Sanday, Orkney Core Sampling

The Storm Chasers are Back!

Actually the Rising Tides team are back up in Orkney, Sanday to be precise, trying to chase environmental signatures of the past while also trying to dodge a weather bomb!  So what is it we are actually doing and what is a weather bomb?  As those of you who have read any of our previous work will know we are particularly interested in understanding palaeo-environments, landscapes and geography in relation to past societies.  Our work on the mainland, that is the mainland of the Orkney Isles, has reconstructed drowned landscapes through geophysical, coring and diving work.  On Sanday, we have come chasing the records of a drowned forest.  Sounds familiar? Well yes, in some ways it is similar to those sites on the west coast of Wales, and from a much older time frame  the sites at Happisburgh where we found the oldest footprints outside Africa last year.  Here in Sanday however we are trying to link back to that critical period in the development of human behaviour, the change from hunter-gatherer in the Mesolithic to the farmers of the Neolithic.

So why Sanday? Well, for one reason that a “drowned” forest has been written about in the past. In 1867, in the History or Orkney the Rev George Barry reported a “strong tradition that the harbour of Otterswick in Sanday was once a forest, which was destroyed by inundation. “and further, a sample of the trees was obtained by Traill-Dennison in March 1890.  We walked the beaches here and ran some speculative geophysics last summer with encouraging results that led us to a bay on the west coast of Sanday where with great luck on a particularly low tide we spotted a small raft of peat.  Coring and measurement of its elevation confirmed that it was equivalent to the Otterswick Bay samples and so here we are, back again on a series of very low spring tides to get further samples. 

So what’s the problem? It’s December, there is limited daylight here and we have the “storm of the century” approaching (think The Perfect Storm)!  The task therefore is to get some samples and undertake some more geophysics before it hits.  The tactics – geophysics (always geophysics) but most importantly some serious extreme geoscience sampling – a JCB! (for those of you who are not familiar with this great vehicle, and actually its not a JCB that we are using, then it’s a backhoe).

The results – instant sections, great samples and all done before today with its horizontal sleet and snow.  We have now dug four test pits (typically in fading light at low tide, actually it was dark!) and found the peat.  Significantly the peat we have dug appears to be full of freshwater molluscs at the base but towards the top there are articulated marine bivalves as well as whelks and other marine molluscs.  This is what we are after – it documents the onset of marine conditions and allows us to begin to understand how marine waters flooded across these Mesolithic landscapes.  Elsewhere we have been augering in probable infilled bays where we discovered more than 2.5m of peats and sands alternating throughout the core.  This documents the interaction between the land and the sea and excitingly these cores are very close to a multi-period archaeological site that started in the Neolithic and continued intermittently until the Viking period.  So mission accomplished so far….watch this space

Dendrochronology Glen Affric, 2014

Scot 2k - Dendrochronology, Highlands, 2014

Scot2K – a dendrochronological project the Scottish Highlands (NERC (NE/K003097/1)) that aims to push back the high resolution climate record of the Scottish Highlands back 2000 years.  It has both local (UK) importance and will also contribute to the wider climate record of Northern Europe and Northern Hemisphere.Growth of Scots Pine trees in the Scottish Highlands is predominantly controlled by growing season temperatures. Using parameters measured from tree-rings (i.e. ring-width and density) it is possible to derive estimates of past summer temperatures. However, the mean age of most pine trees in the Cairngorms is around ~225 years. Therefore, to derive climate estimates prior to ~1750, information must be gleaned from older preserved woody material.

Where to find this material?  Well thankfully, Scotland is not without its lochs and it is into these that many of the older trees have either fallen or have been felled.  Finding these trees and then sampling them was the goal of a recent trip to Glen Affric. The team, under its climate warrior leader, Dr Rob Wilson, had previously scouted out (swimming with snorkels)  some of the small lochs. Others were known from the Trees for Life project (http://www.treesforlife.org.uk/).

