Thursday, February 24, 2011

Science as She Should Be Reported

So Eli was going to work this morning and listening to the morning news on WAMU when the ears perked up, something on sea level rise and land subsidence in the Chesapeake Bay region.

For those who don't know both the Bay and the barrier islands on the Atlantic are low lying. The southern part of the Bay is the Hampton Roads area, ending in Norfolk, which already has flooding issues.

The report was prepared by Sabri Ben-Achour for WAMU

And you know, it was good. Facts, caveats, uncertainties and a clear bottom line, worth a listen. First the hook

Towns are starting to see the effects and they're bracing for it. But there's more than just climate change behind the rising tide.

The beach in Ocean City is a major tourist draw, it stretches hundreds of feet from the board walk, with giant dunes studded with grasses a little farther south.

This beach would probably not be here right now if it weren't for the fact that tons of sand are brought in every few years to replenish it, especially after major storms.

"Beach replenishment serves as storm protection for the town of Ocean City. It's the equivalent of the levees in New Orleans for us," says Terry McGean, the Ocean City beach engineer. "They dredge sand from a couple miles offshore, and we pump that material onto the beach and basically bring the beach back."

Then the statement of the problem

Storms and erosion aren't new, but there's something else going on here, that's making every storm a little more serious: Tidal gauges here have measured an increase in sea level. It's gone up seven inches over 30 years -- that's 5.5 millimeters per year, and almost two feet per century.

Followed by a clear, and accurate discussion which is both simple and correct

Dr. John Boon, a professor emeritus with the Virginia Institute of Marine Science, says the sea level is rising throughout this region, and some parts have it particularly bad.

"We have relative sea-level rise rates that are the highest on the U.S. East Coast," he says.

You may wonder why or how sea level rise might be any different here versus anywhere else.

"The ocean circulation moves water masses to different parts of the globe, and gravity changes as ice masses at the polar regions melt, there's differential heating in the oceans," Boon says.

But in our region there's an extra factor: The ground is sinking. It's called "subsidence," and Boon says it's been going on for a while now.

"Ninety-thousand years ago, we had a very large ice mass to the north of us, an ice sheet of almost a mile thick. This placed a great load over the earth's surface up there, and in adjustment to that we had what is called a glacial forebulge," he says.

It's somewhat like stepping into a mud puddle.

"You notice around your foot where it sinks in there's a little bit of a bulge that arises...The land is the same way," Boon says.

Ah, you ask, where is sea level rise driven by climate change. Well bunnies you could listen to the mp3 OR you could read the rest at the link.

And then, on top of all of that, we have sea-level rise caused by global warming -- something that many scientists expect will accelerate here.

The National Oceanic and Atmospheric Administration predicts sea level could rise in our region by as much as three feet over the next century. But the combination of all the different factors means the water is already rising everywhere in this region, and certain areas are seeing it more than others.

"People have noticed it with their piers and certainly...with storms over the last decade," says John Carlocke, a city planner for Hampton Roads, Va.


n-g said...

Help! The audio starts automatically!

Part 2 might consider why nobody needed to replenish the beaches in the 19th century. Hint: it's not just climate change.

EliRabett said...

That is not a bug, it is a feature. Will turn it off tomorrow, but Eli wanted that others listen first.

EliRabett said...

Oh yeah, you should have heard the loon the last time there was audio on RR.

Anonymous said...

For those who don't know both the Bay and the barrier islands on the Atlantic are low lying. The southern part of the Bay is the Hampton Roads area, ending in Norfolk, which already has flooding issues.

The whole U. S. Gulf Coast is likewise threatened. Foolish, doomed defensive measures are in progress. Here are pictures of a $13M project attempting to make barrier Dauphin Island, AL whole again:

A lot of rich folks own property on the orphaned west end of the island, which explains how this hopeless boondoggle got funded.

-Adam R.

Sloop said...

Rhode Island has established a policy in its coastal zone management plan to anticipate and respond accordingly to a 3-5 foot rise in sea level along its coast by 2100; one of the first such CZM policies in the country. We'll be reviewing the relevant sciences periodically to see if that policy will require updating. Rule-making to implement the policy has been difficult to push through due to building community resistance but state building code minimum freeboard requirements have been increased. Transportation infrastructure and utilities along the shore being impacted already

Snapple said...

I like your blog. Here are some articles on climate change Medill did. One article discusses how some naval bases are affected. This is a great series.

These young people are doing a better job than the old folks, if you ask me.




Anybody seen the London play?

John said...

The sea-level rise and resulting flooding in Norfolk Virginia was the subject of an article in the a New York Times last November
which was promptly reported on Rabbet run.

Flavius Collium said...

Awesome! Also good that it starts automatically and the voice of the engineer is great.

Have you noticed the Anonymous vs Koch brothers thing yet? Might be a spoof...

David B. Benson said...

Science is a she?

EliRabett said...

Ask Ms. Rabett.

Douglas Watts said...

Maine, which unlike the Chesapeake, was fully glaciated, is showing contemporary increases in sea level which would appear to be unrelated to subsidence.

See Belknap, Kelley and Dickson:

"Figure 7 is the tide gauge record for Portland, Maine. Although there are annual and decadal variations in mean tide level, there is an obvious general trend of increase, at a rate of 2.2 mm/yr (0.09 in/yr), from 1930 through 1992. Note that this rate is more than 10 times that the rate at 4000 BP, and 100 times the rate at 1000 BP."

Anonymous said...

That was very nice indeed. I use Ocean City Beach renourishment as part of my class on beach equilibrium including
Aerial survey

Anonymous said...

Here's a related and equally fine idea: The Journal of Universal Rejection.

"The founding principle of the Journal of Universal Rejection (JofUR) is rejection. Universal rejection. That is to say, all submissions, regardless of quality, will be rejected. Despite that apparent drawback, here are a number of reasons you may choose to submit to the JofUR:

- You can send your manuscript here without suffering waves of anxiety regarding the eventual fate of your submission. You know with 100% certainty that it will not be accepted for publication.
- There are no page-fees.
You may claim to have submitted to the most prestigious journal (judged by acceptance rate).
- The JofUR is one-of-a-kind. Merely submitting work to it may be considered a badge of honor.
- You retain complete rights to your work, and are free to resubmit to other journals even before our review process is complete.
- Decisions are often (though not always) rendered within hours of submission."

L. Hamilton

Anonymous said...

Sorry, post above was meant to go with the new journals thread. Possible to move?

L. Hamilton

Aaron said...

Three to five feet of sea level rise in this century? Does that include heat absorbtion and transfer to GLIS by an ice free Arctic Ocean and a new atmospheric circulation? Does it include ice dynamics? These are known issues. We should not use numbers that do not include known issues and factors without some sort of a caveat.