Mapping lobster biomass and the utilities/services on Tristan da Cunha. QGIS reaches the remotest inhabited island of the world!

by iLaria Marengo

Working with GIS and as data manager is exciting, but it becomes even more when the job is taking you to unusual places such as Tristan da Cunha, a small volcanic island in the middle of the Southern Atlantic ocean surrounded only by other two smaller islands, Inaccessible and Nightingale and, further south, Gough.

all_sa_ukots  tristan-group

The project to realise an Information Management System and GIS centre for the South Atlantic UKOTs has reached its final destination and a proper conclusion after three years of life. Getting to Tristan is all but easy thus it took time to arrive, meet the small community and bring QGIS and a flavour of data management in such a remote place.

The QGIS course was not planned in advance but day by day once in Tristan. In fact it was thought that could be more effective to tailor the lessons according to the main needs and existent GIS skills of the users. The majority of the time was spent at the fisheries and electricity and plumbing departments. The directors showed a great interest in receiving a GIS course and their requirement were very specific. They ranged from being able to map lobster biomass per monitoring station, lobster catch (total and average per fishing season) and effort around Tristan, to the network of services, utilities and structures of the settlement of Edinburgh of the seven seas.

total_catch_tristan   tristan-tourism

A series of maps (geological topographical and aerial) have been georeferenced to provide the students with a reference background. Currently the main need is to find a clear image of the settlement as it will help digitising the electricity, water and sewage networks, the buildings and other utilities such as substations, streetlights, stone water tanks and so on.

crawford_map  geological_map

Unfortunately on the island internet is very limited and not reliable. Among the whole South Atlantic UKOTs Tristan has the smallest band width, hence it is virtually impossible to download images or connect to google earth like everyone else would do in the other territories. In terms of GIS a poor internet is partly a limitation as getting new plugins, google maps or updates of the software becomes very difficult. The solution is to work with the long term release releases and get large data (such as imagery) saved as offline images and shipped in on DVDs.

In parallel to the GIS course, time was spent in harvesting metadata. The departments involved in the training course provided metadata about their data and RSPB kindly helped in gathering information on environmental data captured throughout the years with the help of the local conservation department. Almost 40 metadata records were collected and will be available on the metadata catalogue online from the end of November.

Finally, few hours were dedicated with officers of the tourist office and advice on QGIS mapping techniques was given to improve the current maps given to the tourists landing at Tristan. Using QGIS will make mapping much easier and quicker than what is now, entirely based on graphic design software.

The GIS course delivered in Tristan focussed on simple and basic tools that could help straightway the GIS users in achieving their requirements. Indeed, more can be done with GIS but the overall idea, after being on the island, is to let the GIS grow a step at a time according to people’ needs.

Please like & share:

Geocaching in Tristan da Cunha

By iLaria Marengo

Learning about projections and coordinate systems, navigation techniques, compass and bearing, and the use a Global Positioning System (GPS) nowadays can be a bit funnier thanks to geocaching, a modern version of the traditional treasure hunt.

In brief, geocaching consists in getting a pair of coordinates, loading them into a GPS and using the device to navigate to the point where a small box, the geocache, has been hidden. The cache is a small waterproof box and generally contains a logbook and the treasure, which usually are tiny items that have a particular meaning for the person who placed them. The people who find the cache are free to take its objects (except the logbook) but they must leave something of similar value.

geocachegeocache2

It was an unexpected but pleasant surprise to find out that in Tristan da Cunha, the remotest inhabited island in the world, a series of caches had been hidden by the local tourist office as part of a commemorative geotrail. The 200 anniversary of the British Garrison in Tristan da Cunha was celebrated with parties and various initiatives and setting up a geotrail was one of these.