The UK team, including individuals from Sweden and Switzerland (Dr Richard Bates, Dr Cheryl Wood , Stacey-Anne Averill, Dr Mark Neal, Dr Björn Gunnarson, Dr Neil Loader, Dr Daniel Nievergelt, Dr Coralie Mills) arrived in Glen Affric armed with dry suits, saws, corers and a new remote-control survey boat.  The boat, built by students at Aberystwyth University Computer Science Department contained a 900kHz sidescan sonar and GPS logging to small laptop in a hull that was sufficiently small  to be back-packed into some of the more remote lochs.  This was considerably easier than trying to get either of our previous survey vessels, the Zego Boat or Minty (see previous blogs for both) onto the water.  Why use sonar? Well if you have ever swam in an upland loch you would know how murky the peat-ladened waters are that restrict visibility to a few centimetres.

Processing of the sidescan sonar data was using Chesapeake SonarWiz and ultimately data display within GIS.  Targets were identified and the dive team went to work.  Many of the sites contain vast numbers of trees but many are in too deep water or are too far from the shore for recovery (usually an operation using wire cables and winches attached to living trees on the loch shore).  Many of both living and dead tree root structures were visible on the sidescan records as were very curious sinuous features that we have so far been unable to identify due to the murky water.  These are likely branches.

At the end of the week the team had found and sampled over 150 trees – a highly successful hunting trip.  Now for all the analysis though and a hope that the material will contain sufficiently old records to push back the dendro record.To date, 661 sub-fossil pine samples have been collected from lakes in the NW Cairngorms: Loch Gamnha (215), Loch an Eilein (293), Green Loch, Ryvoan (67) and multiple lakes in Abernethy (86) - about a third of which have been dated using radiocarbon dating or tree-ring (dendrochronology) methods. However, dendrochronological dating of the samples has been a challenge. It has become clear that the impact of human disturbance (related to tree felling) has had a profound influence on the growth of the trees which decouples tree-growth from climate. Although these human based disturbances impact on the potential climatic information that can be gleaned from these samples, an unplanned outcome of this work will be the detailing of the human timber extraction/land-use history (likely a part of the Highland Clearances story) of the regions sampled through the Scottish Pine Project (i.e. the native pine woodlands). A network of over 50 pine woodland sites have now been sampled across Scotland (http://www.st-andrews.ac.uk/~rjsw/ScottishPine/). This is an exciting outcome as it will allow a new appreciation of the impact of logging on pine woodlands and their resultant recovery over multiple centuries.

Tree-ring based reconstructions of past summer temperatures are still in development. Through Milos Rydval's Carnegie Trust funded PhD project, Rob’s team have spent a substantial amount of time developing the new Blue Intensity (BI – a proxy of lignin content and cell wall thickness of the latewood) parameter (Rydval et al. 2014; Wilson et al. 2014). Utilising both RW and BI data from Abernethy, Green Loch, Loch an Eilein and Loch Gamnha we can already produce a well calibrated (55% of the July/August temperature variance explained) temperature reconstruction back to AD 1460 (see Figure).

Christchurch - Priory and Mill
While down at Stonehenge (more on this to follow shortly with a press release on Sept. 11th) I managed to spend a morning with an old friend, Peter Fenning, helping out with some local archaeological sites in Christchurch.  In particular, we ran a frequency domain electromagnetic survey over the grounds around Christchurch Priory.  For this we were using the CMD Explorer with gps positioning.  Initial results were very promising with what looks like a signature for the main site well showing up as a very strong anomaly.

The figure above is for the deep conductivity (down to 6m).  We still have to process the data and integrate it with the rest of the site information so more to follow later.  In the mean time follow the Christchurch group at: http://christchurchantiquarians.wordpress.com/blog/

Floodplain hydrology and geophysics in France: by Cristina Evans

In June 2014 we (Cristina Evans, Richard Bates and Chris Sargeant) travelled to the south of France for fieldwork. Our three sites were located along the Rhône River, at Péage-de-Roussillon, Donzère-Mondragon and Mas-Thibert. Didier Graillot and Frédéric Paran from the École Nationale Supérieure des Mines de Saint-Étienne joined us in the field and assisted us with obtaining hydraulic conductivity readings using a Guelph Permeameter. We also collected soil water samples and electromagnetic readings. This data will help us to characterise the soil structure and hydraulic properties at our sites, to understand the subterranean hydrology in the riparian corridor. 

