GeoLog

Energy, Resources and the Environment

Imaggeo on Mondays: Exploring the underground cryosphere

Imaggeo on Mondays: Exploring the underground cryosphere

The winter season is a good time to take advantage of cold weather activities, whether that’s hitting the ski slopes or warming up by a fire, but for Renato R. Colucci, it’s also one of the best time’s to study the Earth’s underground cryosphere.

Colucci, who took this featured photograph, is a researcher at Italian Institute for Marine Sciences (ISMAR) of the National Research Council (CNR) and is a scientific lead partner for the Cave’s Cryosphere and Climate project, C3 for short. The C3 project aims to monitor, study, date, and model alpine ice cave environments.

This photo was taken by Colucci while he and the C3 project team were surveying a large ice deposit in the Vasto cave, situated within the Southeastern Alps of Italy. Speleologists of the E. Boegan Cave Commission began documenting the caves in this region in the 1960s, making it a great site for studying underground cryosphere today. For the past few years the C3 team has been monitoring the microclimates of these caves as well as analysing how the ice masses within are melting and accumulating ice.

There are many different kinds of ice deposits in caves, but the main difference is how these types accumulate their frozen mass. For some cave ice deposits, like the one featured in this photo, the snowfall that reaches the cave interior amasses over time into solid layers of ice, as is typical for many glaciers. However, other deposits take form when water from melting snow or rain percolates through rock’s voids and fractures, then freezes and accumulates into permanent ice bodies in caves.

These high-altitude underground sources of ice are a lesser-known faction of the cryosphere since they are not very common or reachable to scientists, but still an important one. Often the permanent ice deposits in caves contain pivotal information on how Earth’s climate has evolved over time during the Holocene.

However, if the Earth’s global temperatures keep increasing, this data might not be available in the future. While ice masses in caves are more resilient to climate change compared to their aboveground counterparts, many of these deposits, and the vital data they store, are melting away at an accelerating rate. “Global warming is rapidly destroying such important archives,” said Colucci.

Through this project, the researchers involved hope to better understand the palaeoclimate information stored in these deposits and how the ice will respond to future climate change.

By Olivia Trani, 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/.

Make your EGU 2019 experience more environmentally friendly

Make your EGU 2019 experience more environmentally friendly

The annual EGU General Assembly, the largest geoscience conference in Europe, attracts more than 15,000 attendees to Vienna, Austria every year. With such a large number of participants, many flying to the Austrian capital to attend, the meeting has a large environmental impact.

Given this, the EGU is implementing a number of initiatives towards minimising the General Assembly’s carbon footprint. Today we’ve compiled a few of the ways the EGU is working to make your conference experience more environmentally friendly, and how you can help.

Travelling responsibly

The environmental cost of travelling hundreds to thousands of kilometres for a science meeting cannot be ignored.

To reduce this impact, we encourage participants to travel by train to Vienna when possible. For example, we are promoting a discount offered by SBB, the Swiss Federal Railways, to General Assembly participants traveling from Zurich, Switzerland to the meeting. As in previous years, we also encourage participants to use public transportation once in Vienna by including a weekly transportation pass with every week ticket to the meeting.

Looking for ways to make your conference travel carbon neutral? As a repeat from last year, we are giving meeting participants the opportunity to offset the CO2 emissions resulting from their travel to and from Vienna. To take part, simply select the ‘offset your carbon footprint’ option if registering online or through the on-site terminal stationed in the entrance hall of the convention centre.

Depending on the origin of your travel we charge you an amount to compensate your CO2 emissions. The money collected from you will then be forwarded to the Carbon Footprint campaign to be invested in one of the three projects participants can choose from.

If you opt to offset your carbon emissions, the money collected from you will then be forwarded to carbonfootprint.com to be invested in one of these three projects.

This carbon offset initiative was introduced during the 2018 General Assembly, with about 4,800 attendees, almost one third of the total meeting participants, taking part! We collectively raised nearly €17,000 for the carbon offsetting scheme, which was donated to a project that aims to reduce deforestation in Brazil.

