Ocean acidifcation .

[Exile]

Originally Posted by newhaul

at least he admits that the east coast is subsiding . 99% of the MMGWC won't admit it .
So good on Mr fair .

I thought 'subsiding' was being used in the more generic/lay sense.

The 'official' position doesn't mention it, only melting ice & seawater expansion from warming. But that's only ~3" (averaged globally) from the early 90s thus far based on sat measurements, so the dramatic intro photo (from Hilton Head, SC I think) along with much of the vid, is misleadingly alarmist. Future projections based on models, of course, are much higher.

https://climate.nasa.gov/vital-signs/sea-level/

[newhaul]

Originally Posted by Exile

I thought 'subsiding' was being used in the more generic/lay sense.

The 'official' position doesn't mention it, only melting ice & seawater expansion from warming. But that's only ~3" (averaged globally) from the early 90s thus far based on sat measurements, so the dramatic intro photo (from Hilton Head, SC I think) along with much of the vid, is misleadingly alarmist. Future projections based on models, of course, are much higher.

https://climate.nasa.gov/vital-signs/sea-level/

he was in sure saying it in a very generic way , however it is actually a lot bigger deal than they want us to know or believe.

New research using GPS and prehistoric data has shown that nearly the entire coast is affected, from Massachusetts to Florida and parts of Maine

From this article.

https://www.scientificamerican.com/a...y-rising-seas/

[Exile]

Originally Posted by newhaul

he was in sure saying it in a very generic way , however it is actually a lot bigger deal than they want us to know or believe.

New research using GPS and prehistoric data has shown that nearly the entire coast is affected, from Massachusetts to Florida and parts of Maine

From this article.

https://www.scientificamerican.com/a...y-rising-seas/

Informative article, despite its infusions of subtle and not-so-subtle bias. But certainly not as bad as most we see. On the upside, this is the first I've seen acknowledging land subsidence with such specificity. But I'm not surprised . . . .

If I'm reading it correctly, the article cites 3.5" per decade seawater rise overall along much of the US e. coast, with 2.5" attributed to land subsidence (and ground water pumping in areas), and 1" to sea level rise. So a combo of natural & human-caused forces, along with dire predictions from AGW, of course, in the future.

But perhaps a refreshingly more rational perspective:

“'The citizens of Hyde County have dealt with flooding issues since the incorporation of Hyde County in 1712,' said Kris Noble, the county’s planning and economic development director. 'It’s just one of the things we deal with.'”

[GordMay]

It's deplorable how subsidence has been totally ignored by the popular and scientific press.
Of course, excepting modifying our water/gas extraction activities, I don't suppose there's much we can do about it.

“Sinking Atlantic Coastline Meets Rapidly Rising Seas” ~ by John Upton
➥ https://www.scientificamerican.com/a...y-rising-seas/

“Subsidence along the Atlantic Coast of North America: Insights from GPS and late Holocene relative sea level data” ~ by Makan A. Karega et al.
➥ https://agupubs.onlinelibrary.wiley....2/2016GL068015

“Land Subsidence and Relative Sea-Level Rise in the Southern Chesapeake Bay Region” ~ by Jack Eggleston and Jason Pope (U.S. Geological Survey)
➥ https://pubs.usgs.gov/circ/1392/pdf/circ1392.pdf

“Encroaching Tides: How Sea Level Rise and Tidal Flooding Threaten US East and Gulf Coast Communities over the Next 30 Years (2014)” ~ by Erika Spanger-Siegfried et al (for the Union of Concerned Scientists)
➥ https://www.ucsusa.org/sites/default...ull-report.pdf

“Origin of spatial variation in US East Coast sea-level trends during 1900–2017" ~ by Christopher G. Piecuch et al.
➥ https://www.nature.com/articles/s41586-018-0787-6

“Nuisance Flooding and Relative Sea-Level Rise: the Importance of Present-Day Land Motion” ~ by Makan A. Karegar et al.
➥ https://www.nature.com/articles/s41598-017-11544-y

“Sea-Level Rise & the State of Sinking: A Brief Discussion of Land Subsidence Factors in the US “ ~ by Laura Schifman
➥ https://envirobites.org/2018/12/03/s...ors-in-the-us/

“Global Risks and Research Priorities for Coastal Subsidence” ~ by Mead Allison et al.
➥ https://eos.org/features/global-risk...tal-subsidence

“Coastal Subsidence” ~ by Zhongyuan Chen, and John Rybczyk
➥ https://link.springer.com/referencew...4020-3880-1_86

“The case for dynamic subsidence of the U.S. east coast since the Eocene” ~ by Sonja Spasojevic ́ et al.
➥ https://authors.library.caltech.edu/...ojevic2008.pdf

“Coastal Subsidence along Eastern seaboard and Gulf of Mexico” ~ by Timothy H. Dixon et al.
➥ https://www.gps.gov/cgsic/meetings/2015/dixon.pdf

[newhaul]

Originally Posted by GordMay

It's deplorable how subsidence has been totally ignored by the popular and scientific press.
Of course, excepting modifying our water/gas extraction activities, I don't suppose there's much we can do about it.