The opportunity of being the first to do the geotrail was then seized and seen as the best way to engage the oldest students of Saint Mary’s School to have an open air geography lesson about projections, maps and the use of GPS for navigation and marking spatial objects. Thanks to Anne, the head teacher who authorised the half day out, and the help of Sarah, fisheries officer, the kids in class 5 were taken around the settlement to learn how to use a GPS, how to mark a waypoint, enter coordinates of a point and navigate to it in order to find it. The day before the “hunt”, the six pupils were asked to write on a small piece of paper why they enjoyed living in Tristan. The papers would have placed in each cache as treasure for the next geocachers.

ticket_geotrail   ticket_geotrail2

A map of the settlement with a sketch of the geotrail, the coordinates of each cache and a description of the importance of each site in the context of the British garrison period was given to the kids for reference.

geotrail_leafletThe kids of class 5 learned very quickly how to use the GPS in the two hours of cache hunting and navigation. The day before rained heavily, however the muddy and soaked fields did not spoil the day and the amusement of the kids. The hope is to have passed to the kids a new skill which they can well use in Tristan and in any job with conservation, fisheries and public work.

kids_geotrail1   kids_geotrail

It would have been great to show the kids how to map the points in QGIS. However, there was not enough time to plan for a GIS lesson, which was instead given to some of their parents!

Please like & share:

New publication on ingestion of anthropogenic material by turkey vultures in the Falklands

A new study by SAERI was recently published in the journal Polar Biology presenting the first results on the amount of human rubbish ingested by turkey vultures in the Falkland Islands, in particular plastic. The paper is entitled “Anthropogenic debris in the diet of turkey vultures (Cathartes aura) in a remote and low populated South Atlantic island“.

Turkey vultures at the Stanley opern rubbish tip (photo: Amélie Augé)

Turkey vultures at the Stanley open rubbish tip (photo: Amélie Augé)

The abstract of the paper is: “Plastic pollution is becoming an increasing issue for wildlife throughout the world. Even remote areas with relatively little human activity are affected. The Falkland Islands are a South Atlantic archipelago with a small human population (<3,000), mostly concentrated in one town, Stanley. One hundred regurgitated pellets from turkey vultures (Cathartes aura) were collected in Stanley in July and August 2015 to investigate the diet and amount of anthropogenic debris (human-made artificial products) ingested. The frequency of occurrence of anthropogenic debris was 58% of pellets for plastic, 25% for glass, 23% for paper, 21% for aluminium, and 3% for fabric.  Aside from anthropogenic debris the majority of pellets were made of sheep wool (on average 29% of the volume), feathers (19%) and vegetation (18%). On average, when present, anthropogenic debris corresponded to 16.1% of the mass of each pellet, equivalent to 1.6g. The turkey vultures are known to feed in the open-air rubbish dump near the town. This study highlights that they ingest significant amounts of anthropogenic debris. Further investigations should be undertaken to monitor and identify potential health effects. Other birds also use the dump and may be affected. Even in such remote sparsely-populated islands, pollution may be a significant issue. Rubbish management could be put in place to limit birds from feeding at the dumps. A low human population density may not indicate low pollution impacts on wildlife and the environment and should be investigated further in the Falkland Islands and at other remote islands.”

A piece was published in the local newspaper (the Penguin News) last Friday about the results and is available online.

If you want a copy of the full paper, contact me and I’ll send you the pdf.

Please like & share:

Hotspots of Cultural Coastal Values Identified for Marine Spatial Planning

———————-Article written by Denise Herrera from the Marine Spatial Planning team, and published in an edited format in the local Falklands’ newspaper Penguin News on 22 April 2016. The project was supervised by Dr. Amélie Augé (SAERI) and Dr. Kate Sherren (Dalhousie University, Canada).————————————————–

Pssshhhh – we know which spots are the best in the Falklands! Late last year the Marine Spatial Planning (MSP) team at SAERI conducted interviews in the local community to identify coastal areas that people value so they can be included in the MSP process for the Falkland Islands. Interviews took place in both camp and Stanley.

Example of a map during interview, later digitised for analyses (dummy map)

Example of a map during interview, later digitised for analyses (dummy map)

A total of 47 islanders and long-term residents were asked to identify the 15 places most important to them around the islands and whether they valued them for their aesthetic “Natural Beauty” value, recreational value, historical value or sense of place, nicknamed: “Makes me feel at home”. This was done using new techniques in ‘Public Participation Geographic Information Systems’, or simply put: drawing and labelling coastlines on a laminated map of the Falklands. Participants were asked to identify the strength of their attachment, using a variety of colourful marker pens. Our participants embraced this fun and interactive activity with such enthusiasm that a whopping total of 745 lines were drawn!

