From Virginia Tech something that makes you wonder about past storm intensity and the need to protect shorelines from storms coming from the sea. With all the hype surrounding “Superstorm Sandy”, it is interesting to see that 150 years ago, simple engineering made the storm less intense in this one area.
Long-forgotten seawall protected New Jersey homes from Hurricane Sandy’s powerful storm surges
Virginia Tech researchers say relic seawall came in handy for New Jersey town
Picture two residential beach communities on the New Jersey shore: Bay Head and Mantoloking, which sit side-by-side in Ocean County on a narrow barrier island that separates the Atlantic Ocean and Barnegat Bay.
Before Hurricane Sandy landed on Oct. 29, 2012, a motorist traveling north on Ocean Avenue would seamlessly travel through Mantoloking into Bay Head, noticing few changes in residential development, dunes, beaches, and shoreline.
The difference was hidden under the sand.
A forgotten, 1,260-meter seawall buried beneath the beach helped Bay Head weather Sandy’s record storm surges and large waves over multiple high tides, according to a team of engineers and geoscientists led by Jennifer L. Irish, an associate professor of civil and environmental engineering in the College of Engineering at Virginia Tech and an authority on storm surge, tsunami inundation, and erosion.
The stone structure dates back to 1882. Its reappearance surprised many area residents, underscoring the difficulties transient communities have in planning for future threats at their shores, the researchers said.
“It’s amazing that a seawall built nearly 150 years ago, naturally hidden under beach sands, and forgotten, should have a major positive effect under the conditions in which it was originally designed to perform,” said H. Richard Lane, program director in the National Science Foundation‘s (NSF) Division of Earth Sciences, which funded the research. “This finding should have major implications for planning, as sea level rises and storms increase in intensity in response to global warming.”
The discovery, now online in the journal Coastal Engineering and slated for the October print edition, illustrates the need for multi-levels of beach protection in oceanfront communities, the researchers said.
“Once we got there, we immediately saw the seawall,” Irish said. “The beach and dunes did their job to a certain point, then, the seawall took over, providing significant dampening of the waves. It was the difference between houses that were flooded in Bay Head and houses that were reduced to piles of rubble in Mantoloking.”
With recovery efforts under way and storms still circulating through the area, Irish and Robert Weiss, an assistant professor of geosciences in the College of Science at Virginia Tech, with Patrick Lynett, an associate professor of civil and environmental engineering at the University of Southern California, documented high water marks, damage, overwash, and breaches of the barrier island.
All oceanfront homes in the two boroughs were damaged, ranging from ground-floor flooding to complete destruction. As measured by water lines on the interior of homes, flooding was similar in both boroughs. The difference was the extent of the storm’s impact.
In Mantoloking, the entire dune almost vanished. Water washed over the barrier spit and opened three breaches of 165 meters, 59 meters, and 35 meters, where the land was swept away. In Bay Head, only the portion of the dune located seaward of the seawall was eroded and the section of dune behind the seawall received only minor local scouring.
Later, using Google Earth to evaluate aerial images taken two years before and immediately after Hurricane Sandy, the research team evaluated houses, labeling a structure with a different roofline as damaged, one that no longer sits on its foundation as destroyed, and the remaining houses as flooded.
The researchers classified 88 percent of the oceanfront homes in Bay Head as flooded, with just one oceanfront home destroyed. In Mantoloking, more than half of the oceanfront homes were classified as damaged or destroyed.
Despite the immense magnitude and duration of the storm, a relatively small coastal obstacle reduced potential wave loads by a factor of two and was the difference between widespread destruction and minor structural impacts, the researchers said.
“We have a great deal of compassion for the people who have had to endure the devastation of Hurricane Sandy in Bay Head and Mantoloking,” Irish said. “It will have little solace, but we are left with a clear, unintentional example of the need for multiple levels of defense that include hard structures and beach nourishment to protect coastal communities.”
This research was supported by the National Science Foundation via grant EAR-1312813.
