The Science

The expedition team supports international scientific projects through daily observations, installation of equipment, sampling of snow and undertaking measurements.

Antarctic Quest 21 Scientific Projects

Written by our scientific advisor, Dr Charlotte Braungardt – Contact: charly@challenginghabitat.com

The expedition team supports international scientific projects through daily observations, installation of equipment, sampling of snow and undertaking measurements.

UK Antarctic Seismic & GNSS Network (UKANET)

Scientific contact: Dr Pippa WhitehouseDurham University, UK

Link: UKANET is funded by the Natural Environment Research Council (NERC) and linked to the British Antarctic Survey (BAS). Its partners include the Polar Earth Observing Network (POLENET).

Expedition contribution: Service and upgrade instrumentation at Foyn Point

The West Antarctic Ice Sheet is losing ice at a rate accelerated by man-made global climate warming. This ice loss is significant for communities around the globe, as it accounts for about 10% of current sea-level rise, although large uncertainties remain with such estimates [1]. Accurate measurements of present and predictions of future ice loss are challenging, as satellite measurements of ice sheet change are affected by the solid Earth’s response to ice loss. The Earth’s crust floats on the viscous mantle beneath and the solid land masses of the Antarctic are depressed into the mantle under the massive weight of ice sheets. As the ice thins, the load lightens, and the continental crust rises in a process termed isostatic rebound [2]. In recent decades, the collapse of floating ice shelves around the Antarctic Peninsula have triggered the acceleration of glaciers unloading ice into the ocean. Following the collapse of Larsen B ice shelf in 2002, accelerated isostatic rebound has been observed at rates far-exceeding long-term trends in that area [3].

The determination of isostatic rebound on the Antarctic Peninsula is one of the objectives of the project UKANET, using Global Navigation Satellite System (GNSS) stations deployed on rock outcrops around the Antarctic Peninsula. To this end, long-term data are transmitted in real-time from stations installed by international scientists from a range of projects.

One of the instruments adjacent to the former Larsen B ice shelf, at Foyn Point, has been malfunctioning for 6 years and at present, the only method of reaching it is by overland expedition. To evaluate whether the isostatic rebound, and ice loss experienced in this area following the collapse of Larsen B is sustained, diminishing or accelerating, the retrieval of data, repair and upgrade of the instrumentation at Foyn Point is now crucial.

The expedition team will manually haul some 200 kg of equipment and tools across the AP from Portal Point to Foyn Point to make this possible.

References

[1] Shepherd A, Ivins E, Rignot E, et al (2018) Mass balance of the Antarctic Ice Sheet from 1992 to 2017. Nature 558, 219-222. Open Access.

[2] Whitehouse PL (2018) Glacial isostatic adjustment modelling: historical perspectives, recent advances, and future directions. Earth Surface Dynamics 6, 401-429. Open Access.

[3] Nield GA, Barletta VR, Bordoni A, et al. (2014) Rapid bedrock uplift in the Antarctic Peninsula explained by viscoelastic response to recent ice unloading. Earth and Planetary Science Letters 397, 32-41. Open Access.

Geophysical Investigation of the Antarctic Peninsula

Unfortunately, due to a bottleneck in delivering equipment fit for deployment in the harsh Antarctic climate, this project could not go ahead.

Scientific contact: Dr Kate SelwayUniversity of South Australia, Adelaide, Australia

Expedition contribution: temporary emplacement of magnetotelluric equipment on ice sheet

Dr Selway investigates the physical properties of the Earth’s mantle and crust with a range of geophysical methodologies, including magnetotellurics (MT). MT is used to determine the electrical resistivity beneath the Earth’s surface to depths of several hundred kilometres, from measuring variations in the Earth’s natural magnetic and electric (or telluric) fields. MT data is valuable to gain better understanding of geologic structures and the movement of the Earth’s crust, because different materials and structures feature different electrical resistivity. As an example, both, the viscosity and electrical resistivity undergo sharp gradients at the interface between the lower lithosphere (the solid rock of the Earth’s crust) and the astherosphere (the Earth’s mantle) [4].

Dr Selway utilises MT data specifically to run mathematical models for the reconstruction of plate tectonics, climate and biological evolution [5]. Her work in the Arctic and Antarctic supports more accurate measurement of ice loss from polar regions, through improving models of the viscosity of the Earth’s mantle, which controls the rate of isostatic rebound (also see UKANET), a vital factor in determining ice sheet behaviour and predictions of sea-level rise [6]. Recordings over several days to weeks are required to obtain data from deep in the mantle.