Clear hotspots of values were found around our islands. Surf Bay was a clear favourite in recreational value as well as Bull Point and the Chartres estuary. The Natural Beauty of a place received the most responses with hotspots including Sea Lion Island, the Neck at Saunders, Cape Dolphin, Carcass Island and Bull Point.  Of highest historical value was San Carlos, the coast by the Lady Elizabeth wreck, the Mission Station on Keppel Island and the first Settlement on Saunders. What’s more, participants weren’t swayed in their choice by their home settlement meaning a true representation of Cultural Coastal Values was given.

culturalblog2

Natural Beauty valued area (highest attachment in red)

Ecosystem Services are the benefits that we gain, directly and indirectly, from the environment. For example a walk on the beach can bring you happiness and well-being, making you healthier and more productive at work. MSP is a coordinated management for the marine environment that includes ecosystem services and environments as a whole. Often seen as land-use planning for the sea, MSP identifies areas of interactions, current or future, between marine uses and economic, ecological and cultural values. With this in mind, the inclusion of Cultural Coastal Values in MSP for the Falkland Islands will aid in better management, maintaining our unique environments, including your favourite spots. After all, who would like a sewage treatment site next to their favourite beach?!

Please like & share:

Conference presentation: Using local knowledge to predict baleen whale distribution around the Falkland Islands

Veronica Frans, from the Marine Spatial Planning project team at SAERI, attended and presented her research at US-IALE 2016 (the International Association for Landscape Ecology). The conference took place from 3-7 April 2016 in Ashville, USA. Veronica presented the results from the work she has been doing in the Falkland Islands since August 2015 on baleen whale historical distribution and sighting numbers, as well as an innovative species distribution modelling (SDM) technique using local knolwedge data to determine suitable habitat for baleen whales around the islands, now and as their numbers recover. The results will inform the MSP process for the islands. See the abstract here.

blog2

Veronica giving her presentation at US-IALE on Monday 4 April 2016.

 

 

 

 

 

 

 

———-Veronica F Frans, Amélie A Augé, Jan O Engler and Hendrik Edelhoff (2016). A whale of a tale: using local knowledge to predict baleen whale distribution around the Falkland Islands. US-IALE 2016, Ashville, North Carolina, USA.——————————–

The modelling work is conducted in collaboration with German scientists with expertise in SDM, Jan Engler (Zoological Researchmuseum Alexander Koenig) and Hendrik Edelhoff (Dept. of Wildlife Sciences,Georg-August-University Göttingen, Göttingen).

The presentation was very well received with some great feedbacks and interesting ideas to complement and improve the research.

The Darwin Plus Marine Spatial Planning project funded Veronica’s attendance but she was also awarded a NASA travel award that provided assistance with travel costs (congrats Veronica!).

Veronica receiving her NASA award

Veronica officially receiving her NASA award from Jack Liu and Janet Franklin during the conference.

 

Please like & share:

Local stakeholders gathered in Stanley for a 3-day marine spatial planning workshop

Last week, from Tuesday to Thursday, marine stakeholders of the Falkland Islands gathered for a workshop on Marine Spatial Planning (MSP). This workshop was part of the 2-year project funded by Darwin Pus, managed by SAERI. The aim of the project is to initiate the process of MSP for the Islands by preparing data, tools and analyses, and working towards a framework for MSP in the Falkland Islands. The results will inform the Falkland Islands Government and its stakeholders on how to implement MSP and make recommendations on priority zones for management. This workshop was the third and last workshop of the project that will end in July 2016. In December 2015, the MSP team submitted a paper to the Executive Council summarising the benefits that MSP could bring the islands. ExCo has agreed to the production of an MSP Plan, subject to a fine-scale framework. The workshop provided the platform for discussiofor blog postn to define this fine scale framework with local stakeholders and a couple of international experts. An MSP Plan is a strategic coordinated plan for regulating, managing and protecting the marine environment that addresses the multiple, cumulative and potentially conflicting uses of the sea, current and future, and aim to fulfill economic, ecological and social objectives.

Jude and Michael presenting the results of their breakout groups

Jude and Michael presenting the results of their breakout group.

