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Increasing our knowledge of Antarctica with hydrography
Cooperation and expeditions by Members of the IHO Hydrographic Commission on Antarctica.
The environment in Antarctica is changing perhaps more rapidly than anywhere else in the world. So rapidly that ships visiting the region can enter into a bay and be surrounded by water, yet the electronic map onboard shows them to be in the middle of a glacier. It is estimated currently only 10% of Antarctic waters are surveyed to IHO specifications, with some charts dating as far back as the 1900s!
Antarctica is a remote location with a harsh climate. Travelling there and accurately surveying its waters to collect information on coastlines, sea depth, underwater features etc is difficult and expensive. Hydrographic surveys can only be done a few months each year and only a limited number of vessels are capable of carrying out this work. Just like administration falls to the countries of the Antarctic Treaty, responsibility for hydrographic information lies with twenty-four of those countries also members of the Hydrographic Commission on Antarctica (HCA). The Commission provides a forum for countries and observers with an interest in the region to increase collaboration and provide mutual support. It promotes technical co-operation in the domain of hydrographic surveys, marine cartography, and nautical information. This is particularly important considering that retreating ice is severely impacting the marine environment and modifying coastlines. Yet the relevance of hydrography in Antarctica extends beyond regional impacts on surveys and charts. According to the Scientific Committee on Antarctic Research (SCAR), rising temperatures and melting ice in Antarctica alone could contribute 40cm to global sea-level rise by 2100, but even more on a longer timescale.
+2°C global warming could be a threshold for the irreversible retreat of Antarctica’s marine-based ice. If the warming was sustained, it could cause sea-level to rise up to 22 metres over centuries to millennium – Professor Tim Naish, head of SCAR’s Past Antarctic Ice Sheets’ programme.
Already ice loss is having an impact on biodiversity and ecosystems in the region, ecosystems which we are still discovering. For example Orca Seamount was discovered in 1987, but the first maps showing the underwater volcano and its crater were only made in the 90s. Yet recent research is highlighting the importance of its hydrothermal vents for species such as penguins that feed there.
As a sign of the importance of this work, in 2019 Parties to the Antarctic Treaty voted a resolution to increase knowledge of the region and improve hydrographic surveying and charting. While this is particularly challenging as the melting glaciers are constantly changing the environment, this work is as relevant as ever. Gathering accurate and up-to-date hydrographic data will improve navigational safety and support a range of other activities, including scientific research, management and monitoring of the marine environment, hazard and risk assessment, as well as search and rescue activities. It will be provided as open-access digital data which will allow a broad community to use it. Modern technologies such as aerial, surface and underwater drones will help increase the reach and quality of this survey data.
Environmental Changes
Ice loss from the Antarctic Ice Sheet has increased during the early 21st century and could be irreversible over decades to millennia, according to scientists at the Scientific Committee on Antarctic Research (SCAR). Paleoclimate archives and reconstructions show that in the past, small increases in global greenhouse gases and temperature led to ice loss in East Antarctica. In the future, minor changes there could make major contributions to sea level rise.
Not only do such changes have the potential to disrupt Antarctica’s environment, but there could be knock-on effects for the rest of the planet.
Antarctica and the waters around it have a big influence on global sea level, climate, and marine ecosystems.
For example how the Antarctic Ice Sheet responds to warming of the atmosphere and the ocean will determine how much and how fast sea level rises in the coming centuries. Currently, the ocean in Antarctica takes up more anthropogenic heat and carbon than the oceans at other latitudes, and thereby helps slow the pace of atmospheric warming. However, ocean heat is now causing the ice sheet to thin and retreat, and to lose mass at an ever increasing rate. The eventual loss of sea-ice will amplify surface warming by changing the reflectivity (albedo) of the earth’s surface at the southern high latitudes (currently the ice sheets reflect the sun’s rays and heat back into space). The loss of sea-ice and freshening of the surface waters will also cause major changes for the transport of heat around the world, impacting global weather patterns.
Melting glaciers will impact Antarctica but could have knock-on effects for the planet as a whole. Photo © Laura Goldstein, IAATO
Detailed hydrographic surveys provide information on elements such as the size of marine glaciers, sea temperature, salinity etc, and can be used to precisely monitor any changes. Several members of the Hydrographic Commission on Antarctica participate in multi-disciplinary expeditions which provide valuable baseline data.