The expedition is facilitating these measurements by temporarily emplacing magnetotelluric instrumentation on the Forbidden Plateau on the way to Foyn Point, where it will gather data for around two weeks before the team retrieves the equipment on their return journey.

References

[4] Selway K, O’Donnell JP (2019) A small, unextractable melt fraction as the cause for the low velocity zone. Earth and Planetary Science Letters 517, 117-124. Paid Access.

[5] Wannamaker P, Hill G, Stodt J, et al. (2017) Uplift of the central transantarctic mountains. Nature Communications 8: 1588. Open Access.

[6] Selway K, Smirnov MY, Beka T, et al. (2020) Magnetotelluric constraints on the temperature, composition, partial melt content and viscosity of the upper mantle beneath Svalbard. Advancing Earth and Space Science 21(5). Open Access.

Projecting Sea-Level Rise: from Ice Sheets to Local Implications (PROTECT)

Scientific contact: Prof Michiel van den BroekeUtrecht University, Netherlands

Links: PROTECT receives funding from the European Union Horizon 2020 Research and Innovation Programme and is coordinated by the Institute for Geosciences and Environmental Research (IGE) of the French National Centre for Scientific Research (CNRS).

Expedition contribution: sampling of snow deposition on an event-basis

Prof Michiel van den Broeke’s profile states ‘We measure and model precisely how the climate is affecting the ice caps.’ His team utilise a wide range of techniques, including remote sensing, ground-based automated weather stations (AWS) and increasingly sophisticated and detailed computer models to reconstruct, understand and predict past, present and future climate and the mass balance of the large ice sheets of Greenland and Antarctica. The behaviour of these large ice sheets is important for all of us, as their melting alone would result in a 60 m rise in sea-level. The main processes affecting the dynamics of ice sheets include the balance between snowfall and surface meltwater runoff, accelerated melting beneath the ice sheets, ice flow towards and discharge into the ocean (dynamical mass loss), and the interaction with warming ocean waters on the undersides of floating ice shelves and glacier tongues, as well as the influence of isostatic rebound (see UKANET). However, the accurate projection of sea-level rise is hampered by major uncertainties related to the possibility for major ice sheets to suffer irreversible loss of ice because of the warming climate. The onset of this tipping point is difficult to predict [7]

To reduce the uncertainties associated with model predictions, each of these processes and the parameters that determine their direction and rate of progress merits investment in more observation and data collection. In this context, in situ observations remain essential to validate remote sensing data and to develop, evaluate and improve models of regional climate, ice dynamics and subglacial hydrology. For example, snowfall cannot be determined by remote sensing techniques and few automated weather stations are capable of providing such data. Owing to its hostile climate, with extreme snowfall rates (up to one meter per month), the western Antarctic Peninsula is particularly devoid of observations.

The expedition team will undertake rare and much needed direct measurements of snow deposition rates and record meteorological data during their 34-day trek.

References

[7] Hanna E, Pattyn F, Navarro F, et al. (2020) Mass balance of the ice sheets and glaciers – Progress since AR5 and challenges. Earth-Science Reviews 201: 102976. Author Access.

Processes Influencing Carbon Cycling: Observations of the Lower Limb of the Antarctic Overturning (PICCOLO)

Scientific contacts: Dr Simon UssherDr Angela MilneUniversity of Plymouth, UK

Links: PICCOLO is funded by the Natural Environment Research Council (NERC) with links to the British Antarctic Survey (BAS). It is one of five programmes under the umbrella project ‘Role of the Southern Ocean in the Earth System’ (RoSES) that investigates the importance of this ocean in the global carbon cycle.

Expedition contribution: sampling of snowpack

The global carbon cycle is important for the Earth’s climate regulation, because carbon dioxide (CO2) in the atmosphere is a main contributor to the natural greenhouse effect that ensures temperatures on our planet are hospitable to life as we know it. Before the age of industrialisation, the atmospheric concentration of CO2 had been constant at 280 parts per million (ppm) for several thousand years. Since the 18th century, it has risen above 400 ppm CO2, mainly as a result of fossil fuel burning [8]. These elevated CO2 levels amplify the natural greenhouse effect, leading to changes in climate and more frequent and severe, extreme weather events.

All systems on Earth are linked: atmosphere, hydrosphere, cryosphere and biosphere. The oceans, covering 70% of the planet’s surface, are particularly important in climate regulation through absorption of excess heat, regulating temperature through global ocean currents and dissolution of atmospheric CO2 in surface waters. There, it becomes the carbon source for phytoplankton, the primary producers that utilise sunlight to photosynthesise and carbon to form their cells structures and multiply. As on land, primary producers are the base of the food web, upon which all other organisms, such as grazers and predators, depend.