Workshop participants included representatives from marine industries (fishing, oil, shipping), government departments (EPD, Minerals, Fisheries, Marine and Biosecurity  officers), MLAs, Falklands Conservation, Royal Navy, Wildlife Conservation Society, and recreational activities (Yacht Club, diving), SAERI, as well as three international delegates from Scotland, the shetland Islands and Ascension Island.The workshop consisted of brief presentations to show all the maps produced depicting human activities at sea and areas used by wildlife, and of cultural values (check out the MSP webGIS to look at some of the maps), alternated with  a series of sessions where participants worked on small exercises on MSP objectives and targets, shipping, conservation, Berkeley Sound management, interconnectivity between marine activities, people’s values and the environment, and MSP format, actors and roles. The participants provided great insights in the priority needs to ensure coordinated sustainable development of the islands’ maritime activities.

The HMS Clyde at sunrise

The HMS Clyde at sunrise in Port Stanley.

Commander Bill Dawson from the Royal Navy at MPA has been on the MSP project steering committee since its start and he had kindly offered to host one workshop day on board HMS Clyde to illustrate some maritime activities. The workshop participants therefore had the great opportunity to spend a whole day on board last Thursday, partly in the officers’ mess for work sessions and the rest of the time on the deck during a visit in Berkeley Sound where they witnessed ships bunkering in the same area as Sei whales foraging and vessel traffic. The crew were great hosts and made this day very useful and memorable for the workshop.

The MSP workshop group photo on board the HMS Clyde on 7 April

The MSP workshop group photo on board the HMS Clyde on 7 April.

Workshop participants on the photo are back from left: Nick Rendell (EPD), Michael Gras (DNR), Ross James (DNR), David Blockley (SAERI), Pippa Christie (FIPLA), Roddy Cordeiro (DMR), Amélie Augé (SAERI), Graham Harris (WCS), Steve Bamfield (HMS Clyde Captain), Martin Mendez (WSC), Karen Hall (JNCC) Rachel Shucksmith (University of Highlands and Islands), Jude Brown (Ascension Island Government), Emma Beaton (SAERI); Front from left: Chris Locke (Marine Officer), Paul Brickle (SAERI), Andy Stanworth (FC), Tom Blake (FIFCA), Emily Hancox (DMR), and MLA Michael Poole); on-board but missing from photo: Jackie Cotter (FIFCA), Adam Cockwell (Workboat services), Sammy Hirtle (SAERI); other participants that could not attend the HMS Clyde day: Tim Martin (FIPLA), Grant Munro (Austral Biodiversity), Joost Pompert (DNR), Roy Summer (Sulivan Shipping).

The workshop was a great success, with engaged and interested participants, and some great outcomes to help design what MSP should look like in the Falkland Islands. Some of the main outcomes in regard to MSP were a clear need for improve shipping management, of vessels visiting the islands but also in particular, transiting through the Falklands’ waters. Of particular importance was the area around the Jason Islands with a shipping route on the west of this archipelago. Identifying other areas vulnerable to shipping risks, as well as for human safety (eg. cruise ship traffic) was also found a priority. MSP was overall seen as a great tool to improve safety at sea and emergency responses, as well as coordinate management of maritime activities, now and for the future. Rachel Shucksmith from the Shetland Islands’ MSP team at the University of Highlands and Islands was an invited speaker at the workshop. She also gave a very informative and exciting public talk on the Tuesday evening, to a packed room, about the Shetlands and how they use MSP to ensure sustainable maritime development there. For more info on the Falklands’ MSP project, check out the MSP webpage.

Rachel Shucksmith from the University of Highlands and Islands giving a public presentation in Stnaley on 5 April

Rachel Shucksmith from the University of Highlands and Islands giving a public presentation on the Shetland Islands’ marine life and local management in Stanley on 5 April.

Thanks to all the participants for their enthousiasm, and to Sammy for her brilliant logistic assistance and Emma for all the note-taking!

Sammy and all the cakes; Emma ready to take notes!

Sammy and all the cakes; Emma ready to take notes!

Please like & share:

From Rome to Nødebo, learning webGIS techniques and meeting with QGIS developers, educators and other users.

