Electric storms and digital stones: technology reveals the hidden secrets of stone circles on the Isle of Lewis

 Calanis - Beneath the Peat 2019-2020

Over the past few years we have been going to the Calanais site in Lewis, Scotland to try to map parts of the Neolithic landscape that are hidden today.  Rolling back the clock to over 5000yrs ago means that we have to consider significant changes in the landscape that include agricultural practice and natural changes such as the prolific growth of peat across the islands.  Further, there are have been changes associated with coastal position following the rise in sea level to present day heights. The Calanais Virtual Reconstruction Project is a joint venture led by the University of St Andrews with the Calanais Visitor Centre and the University of Bradford. The project team has been surveying the satellite sites near the Tursachan, the main prehistoric stone circle at Calanais. The surveys have revealed evidence for lost stone circles, buried beneath the peat and we have also used this data to create digital reconstructions that will allow visitors to virtually “walk” around the stones.

One rarely visited site surveyed known as Site XI or Airigh na Beinne Bige, consists of a single stone on an exposed hillside overlooking the whole valley and a couple of kilometres directly north of the Tursachan.  At the site we conducted a range of geophysics including electromagnetic ground conductivity mapping, electrical resistivity tomography, surface resistivity, magnetic gradiometry, and also used handheld magnetic susceptibility sensors to measure both the upstanding stone and to take measurements on the local rock exposures. The magnetic gradiometry revealed that the single stone was originally part of a circle of standing stones but that many of these are now buried by the thick peat deposits.

Magnetometry data at Site XI. Red columns indicate features interpreted as the position of lost stones. At the centre of the rough circle of smaller anomalies is a massive, star shaped feature which has resulted from a historic lightning strike

The gradiometry also revealed a very unexpected result – that of a star-shaped magnetic pattern right at the heart of the stone circle. This massive, star-shaped magnetic anomaly in the centre of the circle we believe to be the result of a single, large lighting strike or many smaller strikes on the same spot.

Such clear evidence for lightning strikes is extremely rare in the UK and the association with this stone circle is unlikely to be coincidental. Whether the lightning at Site XI focused on a tree or rock which is no longer there, or the monument itself attracted strikes, is uncertain. However, this remarkable evidence suggests that the forces of nature could have been intimately linked with everyday life and beliefs of the early farming communities on the island.

The project is now studying more archaeological sites in the area around the Tursachan, the main stone circle at Calanais. There are at least a dozen stone circles in the area, but at many sites the stones have fallen and become buried beneath the blanket peat that covers much of the landscape over the millennia. 

A view of the 3D model created by the computer science team at the University of St Andrews under Dr Alan Miller can be seen at https://vimeo.com/273858929.

At site X, also known as Na Dromannan the fallen stones sit on a hill overlooking the main valley.  Here careful scanning of the stones allowed a full 3D model of the site to be built. The virtual recreation allows the passage of the sun and moon around this circle to be tracked for the first time in four millennia. Now, anyone can virtually visit this remote site and get a real sense of what it was like just after it had been constructed. 

You can read a full account of the geophysics is given here:

Geophysical investigation of the Neolithic Calanais landscape Bates, C. R., Bates, M., Gaffney, C., Gaffney, V. & Raub, T. D., 11 Dec 2019, In: Remote Sensing. 11, 24, 2975.

https://www.mdpi.com/2072-4292/11/24/2975. 

Durrington Pits – monumental structures in the Stonehenge landscape 2020

The pandemic provided some unusual opportunities and for me this was especially marked in the Stonehenge landscape by the absence of hordes of visitors.  This allowed a reuniting of brothers in survey, Vince and Chris Gaffney from Bradford University together with my brother, Martin from University of Trinity St Davids. We were joined in our field campaign by Eamonn Baldwin from Birmingham and my colleague Tim Kinnaird from St Andrews. The focus of our attention was a series of curious features seen on the magnetic gradiometer survey data. The features were evident as over 20 separate 10-20m diameter circles arranged in a concentric pattern around the Durrington Walls.  Fieldwork and analysis revealed evidence suggesting that they were massive shafts, measuring more than 5 metres deep. The circle formed by the shafts encloses an area greater than 3 square kilometres around the Durrington Walls henge, itself one of Britain’s largest henge monuments, and the famous, smaller prehistoric circle at Woodhenge.