The Southern Ocean is particularly interesting for climate regulation, having been identified as a major sink for atmospheric carbon dioxide [9]. The main Antarctic deep water branch of the global ocean circulation system forms in the Weddell Sea, where surface water cools on the continental shelf and sinks. The sinking water ‘exports’ the decay products and faeces of a myriad of organisms into the deep ocean and with it, exports the carbon originally captured by the phytoplankton.

The fresh supply of nutrients, other than carbon, in the Southern Ocean is limited by its remoteness and scarcity of exposed land and river, which, at lower latitudes, provide nutrients to the seas surrounding the continents. As a result, primary producers rely more heavily on nutrients available through recycling within the water column [10]. The potential scarcity of essential elements, such as iron and manganese, may limit the productivity of the Southern Ocean, and with it, the effectiveness of the carbon pump that supports climate regulation.

Weather systems transport air masses and moisture across great distances and entrained with these, particles and nutrients that are deposited on ice sheets, ice shelves and the ocean surface. This atmospheric deposition is an important pathway, by which essential element are transported. As plants on land, phytoplankton require macro-nutrients, such as nitrogen and phosphorous, and micro-nutrients, including iron, cobalt, nickel and manganese [11]. Drs Simon Ussher and Angela Milne investigate the processes that determine the carbon export in that region and consider that increased surface melting of snow and ice on the Antarctic Peninsula, one of the most rapidly warming regions on the planet [12], could make a significant difference to the fluxes of nutrients and the productivity of the Southern Ocean.

The expedition team will take snow-pack samples from cores up to a depth of 10 m along their route.

The analysis of these samples at the University of Plymouth will provide insights into the magnitude of atmospheric deposition of essential elements, their concentration in melt water and any recent changes that may have occurred. The data will be included in models of processes that influence biomass production. A better understanding of this system will help to improve Earth system models of contemporary climate change and predictions of its future evolution.

References

[8] Lindsey R (2020) Climate Change: Atmospheric Carbon Dioxide. NOAA Climate.gov. Science and information for a climate-smart nation. Online.

[9] Fogwill CJ, Turney CSM, Menviel L, et al. Southern Ocean carbon sink enhanced by sea-ice feedbacks at the Antarctic Cold Reversal. Nature Geoscience 13, 489-497. Paid Access.

[10] Tagliabue A, Bowie AR, DeVries T, et al. The interplay between regeneration and scavenging fluxes drives ocean iron cycling. Nature Communications 10:4960.Open Access.

[11] Fishwick MP, Ussher SJ, Sedwick PN et al. (2018) Impact of surface ocean conditions and aerosol provenance on the dissolution of aerosol manganese, cobalt, nickel and lead in seawater. Marine Chemistry 198, 28-43. Open Access.

[12] Sato K, Inoue J, Simmonds I, Rudeva I (2021) Antarctic Peninsula warm winters influenced by Tasman Sea temperatures. Nature Communications 12: 1497. Open Access.

Long-Range Atmospheric Transport of Microplastics

Scientific contacts: Dr Imogen NapperUniversity of Plymouth, UK

Links: Dr Napper is a National Geographic Explorer and Sky Ocean Rescue Scholar.

Expedition contribution: sampling of snowpack

In 2004, Prof Richard Thompson OBE coined the term ‘microplastic’ with a definition of particles smaller than 5 mm in size. Since then, his research team at the University of Plymouth has won the Queen’s Anniversary Prize for Further and Higher Education for their cutting-edge research into the sources, pathways and distribution in the environment and accumulation of microplastics in the food chain. One of Dr Napper’s recent studies revealed the abundance, characteristics and seasonal variations of microplastics in the Ganges river [13], and another highlighted the impact of tourism on what was once a remote and pristine environment: Mount Everest. Here, microplastic pollution found at altitudes up to 8440m was consistent with the materials used in synthetic clothing and equipment [14].

Microplastic pollution has been reported on all inhabited continents, in the atmosphere and in the sea, from coastal surface waters to the deep ocean. They have been reported in ecosystems and food webs, on our plates and in our glasses [15][16]. It is now important to gain a better understanding of the processes microplastics undergo in the environment, and this includes the pathways that lead to their ubiquitous distribution in the remotest areas of the planet. Dr Napper states: “Understanding exactly how far microplastics can travel is the next big scientific question”.

The expedition team will take snow-pack samples from cores up to a depth of 10 m along their route.

The analysis of these samples from areas on the Antarctic Peninsula, where no person has been before, will provide an insight into potential long-range atmospheric transport of microplastics and will identify whether their concentrations increased over recent years.