By iLaria Marengo

One of the aims of the IMS-GIS data centre is to make open data available to all. The best way to reach multiple users, who may or may not have skills and insight on GIS, is to develop and provide a webGIS service. Through the web, data can be visualised, queried and then downloaded.

In Rome I attended a two day course that was run by Paolo Cavallini (http://www.faunalia.eu/en/), one of the promoters of QGIS. The course was essential to understand how QGIS server runs and how it allows the user to work on a QGIS project and publish it to the web to make it accessible to a wider public.

The course was very good, with 5 participants and taught by Paolo with the help of Andrea Fantini (http://www.tecnostudiambiente.it/). First of all we explored a few plugins that allow publishing data online. Then we moved to the core of the course, which was the installation of QGIS server (it runs better on a Linux server) and the use of Lizmap as web interface. We were given a virtual machine to run the installations during the course, but now that I am back to the Falklands I will be installing QGIS server on the real server at SAERI, with the assistance of Synergy, the local IT Company.

The advantage of using QGIS server is that the webGIS reflects exactly what is in the project, symbology and attribute tables. Hence publishing data online and creating webGIS services is very easy and quick and all the changes and modification can be executed directly from QGIS. By the end of 2015 a webGIS service should be available for Falkland Islands users.

IMG_4257

IMG_4258

 

From chaotic but beautiful Rome, I then moved to tranquil and relaxing Nødebo (Denmark) to attend the first QGIS conference for users, developers and educators. Around 150 people gathered for the event, representing and 25 countries.

conference-user-map

The setting was ideal, the Skovskolen (Landscape and Forestry College of the University of Copenhagen) provided all the facilities and the organisation was superb thanks to the hard work of Lene Fischer and her team.

I had the chance to present the QGIS training courses and GIS development promoted by the IMS-GIS data centre across the UK Overseas Territories in the South Atlantic. I also had the opportunity to listen to many case studies presented by other users. The second day focussed on workshops and gave everyone the opportunity to have the developers of QGIS tools and plugins as teachers for a day.

What I really appreciated in my two days in Nødebo was feeling at ease and comfortable with the “geo-geeks”.  All of them were very approachable, helpful and interested to hear from the users, talk to them and understand the sort of issues we have encountered whilst using the software. I started using QGIS almost 2 years ago and I am extremely happy with the software. It performs very well, but above all it is supported by a wide community, which thrives on and is full of ideas and new developments.

Socialising at the conference was not difficult at all and it would have been great to be able to spend more time with the developers, as I found all of them extremely keen on making QGIS a better product. The strength and potential of open source was tangible, and it is important that the users contribute to improve QGIS by finding  bugs, asking for new plugins and highlighting those that still require some polishing. Promoting and sponsoring QGIS is also very important to broaden the community and make the use of QGIS more wide spread.

It was a great experience and I was happy to participate in this first event, which I hope is the first of many. I would like to thank the organisers, the developers that spent time listening to us and the rest of the users and educators that gave examples of the use and application of QGIS.

nodebo-conference

 

 

Please like & share:

New funding opportunities for environmental projects in the South Atlantic: BEST 2.0

The European Commission has announced that in order to address the need for facilitated access to funding in the European Overseas Countries and Territories (OCTs), it is allocating new resources for concrete projects in the OCTs through a 5 year programme; BEST 2.0 (Biodiversity and Ecosystem Services in European Outermost Regions and Overseas Countries and Territories). This will mean a new source of funding that can be accessed for environmental projects within the South Atlantic Overseas Territories (OTs). The European Commission’s Directorate General for International Cooperation and Development (EuropeAid) has two calls for proposals organised in the coming two years, with a total budget of over € 6 million for this initiative.

BEST hubs

BEST 2.0 has been born from a recognised need for current support of projects on the ground whilst a long term financial mechanism is created from the existing BEST III initiative, which began last year. The aim of the BEST III project is to support and maintain biodiversity and sustainable use of ecosystem services, including looking at ecosystem-based approaches to climate change adaption and mitigation methods. This is taking place simultaneously across all European OCTs. The South Atlantic Environmental Research Institute (SAERI) is the coordinator for the South Atlantic Hub, which includes Ascension Island, St Helena and Tristan da Cunha, the Falkland Islands and South Georgia & South Sandwich Isles.

Five of the existing BEST III knowledge hubs (Caribbean, Indian Ocean, Pacific, Polar/Sub-Polar, South Atlantic) will help assure the calls are adapted to the varying conditions and situations encountered in OCTs and will provide support to local organisations for submission of proposals. Independent regional advisory committees, with experts in the relevant fields, will assess the proposals and advise a decision board.

The objective of BEST 2.0 is to empower local actors, authorities and civil society organisations in OCTs. Within the South Atlantic OTs this will involve organisations who are committed to local development, maintaining biodiversity and the sustainable use of ecosystem services. This will particularly apply to the key biodiversity areas identified through the participative Ecosystem profiles process led by the BEST knowledge hub for the region. Eligible beneficiaries will be local authorities and services, civil society organisations and stakeholders working within the South Atlantic OTs.

The first call for proposals will take place in June this year. Please regularly check this website or the BEST webpage for further information.

For more information please contact:

SAERI: Maria Taylor and Dr Paul Brickle

EC logoIUCN logob4Life logoLogo_BEST

Please like & share:

Learning Side Scan Sonar Techniques And Sharing Knowledge Across The South Atlantic Territories

A successful and exciting week of training in the use of side scan sonar (SSS) for habitat mapping has just ended in Ascension Island. Participating in the course were, Sam Cherrett from Saint Helena , who led the course, Andy Richardson, Emma Nolan and Kate Downes (the AIMS team) from Ascension, Debs Davidson and iLaria Marengo from the Falkland Islands.

SSS is a valuable technique for the investigation of the type seabed and for the detection of different submarine features. Acoustic pings (pulses) sent by the sonar are reflected differently by sand, mud, bedrocks and artificial objects, such as metal (e.g. pipelines and wrecks). The sea state can influence the quality of the images, however, good results depend as much on a careful survey design and a proper setting of the device used.

The goal for the Ascension team was to learn how to use side scan sonar and drop down cameras, the latter for ground truthing and features/seabed verification, in order to undertake a fine scale marine  habitat classification and mapping up to 1000 metres from the coast. To provide a complete and accurate picture of the underwater environment, a series of targeted dives are also planned. These will be a valuable addition to the data retrieved and processed from the side scan sonar.

Similarly, the Falklands team came all the way to Ascension to gain essential skills, not in how to survive the equatorial heat, but how to identify seabed types in order to better understand and map marine habitats in inshore waters. Acquiring this knowledge is going to be important in making decision for the development of inshore fisheries, marine spatial planning and to support Environmental Impact Assessments.

The course completely hooked all the participants as it was cleverly planned by Sam Cherrett to focus on the practical and operational aspects and techniques of  survey planning, deployment of the side scan sonar (Starfish device and Scanline software) and processing of the images (Triton Perspective software). The days were split on the boat collecting data and in the office processing the raw data to produce images.

The areas at sea where the side scan sonar was towed were identified by the Ascension team, so that the data collected could be used for one of the deliveries of the AIMS project (supported by Darwin Initiative funding). The tows took place at PanAm, Comfortless Cove, White Rock and the Georgetown moorings. A series of tests were carried out to understand the best setting of the weight to be applied to the Starfish. Then, the drop down camera was utilised to verify 27 points which were considered particularly interesting after the processing of the images.

SSSRuns_LastWeekOnly

The seabed in the surveyed areas were found to be made by medium to coarse sand, maerl and bedrock. The green turtles, which are nesting in Ascension, were pleasant company and appeared as features in the images too.

Sonar_images

From the work carried out on boat and afterwards in the office, the participants could learn how the side scan sonar records the data, how significant ground truthing is, how influential the conditions of the sea are, how bottom tracking can be tedious in case of a bad scan, how important team working and communication is, how boat engines are “delicate” and sun cream might not be enough to avoid sunburn!

IMG_0694 OLYMPUS DIGITAL CAMERA

A major success of the course was actually the capacity to work in synergy that was shown by the participants. The collaboration of everyone was the main factor that made the full week extremely productive and enjoyable. Everybody contributed positively to the course by exchanging marine biology knowledge, sharing interests in working with fisheries and spatial data, and comparing research and life experience in the three islands of the South Atlantic.

