LiDAR Sheds New Light on Hadrian’s Wall

Pardon the groaner in that headline … this is actually hype for a television programme on the BBC but it looks rather interesting:

Hundreds of miles away from Hadrian’s Wall, a man surfing the internet from the comfort of his home stumbled across something that astonished the professionals.

Bryn Gethin’s discovery on his computer in Warwickshire, was one of a number, based on aerial photography and imaging techniques, that are rewriting a whole era of Roman history.

He spotted something while browsing old LIDAR (light detection and ranging) images, which show remains even if covered by trees or buildings.

Experts say he had potentially discovered the camp of the men who actually built the wall that runs across the country from Tyneside to Cumbria.

Surveyor Humphrey Welfare, currently investigating the site, said the camp would not have been seen without aerial images.

“It gives us another little insight, a little window into what happened during the construction of the wall,” he said.

“And that’s how archaeology builds up, piece by piece.”

It was known the wall supported civilian communities which provided goods and services in a local economy that benefitted both occupiers and natives.

But it seems there were Iron Age settlements hundreds of years before the arrival of the Romans who, rather than being an aggressive conquering force, forged working relationships with the resident population.

‘Whole new world’

“What we thought we saw was a very militaristic landscape, very sparsely populated and all we saw was what survived at the surface,” said Dr David Woolliscroft from Liverpool University.

“Then suddenly, when we started to fly, a whole new world emerged. Huge numbers – tens of thousands – of isolated farms, completely undefended.

“You can only have a landscape like that when people are so used to peace that they take it for granted.

“And that utterly changes the story of how we see the Romans.”

There is also evidence, discovered from the air, that throws into doubt the accepted belief that the wall was a barrier between the empire and the barbarian north.

Aerial pictures of a Roman aqueduct show it built north of the wall and right next to a native settlement.

“That shows a comfort in their own security and power, in that they’re happy for something as important as a water resource to be placed north of the frontier,” Dave Macleod, from English Heritage aerial survey team, said.

Aerial archaeologist Ben Robinson uncovers new revelations about life on Hadrian’s Wall in Northumberland

“You don’t put your water supply into enemy hands,” Dr Woolliscroft agreed. “Clearly they were very confident that this was an area that was theirs, even though it was beyond the wall.”

The area around Hadrian’s Wall has been mapped from the air by English Heritage but amateur research has also thrown up some surprising findings.

Ancient camps, ovens, rubbish pits and ditches show up from the air as crop marks, where plants grow differently – often invisible from the ground.

Work on Emperor Hadrian’s wall began in 122AD.

Archaeologists believed soldiers had settled in a nearby fort – Vindolanda – from about 85AD.

But another photograph shows something Dr Andrew Birley from the Vindolanda Trust believes is a fort built ten years earlier, 50 years before the wall.

“As we started excavating the ditches we were getting more and more evidence to suggest that this actually could pre-date anything on this part of the site that we’d previously known about,” he said.

If they find the timber fort gates – and it might take years – the rings on the wood could lead conclusively to a construction date.

It might prove the Romans established their frontier long before the history books currently say.

… the original article includes some photos and some Flash media which I couldn’t get to work because Flash seem to be doing weird things these past couple of days.

Review: Rome’s Lost Empire

Not sure how long this one will be up on Youtube, so it might be a good idea to watch it now … my review follows:

We’ll begin by noting that when this one first appeared on the BBC a week or two ago, it seemed to be universally-panned by folks on twitter and facebook. It had been hyped by the BBC (who produced the program).and by the University of Alabama (whence comes Sarah Parcak, whose work sparked the show: Birmingham Egyptologist Sarah Parcak featured in BBC show on lost treasures rediscovered from space). In case you didn’t know, Parcak was the “space archaeologist” who was in the news a year and a half ago for finding a pile of Egyptian sites (including pyramids) using her satellite methods (e.g. Egyptian pyramids found by infra-red satellite images … BBC). She also gave a very interesting TED talk that you should check out if you get a chance: Sarah Parcak: Archeology from space ).

That said, we have to note that this particular documentary has a pile of the ‘devices’ that I find incredibly annoying in documentaries about the ancient world, and all of them are connected to trying to create ‘drama’. For example, although the thing is hosted by the very capable Dan Snow, I really don’t care about his parents dragging him around ancient sites or Dr Parcak’s imaginary space ship.  We really don’t need silly statements about Dr Parcak being an ‘ordinary lecturer’ by day, but someone who sits in front of a computer at night doing research (don’t we all do that?). I don’t like the ‘contrivedness’ of having Dr Parcak being set up in the ruins of Portus/Ostia (can’t tell which), supposedly doing the research for the first time when we all know it was all done well in advance of any footage being shot. We also don’t need the shots of her working long hours into the night or confessions of self doubt, yadda yadda yadda. The UK version of all this is an hour and twenty minutes long; when the program comes to the US this summer, it is apparently going to be shorter. If they’re looking for things to cut out, that’s a nice list.