Reducing and reusing

At the conference venue, the Austria Center Vienna (ACV), the EGU has been implementing several environmental measures with our carbon footprint in mind. The following actions from the EGU are focused on limiting the amount of waste generated at the meeting:

  • EGU’s daily newsletter at the General Assembly, EGU Today, will now only be available online, and we are moving towards producing digital versions of the programme book exclusively.
  • Carpeting will be limited to the poster halls on the basement level.
  • Lanyards used at the conference will be produced using 100% recycled material, and the badges contain FSC-recycled paper, which can be recycled in the paper products bins.
  • The plenary and division meetings will serve lunch bags with recyclable PET bottles, which will have designated boxes for disposal by the exits of the rooms.
  • Single-use water bottles will not be offered at coffee breaks. Instead water fountains will be placed throughout the centre. Bringing your own water bottle and mug for hot drinks is highly encouraged! We will also sell multi-use water bottles and coffee mugs at the EGU booth.

The ACV also has a number of green measures in place, including having energy-saving LEDs throughout the centre, using a solar array to heat the water used in the kitchens and toilets, and working with an in-house catering company compliant with green standards.

Join the discussion

If you would like to learn more about the EGU’s efforts to make the General Assembly more sustainable and share your own ideas to make the meeting more environmentally friendly, we encourage to participate in the townhall session “The carbon footprint of EGU’s General Assembly,” taking place on Thursday 11 April, 19:00-20:00 in room -2.47 of the convention centre.

The EGU General Assembly is taking place in Vienna, Austria from 7 to 12 April. Check out the full session programme on the General Assembly website and follow the Assembly’s online conversation on Twitter (#EGU19 is the official conference hashtag) and Facebook.

Imaggeo on Mondays: Patterns in the peatland

Imaggeo on Mondays: Patterns in the peatland

This magnificent pattern is the result of hundreds and hundreds of years of evolution. In this structured minerotrophic peatland in Northern Quebec (Canada), which can also be called a string fen or aapa mire, the green peat ridges (or strings) alternate with water-filled hollows (or flarks). Often flarks are replaced by ponds, which vary in number and size. This pattern of strings and flarks (or ponds) runs perpendicular to the flow of ground water.

Many theories exist to explain the dynamics of this pattern; however, we still do not know the mechanism responsible. Almost all of the present theories suggest that the movement of water could be a major driver of the landscape’s features. The permafrost and frost action, the gradual down-slope slipping, and expansion of peat, the merging of hollows, and fire outbreaks are also considered to be potential factors. Further research is going on to deeply understand the complex relation between abiotic and biotic factors influencing how the string fens take shape.

Vegetation in string fens differs between strings and flarks. Strings are dominated by sedges like Carex exilis, Trichophorum cespitosum, Eriophorum angustifolium, and dwarf birches (Betula glandulosa). On the other hand, flarks or ponds are dominated by Menyanthes trifoliata (also known as bogbean), depending on the level of the water within the ground. The peat moss Sphagnum subfulvum is found on strings while a different species of moss Sphagnum majus can be found on floating mats, at the margin of ponds.

This type of peatland is abundant in the boreal regions of the world, and its predominance can be explained by cooler weather conditions, that limit Sphagnum growth and foster greater surface water flow, especially when the snow melts in the spring.

I encountered this beauty on a field trip during summer of 2016 when I was looking for fens burned by natural wildfires. Unfortunately (or not) this one did not burn, even though all the forests at the margin of the peatland burned pretty heavily. Indeed, the ground of the burned forests was covered by Polytrichum strictum, a pioneer moss known to colonize burned forests or peatland soils (look for the apple green vegetation in the bottom of the photograph).

By Mélina Guêné-Nanchen, Laval University, Québec, Canada

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/.

Geosciences Column: Scientists pinpoint where seawater could be leaking into Antarctic ice shelves

Geosciences Column: Scientists pinpoint where seawater could be leaking into Antarctic ice shelves

Over the last few decades, Antarctic ice shelves have been disintegrating at a rapid rate, likely due to warming atmospheric and ocean temperatures, according to scientists. New research reveals that one type of threat to ice shelf stability might be more widespread that previously thought.

A study recently published in EGU’s open access journal The Cryosphere identified several regions in Antarctica were liquid seawater could be leaking into vulnerable layers of an ice shelf.

Scientists have known for some time now that seawater can seep into an ice shelf’s firn layer, the region of compacted snow that is on its way to becoming ice. This seawater infiltration presents an issue to the ice shelf’s stability, since as the seawater spreads throughout the firn layer, the water can create fractures and help expand crevasses already present in the frozen material. Past research has shown that the presence of liquid brine from seawater within an ice shelf is correlated to increased fracturing and calving.

