The Golden Gate Barrage: New Ideas To Counter Sea Level Rise 341
waderoush writes "What do Google, Facebook, Yahoo, Oracle, LinkedIn, and Intuit have in common? They're just a few of the tech companies whose campuses alongside San Francisco Bay could be underwater by mid-century as sea levels rise. It's time for these organizations and other innovators to put some of their fabled brainpower into coming up with new ideas to counter the threat, Xconomy argues today. One idea: the Golden Gate Barrage, a massive system of dams, locks, and pumps located in the shadow of the iconic bridge. Taller than the Three Gorges Dam in China, it would be one of the largest and costliest projects in the history of civil engineering. But at least one Bay Area government official says might turn out to be the simplest way to save hundreds of square miles of land around the bay from inundation."
Amazing (Score:5, Informative)
According to NOAA, the actual average sea level rise over the last 100 years has been about 2 MILLIMETERS per year, or 200mm/century, or about 8 inches per 100 years. Here's the official data http://tidesandcurrents.noaa.gov/sltrends/sltrends_station.shtml?stnid=9414290. If you look at the chart you'll see that the trend has actually dropped to about zero mm / year for the last 30 years.
So, in light of this, we need the biggest engineering project in history?
Re:Or... (Score:5, Informative)
You are aware, I trust, that it is rising.
http://oceanservice.noaa.gov/facts/sealevel.html [noaa.gov]
It's more pronounced in some areas than others, but still, it's rising. So if you live in a low-lying coastal area, then this ought to be of concern to you.
Re:Or... (Score:4, Informative)
Re:Or... (Score:5, Informative)
Why is it more pronounced in some areas?
Because the ocean isn't perfectly even. Tidal forces, wind and waves, currents, plate activity, volcanoes, it's constantly flowing every which way. I'd be surprised if the sea level rose exactly the same amount in Oahu and Cardiff.
Re:Or... (Score:0, Informative)
Because the ocean isn't perfectly even. Tidal forces, wind and waves, currents, plate activity, volcanoes, it's constantly flowing every which way. I'd be surprised if the sea level rose exactly the same amount in Oahu and Cardiff.
Strictly speaking, if the ocean is constantly moving then you can't actually measure if it's rising or falling. Because it would need to stop moving to measure it.
Re:Or... (Score:2, Informative)
The reference quoted also shows that the US production of atmospheric CO2 is roughly flat over the years from 2008 through 2011 while China's has been steadily increasing. In 2011 according to that data, China was producing something like 55% MORE than the USA.
I know it is fashionable to bash the USA and it is a fun sport, but every now and again it may pay to take off the tinfoil hat and look at real data.
Re:Or... (Score:5, Informative)
> when and if sea level actually starts to rise... we'll talk
Water level measurements from the San Francisco gage (CA Station ID: 9414290) indicate that mean sea level rose by an average of 2.01 millimeters (mm) per year from 1897 to 2006, equivalent to a change of eight inches in the last century. The rate of rise has increased to about 3 mm per year over the past 15 years.
This is the oldest tidal guage in continuous operation in the United States, and is located near the Golden Gate.
http://www.energy.ca.gov/2012publications/CEC-500-2012-014/CEC-500-2012-014.pdf [ca.gov]
Re:Or... (Score:5, Informative)
Essentially your starting point is inherently invalid: a rise in the Pacific Ocean wont necessary result in a raise of all the other oceans. As pointed out, already the Pacific Ocean is higher than the Atlantic. This is most easily seen at the Panama Canal, where there's only 50 miles of seperation, yet a 30 foot difference in elevation (which when talking about oceans, is a HUGE difference in volume). You'd think there would be flow around the continents to even out the sea levels, but thats ignoring how the difference came to be int eh first place. The difference is created and maintained by the thermohaline circulation of the ocean.
Simiarly tides aren't uniform around the world. Some places the tidal range is less than a foot. Other's its >30 feet. The record is 53 feet, located somewhere in Nova Scotia (i think). Local geography (water basin shape/size) and local gravity distortions (mountains/valleys) all have an effect on tides.
Water flows. Changes in water level aren't instantaneous. Even ignoring any of the internal currents, tides, geography (that would affect flow rates), and the thermohaline circulation inherent in the ocean and assuming the ocean has a prismatic uniformity of nature, the ocean is so large that even small changes in sea level would take a long time to propogate worldwide. And as point out, some differences in sea level wont propagate.
And of course the ocean ISNT uniform in nature. its very dynamic, precisely because of its large size. the thermohaline circulation has a lot to do with why the ocean doesnt have a uniformity of elevation worldwide, and is probably similarly responsible for the most different rates/amounts of local sea level rise. then there's still the tides and such as well on top of that.