Figure 1. Shaft locations surrounding Durrington Walls.

 Geophysical investigations included electromagnetic ground conductivity surveys, magnetic gradiometer, ground penetrating radar and electrical resistivity tomography.  The results of ground penetrating radar as a series of time slices are show in in figure 2.

 

Figure 2 Anomaly 8A – 250MHz antenna: Ground penetrating radar time slices at 10cm depth intervals, decreasing L–R from ground surface (top left) down to approximately 3.3m depth (bottom right).

Coring of the shafts provided radiocarbon and Optically Stimulated Luminescence dates suggesting these features are Neolithic and were excavated more than 4500 years ago, around the time that Durrington Walls was constructed.  The shafts may have served as a boundary to a sacred area or precinct associated with the henge. The Neolithic period, which is associated with the first farmers in Britain, is characterised by the development of ornate, and occasionally very large, rituals structures and enclosures, including the great stone circle at Stonehenge. However, no comparative prehistoric structure in the UK encloses such a large area as the circle of shafts at Durrington, and the structure is currently unique. 

 

Figure 3. Coring the sites with a mini-percussion corer

Aside from the scale of the structure, the circuit of shafts has other surprising characteristics. The boundary appears to have been deliberately laid out to include an earlier prehistoric monument within the boundary - the Larkhill Causewayed Enclosure. This site was built more than 1500 years before the henge at Durrington. This distance between the henge and earlier enclosure, more than 800 metres, seems to guide the placement of shafts around Durrington.  The evidence for how these pits were laid out is extremely important as it implies that the early inhabitants of Britain used a tally or counting system to track pacing across long distances (Figure 4).  Evidence for such careful planning, at such a scale, is unexpected at such an early period and emphasises how important the positioning of these pits was.

Figure 4. Least cost pathway analysis showing the use of pacing to mark out location of the pits.  They are further distance away down slope than parallel to slope

Archaeologists believe the effort invested in the great circle inscribed by the pits reflects an important  cosmological link between these two ritual sites, and that the large shafts were dug to record what must have been an important, sacred boundary.  The presence of these massive pits, and perhaps an internal post line, guided people towards the religious sites within the circle or even warned those who were not permitted to cross the boundary marked by the shafts.

Research on the pits at Durrington was undertaken by a consortium of archaeologists led by the University of Bradford as part of the Stonehenge Hidden landscape Project, and with the Ludwig Boltzmann Institute for Archaeological Prospection and Virtual Archaeology, the universities of Birmingham, St Andrews, Warwick, Trinity Saint David (university of Wales), and the Scottish Universities Environmental Research Centre (University of Glasgow).

Animation illustrating the landscape setting of the Durrington pit group, major monuments and the average distance from Durrington Walls to identified features as a line.

© Crown copyright and database rights 2013 (OS Profile DTM Scale 1:10000); EDINA Digimap Ordnance Survey Service (100025252) http://digimap.edina.ac.uk

To read more on this project:

Gaffney, V. et al. 2020 A Massive, Late Neolithic Pit Structure associated with Durrington Walls Henge, Internet Archaeology 55

https://intarch.ac.uk/journal/issue55/4/index.html

Notes

The universities undertaking field research supporting this press release included the University of Bradford with the Ludwig Boltzmann Institute for Archaeological Prospection and Virtual Archaeology the universities of Birmingham, St Andrews, Trinity Saint David (University of Wales), Warwick,, and the Scottish Universities Environmental Research Centre.  The work was undertaken a part of the Stonehenge Hidden Landscapes Project and brought together experts in non-invasive geophysical prospection and remote sensing, and specialists in British prehistory and landscape archaeology in order to carry out research in one of the most important archaeological landscapes  in Europe. The outstanding geophysical survey and visualization capabilities of the team has been made possible only because of the unique expertise and combined resources of the wider project partnership. an international collaboration of the Ludwig Boltzmann Gesellschaft (Austria), Amt der NiederösterreichischenLandesregierung (Austria),the University of Vienna (Austria), the Vienna University of Technology (Austria), ZAMG– the Central Institute for Meteorology and Geodynamics (Austria), Airborne Technologies (Austria), 7reasons (Austria), ÖAW– Austrian Academy of Sciences (Austria), ÖAI – Austrian Archaeological Institute (Austria), RGZM Mainz – Römisch‐GermanischesZentralmuseum Mainz (Germany), the University of Birmingham in collaboration with the University of Bradford (GB), Arkeologerna of StatensHistoriskaMuseer (Sweden), NIKU – Norwegian Institute for Cultural Heritage (Norway), and Vestfold fylkeskommune – Kulturarv (Norway).