As long as we’re talking about editing things out, I should also note that in general, the documentary puts one in the same mood as one might have been listening to the Rolling Stones’ Exile On Main Street for the first time: so much good stuff if the other bits were stripped out. In particular, the supposed unifying element in this program — the question of how Rome maintained such a vast empire with so few soldiers — is completely unneeded and the focus should have been from the start simply what the new technologies can tell us that we didn’t need to learn before. We don’t need to make it look like we are suddenly coming up with a new theory when we’re just finding evidence confirming what is already believed by a majority of scholars.

That said, there is some really good information here, but not all of it is without controversy. The first segment is devoted to Portus and is seeking to help Simon Keay and crew find things like canals and the lighthouse. Back in 2010, a canal find at Portus was big news (Major Roman Canal from Portus!). In 2011, we read about a shipyard find (Huge Roman Shipyard Found (Maybe)) .

Unfortunately, the segment with Keay and crew is just an introductory tease and we are taken to the land of the Dacians — which, of course, is more dramatically referred to as ‘Transylvania’. Outside of the use of sonar to ‘sort of” find the footings of the bridge Trajan built across the Danube (and the expected graphical recreations), what is really important here is the use of LiDAR to find evidence of rampants around Sarmizgetusa. The segment involves a big gun in Dacian archaeology (Gelu Florea) and really deserved a bit more attention than it had. But it’s really our first indication of what these new technologies can reveal to us.

Back to Portus where Parcak has (finally, it dramatically appears) located something with her infrared-enhanced satellite technology: a major canal running up the *east* side of the Tiber. This is an incredible find and it would have been very nice if they could have somehow followed it further to see how far it actually went. As with the previously-mentioned canal find (above), I can only ask  what effect all these canals had on the water levels of the Tiber. Someone needs to correlate reports of flooding of the Tiber to construction of canals like these.

Unfortunately (again), they don’t really go very deep into the matter and suddenly have a need to dash off to Jordan. There’s lots of dramatic silliness until we meet up with Chris Tuttle, who has been working in the environs of Petra over the past few years. The goal of this segment is to find evidence of “abundance” under the pax Romana and Parcak locates a promising site with the infrared satellite thing. The trio (Snow, Parcak, and Tuttle) do a quick survey and find potsherds, some of which are apparently Roman. Supposedly this is evidence of “abundance” … more detail is needed here.

Back to Portus, where Parcak identifies what is possibly a Roman amphitheatre. This is presented as a new find and is really quite dishonest as presented. In fact, Keay made the claim to have found this back in 2009 — and for some reason it doesn’t seem to have been mentioned by me. Happily, the Science Daily coverage is still up: Archaeologists Discover Amphitheatre In Excavation Of Portus, Ancient Port Of Rome … as is Mary Beard’s criticism of all the hype: The luxury amphitheatre at Portus. After the tease, we are shown the shipyards mentioned above (also not a new discovery, obviously).

Then we’re off to Tunisia, which apparently was “Rome’s granary” (as if Sicily and Egypt suddenly weren’t producing). The big name here is David Mattingly, who is pleased to learn from the satellite technology about a fort (which the gang explores … and it is apparent that some diggers have already been there). Along the way we are shown remains of a Roman frontier wall … it would have been nice to see the extent of this — does it rival Hadrian’s Wall?

Finally, we head back to Portus, where this time the LiDAR is used to identify a big platform. Keay concludes that it must be the platform the lighthouse stood on and there follows much recreation — interestingly, the Portus Project’s webpage sort of downplays the recreation of the lighthouse, although it finds it useful. Missing in this segment would have been an overlay of the harbour itself to see if this platform actually extended into the water. As presented, it’s a few dotted red lines on a satellite shot. I still can’t quite figure this one out.

In closing, I should also mention something that I found annoying in all this: there were no subtitles to identify the various archaeologists and they don’t appear to be mentioned individually in the credits (although they might be clipped from the Youtube version).  Definitely something that should have been included, if only to allow people to follow up on things. Stripped away of the docuembellishments and other shortcomings, though, the program does go far to show the utility of Parcak’s satellite-infrared approach to finding sites as well as the incredible potential for LiDAR. We’ll very likely be seeing similar docu-applications in the future.

Some other reviews: