Rising sea levels: Survival tips from 5000 BC

[Dover]

26 May 2009 by Catherine
Brahic Magazine issue 2709.




WITH rising seas lapping at coastal cities and threatening to engulf entire islands in the not-too-distant future, it's easy to assume our only option will be to abandon them and head for the hills. There may be another way, however. Archaeological sites in the Caribbean, dating back to 5000 BC, show that some ancient civilisations had it just as bad as anything we are expecting. Yet not only did they survive a changing coastline and more storm surges and hurricanes: they stayed put and successfully adapted to the changing world. Now archaeologists are working out how they managed it and finding ways that we might learn from their example.

The sea-level rise that our ancestors dealt with had nothing to do with human-induced climate change, of course: it was a hangover from the last ice age. As the massive ice sheet that lay on North America melted, the continent was buoyed upwards. As a result, the northern Caribbean, on the other end of the same tectonic plate, sank, making seas in the region rise up to 5 metres over 5000 years.

Although the cause of this rise was very different to what we face today, the effects were probably the same. Rising waters not only nibble away at coastlines, they also mean that hurricanes and storm surges reach further inland. Higher seas also mean that groundwater becomes contaminated with salt, and as the water table rises the waterlogged land becomes more likely to flood.

Despite these changes, excavations of ancient houses in what is now the province of Ciego de Avila in northern Cuba suggest that the region was inhabited between 5000 BC and just 300 years ago. One of the best-preserved ancient sites is the village of Los Buchillones (see image), now 150 metres out to sea, which was inhabited from AD 1260 until the mid-1600s by people known as the Taino. For Jago Cooper, an archaeologist at the University of Leicester, UK, who studies the site and others across the Caribbean, the village provides a rare chance to study the pinnacle of Taino knowledge (see image). "The people at Los Buchillones represent a way of living that capitalises on hundreds or even thousands of years of experience of living in the area," he says.

So how did they survive as the waters rose? The first clue comes in the proverbial wisdom that every real estate agent knows: location, location, location. Palaeoclimatologist Matthew Peros of the University of Ottawa in Canada and his colleagues have taken sediment cores between the modern shore and the remains of the village, and these show that houses in Los Buchillones were built on stilts over a lagoon (see image). The land barrier that lay between the lagoon and the ocean would have provided the village with some protection from storm surges. Other settlements in the area were in similarly protected pockets, or built on the leeward side of hills.

Building in sheltered spots may seem an obvious precaution, but Cooper argues it's a crucial bit of know-how that the region has since lost. Modern towns and cities, he says, tend to be in more vulnerable, exposed places.

Cont'd

http://www.newscientist.com/article/mg20227096.600-rising-sea-levels-survival-tips-from-5000-bc.html



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[dixiegrrrrl]

1. You wanna hear really stupid sea level building???

Lying very close to city of Mobile is a sand spit, called Dauphin Island.
It is a barrier island, only 15 feet or so above the water.

Prime real estate location. People build houses on the island.
Hurricanes come every 4-5 years and wash the houses and parts of the Island away.
the city and country get the Army Corp. of Engineers to dredge sand up from the shallow Gulf and pile it back up on the spit, creating more land, and the houses get rebuilt, until the next hurricane.

Katrina was the last hurricane to wash over the spit, leaving 2 separate islands.
lawsuits followed, whose house/land was under water and who owed what to who.
And more houses were rebuilt.
But this time insurance companies raised the insurance rates by a zillion per cent.
Homeowners cried 'Foul".
2 pics below.

Before:


and after Katrina

[Dover]

4. That is nuts!

Reminds me of the islands off of North Carolina. A friend once invited me to fly over them and it looked much like the pictures you posted. SO small, narrow and vulnerable! And many of the houses are not even built on stilts but at ground level (sometimes just a foot or so about sea level!). Sand castles....

I'm guessing that insurance companies will begin to refuse any coverage at all, and if the economy continues to fall apart, many may not choose to rebuild after the next storm.
I know some people who have been through SEVERAL devastating natural events that have wiped them
out 4 times in the last decade, and yet they continue to return to their spot of sand and rebuild.
I would have taken the first disaster or two as a sign to move.
Maybe they'll wind up like the inhabitants in that movie Water World.

[dixiegrrrrl]

5. Remember Galveston? Twice wiped out by hurricanes.

It's just a huge sand spit.

Sand spits move naturally, anyhow, the tides shove them along the coast over time.

When I was in Ca. I watched people's houses fall off rain soaked cliffs.
But hey, the developers had made their money and moved on, right?

[OKIsItJustMe]

2. More here…

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=115&topic_id=197018&mesg_id=197018

[Dover]

3. Thanks! Sorry, I didn't spot your post before posting my own...n/t

[OKIsItJustMe]

6. Not a problem

We all do it, and (especially when it's something important) having a couple of postings on a topic doesn't hurt.

I just like to tie them together when I notice them.