While ice shelf collapse doesn’t directly contribute to sea level rise, since the ice is already floating, stable ice shelves often push back on land-based ice sheets and glaciers, slowing down ice flow into the ocean. Past research has suggested that once an ice shelf collapses, the rate of ice flow from unsupported glaciers can greatly accelerate.

To better understand Antarctic ice shelves’ risk of collapse, the researchers involved with this new study sought to identify where ice shelf firn layers are vulnerable to seawater infiltration. Using Antarctic geometry data, they mapped out the potential ‘brine zones’ within the continent’s ice shelves. These are regions of the ice shelf where the firn layer is both below the sea level and permeable enough to let seawater percolate through.

The results of their analysis revealed that almost all ice shelves in Antarctica have spots where seawater can potentially leak through their layers, with about 10-40 percent of the continent’s total ice shelf area possibly at risk of infiltration.

Map of potential brine zones areas around Antarctica. Map shows areas where permeable firn lies below sea level (the brine zone), with the threshold for firn permeability defined as 750 kg m−3 (red), 800 kg m−3 (yellow) and 830 kg m−3 (blue) calculated using Bedmap2 surface elevation. Bar charts show the mean percentage area of selected ice shelves covered by the brine zone. (Credit: S. Cook et al. 2018)

The researchers compared their estimated points to a map of previously confirmed brine zones, observed through ice cores or radar surveys. After reviewing these records, they identified only one record of brine presence that hadn’t been highlighted by their developed model.

The study found many areas in Antarctica where seawater infiltration could be possible, but has not been previously observed. The findings suggest that this firn layer vulnerability to seawater might be more widespread than previously believed.

The researchers suggest that the most likely new regions where brine from seawater may be present includes the Abbot Ice Shelf, Nickerson Ice Shelf, Sulzberger Ice Shelf, Rennick Ice Shelf, and slower-moving areas of Shackleton Ice Shelf. The regions all contain large swathes of permeable firn below sea level while also subject to relatively warm air temperatures and low flow speeds, the ideal conditions for maintaining liquid brine.

The study points out that there are still many uncertainties in this research, considering the unknowns still present in the data used for mapping and the factors that may influence seawater infiltration. For example, some areas that have large predicted brine zones have an unusually think layer of firn from heavy snowfall. This is the case for the Edward VIII Bay in eastern Antarctica. “Our results indicate the total ice shelf area where permeable firn lies below sea level, but this does not necessarily imply that the firn contains brine,” the authors of the study noted in their article.

Given their findings, the researchers involved recommend that this potentially widespread influence on ice shelves should be further examined and assessed by future studies.

By Olivia Trani, EGU Communications Officer

References

Cook, S., Galton-Fenzi, B. K., Ligtenberg, S. R. M. and Coleman, R.: Brief communication: widespread potential for seawater infiltration on Antarctic ice shelves, The Cryosphere, 12(12), 3853–3859, doi:10.5194/tc-12-3853-2018, 2018.

Hoegh-Guldberg, O., D. Jacob, M. Taylor, M. Bindi, S. Brown, I. Camilloni, A. Diedhiou, R. Djalante, K.L. Ebi, F. Engelbrecht, J.Guiot, Y. Hijioka, S. Mehrotra, A. Payne, S.I. Seneviratne, A. Thomas, R. Warren, and G. Zhou, 2018: Impacts of 1.5ºC Global Warming on Natural and Human Systems. In: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [Masson-Delmotte, V., P. Zhai, H.-O. Pörtner, D. Roberts, J. Skea, P.R. Shukla, A. Pirani, W. Moufouma-Okia, C. Péan, R. Pidcock, S. Connors, J.B.R. Matthews, Y. Chen, X. Zhou, M.I.Gomis, E. Lonnoy, T.Maycock, M.Tignor, and T. Waterfield (eds.)]. In Press

Scambos, T. A.: Glacier acceleration and thinning after ice shelf collapse in the Larsen B embayment, Antarctica, Geophysical Research Letters, 31(18), doi:10.1029/2004gl020670, 2004.

Scambos, T., Fricker, H. A., Liu, C.-C., Bohlander, J., Fastook, J., Sargent, A., Massom, R. and Wu, A.-M.: Ice shelf disintegration by plate bending and hydro-fracture: Satellite observations and model results of the 2008 Wilkins ice shelf break-ups, Earth and Planetary Science Letters, 280(1–4), 51–60, doi:10.1016/j.epsl.2008.12.027, 2009.

State of the Cryosphere: Ice Shelves. National Snow & Ice Data Center