The following video tells the story of our trip. I hope you enjoy it!

http://www.youtube.com/watch?v=3RmNHGgVxJo

Cristina

Operation Iceberg

Operation Iceberg and other fun in Greenland - over the last few summers I have been working with a number of colleagues up in Greenland.  It's the best kept secret holiday location if you want stable weather, blue skies and 24hrs of daylight.  Rather than blogging here I have written a short piece for the "Travelling Geologist" - Chris Spencer - check out some of his great blogs on http://www.travelinggeologist.com/

richard 

Peering inside volcanoes: A guest post by Oliver Lamb

Picture yourself here. You are a scientist monitoring an active or erupting volcano. In the past, this volcano and others like it have produced lava domes which are prone to suddenly and violently explode or collapse to produce devastating pyroclastic flows, often without warning. Unfortunately, it's this sort of behaviour by Sinabung in Indonesia that recently took the lives of 14 people (see the video below for a spectacular example from Sinabung). So what can you, as the scientist, use to work out when the growing dome is going to explode or collapse next? What is already known is that the transition from quiet to violent activity during dome growth is because of a complex range of processes, particularly before explosions.

Fortunately for scientists like me, active volcanic systems produce a wide range of seismic signals prior to and during an eruption and these signals are easily picked up by seismometers deployed around the system. For my PhD at the University of Liverpool I am carefully analysing the seismicity from recent or ongoing dome-forming activity, focusing particularly on any signals that can tell us something about the conditions within the volcano before explosions or dome collapses. Hopefully by the end of this project, I will have looked at seismicity from at least four different active volcanoes: Volcan de Colima, Santa Maria, Mt Unzen and Mt. St Helens.

'Drumbeats' recorded over a 24 hour period at Mt St Helens, 15 November 2004

To give you an idea of the size of the dataset for this project, I've included the snapshot above of the seismicity from Mt St Helens during its eruption from 2004 to 2008. What you're looking at is the seismograph from a single day during this eruption, and each of those peaks is an individual volcanic earthquake. Now imagine trying to analyse each event, every day, every month,  for well over a year, then you have a gigantic number of events to look at! Thankfully, at least for my sanity, we have tools which we can use to automatically count all these events and measure different traits about each event. These traits include how big the event was, how long it lasted for, how long was it since the last event, the frequency content and much more. With these tools, we can now begin to track how these events change over time and begin to get a better idea of what's going on as the eruption progresses. I have already used the tools on seismicity from  Mt St Helens, and by my latest count the volcano experienced well over 500 000 seismic events from November 2004 to March 2006, an average of around 50 events per hour. I hope that emphasises how large the dataset is!

Left: Volcán de Colima, Mexico, during more peaceful times, taken August 2012.
Centre: Mt Unzen, Japan, nearly 20 years after it ceased erupting. (Credit: J. Kendrick, Liverpool).
Right: Santiaguito, Guatemala, taken December 2007. (Source: photovolcanica.com) 

But the project doesn't stop there. There are plans afoot for a whole raft of other analytical methods to be used. Methods such as locating each event as the eruption progressed, looking for events which may have come from the same source, and then some statistical analysis on top of that. Eventually, armed with all the geophysical results, my project will then begin the experimental phase. During the experiments, I will be placing samples into similar pressures and temperatures as we think the seismicity is being produced in, and break the samples apart and record the resulting acoustic emissions. The current idea is that by the comparing the experimental and volcanic waveforms, we can then help figure out what's going on inside the volcano during a dome-forming eruption.