References

[13] Napper IE, Baroth A, Barrett AC, et al. (2021) The abundance and characteristics of microplastics in surface water in the transboundary Ganges River. Environmental Pollution 274:116348. Paid Access.

[14] Napper IE, Bede FR, Davies HC, et al. (2020) Reaching new heights in plastic pollution – preliminary findings of microplastics on Mount Everest. One Earth 3, 621-630. Open Access.

[15] Mercogliano R, Avio CG, Regoli F, et al. (2020) Occurrence of microplastics in commercial seafood under the perspective of the human food chain. A Review. Journal of Agricultural and Food Chemistry 68, 5296-5301. Open Access.

[16] Diaz-Basantes MF, Conesa JA, Fullana A (2020) Microplastics in honey, beer, milk and refreshments in Ecuador as emerging contaminants. Sustainability 12: 5514. Open Access.

Ultraviolet Radiation Dose at the Earth’s Surface

Scientific contacts: Dr Andrew SmedleyUniversity of Manchester, UK

Expedition contribution: deployment of polysulphone ultraviolet dosimetry badges

The Earth’s atmosphere is mainly composed of nitrogen (N2, ~78% by volume), oxygen (O2, ~21%) and argon (Ar, ~1%), with relatively constant proportions. Other gases, such as ozone (O3, less than 0.000008%) are present in comparatively minute amounts and vary with seasons, latitudes and human activity. The highest ozone concentration occurs naturally in the lower stratosphere, about 7 to 35 km above ground level. It is a very reactive and unstable molecule and as a result, it is formed and destroyed in the lower stratosphere, a process that completely absorbs the highest-energy ultraviolet UVA radiation and blocks most of the harmful UVB radiation from the sun. As such, stratospheric ozone acts as a protective shield against radiation that may harm the biosphere in a variety of ways, from inhibition of photosynthesis in plants and algae to eye and skin damage in mammals [17].

The release of synthetic, halogenated, long-lived ozone-depleting substances resulted in the loss of stratospheric ozone, with particularly severe thinning of the ozone layer over polar regions (greater than 60° N and S), commonly termed the ‘ozone hole’. Amidst concerns for human health, especially the increased risk of skin cancers, ozone-depleting substances were successfully banned following the Montreal Protocol in 1987 [18]. Nevertheless, measuring and modelling total column ozone remains a challenge that is hampered by large uncertainties when evaluating whether or not the ozone layer is recovering [17].

However, the actual impact of trends in total column ozone can be evaluated by measuring the UV radiation dose at the Earth’s surface, and from that, the risk to human health can be assessed. This is particularly important for populations living and working in high latitudes, including scientific staff operating in Antarctica. During the Spirit of Scott expedition in 2012, polysulphone ultraviolet dosimetry badges, which absorb UVB radiation, were deployed on sledges hauled across the Antarctic Peninsula. Dr Smedley analysed the badges at the University of Manchester to determine the daily UVB radiation dose at the Earth’s surface, and the results provided valuable complementary data to remote sensing and stationary monitoring equipment [19]. It is of value to his research effort to repeat these measurements to assess changes over time.

The expedition team will deploy polysulphone ultraviolet dosimetry badges on a daily basis during the 34-day trek across the Antarctic Peninsula.

[17] Ball WT, Alsing J, Staehelin J, et al. (2019) Stratospheric ozone trends for 1985-2018: sensitivity to recent large variability. Atmospheric Chemistry and Physics 19, 12731-12748. Open Access.

[18] UNEP (n.d.) About the Montreal Protocol. United Nations Environment Programme (UNEP) Ozonaction. Online.

[19] Russell A, Gohlan M, Smedley A, Densham M (2014) The ultraviolet radiation environment during an expedition across the Drake Passage and on the Antarctic Peninsula. Antarctic Science 27(3) 307-316. Paid Access.

Tardigrades on Antarctic Cryptograms

Scientific contacts: Dr Nigel MarleyUniversity of Plymouth, UK

Links: Dr Marley’s work is linked to the British Antarctic Survey (BAS) through his co-investigator Dr Sandra McInnesemeritus researcher at BAS.

Expedition contribution: sampling of cryptograms (mosses, lichens, liverworts and algae)

For those familiar with tardigrades (or waterbears), they capture our imagination as the ultimate resilient organism: they have survived five mass extinction events in Earth’s history and are able to withstand exposure to near-absolute zero temperatures (-273 degrees Celsius), the vacuum of outer space, high doses of ionising radiation, toxic chemicals, and pressures higher than those found in the deepest ocean trenches. Terrestrial and freshwater tardigrades achieve these feats by developing a ‘tun’, whereby the creatures lose up to 97% of their body moisture, slow their metabolic rate to less than 1/10,000 of normal and suspend food and water intake for periods of years, decades or more [20].