International Cooperation
The IHO Hydrographic Commission on Antarctica fosters cooperation among states to increase knowledge of Antarctica, information which is essential for safe maritime operations and the protection of the marine environment. This includes cooperation on expeditions to the region with the sharing of resources, expertise, and information. Countries such as Australia, Italy, Spain, Peru and Chile carry out expeditions there, gathering a wide array of data. As a result, 142 Electronic Navigational Charts (ENC) and 93 international paper charts of Antarctica have been produced and are maintained as a result of close HCA member cooperation since 2003. The International Association of Antarctica Tour Operators (IAATO) has been carrying out bathymetric crowd-sourcing, using data from their members’ vessels’ echo sounders and GPS to record data which can then be used for maps of the seabed.
Numerous HCA members are strengthening their engagement for the Antarctic in terms of new ship´s capacity for survey and research, facility infrastructure improvements and investment in new carrier technology such as Autonomous Surface Vessels.
The Australian Antarctic Division's new vessel RSV Nuyina is fitted with two “in hull” multi-beam systems, a full suite of modern scientific instrumentation and a dedicated science tender which also has its own multi-beam system. Photo © Lloyd Symons/Australian Antarctic Division
Unravelling the secrets of Orca Seamount
Orca Seamount, an underwater volcano, was discovered in 1987, but the first maps showing its crater were only made in the 90s. Located in the rifting zone of Bransfield Strait, the area is still active with volcanic activity and hydrothermal vents, making it important from an environmental point of view and a feeding ground for many species including penguins.
Map of the volcano crater at Orca Seamount. Photo © Istituto Idrografico della Marina
The HCA fosters cooperation among its members and there are many examples of the countries pooling their resources and carrying out successful projects. One example is the cooperation between Italy and Peru. Italy participated in the Peruvian campaigns onboard the BAP Carrasco and gathered a wide array of data on the water column. This included information about physical parameters (temperature, salinity), biogeochemical parameters (pH, chlorophyll, fluorine, turbidity) and acoustic data (currents and density). The researchers also studied the samples to assess the presence of microorganisms and particles as well as contaminants and microplastics.
Many members of the Hydrographic Commission on Antarctica cooperate during expeditions. Photo © Istituto Idrografico della Marina
Thanks to these various expeditions to Antarctica, Italy was able to update its charts from thematic bathymetric charts to more detailed nautical charts (paper and ENC).
Australia Measuring Tides
The measurement of tides is central to the production of hydrographic charts. Photo © Imojen Pearce/Australian Antarctic Division
One of the unique challenges of operating tide gauges in the Antarctic is… ice! When you’re trying to measure the water level with respect to shore based benchmarks, having up to 1.8 metres of sea ice between the land and the water does complicate matters.
Australia’s current focus with the tide gauges is to support hydrographic survey work around their stations, as maps of the approaches could be improved upon. A significant programme of mapping will be undertaken over the next few years with their new vessel RSV Nuyina.
The Australian Antarctic Division has developed a GNSS based tidal buoy system which can be opportunistically deployed to get independent measurements of water level. This data can then be used to calibrate long-term datasets obtained from underwater pressure gauges.
Australia wanted equipment which could be deployed and recovered by non-specialist personnel at their Antarctic stations. Instead of differential GPS setups, they decided to use relatively inexpensive GNSS receivers. The data from these receivers can be post processed in conjunction with data from continuously operating reference stations (CORS) operated by Geoscience Australia at each of the sites. The GNSS buoys can be deployed either in open water or holes can be cut through sea ice for temporary deployment.
The resulting data product is accurate to a few centimetres and is good enough to allow the water pressure data to be converted to tidal levels.
Spain & the South Shetland Islands
Spain cooperates with other members of the HCA such as Argentina, Chile, Portugal and the UK. Photo © Instituto Hidrográfico de la Marina
Spain has maintained bases in Antarctica since 1988, BAE “Juan Carlos I” on Livingston Island and BAE “Gabriel de Castilla” on Deception Island, both in the South Shetland Islands archipelago, some 1000 km South of Cape Horn. The Spanish Hydrographic Institute of the Navy (IHM) has been carrying out hydrographic surveys in Antarctic waters since then, some as dedicated hydrographic cruises and sometimes in collaboration with researchers or international Hydrographic Offices.
For example Portuguese hydrographers embarked on BIO Hesperides during Spanish campaigns while Spanish hydrographers embarked on the BAP Carrasco from Peru and ARA Almirante Irizar from Argentina during their Antarctic campaigns.
There have also been exchanges of information between Spain, Chile, Argentina and the UK around their common interest in Deception Island.