“Sinking Atlantic Coastline Meets Rapidly Rising Seas” ~ by John Upton
➥ https://www.scientificamerican.com/a...y-rising-seas/

“Subsidence along the Atlantic Coast of North America: Insights from GPS and late Holocene relative sea level data” ~ by Makan A. Karega et al.
➥ https://agupubs.onlinelibrary.wiley....2/2016GL068015

“Land Subsidence and Relative Sea-Level Rise in the Southern Chesapeake Bay Region” ~ by Jack Eggleston and Jason Pope (U.S. Geological Survey)
➥ https://pubs.usgs.gov/circ/1392/pdf/circ1392.pdf

“Encroaching Tides: How Sea Level Rise and Tidal Flooding Threaten US East and Gulf Coast Communities over the Next 30 Years (2014)” ~ by Erika Spanger-Siegfried et al (for the Union of Concerned Scientists)
➥ https://www.ucsusa.org/sites/default...ull-report.pdf

“Origin of spatial variation in US East Coast sea-level trends during 1900–2017" ~ by Christopher G. Piecuch et al.
➥ https://www.nature.com/articles/s41586-018-0787-6

“Nuisance Flooding and Relative Sea-Level Rise: the Importance of Present-Day Land Motion” ~ by Makan A. Karegar et al.
➥ https://www.nature.com/articles/s41598-017-11544-y

“Sea-Level Rise & the State of Sinking: A Brief Discussion of Land Subsidence Factors in the US “ ~ by Laura Schifman
➥ https://envirobites.org/2018/12/03/s...ors-in-the-us/

“Global Risks and Research Priorities for Coastal Subsidence” ~ by Mead Allison et al.
➥ https://eos.org/features/global-risk...tal-subsidence

“Coastal Subsidence” ~ by Zhongyuan Chen, and John Rybczyk
➥ https://link.springer.com/referencew...4020-3880-1_86

“The case for dynamic subsidence of the U.S. east coast since the Eocene” ~ by Sonja Spasojevic ́ et al.
➥ https://authors.library.caltech.edu/...ojevic2008.pdf

“Coastal Subsidence along Eastern seaboard and Gulf of Mexico” ~ by Timothy H. Dixon et al.
➥ https://www.gps.gov/cgsic/meetings/2015/dixon.pdf

I keep saying it and jack keeps saying I'm wrong
Isotastic rebound effects .
a sea saw .
Thank you Gord for all the links . Another piece of the puzzle is found .

[jackdale]

Originally Posted by newhaul

I keep saying it and jack keeps saying I'm wrong
Isotastic rebound effects .
a sea saw .
Thank you Gord for all the links . Another piece of the puzzle is found .

Subsidence and isostatic rebound are opposites . and Flroda is not on athe North American craton.

isostatic rebound
Isostatic rebound (also called continental rebound, post-glacial rebound or isostatic adjustment) is the rise of land masses that were depressed by the huge weight of ice sheets during the last ice age

https://gsa.confex.com/gsa/2012AM/we...per212853.html

[Exile]

Originally Posted by GordMay

It's deplorable how subsidence has been totally ignored by the popular and scientific press.
Of course, excepting modifying our water/gas extraction activities, I don't suppose there's much we can do about it.

* * *

Maybe not ignored in the scientific press, but probably fair to say it largely is in the popular press. And rarely mentioned in these threads, at least to the level of actual measurements we read in the Scientific American article.

Is there evidence that natural gas extraction also contributes, or just ground water?

[GordMay]

Originally Posted by newhaul

I keep saying it and jack keeps saying I'm wrong
Isotastic rebound effects ...

And wrong you remain.

Originally Posted by Exile

... Is there evidence that natural gas extraction also contributes, or just ground water?

Yes, it's well understood that gas/oil extraction also contributes to subsidence.

I would guess that gas extraction related sinking occurs mostly in the continental interior, where it may have little-to-no direct effect on apparent temporal sea level. (I haven't studied this.)

