It is time to stop quivering in our boots in pointless fear of the future and just roll up our sleeves and build it.
- Ray Pierrehumbert

Monday, September 6, 2010

Ganvie, Benin


I picked up a new follower from Benin, and in his or her honor, I spent some time looking at Benin on line. The main city of Benin, Cotonou, population approximately 1 million, is right at sea level between the Gulf of Guinea and a large bay or lake that seems geographically like Lake Pontchartrain by New Orleans. The entire short coastline of Benin is threatened by sea level rise. Perhaps the most interesting thing about the Bay is the town of Ganvie, whose transportation needs are served entirely by boat. Wikipedia says little about Ganvie, but what it says is quite interesting. I wonder what the submerged rectangular forms on the satellite view show.


Images: Ganvie via Google Maps, Wikipedia.

23 comments:

dhogaza said...

"Beware, beware the Bight of the Benin, for few come out though many go in."

Rattus Norvegicus said...

One of my favorite world music artists is from Benin: Angelique Kidjo. She's awesome.

Steve Bloom said...
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Tom said...
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dhogaza said...
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dhogaza said...
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Rattus Norvegicus said...
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Tom said...
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Michael Tobis said...

How did this thread get to be about Fuller?

Steve Bloom said...

Possibly because there was considerable recent discussion on a thread that's now rotated off the front page such that most people won't see any new comment? Your blog, your rules, though, although FYI some of my motivation to participate here just went down the drain.

Scruffy Dan said...

Reminds me of Koh Panyi in Thailand. It is an entire village constructed on a partially submerged mud flat

http://www.flickr.com/photos/scruffydan/sets/72057594065194258/

Michael Tobis said...

Steve, aside from your brief suggestion that the submerged areas on the satellite image are fish farms, all the deleted messages consisted of people snarking at Tom and Tom snarking back.

I didn't have "off topic" as among the things I reject, but the messages were indeed rude, excessively contentious and repetitive, so I don't think I'm out of line here. My idea is to provide a comments section that is worth reading. I don't care about quantity.

If anyone wants to read them, here they are. Let me know if you miss them terribly.

skanky said...

"Fishing is the main livelihood of these towns, and their techniques are very interesting. They build enormous traps that are basically gates made out of nets and a type of bambooish plant that acts as a fence. They start them out HUGE, and the bamboo-like plant attracts all the fish. They gradually rein in (or reduce the area of) the nets so that eventually they have a small area chock full of fish that they can catch with their nets. We saw these fishing areas spread out like and marked off like agriculture fields throughout the lake and along the wider areas of the river."

From: http://www.travelpod.com/travel-blog-entries/suzyinbenin/beninpc/1058648280/tpod.html

The fishing catch has, according to here http://tinyurl.com/2abk8xr dropped from ~15,000t to ~8000t (no idea if that's metric or imperial).

Ron Broberg said...

Mr. Fuller cites the following for support that the ice mass of Antarctica is slightly increasing. Mr Fuller has raised this point as evidence that loss of ice from Antartica is unlikely to contribute much to sea leavel rise in the 21st Century:

Mass balance of the Antarctic ice sheet
www.cpom.org/research/djw-ptrsa364.pdf


Lets read the conclusion:

We show that 72% of the Antarctic ice sheet is gaining 27G29 Gt yrK1, a sink of ocean mass sufficient to lower global sea levels by 0.08 mm yrK1. The IPCC third assessment (Church & Gregory 2001) partially offset an ongoing sea-level rise due to Antarctic retreat since the last glacial maximum (0.0–0.5 mm yrK1) with a twentieth century fall due to increased snowfall (K0.2–0.0 mm yrK1). But that assessment relied solely on models that neither captured ice streams nor the Peninsula warming, and the data show both have dominated at least the late twentieth century ice sheet. Even allowing a G30 Gt yrK1 fluctuation in unsurveyed areas, they provide a range of K35–C115 Gt yrK1. This range equates to a sea level contribution of K0.3–C0.1 mm yrK1 and so Antarctica has provided, at most, a negligible component of observed sea-level rise. In consequence, the data places a further burden on accounting (Munk 2003) for the twentieth century rise of 1.5–2 mm yrK1. What is clear, from the data, is that fluctuations in some coastal regions reflect long-term losses of ice mass, whereas fluctuations elsewhere appear to be short-term changes in snowfall. While the latter are bound to fluctuate about the long-term MAR, the former are not, and so the contribution of retreating glaciers will govern the twenty-first century mass balance of the Antarctic ice sheet.
(emphasis mine)