Between 0.5 and 1.2 millimetre in size, with a plump, segmented body and eight clawed legs, their typical habitats are mosses, lichens, and bacterial mats, within which they feed on algae, plant cells, bacteria and smaller invertebrates. Some of the more than 1300 described species occupy soils, dunes or sediments of freshwater and saline waters. Their distribution include all latitudes, the highest mountains and ocean floor thousands of meters below the surface, and in Antarctica they live in the polar deserts and the ice fringes, the 0.3% of the continent not covered in ice [21].

Tardigrades are one of the most important groups in the challenging ecosystem of the Antarctic continent, on which some 70 species have been recorded. They are key consumers and decomposers, breaking down organic matter and taking part in soil formation, as well as being prey. As a relatively simple organism, they are regarded as biological indicator of environmental change, for example due to the consequences of climate change.

Relatively little is known about tardigrade biodiversity and distribution on the Antarctic mainland [22]. Although the Antarctic Peninsula has the highest biodiversity of the entire continent, tardigrades and associated vegetation, other microscopic animals and bacteria have not yet been studied widely and no data is available for the most of region of the Antarctic Quest 21 expedition. To be able to monitor future change, it is important to obtain baseline data from such remote areas and the expedition provides a rare opportunity to do so. In addition, any samples from areas on the fringe of the ice sheets on the Antarctic Peninsula have the potential to reveal new species of microscopic animals.

The expedition team will collect small (5×5 cm) samples of mosses, lichens, liverworts and/or algae on the ground and edges of ice-fields, and the microscopic animals that live within.

[20] Miller WR (2011) Tardigrades. American Scientist 99 (5): 384. Open Access.

[21] Marshall T (2014) New water bear found in Antarctia. Planet Earth. Stories – online publication of the Natural Environment Research Council, 17 June 2014. Open Access.

[22] Kihm J-H et al (2020) Integrative description of a new Dactylobiotus (Eutardigrada: Parachela) from Antarctica that reveals an intraspecific variation in tardigrade egg morphology. Nature Scientific Reports 10:9122. https://www.nature.com/articles/s41598-020-65573-1

Citizen Science: GLOBE Observer: Clouds

Scientific Base: NASA GLOBE Observer and GLOBE Programme, USA

Expedition contribution: meteorological observations for NASA citizen science programme

Clouds are not just an aspect of our daily weather, they also reflect, absorb and scatter sunlight and infrared emissions from Earth. As such, they prevent direct sunlight reaching and heat the ground and they work as a blanket that reduces the amount of heat, or infrared radiation, that escapes from the ground and lower atmosphere into space. In this way, clouds control the exchange of heat in the atmosphere, and therefore play an important role in regulating the Earth’s climate. Different types of clouds have different effects on this energy regulation and long-term changes in cloud cover and prevalence of certain cloud types can have significant impacts on climate and in turn, changes in climate can have significant impacts on cloud formation. For this reason, accurate and frequent data collection on clouds in all areas of the planet are important for understanding their changes and their impact over time.

Satellites continuously observe clouds and measure the Earth’s energy balance from space. However, satellites only ‘see’ the top of clouds and are unable to provide information about the cloud base or multiple layers of clouds. Furthermore, some cloud types are difficult to detect and clouds above areas covered in snow can be hard to distinguish from the white ground cover. Observations from the ground made by informed eyes and supported by photographic evidence complement the satellite data by adding valuable detail, enabling researchers to get a more complete picture of clouds in the atmosphere.

In this context, ground observations that are matched to satellite overpasses or geostationary satellites are particularly valuable, as they allow the creation of composite images by an observer on the ground and a satellite looking at the same cloud within a 15-minute time window. The GLOBE Observer: Clouds data requirements include location, overall cloud cover and surface conditions as standard and welcome optional observations of cloud types, cloud opacity, sky conditions and visibility, as well as photos. Data collection is supported by a Citizen Science app, as well as a library of resources that provides tuition, references, videos and book lists.

The expedition team will make several daily meteorological observations along their route, as well as specifically associated with taking samples and measurements. These data will be shared with the scientific teams associated with the expedition and with the GLOBE Observer: Clouds.

NASA GLOBE Observer is part of the GLOBE Program, which means that thousands of schools across the world can access the collected data by citizen scientist around the world, supporting science education and student research. By contributing rare cloud observations from remote regions of the Antarctic Peninsula, the expedition will make a significant contribution to data bases used for both, research and education.

Antarctic Quest21