Tech is really skunking UVA. But then they did not have the handicap of Mann.
What I want to know from the experts is this: will global warming lead to the same effect as below? Just askin. :-p
‘Damping’ versus ‘dampening’ –only editors make the distinction nowadays? –AGF
Sustained wind speeds measured at the surface define storm strength.
The recorded sustained surface wind speeds of Sandy were well below hurricane threshold.
@ur momisugly Alan the Brit says:
July 17, 2013 at 1:46 am Always remember, Murphy was an optimist.
Neat idea: Maybe government should stick to things like infrastructure instead of what size soda people are drinking
Galveston had a seawall,
Just to keep the water down,
But the high tide from the ocean,
Blew the water all over town,
— “Wasn’t that a mighty storm” – old blues tune
Must have been caused by climate change! /sarc
What is: cheap and abundant illegal alien labor for $50, alex?
“It’s amazing that a seawall built nearly 150 years ago, naturally hidden under beach sands, and forgotten, should have a major positive effect under the conditions in which it was originally designed to perform,” said H. Richard Lane, program director in the National Science Foundation‘s (NSF) Division of Earth Sciences, which funded the research. “This finding should have major implications for planning, as sea level rises and storms increase in intensity in response to global warming.”
This is pretty well gibberish. It is a surprise that the wall did what it was meant to do? That makes no sense. The conclusion is equally dim. If and when “sea level rises” or “storms increase,” the discovery that sea walls work has a “major” implication for planners? Gosh.
But- storms are NOT worse than before; the alarmist propaganda mill notwithstanding, as a matter of record.
Shouldn’t it be under water by now?
izen says:
July 17, 2013 at 5:41 am
1882 was one year when Tyndall gave Royal Institution lectures on heat, visible and invisible and water and air. Athough the discovery of the absorbative properties of CO2, the basis for the ‘greenhouse effect’, was actually measured a couple of decades earlier.
Unlike todays carbon clowns of climatism, John Tyndall was a true scientist. If he were alive today, he’d be profoundly shocked and saddened by what has been done to science by the Warmist Brotherhood. Indeed, he would almost certainly be in the “denier” camp.
The sea wall resembles ship ballast. The whole wall was probably free and just one family recycling ship ballast into a wall to protect private property. So the wise use of garbage is the answer to some of our biggest “problems”. Just think what we could do with all the sea cans that China sends us.
Yeah, Duster, that phrase, “It’s amazing … ,” was the ENTIRE article in a nutshell. (head shake).
That ANYONE (“scientist” or not) would publicly assert such a thing is what is amazing.
I mean, MAN ALIVE, it’s like that Dumb [Communist — a group I don’t MIND offending] Joke, where the man saws and saws and saws all day with his new saw, but, only managing to cut WAY less than the guaranteed cords per day, walks back into the hardware store to get his money back and, upon the store owner firing up the chain saw, gasps, “What’s that noise?! Or, to quote my scientist brother, ‘Amazing.’ ”
********************
“breakwater” — “bulkhead” — “rip-rap” — “sea wall” — NEVER heard it called a “groyne.” Never. And, unless an Australian comes to town, we never will, either (at least, not in this neck of the U.S.A. woods) LOL.
From Wikipedia,
A groyne (groin in the United States) is a rigid hydraulic structure built from an ocean shore (in coastal engineering) or from a bank (in rivers) that interrupts water flow and limits the movement of sediment. In the ocean, groynes create beaches, or avoid having them washed away by longshore drift. In a river, groynes prevent erosion and ice-jamming, which in turn aids navigation. Ocean groynes run generally perpendicular to the shore, extending from the upper foreshore or beach into the water.
A groyne creates and maintains a wide area of beach or sediment on its updrift side, and reduces erosion on the other. It is a physical barrier to stop sediment transport in the direction of longshore drift (also called longshore transport). This causes a build-up, which is often accompanied by accelerated erosion of the downdrift beach, which receives little or no sand from longshore drift (this is known as terminal groyne syndrome, as it occurs after the terminal groyne in a group of groynes).
We vacation almost every year at the Delaware shore. A couple of summers ago, I bought a book on the local history. The inlets up and down that coast had been violently relocated by hurricanes and tropical storms roughly every 50 years. That stopped when massive construction projects carved and cemented “permanent” inlets. The beach house we rent is on a section of beach that didn’t exist 100 years ago. A major storm relocated the river that flowed into the sound and silt then depositied to fill in the sound as the river found another outlet.
I wonder what climate scientists would have predicted for that beach back then?
Oh, fortunately, “climate scientists” didn’t exit back then, and the scientists that did study such issues weren’t so arrogant as to have tried to predict 100 years out. Of course, they had no NSF to encourage them in their false arrogance.
That seawall was most likely built by the NY&LB Railroad. Bay Head was and still is the southern terminus for that line (now NJ Transit operated); although at one time a spur ran down through Mantoloking to Seaside, it was not worth protecting as it only handled summer excursion traffic.
There is a similar wall at Sea Bright, further north near Sandy Hook. The railroad there is long gone, but the seawall has kept Sea Bright from being swept away on an almost decadal basis.
As for Sandy’s storm strength, winds were at or just below hurricane strength as it came ashore from near Atlantic City to New York harbor. Due to the large radius of the storm, winds, waves and tides had a long “fetch”. If I remember correctly, it also occurred within a day of a full moon (increased tide height). Winds at Belmar were a good steady (not gusts) 40mph from the east at 4 PM when the storm center was still about 200 miles offshore and 300 miles from Belmar.
Yes, them old guys did know a thing or two, especially about protecting their capital investment.
@ur momisugly Phillip Bradley — Never. You won’t catch ANY red-blooded American in these parts (along the west coast of Washington State) using that term in that context. No matter HOW MANY TIMES you post about it on WUWT. #[:)]
Thanks so much for sharing.
Dear Mr. Bradley,
Please forgive my misspelling your name!
Take care,
Janice
Shhhh! You are not supposed to mention historical things like this, the sheeple are supposed to forget common sense and accumulated knowledge from generation to generation. How else can the bureaucrats keep them properly herded? You’re gonna spoil a perfectly good meme here, that the Jersey shore is an innocent coast subject to unprecedented torture from human-corrupted seas.
You’ve heard of corporate welfare, welcome to coastal welfare. It is a key component of the AGW hoax. The leftists with exploit every possible angle of the weather to run up the red ink of public spending to collapse the entire system.
Here’s a Google map of where Hurricane ( aka Tropical Storm ) Sandy came ashore above Atlantic City and below Seaside Heights …
http://goo.gl/maps/q80X8
… click it to satellite view and scroll in to zoom and you will see a coastline that is woefully vulnerable to everything from storms to plain old rain. For extra bonus points have a look at the almost indestructible piers in Atlantic City versus the dilapidated shoddy junk up in Seaside where government handouts will be spent.
I wonder if Governor Krispy Kreme and President DingleBarry ever wondered how that coast became a narrow strip of barrier Islands in the first place? The locals choose to reside on the tattered remains of thousands of years of tidal weathering, radical sea-level rise and fierce winds, yet they expect the rest of the country to bail them out, literally. It’s like our very own little Maldives. How awesome.
Possibly; whatever the reason, modifications to the New Jersey Beach was big news in the late nineteenth and early twentieth century. People, especially in New York City and Philadelphia spent part or all of their summers down at the Jersey shore. A month at the shore was not uncommon.
New Jersey has a long coastline of beautiful yellow sand. Not as fine a sand as the sugar sand found along the Florida panhandle, but fine enough that the sand flowed readily, drained and dried easily and is pleasant to walk or lounge on. Rocks are almost always brought in by man. Like building those groynes (groins groynes whatever, I learned groyne). That bit is just for you Janice. ;> hearing people use the word groyne is similar to people requesting a John Hartford song and getting “Hey babe, you want to boogie?” (Don’t blame me if you go listen, you deserve it then.)
The railroad mentioned by Charlie and others ran regular trips bringing beachgoers to and from the beach. Any changes to ‘their’ beach was followed closely by beachgoers planning their next trip.
Whatever the reason; newspapers in Philadelphia, Atlantic City and New York probably kept up with the modifications. Atlantic City or the archives in Ocean County likely have copies of the original permits.
What is not likely, is that the wall was built as any type of true sea wall to protect residences. Whether as railroad grade, a strong possibility or just as beach erosion protection the wall is not high enough to be a true sea wall. The wall may have served to protect Bay Head from significant damage from Sandy, but I doubt that it would serve as such for a major hurricane.
For a side note; my family once had a great time collecting clams at Sandy Hook when I was young. There was a hurricane passing close off shore and the surf was dredging up lots of clams and flinging them on the beach. My Father took one look at the surf’s actions and went to ask the park ranger, came back and handed out buckets to us young clam collectors. Yes, we were the only crackpots on the beach and since the surf was way too rough for fun, well clam bakes are always wonderful.
bw said, on July 17, 2013 at 7:57 AM:
“Sustained wind speeds measured at the surface define storm strength. The recorded sustained surface wind speeds of Sandy were well below hurricane threshold.”
But what about all the hurricanes that are classified while they are over areas lacking surface instruments? That is why the National Hurricane Center often uses extrapolations from various non-surface means. And, especially in “Nor’Easter country”, worse still inland, the wind is very unsteady and sustained qualifying winds get spotty – despite lots of very impressive gusts.
Nevertheless, Sandy did achieve a “hurricane-qualifying” land-based wind measurement, somewhere on Long Island near NYC, at altitude above the surface higher than the official 10 meters but unlikely by much. While its worst sustained winds were over water, and in an unusual region of the hurricane – probably due to Sandy being *at least almost* more a Nor’Easter than a hurricane an hour or 2 before landfall.
Consider the wind speeds of the should-still-be-famous late October 1991 storm – that sucked in a hurricane, and degraded into a hurricane. But while it was biggest and worst, as a Nor’Easter, it was spectacularly bad – despite low presence of “hurricane-qualifying-sustained” winds.
While not disputing any of the history of the area, especially as cited by the locals, it is worth remembering that building isolated seawalls is not all it is cracked up to be. In fact, it can worsen erosion by deflecting the wave energy and the water to places either side of the seawall (which might be why the adjoining communities in this example fared much worse). Depending on the circumstances, it can also accelerate the loss of sand directly in front of the seawall, meaning that over time the wall itself is subjected to more and more battering and erosion from underneath, and can then collapse dramatically in a big storm leaving the land behind it more exposed than it would have been if the coastline had developed naturally over a period.
Coastlines are tricky things for humans to manage, especially in places subject to erosion, and the ‘solutions’ that seem intuitively correct can be counter-productive
Janice Moore says:
July 17, 2013 at 3:56 pm
I don’t know what the etymology of groyne or groin is for any definition, but IIRC the various definitions of the terms you mention are:
breakwater
A structure parallel to the coast (and with legs connecting to the coast) designed to block waves from the coast. Typically used to create calm water ports.
bulkhead
I’ve only heard this in ship design, not coastal construction. Hmm, maybe as the wall along a channel.
rip-rap
Like a seawall, but generally just large rocks or concrete pieces dumped along a shoreline to stop erosion.
sea wall
Like rip-rap, but done with design and care, and it often concrete poured in place.
On the other hand, a groin is perpendicular to the coast and is designed to impede the littoral transport of sand and other sediments along the coast. They risk causing some erosion next to the groin where the sand supply is blocked.
I don’t have much experience along the west coast except in the rocky areas, so I don’t recall seeing groins there. They’re common along the east coast.
@Ric Werme – A jetty. At least from your description, that is what we call them. Basically a line of a pile of rocks to prevent the beach from moving up or down the coast.
Yes, Phil Jourdan, that’s what we call them out here, too.