imaggeo in 2018

Imaggeo on Mondays: The best of imaggeo in 2018

Imaggeo, our open access image repository, is packed with beautiful images showcasing the best of the Earth, space and planetary sciences. Throughout the year we use the photographs submitted to the repository to illustrate our social media and blog posts.

For the past few years we’ve celebrated the end of the year by rounding-up some of the best Imaggeo images. But it’s no easy task to pick which of the featured images are the best! Instead, we turned the job over to you!  We compiled a Facebook album which included all the images we’ve used  as header images across our social media channels and on Imaggeo on Mondays blog post in 2018 an asked you to vote for your favourites.

Today’s blog post rounds-up the best 12 images of Imaggeo in 2018, as chosen by you, our readers.

Of course, these are only a few of the very special images we highlighted in 2018, but take a look at our image repository, Imaggeo, for many other spectacular geo-themed pictures, including the winning images of the 2018 Photo Contest. The competition will be running again this year, so if you’ve got a flair for photography or have managed to capture a unique field work moment, consider uploading your images to Imaggeo and entering the 2019 Photo Competition.

A view of the southern edge of the Ladebakte mountain in the Sarek national park in north Sweden. At this place the rivers Rahpajaka and Sarvesjaka meet to form the biggest river of the Sarek national park, the Rahpaädno. The rivers are fed by glaciers and carry a lot of rock material which lead to a distinct sedimentation and a fascinating river delta for which the Sarek park laying west of the Kungsleden hiking trail is famous.

 

Melt ponds. Credit: Michael Tjernström (distributed via imaggeo.egu.eu)

The February 2018 header image used across our social media channels. The photos features ponds of melted snow on top of sea ice in summer. The photo was taken from the Swedish icebreaker Oden during the “Arctic Summer Cloud Ocean Study” in 2008 as part of the International Polar Year.

 

Karstification in Chabahar Beach, IRAN. Credit: Reza Derakhshani (distributed via imaggeo.egu.eu)

The June 2018 header image used for our social media channels. The photo was taken on the Northern coast of the Oman Sea, where the subduction of Oman’s oceanic plate under the continental plate of Iran is taking place.

 

River in a Charoite Schist. Credit: Bernardo Cesare (distributed via imaggeo.egu.eu)

A polarized light photomicrograph of a thin section of a charoite-bearing schist. Charoite is a rare silicate found only at one location in Yakutia, Russia. For its beautiful and uncommon purple color it is used as a semi-precious stone in jewelry.

Under the microscope charoite-bearing rocks give an overall feeling of movement, with charoite forming fibrous mats that swirl and fold as a result of deformation during metamorphism. It may be difficult to conceive, but these microstructures tell us that solid rocks can flow!

 

Refuge in a cloudscape. Credit: Julien Seguinot (distributed via imaggeo.egu.eu)

The action of glaciers combined with the structure of the rock to form this little platform, probably once a small lake enclosed between a moraine at the mountain side and the ice in the valley.

Now it has become a green haven in the mountain landscape, a perfect place for an alp. In the Alps, stratus clouds opening up on autumn mornings often create gorgeous light display.

 

Antarctic Fur Seal and columnar basalt Credit: Etienne Pauthenet (distributed via imaggeo.egu.eu).

This female fur seal is sitting on hexagonal columns of basalt rock, that can be found in Pointe Suzanne at the extreme East of the Kerguelen Islands, near Antarctica. This photo was the November 2018 header image for our social media channels.

 

Silent swamp predator. Credit: Nikita Churilin (distributed via imaggeo.egu.eu).

A macro shot of a Drosera rotundifolia modified sundew leaf waiting for an insect at swamp Krugloe. This photo was the January 2018 header image and one of the finalists in the 2017 Imaggeo Photo Competition.

 

Once there was a road…the clay wall. Credit: Chiara Arrighi (distributed via imaggeo.egu.eu)

The badlands valley of Civita di Bagnoregio is a hidden natural gem in the province of Viterbo, Italy, just 100 kilometres from Rome. Pictured here is the ‘wall,’ one of the valley’s most peculiar features, where you can even find the wooden structural remains of a trail used for agricultural purposes in the 19th and 20th centuries.

 

New life on ancient rock. Credit: Gerrit de Rooij (distributed via imaggeo.egu.eu).

“After two days of canooing in the rain on lake Juvuln in the westen part of the middle of Sweden, the weather finally improved in the evening, just before we reached the small, unnamed, uninhabited but blueberry-rich island on which this picture was taken. The wind was nearly gone, and the ragged clouds were the remainder of the heavier daytime cloud cover,” said Gerrit de Rooij, who took this photograph and provided some information about the picture, which features some of the oldest rocks in the world but is bursting with new life, in this blog post.

 

Cordillera de la Sal. Credit: Martin Mergili (distributed via imaggeo.egu.eu)

The photograph shows the Valle de la Luna, part of the amazing Cordillera de la Sal mountain range in northern Chile. Rising only 200 metres above the basin of the Salar de Atacama salt flat, the ridges of the Cordillera de la Sal represent a strongly folded sequence of clastic sediments and evapourites (salt can be seen in the left portion of the image), with interspersed volcanic material.

 

Robberg Peninsula – a home of seals. Credit: Elizaveta Kovaleva (distributed via imaggeo.egu.eu).

“This picture is taken from the Robberg Peninsula, one of the most beautiful places, and definitely one of my favorite places in South Africa. The Peninsula forms the Robberg Nature Reserve and is situated close to the Plettenberg Bay on the picturesque Garden Route. “Rob” in Dutch means “seal”, so the name of the Peninsula is translated as “the seal mountain”. This name was given to the landmark by the early Dutch mariners, who observed large colonies of these noisy and restless animals on the rocky cliffs of the Peninsula,” said Elizaveta Kovaleva in this blog post.

 

The great jump of the Tequendama. Credit: Maria Cristina Arenas Bautista (distributed via imaggeo.egu.eu)

Tequendama fall is a natural waterfall of Colombia. This blog post highlights a Colombian myth about the origins of the waterfall, which is tied to a real climate event.

 

If you pre-register for the 2019 General Assembly (Vienna, 07 – 12 April), you can take part in our annual photo competition! From 15 January up until 15 February, every participant pre-registered for the General Assembly can submit up three original photos and one moving image related to the Earth, planetary, and space sciences in competition for free registration to next year’s General Assembly!  These can include fantastic field photos, a stunning shot of your favourite thin section, what you’ve captured out on holiday or under the electron microscope – if it’s geoscientific, it fits the bill. Find out more about how to take part at http://imaggeo.egu.eu/photo-contest/information/.