Archaeology at Disney World. Seriously.

I am writing this from Disney World, where I have gone to talk about archaeology, particularly global change threats to the archaeological and paleoecological records.  The Society for American Archaeology is having its 81st Annual Meeting here, so I am sitting on the 11th floor of a hotel with a view across a lot of fairly low lying land.  It might be high enough to survive several meters of sea level rise, but by 20m, the Orlando airport looks like it gets iffy.

I organized a session on, surprise, global change threats to the archaeological and paleoecological records.  It should be good, with people presenting on various aspects of the problem in various part of the world (mostly the North), and some possible solutions being tried as well.  The session is Saturday morning, and we’ve got Ben Fitzhugh from UW as discussant, as well as a 15 minute discussion slot.  I hope we get good attendance, because this is a critical issue for the future of the discipline (and maybe of people in general).  Of course, in their infinite wisdom, the schedulers put us directly opposite the session in honor of Lou Giddings, which deals with coastal Alaska.  I actually have to read a paper for someone because the primary author couldn’t travel and the second author is giving a paper in the Giddings session at the same time!  Meanwhile, I’d already gone to most of the papers I want to see today by 10:30 AM.

Last night I went to the President’s Forum, which was on Climate Change and Archaeology.  Dan Sandweiss had organized a nice set of speakers.  One of them was Paul Mayewski,who specializes in ice cores and their analysis. He talked about some new software they have, and then he described a new instrument they have which can sample cores in tiny increments, so they can actually see individual storms thousands of years ago in the right type of core!  I introduced myself afterwards, and asked if it might work on ice wedges, following up on a suggestion Vlad Romanovsky had made during ASSW.  He thought so, and offered to pay to ship a trial wedge sample to his lab so they could try it.  Now I just have to get a good sample.  Hopefully it works, but either way it will be interesting.

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I’ve got a meeting later today (and another on Saturday for those who can’t make today’s) for folks who want to help with 2016 Walakpa Archaeological Salvage (WASP 2016).  Today we meet at 5PM at registration, and anyone who is interested is free to come along.  Now I have to run off and find the meeting of the newest SAA committee, Climate Change Strategies and Archaeological Resources (CCSAR).

Taking the temperature of permafrost and archaeology

Today the Saturday Schoolyard talk was about warming permafrost.  The speaker was Dr. Vladimir Romanovsky, head of the Permafrost Laboratory at the Geophysical Institute at UAF.  He gave a really good talk, explaining what permafrost is (permanently frozen ground, basically), why it matters if it melts, and how permafrost researchers go about taking its temperature (with thermistor (temperature sensor) strings down boreholes, mostly).  He then went on to show how permafrost temperatures had changed through time as the atmospheric temperature had changed.

After that, he moved to predictive modeling based on climatic models.  Using even a fairly middle-of-the-road climate model, it doesn’t look too good for permafrost in Alaska by the end of the century.  He also showed active layer (the soil layer at the top that freezes and thaws every year) modeling done on a similar basis some years ago, and pointed out that over the 10 years since the model was run it had been spot on in its predictions.  The active layer is clearly going to be a lot deeper if the predictions hold.

This is not good news for Arctic archaeology.  Compared to most of the rest of the world, where archaeologists are left to puzzle out what people were doing from a few stone tools, waste flakes and potsherds, we get really good organic preservation here, which makes it possible to look at questions that can’t be addressed elsewhere for lack of relevant data.  The reason the preservation is so good is in large part permafrost, and permanently frozen sites.  Last week, when Claire was here, we were getting a lot of well-preserved 1600-1700 year old marine invertebrates from the samples.  They exist because the layer was frozen for most, if not all, of that time.

I’m been thinking a lot about site destruction, and how to determine which areas are at highest risk, in order to prioritize field efforts.  Perhaps because coastal erosion is the big and immediate threat at Nuvuk (and all the other coastal sites I’ve worked at except for Ipuitak, where the immediate threat was the seawall being built to prevent coastal erosion), I’ve tended to focus on that, as well as eroding river banks for sites along rivers.  The melting of exposed ice wedges, which then leads to collapse of the overlying ground is also something I’ve been concerned about.  And these are major threats, which can tumble entire houses upside down on the beach for the waves to destroy.

Undercutting by waves caused the gravel to slump from underneath this grave at Nuvuk.
Storm-driven surf tears into the mound at Ukkuqsi in Barrow.
Tunnel remnants after the storm. The house was to the left, where only thin air can be seen.
Ice wedge in bluffs near Barrow. They can be much larger.
Slump block on beach at Barrow after a storm.
Slumps from thawing ground along a Colville River cut bank.
A Colville River cut bank from the air. Notice the earlier slump that has stabilized and even grown over, and the fresh cut at the bottom from the river's current.

I hadn’t thought much at all about the risks to Arctic archaeology from a significant deepening of the active layer, which will mean that artifacts and ecofacts (animal bones, insects, etc.) will freeze and thaw every year (which is hard on things to begin with, often causing rocks and bones to split) and while they are thawed, they will be decaying.  Even now, really old sites don’t have much organic preservation.  Even sites that are in no danger of eroding are threatened with the gradual invisible loss of a great deal of the information they now contain.

Obviously, if we are going to develop a “threat matrix” for Arctic archaeological sites, this has to be part of it.  I talked to Vlad a bit after the talk, and he thought he had students who could be put to work on this problem, perhaps by combining what we know about site locations in Alaska (by no means a complete listing) and the existing models for permafrost change.  He also said that one could do active layer modeling for a specific site with a year’s worth of soil and air temperatures, so that’s something we definitely need to get started on.