The author, on the south flank of Volcán de Colima in July 2012

There you go, there's my project in short. For those of you who don't know me, I'm Oliver Lamb and I am a first year postgraduate research student with the Department of Earth, Ocean and Ecological Sciences at the University of Liverpool. If you have any questions or comments about what I've written here, then please feel free to get in touch with me via e-mail, olamb245@gmail.com, or find me on twitter, @olamb245. Thanks for reading!

Iceland - Orca 2014

Grundarfjörður

Iceland - Orca 2014

Iceland - a change of scene and most definitely a change in temperature since Tanzania!  I have spent the last couple of weeks working with the University of St Andrews Sea Mammal Research Unit (SMRU) on a project led by Dr Patrick Millar  investigating methods for measuring and monitoring the health/body condition of cetaceans, in this case, orca. 

Orca off the bow

Our part of the project will be testing sonar as a tool for specifically measuring body condition from body measurements.  This might seem like a far cry from mapping seabed or reconstructing palaeo-landscapes, the more usual deployment of sonar in my work, but really it’s not such a far cry.  The idea is to use a new generation of very high resolution sonar to map in real time the acoustic reflections from the body surfaces of whales as they swim past the boat or as we can manoeuvre the boat into a position to observe their habits such as feeding.  Ultimately, if we can obtain consistent and representative measures of body dimensions then SMRU might be able to observe aspects of body condition change during a season.

The sonar we are working with is the latest 3D sonar from CodaOctopus the Echoscope.  This sonar sends out a broad spectrum of acoustic energy about two, main frequencies, namely 375kHz and 610kHz.  The energy is recorded on an array in 3D that allows the reflected signal to be correctly positioned within a cone of insonification that is about 50degree in width and height.  With the addition of positioning and motion reference to the sonar, together with an insonification rate of up to 10 pings per second it should be possible to track the whales in real time.  What we are up here determining is if we can not only track them and thus ascertain their behavioural characteristics but if the sonar will also give us the resolution to be able to make precise body measurements.  This will require quite a bit of processing to first remove any noise in the data such as the fish schools that the whales are often hunting, the clutter from wave action at the surface and the seafloor.

SMRU boat Tango with Echocope fitted to starboard

So here we are in Grundarfjordur, on the Snefels peninsular with the team (Filipa Samarra, Sara Tauares, Miguel Neves, Fedutin Ivan, Olga Filatora, Sebastien Houillier, Paul Wensveen, Kagari Aoki, Julie Becsau, Jose Guilabert, Melanie Chocholek and Luke O’Connor) that will also be making a record of photo ID, sound recordings, tagging whales with motion sensors and taking samples for biopsy.  Why Grudarfjordur? Well over the last few years there have been large number of orca that visit the fjords in winter to feed on the vast stocks of herring that congregate in the still, cold and somewhat protected waters. 

The setting is spectacular with snow-capped mountains of layered basalts surrounding the fjord. Sure, its cold with frozen ground and even the snow at sealevel with an icy crust but that does not seem to daunt the Icelandic horses with their heads bowed to the constant north-easterly winds. 

Our mornings start with a check for orca in the fjord.  If there, and this is usually given away by the flocks of gulls and the odd eagle that flock above the feeding whales, then we launch the boat.  The sonar is deployed after making observations of behaviour in order that we can determine if the sonar is having a detrimental effect on the orca and then it’s a gentle approach to groups where they are feeding in order to obtain data.  On a good day we will get sonar data, photo ID of the whales and if lucky some biopsy samples. 

Image from Echoscope showing large male orca and young orca in background

Processing is going to take some weeks to obtain quantitative information but at the end of the trip we have managed to record some great data showing behaviour including groups working the herring schools up to the surface for feeding.

There is a great team here and it’s a real privilege to work on this project and in this part of the world – well worth a visit if you are interested in whales, outdoor scenery or of course for views of the northern lights!  Next time I must remember to bring my ice climbing and skiing gear for those days that the whales do not turn up!

Kilwa Marine Geophysics Survey, 2014

I have just returned from Tanzania working with Dr Ted Pollard from the British Institute in Eastern Africa and Elgidius Ichumbaki from the University of Dar es Salaam. Ted (also an honorary researcher at St Andrews) has been researching coastal archaeological sites along the southern Tanzanian islands near World Heritage site of Kilwa for over 10years.  His studies have documented settlements and trade back to Middle Stone Age with extensive developments from the 14C and 15C based on gold trade  that originated in modern Zimbabwe. To date, most of his work has been focused around recording intertidal sites in relation to the changing geomorphology that will have dictated the land use.  He has shown how river channels and harbours have silted up, settlements abandoned both as a result of nature and from human pressure.  There is a fascinating story in this coast line and one that despite the obvious immediate differences (its hot and the water is warm) has many similarities to the work that many of us are conducting around the North Sea.  

Kilwa Fort, Kilwa World Heritage Site, Tanzania

So this year Ted wanted to investigate the sub-tidal part of the study area.  In order to do this I have brought out our SwathPlus 468kHz bathymetric sidescan.  This is the sonar that we have been using up in Orkney, Scotland (see earlier posts) to successfully map the submerged topography (the drowned landscape) but also using to map different types of biological habitat on the seafloor.  It was deployed with a TSS DMS205 motion reference unit, sound velocity probe, Vector Hemisphere GPS and Topcon RTK dGPS.  Unfortunately here I do not have the advantage of bringing a custom survey vessel so we are relying on the collaboration with the Tanzanian Antiquities Department.  Check the video clip to see how the survey went and get a feel for the place. The boat required a fair amount of impromptu rigging and a couple of visits to a local woodworking shop - here my demands on yokes to go around the keel of a boat were a welcome change from making bed frames I think.

Charles Okeny from BIEA surveying using the SwathPlus bathymetric sonar

Over the course of the two weeks we managed to get a fair amount of the inner harbours covered including some great detail around the old fort and palace. Water depths ranged down to 65m and from the mapping it appears that there are a number of submerged coral terraces plus some great sediment features. 

As with any geophysics, it is only as good as the ground truth and so there was nothing for it here but to jump into the water to get some.  Whereas I am usually a fan of putting down an ROV (remotely operated camera) there was just not the facilities to do this and so we hired kit from a local dive centre and had to do the honourable thing – diving around coral reefs can be a hardship, honest!

The final map of bathymetry showing a deep (>60m) channel with steep coral shelf breaks

Dr Ted Pollard 

The result of the day of targeted dives proved out many of the sonar targets and gave some valuable information on seafloor type.  It also gave us the first confirmation of archaeological significance with a large pottery scatter at one site.  Ted will now be following this up with careful analysis/identification of the pottery.

Hominin footprints at Happisburgh (written by Dr Martin Bates, University of Lampeter)

View from clifftop looking towards the area of footprints revealed by the coastal erosion.

Well it is out there now after nearly a year of sitting on the news. The announcement last week at the British Museum that the world’s oldest footprints (outside Africa) had been discovered in Norfolk has made the news across the world. Again the small settlement of Happisburgh is in the news for the exciting discoveries about our Prehistoric past. From the BBC news to the tabloid newspapers, web media sites to blogs and tweets (even an appearance on Radio 4 Thought for the Day) the evidence is now available to all to examine. Our scientific findings were published last week on PLOS ONE and this shows that a small group of children and adults walked across the mudflats some 900,000 years ago. But how were these traces discovered? It happened last May when we were undertaking work for the British Museum as part of their English Heritage funded work to map the channels associated with the archaeological remains that exist beneath the cliffs of sands and silts laid down by ice sheets some half a million years ago.

Dr Richard Bates surveying area of footprints. Note the cliffs in the background are deposits (sands and silts) left by ice following retreat of the ice sheet that buried the surface with the footprints. Today the erosion by the sea is removing the sands and silts to reveal the deposits containing the archaeology and footprints.

We have been working on this project for the last 2 years or so and it was in the downtime while we were waiting for the geophysical equipment to take its readings that we saw what appeared to be odd patterns in the silts deposited in a former tidal channel. This system was probably part of the mouth of the Thames at that time. These traces were strange, elongated shapes totally unlike any of the natural ripple marks and mud cracks that occurred on other surfaces at the site. In fact they appeared very similar to features known from Holocene (last 10,000 years) sites in the Severn Estuary that had been identified as human footprints. We pointed this out to the archaeologists on the project and quickly a team was mobilised over the next couple of weeks to visit the beach to record these features and sample them for analysis. It is unlikely that these prints are the only ones preserved in the area and as the coast retreats further it is likely that more such surfaces will be exposed so the hunt is now on for more. Surprisingly there are no animal prints mixed in with the humans despite the fact the bones recovered from the site show a range of different animals were present with the humans. It has been hard to keep quiet about these discoveries for nearly 12 months knowing their importance but scientific rigor has to take precedent and that before announcing to the world their presence we had to be sure that these really were ancient footprints. Now we have the data and hopefully more will come to light when conditions are right to reveal them.

 

Close up detail of individual footprints at Happisburgh.

Chew Bahir, ERT 2013

I am just about to leave for Tanzania to do some offshore archaeological surveying with Ted Pollard from BIEA (I will be blogging on this on my return) but I thought before I went I would post a short video that was compiled during a field campaign late last year to the Rift Valley in southern Ethiopia. 

I made this trip together with Dei Huws (Bangor Uni) and Tigistu Haile (Addis Ababa Uni) as part of a much larger, international project that is drilling a number of locations throughout East Africa that are linked to key Hominid sites.  The overall aim of this is to be able to provide dated information about environment and climate at key stages of hominin development and migration.

The Chew Bahir site is located in SW Ethiopia close to the boarder with Kenya.  The large valley generally drains to the south into Lake Stephanie but the northern part where we hope to drill our core is only flooded on an infrequent basis.  As with many of arid areas, when it rains it does so often causing drastic and violent floods from the surrounding uplands that wash coarse river gravels far out into the generally flat valley floor.  Since our drilling objective is to obtain as simple a geologic sequence as possible the first task is to locate an appropriate site that has not been affected by the alluvial fans on the valley side or any of the ancestral rivers that migrate across the valley bottom. 

So, in November we made a preliminary field visit to the site armed with magnetic and electrical resistivity tomography/imaging (ERT) equipment in order to find appropriate sites.  Our choice of locations for the geophysics was based on some regional background work on geophysical signatures and also on some local knowledge kindly shared by Tullow Oil Plc.

The site is quite special and like nowhere I have worked before as you can see from the video.  We managed a couple of sites during our survey, one in the centre of the basin, the preferred core location, and one over an alluvial fan sequence at the edge of the basin.  The ERT gave some great results despite the arid conditions mainly I think because of the relatively high conductivity of the lake sediments – likely a result of the periodic wetting and drying. The alluvial fan was readily recognised in the ERT sections at the basin edge but no signatures of this were recorded at the centre of the basin where a fairly uniform sequence was modelled.

The next stage from us it to return to do a seismic reflection survey in order to image the top 400m (the core depth) in much greater detail. 

La Cotte de St Brelade

From Feb to Sept 2014 a new exhibit will be on show at the Natural History Museum, London that highlights some of the research undertaken by scientist in St Andrews and elsewhere in the UK as part of the Ancient Human Occupation of Britain project over the last 10years.  Britain: One Million Years of the Human Story presents key material and evidence from a number of important sites in and around the UK that help to document the dramatic story of changing landscapes and the people who lived in them over the last million years.  Two of the sites that this major exhibition showcases have been the focus of research for the dept E&E over the last 5years.  La Cotte de St Brelade is briefly described here, Happisburgh has been presented in a previous blog and will be the focus of a future blog as new results are published.