The first Spanish Antarctic Nautical Chart, 001 ANT, was published in 1988. Spain now has ambitious survey plans which will enable the creation of more charts, especially around the South Shetland Islands archipelago. Photo © Instituto Hidrográfico de la Marina
Chilean expeditions since 1947
Chile has been conducting Antarctic expeditions every year since 1947. During the summer season the personnel who were commissioned to stay in Antarctica during the winter season are relieved and supplies are provided to the bases. A hydrographic team collects bathymetric data, conducts geodetic measurements, measures tides and currents specifically in anchorage areas or narrow passages. Chile works with HCA members on the “ INT” chart scheme and to prioritise hydrographic surveys to complete the coverage of the main routes and anchorages.
Crowdsourced data
IAATO supports long-term monitoring to help identify environmental change, offering vessels as platforms for research. This includes monitoring penguin and seal populations as well as hydrographic surveying which provides important baseline information. Photo © IAATO
There is limited availability of navigational data in Antarctica, some of which dates as far back as the early 1900s and – like many areas of the world - does not comply with the latest international standards. Yet safety at sea requires charts that are regularly updated and accurate. To increase available data, several crowdsourcing initiatives have been developed. The International Association of Antarctica tour Operators (IAATO) uses OLEX bathymetric crowd-sourcing unit which gather data from the member vessels echo sounders and GPS to record the vessel data to build a map of the seabed based on the tracks. The more data users share, the more complete the map of the seabed is.
Private and commercial vessels can gather hydrographic information and contribute to increasing our knowledge. Photo © Hydro International
Private and commercial vessels on expeditions in Antarctica can perform hydrographic surveys and contribute to producing much needed navigational charts. During a seven-day survey in January 2013, a team on-board Xplore, an IAATO sailing yacht skippered by Mr Stephen Wilkins (Australia) surveyed 15.2 square nautical miles which included identifying and accurately positioning a shoal which had been marked as “position doubtful”. This has since been officially named "SHOM Rock" to thank the French Hydrographic Office for their support in the project carried by Yoann Boulaire (Shom, France) and Fernando Landet (Chile). The qualified data from the Xplore survey was provided to the IHO Secretariat and then shared with the relevant charting authorities (Argentina, Chile and the UK).
IAATO works with several members of the Hydrographic Commission on Antarctica such as the UK Hydrographic Office. IAATO for example shares their vessel tracks so the UKHO can better assess the travel patterns and where new charts might be needed.
HCA members and observers work with a variety of scientific organizations. IAATO for example coordinates for scientists to be on member ships during expeditions to make observations and take samples. One successful expedition enabled a scientist to observe and take samples of the “type D killer whale”, confirming the existence of this 5th species.
Increased data will help improve maps of Antarctica.
Antarctic Treaty & the IHO
The IHO has been working with the Antarctic Treaty since 1989 when the increase in both the number and size of vessels operating in Antarctic waters led the Parties to agree to increase mutual cooperation for hydrographic surveys. The objective was to ensure the safety of life at sea and protect the Antarctic marine environment and ecosystems.
29 countries (Consultative Parties) participate in the Antarctic Treaty decision-making process. Photo © Lee Truscott, UK Hydrographic Office
Over the years, a series of resolutions focussed on hydrography in Antarctic Waters and strengthening cooperation between the ATCM and the IHO. The latest was in 2019 which encourages cooperation on hydrographic surveying and charting in the Antarctic region. It also encourages governments to collect new bathymetric data and to share this data with the IHO Data Centre for digital Bathymetry (DCDB) so it can be kept and made publicly available.
Hydrography was also addressed during three Antarctic Treaty Meetings of Experts. This included guidelines for Antarctic shipping (2000), ship-borne Tourism (2009) and climate change issues (2010).
Protection of the Antarctic environment is a central theme in the cooperation among Antarctic Treaty Parties, and led to the adoption of the Protocol on Environmental Protection to the Antarctic Treaty in 1991, which designates the area as a natural reserve.
Acknowledgements:
Wording: IHO Secretariat (Sarah Jones Couture) thanks to input and images from:
Members of the IHO Hydrographic Commission on Antarctica:
Australia (Jasbir Randhawa and al.)
Chile (Hugo Gorziglia and al.)
Italy (Luigi Sinapi and al.)
Spain (Salvador Moreno Soba and al.)
UK (Lee Truscott and al.)
USA (Patrick Dorr and al.)
And HCA Observer Organizations:
Antarctic Treaty Secretariat (Albert Lluberas Bonaba and al.)
IAATO (Lisa Kelley and al.)
SCAR (Dr Chandrika Nath, Tim Naish, Johanna Grabow and al.)