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.