La Cotte from the sea

La Cotte de St Brelade in Jersey is a cave site that contains a 250kyr record of human use.  Investigations have been conducted at the site over the last 100yrs but there still remains much material that has yet to be uncovered.  It’s position however, on the shore in a highly vulnerable situation, means that much of the material is in danger of being lost forever and the site has been subject to intense recent study under a NERC emergency project.

A geophysical programme was initiated in 2012 to survey the wider palaeo-environmental context of the site.  This included high resolution marine mapping combined with geophysical modelling to allow the archaeologists to drain away the sea and literally step back in time to walk through the ancient landscapes. 

The palaeolandscape was surveyed using multibeam sonar aboard two research vessels, a 15m research yacht, Gambo and also using my inshore craft, the zego boat.  The resulting landscape model shows a complex valley system offshore, through which the herds of game would have been forced along routes leading up to the dead-end valley infront of the cave site.

 

Watch as sea rises over the submerged landscape of eroded granite terrain and then fly over the valleys up to La Cotte to get a view looking out from the cave

The new views from the mammoth butchery cave site are providing alternate context for understanding the prolific finds that have been dug from the site over the last century. 

 Work continues at the site and in 2014 we hope to start exploring the relationships between landscape, geology and the geology of tool assemblages from the cave.

Happisburgh ERT Geophysical Survey, Jan 2014

Happy Days are here again!

Why happy? Well we are back in Happisburgh on the north Norfolk coast staying in the Hill House pub (of Sherlock fame – the Dancing Men, and also with a cracking set of handpump real ale) and running electrical sections across the country side. 

The site has previously yielded evidence of the UK’s oldest ancestors.  It was here in the early 2000s that artefacts and associated plant and animal remains were discovered that is the earliest evidence outside southern Europe for human activity, older than 780,000 years before present. Not only that but the biological remains suggested these people were living in an environment similar to that of present day southern Scandinavia.  These remains were found in a river channel close to the sea that was subsequently buried by thick sequences of deposits when East Anglia was covered in ice around half a million years ago.



ERT line at the big manor, Happisburgh

Over the last couple of years we have been visiting the site and using different geophysical methods to try to reconstruct the palaeo-landscapes at the key time periods in relation to the artefacts.  We have used both electric and electromagnetic surveys on the foreshore across the semi-buried channels and inland from these trying to chase the channels as they are buried beneath other sediments.  Specifically we have used a Geonics EM31 to map the lateral extent of the channels on the beach and then an Abem Terrameter to acquire 2D geo-electric sections (ERT) in a grid pattern across the fields surrounding the village in order to understand the landscape structure.  The data is processed using RES2DINV and then visualised in Fledermaus.  Ultimately, these landscape reconstructions will enable better targeting of the archaeological investigations and also allow us to try and understand where the early people were possibly living and how they were using the landscape.  

Many may know this part of the coast for its rapid and drastic erosion and retreat.  Since we have been coming here the cliffs have shot back well over 40m! Devastating for many locals, some of whom have lost their entire houses to the North Sea, but for us it comes as a mixed blessing as we get new geologic sections to investigate each time we visit with the possibility of new artefacts. Watch the press and this blog for announcements on this next month!




ERT survey line over newly exposed basal member of the Happisburgh Till

For more on this work then if any of you are down in London over the next 6 months then make sure to get to the Natural History Museum for a new exhibit on Palaeolithic Britain “Britain: One Million Years of the Human Story” with a special part on Happisburgh.  Much of this work came from the Ancient Human Occupation of Britain (AHOB) project. So finally, a blog will shortly be written on our other site in Jersey – La Cotte de St Brelade.

The Bates Brothers discuss the latest results (photo Erin Kavanagh)



Some of Last year’s projects - The Beginning of Time?