I believe that Mr.Fuller has characterized the current state of the data well enough. It is highly uncertain with multiple (and conflicting) lines of evidence that show that Antarctica, on the continental scale, *may* be gaining ice mass. That he is concentrating on those papers which show ice mass gaining is reasonable, since that is his argument. He should not have to argue both sides of the issue. He is not presenting himself as a fair or balanced analyst. He is pursuing a line of argument. But given that he has cited Wingham 2006 in defense of his case, it's interesting that he fails to mention the conclusion of that paper.

Tom, did you deliberately choose to overlook the conclusions of Wingham et al in the paper that *you* cited? Or do you believe that Wingham 2006 supports your contention that Antarctica will contribute little to sea level in the 21st century *despite* their conclusions? Is there some other reason you fail to note the conclusions of the paper that you cited?

Ron Broberg said...

The above is posted to the wrong thread. My apologies and please delete. Thanks!

EliRabett said...

Care to tell Eli exactly what ice911 proposes? The web site does not do a very good job, which sets off the scam alert.

John Mashey said...

Eli: ice911:
1) Leslie Field, the driver of this, is a neighbor in my little town. I know 2 of the current Advisors (Terry Root, Steve Toben) and of course the deceased SHS.

2)It is not a scam. It is a shoestring operation for now, and I'll talk to Lesli about saying more on the website next time I see her. Maybe some lawyer told her to say less about the details for patent issues, or something, although she is certainly not in this for the money.

3) She gave a talk about a year ago at our town center, showing samples.

4) Right now, they are *researching* various kinds of materials to evaluate their suitability for manufacture, albedo raising, survivability and if need be, removability.

5) Again, a simple instantiation is to imagine floating hula hoops with covers of some white material, possibly with other stuff in between. Lessens absorption of heat by the water, if deployed at edge of icepack, slows the melt, and in some marginal cases, maybe even stops or reverses it locally if snow/ice reforms on top.

6) Whether one can actually make this work in practice, I don't know, but Leslie is a serious engineer and is going about this by doing the right sorts of research.

EliRabett said...

I assumed it was the equivalent of throwing sawdust on ice. There are interesting questions about snow covering the ice and having to respread.

John Mashey said...

Back to the original topic, sort of.
See images of Dutch floating houses.

The "wave" of the future.
The Dutch are no dummies when it comes to water, and fortunately, while the North Sea can be nasty, they don't get hurricanes.

Michael Tobis said...

John, that looks like the wrong link.

John Mashey said...

Yep, it was, of some reason, Academic Integrity policies at UPenn were on my mind. I thought I'd fixed this already, but not.

here's the right one, for sure:

Dutch floating houses.

awaylaughingonafastcamel said...

I've seen Ganvie firsthand, and it's intrigueing but offputting. The village is definitely in it for the money, and also really resents tourists, yelling things like "whore" at us in French. Children offered to let us take pictures fo them naked for a fee, so it would looke more "native". If you want an example of great sustainability, environmental concern and poverty reduction, check out the Centre Songhai in Porto-Novo.
~Delia

skanky said...

"Right now, they are *researching* various kinds of materials to evaluate their suitability for manufacture, albedo raising, survivability and if need be, removability."

Have they looked into Fullerenes?

;)