 

 

 

Playing catchup - Summary of projets 2019-2022

Finally catching up

I think that all of us are feeling like we have a couple of lost years behind us but now are trying to play catch up with so many projects and parts of our lives.  For me, some of the research was put on temporary hold, some continued and parts of the time was spent writing up projects that were way-overdue in being published.  For the published work then this should gradually be coming out over the next few months and can be seen through my Uni web pages.  For the rest, then I will make up for it with a sting of blog summaries of what has been going on.

2019

Stonehenge - Durrington Pits

Calanais Lightning Strike

Armenia more lightning strikes and stone circles

2020

Fife Coast - reconstructing past climate

Tanzania Music - musicalising heritage

Viking Orkney - navigation pathways through the Orkney Isles

2021

Stonehenge and Durrington Pits

Uganda - exploration into new heritage territory

Greenland Humboldt glacier revisited

Tanzania - Hominid Footprints

2022

Antarctica - multibeam for climate action

Tuscany - demise of an Etruscan site in central Italy

Great Lakes - multibeam for wreck hunting

Curious Travellers: rebuilding the past through citizen science - 2019-2020

This work was summarised for my by Jamie Locke-Jones @ the Research Impact Office, University of St Andrews

Those who try to understand the past rarely have the luxury of complete records that detail the lives of our ancestors. Instead, history is often reconstructed through the fragments of evidence that have survived the ravages of time. Today, around the world, this tangible heritage, which includes buildings, monuments, and objects, is crumbling to ruin due to natural disasters and climate change. In 2018, following the bombing of Palmyra by the terrorist organisation Islamic State, Professor Richard Bates from the School of Earth & Environmental Sciences worked with colleagues at Bradford University and Durham University to initiate a citizen-science project to crowdsource images of the lost sites to document and digitally recreate them. The project grew to consider other threatened and damaged archaeological sites, from those impacted by earthquakes in Nepal to sites closer to home such as Yorkshire’s Fountain Abbey, which was suffering from the impacts of climate change.

Reconstructing Heritage 

Their website, Curious Travellers, operates as a piece of crowdsourced infrastructure, receiving photographs and videos donated by the public while also scouring the internet for additional fragments of information. The Curious Travellers team then combines these various data sources to create 3D representations of monuments and ancient sites that can be accessed online. One example is the Temple of Bel, Palmyra, Syria, which was dedicated almost 2,000 years ago in AD 32. Its ruins were thought to be the best-preserved in the whole of Palmyra, an ancient city dating back to the Neolithic period, before they were mostly destroyed by terrorists in 2015. The digitally reconstructed version, which can be seen below, has been painstakingly rebuilt from over 700 images found online and donated by members of the public. In this way, the monument can be seen authentically, without artistic license or academic guesswork. While still incomplete, the Curious Travellers reconstruction gives would-be visitors permanent way to see the Temple in its most complete and authentic possible state.  

Building upon this work, the Curious Travellers team has moved on to acquiring data for other at-risk heritage sites such as Kilwa Kisiwani, a World Heritage Site in Tanzania. Here, working together with colleagues from the University of Dar es Salaam and the Tanzanian Department of Antiquities, the team has used ground-based and drone-based methods to document what remains to be seen at the site. Rising sea levels have flooded and eroded parts of the monument, and so work has also focused on exploring and documenting what can be found below the water. The resulting data has been used by the Government of Tanzania as part of a new Digital Heritage Database, created by the team specifically for the long-term management of their national heritage. Together with its Malawi counterpart, the Digital Heritage Databases are the first of their kind in the world, recording over 300 sites not previously documented in one place such as the World Heritage Sites Kilwa Kisiwan in Tanzania and the Chongoni Rock-Art Area in Malawi. 

Bates’ research initially focused on using geophysical sensing techniques to record and then reconstruct tangible heritage. This included land-based, airborne and marine-based systems, and development of these techniques allowed for their use at a range of scales, from recording individual buildings to whole landscapes. However, people’s lives extend beyond their tangible possessions, and our understanding of heritage has expanded over time to include the intangible culture that often provide meaning to what we can physically touch and see. With their models crowdsourced from photos taken by their namesake, Curious Travellers demonstrates how, without cultural meaning, even the most imposing temple can fade from memory.  Intangible heritage is now being actively recorded by the team, with stories, songs, cultural practices and ways of life all finding invaluable preservation in the Digital Heritage Database. 

The impact of heritage protection goes beyond an enhancement of our archaeological knowledge. By recreating cultural monuments that were destroyed due to conflict or other factors, Bates and the Curious Travellers team are rebuilding a sense of heritage within communities around the world. Cultural sites are directly linked to cultural identity and familiarity; to preserve these sites, even digitally, is to embrace their community’s history and celebrate the culture of societies that might otherwise be forgotten.  

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This work contributed to the University of St Andrews’ REF 2021 submission.

The Research Excellence Framework (REF) is a system which assesses research at UK Higher Education Institutions by discipline, based on three elements: outputs, impact and environment. This blogpost is based upon an impact case study that contributed to St Andrews’ outstanding results this REF cycle. Visit REF to view the submitted case study in the UKRI’s impact case study database.

Preserving Maritime Cultural Heritage through Music - 2019-2021

Tanzania - This Post was summarised for me by Jamie Locke-Jones @ the Research Impact Office, University of St Andrews

Once described by Moroccan traveller Ibn Batutta as one of the most beautiful cities in the world, the UNESCO World Heritage site of the Ruins of Kilwa Kisiwani and Songo Mnara, south of Dar es Salaam on the coast of Tanzania, date between the 11th and 18th century. Today, the remains of the palace, the grand mosque and merchant trade centre stand in ruins close to a shoreline that is increasing impacted by changing climate. Unlike better-known World Heritage sites, such as the Pyramids of Giza or the Great Wall of China, the Ruins of Kilwa Kisiwani and Songo Mnara have not received the attention they need if they are to survive another eight centuries. 

A collaboration between the University of Dar es Salaam (UDSM) and the School of Earth and Environmental Sciences at the University of St Andrews sought to address this through a thorough assessment of the sites’ fragility. The group conducted marine geophysical surveys which showed several locations of potential wreck sites, with follow-up diving confirming that one was a 13th century wreck. The team’s goal was to investigate the wreck and at the same time build local capacity by training divers from across Tanzania in underwater archaeological techniques. This work has since led to the development of the first National Digital Heritage Databases for Tanzania.

A step change in engagement came with the recording of a music video (above) sung by a popular Tanzanian female rapper Claudia Lubao, known as Chemical, and composed by the team’s academic archaeological partner, Dr Elgidius Ichumbaki, at UDSM.  The song highlights the importance of heritage with a connection to local people, warning about the impact of climate change to the sites and the environment surrounding them. 

Now a PhD student at the University of St Andrews, Claudia’s music has set a precedent in bringing cultural heritage to new audiences. The Kilwa Yetu song brought widespread attention to the plight of the site that other methods of promotion could not have achieved by reaching audiences outside the reach of more traditional, academic avenues. A further video on Africa’s heritage was launched at UNESCO’s headquarters in Paris in May 2018. This video gave the local community a voice to discuss their heritage, which has led to significant policy changes at a national level.

Policy changes (click to expand)

These collaborative initiatives and the music videos behind them have provided a more inclusive mechanism to promote information on the cultural heritage, moving outside the immediate intellectual circle of academic publishing. With a latest video, funded by the British Council’s Cultural Protection Fund, the team was able to expand their interests to include heritage across more of Eastern Africa with contributions from academics and artists from Kenya, Uganda, Ethiopia, Sudan and Rwanda. At workshops held in Dar es Salaam, the Cultural Heritage Artists Network in Eastern Africa (CHANEA) was established with the aims of preserving, protecting, and promoting both tangible and intangible heritage throughout Eastern Africa. Key sites highlighted in the video and from these countries include Zanzibar, Mt Kilimanjaro, Thimlich Ohinga, Kilwa Kisiwani, Mt. Rwanda, and Mt Kenya. Watch the latest music video below:

If you enjoyed CHANEA’s latest video, watch a behind-the-scenes documentary on its production here.