The Begging of Time 

Last summer, just about the time that the midges come out in full force a team of archaeologists and geophysicists from the Universities of Birmingham, St Andrews and Bradford got together in a field in Aberdeenshire near Crathes Castle.  The outing was prompted by the keen-eyed and insightful thinking of Prof Vince Gaffney who had spotted a curious arrangement of Mesolithic pits form air photos and a previous archaeological site report.  

Air photo and site investigation of sinuous pit alignment

The alignment was unlike most other early monuments in the UK where obvious orientations align with solar and lunar events.  This new site showed a sinuous arrangement to the pits.  While most of us would see no significance in this, Vince’s curiosity was piqued and his brain went into overdrive.  The end result, a geophysical survey, a new interpretation and the theory presented that at 10,000yrs old the feature could be the world’s oldest calendar!

The geophysics: This included electromagnetics, (Geonics EM31 and EM38), magnetics (Foerster Mag) electrical (Geoscan) and ground penetrating radar (PulseEkko).

The end result was modeled to examine what the exact solar and lunar tracts would have looked like 10,000yrs ago.  This showed the site mimics the phases of the moon in order to track lunar months over the course of the year. But that is not all, it also contains elements for alignment with the midwinter sunrise thus providing an annual astronomic correction in order to maintain the link between the passage of time indicated by the moon, the asynchronous solar year and the associated seasons.  Pretty smart of those old Scots running around the glens hunting the deer and fishing for the salmon!

For more information see Time and a Place: A luni-solar ‘time reckoner’ from 8^th millennium BC Scotland. Internet Archaeology, July 15 2013 (http://dx.doi.org/10.11141/ia.34.1)

 

Inphase results using EM31 (high resolution over site, lower for rest of field)

Seismic Data, Orkney

Previous Rising Tides Geophysics Results
Over the past couple of years we have been collecting bathymetry and sub-bottom seismic information from the Bay of Firth and Loch of Stenness.  These give us the first hint at palaeo-landscapes. 

Bathymetry in Bay of Firth showing deep inner basin

 The bathymetry information was acquired using a SEA Swathplus 468kHz sonar deployed on our department boat, Envoy and also on my specially adapted Zego Boat.  The sub-bottom information was acquired with a Sesistec Boomer system in the Bay of Firth and using a Tritech SeaKing Parametric Sonar on Loch of Stenness.

The results allow us to target areas of the seafloor that are rock and those of sediment.  The rock areas are investigated by ROV (remotely operated vehicle) or diver and the sediment by coring

Section of bathymetry from Loch of Stenness near Brodgar World Heritage Site

Sub-bottom profiles through stone features and sediment sequences in Stenness

Rising Tides - January Coring

Orkney - The Rising Tides Project

Its January and its Orkney - Coring on a new raft I have built in the Bay of Firth and the Loch of Stenness.  This is part of the Rising Tides Project, an archaeological study of how sealevel rise has inundated lost landscapes that were used by early settlers in Orkney during the Mesolithic and Neolithic.  

We have been working in Orkney for a number of years, as a multi-disciplinary team of archaeologists, geologists and geophysicists. For my part I have been acquiring geophysics of the sea floor and sub-seafloor sediments. Using this seismic information I am building models of submerged and buried surfaces that we will interpret as palaeo-landscapes once the others have done their work on the sediments.  Getting ground truth sediment has been quite a challenge but now armed with a new raft (a segmented, modular assembly from which we can operate a vibro-corer) we can acquire the necessary sediment cores to be able to analyse the environments that the geophysics has hinted at.  The cores are not only vital to interpretation of the geophysics but are a crucial step in trying to re-people the landscapes.  

So, first week in Jan and the raft arrives on site and is assembled.

Its all bolted together ad floated out.  Since its the maiden voyage a can of Guinness was sacrificed in the launch!

Out to site and the Vibro-corer is attached.

Perfect sediment record.

The whole exercise in both the Loch of Stenness and Bay of Firth caused a bit of a stir locally that prompted a Radio Orkney reporter to venture out

Its now back to the lab for core analysis of micro-fossils and sediment dating....more to report once all this is done