Special thanks to Ascension Island sea rescue team and Blaine Chester, skilful boatman of Swampdog.

SSS_Group

Please like & share:

Climate Change Institute on the Black Tarn, Mt. Usborne

By Dr Brenda Hall, Climate Change Institute, University of Maine

Science Objectives:

The goal of our project is to examine glacial deposits in and around cirques at Mt. Usborne in order to gain a better understanding of the glacial and climate history of the Falkland Islands.

Black Tarn

The Black Tarn, Mt. Usborne, East Falkland

Specific Activities Conducted:

From March 16-19, 2014, a field party of three carried out glacial geologic field work in the Black Tarn area of Mt. Usborne. Field members consisted of Drs. Brenda Hall and Thomas Lowell, both from universities in the United States, and Mr. Antony Smith of Discovery Falklands, who provided logistics and a wealth of local knowledge. The party arrived at a camp site ~750 m from the Black Tarn on March 16 and was able to spend the afternoon carrying gear to the pond and making a bathymetric map (Fig. 1). The map was constructed using a portable depth sounder and by making transects across the lake in an inflatable row boat. Maximum depth recorded was ~10 m. This was less than indicated previously (McAdam and Roberts, 1981, Falkland Islands Journal, p. 23-28) by ~ 3 m, but no deeper area could be found. During this time, the field team also made preliminary observations on the glacial geology surrounding the tarn.

On March 17, the remaining gear was carried to the field site and Drs. Hall and Lowell began coring. A piston coring system was set up from the inflatable boat anchored over the deepest part of the pond. Briefly, this consisted of a polycarbonate tube with a piston that moved up the tube as it was pushed into the mud. The piston provided suction that kept sediments in the tube and allowed recovery. The corer was deployed using a rope. The initial coring drive was successful and a little over one meter of sediment was recovered (Fig. 2). This sediment shows some structure and changes in both color, composition, and grain size and will be the subject of future reports. Without laboratory analysis, it is impossible to say much for certain, but it seems as if the sediments record several wet and dry periods, the timescale of which will become clear as analyses progress. We extruded the core and took subsamples for analysis. We then attempted to take a second meter of core as we had not hit bedrock with the first drive. However, this attempt did not prove successful. We penetrated to two meters depth, but the sediments did not remain in the tube when it was pulled out. This is due mostly to the fact that we needed a different type of equipment than we had with us. The one previous coring trip to the area in the 1970s (McAdam and Roberts, 1981) had retrieved only 45 cm of sediment before meeting refusal, so we had not expected such thick sediment sequences. In the future, bringing a different type of equipment would allow us to recover this sediment and a longer climate record.

On March 18, high winds prevented us from working on the lake. We remained on shore and sampled sediments immediately adjacent to the lake using the same piston core technique. We were able to penetrate nearly three meters and retrieve silt identical to that from our lake core. This core also was subsampled. On March 19, due to increasingly bad weather and the rapidly deteriorating ground on the route out, we packed up camp and returned to Stanley.In general, except for the first day, weather conditions were wet and at freezing. Ground conditions for accessing the site by Land Rover were much worse than anticipated and a function of a rather wet March. Despite these issues, we were able to camp within a short walk of the tarn and were able to meet our scientific goals. We are excited, because there proved to be a lot more to the Black Tarn record than expected based on previous work. Our task now is to analyze the samples, particularly for radiocarbon dating, to begin to assign a timeline to the changes in sediment types that we see in the cores. At present, our best guess is that these cores span time on the order of thousands to tens of thousands of years. Samples have been submitted to the accelerator laboratory for radiocarbon dating, and we expect results in about two months.

Balck Tarn Bathymetry

 

Fig. 1. Bathymetry of the Black Tarn obtained by repeat transects with an electronic depth sounder.

 

 

OLYMPUS DIGITAL CAMERA

 

Fig. 2. Core BT-14-1, from the Black Tarn, consisting of 1.2 m of sediment.  From the base, the sequence consists of gray clay overlain by moss, overlain in turn by a thick layer of tan-gray silt. This is overlain by moss and then by a sticky gray silt layer. The entire sequence is capped by stiff, orange, sandy silt.

 

 

Please like & share: