Sea level rate of change

This seems more than a little odd to me:

"U.S. Geological Survey scientists call the 600-mile swath a “hot spot”
for climbing sea levels caused by global warming. Along the region,
the Atlantic Ocean is rising at an annual rate three times to four times
faster than the global average since 1990, according to the study
published Sunday in the journal Nature Climate Change."

Why would the sea level be higher in N. carolina than the other East
Coast states lying to the north and south?
Does the ocean's surface inexplicably pile up into a hump there?
Is that even possible?

One posssibility: Could it be that the coast of N. Carolina is subsiding,
sinking?

Ok, but why?

As a knee-jerk response, I'd blame it on all the tourists that flock to
the Outer Banks each summer. There's millions of 'em and even at,
let's say an average of 200 lbs each -- includes beach gear, food, beer,
etc -- that adds up. An we've not yet added in the all too numerous
monstrosity-class SUVs that brought them there.

 

This is another example of low-tech and high-tech coming together in useful ways. Nothing more low-tech than reading a tide guage for oh, 100 years or so. Nothing more high-tech than GRACE and GPS satellites revealing vertical crust motions. The North Atlantic gyre is a great example of how sea level is not the same everywhere (Topex Poseidon satellite I think), which is counter-intuitive to what we can observe with our eyes.

Put 'em together and you can (finally) make useful local predictions within the 1-meter range which is so important, as we have bunched up human poulations and infrastructure on the world's coasts.

I don't think Sallenger et al. would have written the Washington Post title though, as they did not examine 'the rest of the world'. Communicating science to the public at large remains a challenge

The legislature of the Commonwealth of Virgnia is legislating how sea-level changes should be extrapolated, so I hope that some of them find time to read Sallenger et al.

 

Also, Nature Climate Change is a new subsidiary journal to Nature, and is well worth watching for those interested. Many (not all) of their articles are free to download. For the others, the Great Paywall still exists, but it is porous. You can always email the authors for a pdf.

For a different view of NCC, visit Judith Curry's website where she bemoans the type of papers getting published there. By all means read widely as you decide how to assess any particular piece of evidence. This field is moving very fast, and I doubt if anyone will be well served by getting their information Nth hand from affinity websites.

Including PriusChat. You have been warned

 

Fascinating, never would have thought such variations were possible. Thanks for the information and links guys!

 

Tectonic issues are one reason why the effective sea level rise for California is faster than here in Washington and Oregon. That was news here recently, but is also noted in the linked WP article.

Not noted in the WP piece is that a single subduction zone quake could drop our coast several feet in just a minute. It has happened numerous times before, most recently January 26, 1700.

 

The north part of North Carolina is subsiding, the south part is rising. This has to do with plate movements, and AFAIK has nothing to do with AGW. If someone claims the east coast is sinking faster than the rest of the world because of ghg, ask them to explain how. If they have any scientific understanding, they will quickly realise it has nothing to do with ghg.

Norfolk would have had rising sea levels even with no melting ice caps.​

What makes sea level rise uneven

AGW isn't singling out the area, there are other reasons why some places have sea levels rise more than others or actually fall. GHG are causing the sea levels to rise faster though, and the areas at risk are not random.

 

Its from NOAA, but don't remember exactly where I read it. Certainly if you still don't belive me after reading the rest, I will find a scholarly paper.

I think you are confusing what I am saying. Sea levels have been rising since the last ice age, and this is true with or without human contributions. The rise is uneven though, with some places rising faster than others. Again this pattern has little to do with human contribution except in places where large quantities of ice are melting. Its not the ghg that cause the differences it is plate teutonics and gravitational pull. In the case of NC it is mainly plate teutonics, with additional effects of sediment moving down rivers. Other places ocean currents make an impact.

Now if these other factors were not involved than their would be a uniform rise in sea level at the same lattitude, something the authors expressly say is not happening.

Fear not bob, ghg do have something to do here though. They are accelerating the ice melt, and therefore the sea level rise. But this is uneven, we can not simply estimate global sea level rise and apply it to local conditions. This is why the authors measured the real rates, instead of calculating a rate simply based on ice melts. Collecting data is important, sea levels actually fell in 2010 because of unusual rainfall patterns. A 1 meter rise in global sea level may be a much larger rise in say Norfolk where other factors are involved. EPA has done an estimated map of areas at risk, and this should be perhaps updated every 5 years based on observational data.

 

There are a combination of factors, but for the east coast -
http://ccrm.vims.edu/cara_web/case%20studies_files/SEA%20COAST%20AND%20SEA%20LEVEL%20TRENDS%203.pdf

 

In case anyone missed it the last time I linked

Fileost-Glacial Sea Level.png - Wikipedia, the free encyclopedia

The big sea-level rise for the current interglacial was meltwater pulse 1A, averaging 30 cm/year. It occurred at a time when there was a whole lot of grounded ice was 'going down'. We could not approach that rate now; we haven't the ice.

Over the last 4000 years, average about 0.5 mm/year. Currently about 3 mm/year. Could this quadruple in a (warmer) 21st century? I have already suggested reading Drs. Church and White about that.

On regional scales, isostatic rebound is an important factor ...where it is important. On local scales the Tohoku earthquke caused more than a meter of subsidence here & there. Locally 2.4 meters in Alaska (1964). 1700 in Cascadia, up to 3 meters.

On a local scale, geology can trump icemelt. It's not even close. Yet, people live in Seattle and many other high-risk areas. Human behavior may eventually converge on 'rational', but we are not quite there yet

 

Clearly he was wrong about temp effects of CO2,as we know the CO2 effect is logarithmic.
Lets hope hes correct about forestalling an ice age,but we will soon witness that he was wrong about that as well.As the Earth will soon begin a "Little Ice Age" cooling period.
Im not going into what else he was was wrong about,but imagine if he were an AGW skeptic ,the believers would have a field day building strawmen.

"Arrhenius estimated that halving of CO2 would decrease temperatures by 4–5 °C (Celsius) and a doubling of CO2 would cause a temperature rise of 5–6 °C."

 

I am going to proceed solely on trust, that many of our readers understand a bit better the relationship between doubling and logarithms. A bit from wiki might make it clear. Or not

"In its original form, Arrhenius' greenhouse law reads as follows:
if the quantity of carbonic acid increases in geometric progression, the augmentation of the temperature will increase nearly in arithmetic progression.
This simplified expression is still used today:
ΔF = α ln(C/)
"
If you have anything esle that you're (equally) sure he was wrong about, well then I suppose we'll need to go through them singly.
That urgently arriving ice age (as predicted by iceagenow web site, don't miss it) Is going to blow right through the radiative forcing of 395 ppm of CO2?

That would defintely be a 'sit up and take notice' kind of a thing. Two weak solar cycles back to back (circa 1900, I posted before) didn't ice us, and that was with but 280 (ish) ppm CO2. This time it's going to be different though. Web sites say so.

+++

But back to the sea leveling, the National Academies Press put up their centenial assessment for the US west coast Friday. Somehow I missed the memo

Sea-Level Rise for the Coasts of California, Oregon, and Washington: Past, Present, and Future

Read all about it. Subsidence focused on the Cascadia subduction zone (home of the 1700 quake) is supposed to be a larger factor than melting or sterics (thermal expansion of sea water). It rounds out the east-coast discussions that we had been having.

 

Its definitely not my area of expertise, perhaps someone with more experience can chime in. The place that the north american plate is subducting is the Puerto Rico Trench far away. I assumed that those writing about this land mass subducting are talking about minor movements on the plate, not active regions.

If there is better language to discuss changes to the land mass let me know.

 

hmmm, just saw a video with a guy claiming that even if we stopped all GHG emissions right now, it would take the Earth 20 years or more to stabilize. iow, we probably already should plan to move