Forbulge collapse (waterbed effect) is one of the larger causes of land sinking, such as around the Chesapeake Bay area.
The correction for Glacial Isostatic Adjustment (GIA) accounts for the fact that the ocean basins are getting slightly larger, since the end of the last glacial cycle. GIA is not caused by current glacier melt, but by the rebound of the Earth from the several kilometer thick ice sheets that covered much of North America and Europe around 20,000 years ago. Mantle material is still moving from under the oceans into previously glaciated regions on land.
The effect is that currently some land surfaces are rising, and some ocean bottoms are falling, relative to the center of the Earth (the center of the reference frame of the satellite altimeter). Averaged over the global ocean surface, the mean rate of sea level change due to GIA is independently estimated from models at -0.3 mm/year. The magnitude of this correction is small.
However, since the ocean basins are getting larger, due to GIA, this will reduce by a very small amount the relative sea level rise that is seen along the coasts.
Glacial Isostatic Adjustment (GIA) is a complex field of study (and studied it is - but not by me), so I like to let the experts explain it - including how it is accounted for in determining Global Mean Sea Level (GMSL).

[newhaul]

Originally Posted by GordMay

And wrong you remain.


Yes, it's well understood that gas/oil extraction also contributes to subsidence.

I would guess that gas extraction related sinking occurs mostly in the continental interior, where it may have little-to-no direct effect on apparent temporal sea level. (I haven't studied this.)

Forbulge collapse (waterbed effect) is one of the larger causes of land sinking, such as around the Chesapeake Bay area.
The correction for Glacial Isostatic Adjustment (GIA) accounts for the fact that the ocean basins are getting slightly larger, since the end of the last glacial cycle. GIA is not caused by current glacier melt, but by the rebound of the Earth from the several kilometer thick ice sheets that covered much of North America and Europe around 20,000 years ago. Mantle material is still moving from under the oceans into previously glaciated regions on land.
The effect is that currently some land surfaces are rising, and some ocean bottoms are falling, relative to the center of the Earth (the center of the reference frame of the satellite altimeter). Averaged over the global ocean surface, the mean rate of sea level change due to GIA is independently estimated from models at -0.3 mm/year. The magnitude of this correction is small.
However, since the ocean basins are getting larger, due to GIA, this will reduce by a very small amount the relative sea level rise that is seen along the coasts.
Glacial Isostatic Adjustment (GIA) is a complex field of study (and studied it is - but not by me), so I like to let the experts explain it - including how it is accounted for in determining Global Mean Sea Level (GMSL).

fine glacial isotastic adjustment. Same same

[newhaul]

Originally Posted by jackdale

Subsidence and isostatic rebound are opposites . and Flroda is not on athe North American craton.



https://gsa.confex.com/gsa/2012AM/we...per212853.html

actually jack they are the same one rises one has to fall its all the same thing.

You really need to update your database 2012 the paper I posted is a lot newer and not as influenced by the MMGWC

[GordMay]

A few key concepts illustrate how measuring sea level is pretty complex:

The ocean level is not uniform across the planet.
The Earth is not perfectly spherical, but an ellipsoid, due to its spin. This means that the Earth is “fatter” at the equator and slightly flattened at the poles, so that: if you thought Earth were a sphere and defined sea level by standing on the sea ice at the north pole, then the surface of the ocean at the equator would be about 21km above sea level.
Differential density of the interior of the Earth so that gravity is slightly stronger or weaker at different points around the globe, and the oceans tend to "puddle" more nearer to the dense spots.
The mass of the continental plates creates a greater gravitational pull on ocean water, than the ocean basin, so that mass gravitationally attracts oceans, while valleys in the ocean floor have less mass and the oceans flow away, shallower.
These factors, together with geographic variations of continents and submerged terrains, climate systems, water volume, tectonics, etc., the surface of the ocean, and hence sea level, change on various time scales, ranging from minutes to millennia.
Therefore, it is a challenge to determine the exact sea level of the Earth, but it is done.

Sea level can have several definitions:
Global Sea Level - the average height of the Earth's oceans combined (relative to the Earth's center). Influenced primarily by the factors that influence the volume of seawater, and size of ocean basins, etc. Often referred to as "Eustatic Sea Level"
Local (or regional) Sea Level - the height of seawater relative to a fixed point on land that is used as a continuous reference. Influenced by meteorological factors, tidal range, ocean currents, rates of subsidence/uplift. Also referred to a "Relative Sea Level"
Mean Sea Level (MSL) - the average height of seawater relative to a fixed datum established by a statistical average of water heights over a period of time. This is the most functional definition for sea level because it helps establish the elevation of all points on Earth (topographic elevation, and bathymetric elevation). In the U.S., MSL is often reported relative to the 1983-2001 NTDE (National Tidal Datum Epoch)(updated from the 1960-1978) . Tidal datums (generally a 19-year cycle) need to be updated every couple of decades because sea level is not stable, and a new datum is likely to be announced soon. (considered for revision every 20-25 years, so we’re overdue).

Sea level, with respect to a fixed nearby point on land, is often measured locally by tide gauges (and averaged over tidal cycles) that detect high and low points in a given period of time.
With the advent of satellite altimetry in the 1960s, measurements of the sea surface around the globe took on a whole new level of accuracy. These measurements utilize multi-beam methods that are very precise and can measure changes in elevation on the Earth's surface to great precision in the range of centimeters. Satellite altimetry data collection began in earnest with the launch in 1992 of the TOPEX/Poseidon joint satellite mission between NASA and CNES, the French space agency.

Right now, sea level is (& has been) rising, due to greater volume of water (terrestrial glacier melt), and steric contribution (thermal expansion - warmer water expands).

Combined tide-gauge and satellite altimetry data indicate that average global sea level rose by around 20 centimetres between 1880 and 2014. There was an increase in average global sea level of around 3 millimetres a year during the 20th century.

Since the 1970s, ocean thermal expansion has contributed around 40 per cent of the observed rise, with a similar amount from glaciers and ice sheets. Between 1993 and 2014, Greenland’s contribution increased from 5 per cent to 25 per cent of total sea-level change. The ice sheets stand to make a much more significant contribution in the future. Extraction of groundwater, which eventually ends up in the oceans after its use on land, also makes a small contribution of around 5 per cent.


Or perhaps, as newhaul would have us believe, all the land is sinking, so it just appears that the seas are rising. Oh, and the AGW conspirators must be fudging the sat. altimetry data.

[Exile]

Originally Posted by GordMay

* * *

Right now, sea level is (& has been) rising, due to greater volume of water (terrestrial glacier melt), and steric contribution (thermal expansion - warmer water expands).

Combined tide-gauge and satellite altimetry data indicate that average global sea level rose by around 20 centimetres between 1880 and 2014. There was an increase in average global sea level of around 3 millimetres a year during the 20th century.

Since the 1970s, ocean thermal expansion has contributed around 40 per cent of the observed rise, with a similar amount from glaciers and ice sheets. Between 1993 and 2014, Greenland’s contribution increased from 5 per cent to 25 per cent of total sea-level change. The ice sheets stand to make a much more significant contribution in the future. Extraction of groundwater, which eventually ends up in the oceans after its use on land, also makes a small contribution of around 5 per cent.

Or perhaps, as newhaul would have us believe, all the land is sinking, so it just appears that the seas are rising. Oh, and the AGW conspirators must be fudging the sat. altimetry data.

I don't recall any claims that it's all about sinking land or that the sat data is fudged. What I do recall, however, are constant claims from popular media outlets, politicians, and self-anointed internet pundits blaming "climate change" on just about every large storm and/or flooding event over the past decade or two. As your studies just demonstrated, the global avg. sea level rise has been just over 1"/30mm per decade thus far. And along regions like much of the US e. coast, that only accounts for less than 1/3 of the total change in light of land subsidence and the other mostly natural phenomena discussed (3.5"/decade total). And this assumes that all of the warming is the result of anthropogenic forces, a conclusion that not even the IPCC has reached.

So if the activists can't get get it right (or play it straight) when it comes to reporting sea level rise for which recorded measurements appear to be largely agreed upon, then how can we expect the public to believe future dire predictions based on the models? I don't think it's the result of some grand AGW conspiracy, but of an unfortunate combo of agenda-driven activists, biased media & pundits, opportunistic politicians, and a gullible public who doesn't understand some of the nuances within the science. It's not the skeptics & doubters, after all, who have saturated public opinion with the apparent myth that rising seas are all about AGW.

[ImaginaryNumber]

https://www.geomar.de/en/news/articl...giftiger-alge/

[Marc1]

Originally Posted by Exile

I don't recall any claims that it's all about sinking land or that the sat data is fudged. What I do recall, however, are constant claims from popular media outlets, politicians, and self-anointed internet pundits blaming "climate change" on just about every large storm and/or flooding event over the past decade or two. As your studies just demonstrated, the global avg. sea level rise has been just over 1"/30mm per decade thus far. And along regions like much of the US e. coast, that only accounts for less than 1/3 of the total change in light of land subsidence and the other mostly natural phenomena discussed (3.5"/decade total). And this assumes that all of the warming is the result of anthropogenic forces, a conclusion that not even the IPCC has reached.

So if the activists can't get get it right (or play it straight) when it comes to reporting sea level rise for which recorded measurements appear to be largely agreed upon, then how can we expect the public to believe future dire predictions based on the models? I don't think it's the result of some grand AGW conspiracy, but of an unfortunate combo of agenda-driven activists, biased media & pundits, opportunistic politicians, and a gullible public who doesn't understand some of the nuances within the science. It's not the skeptics & doubters, after all, who have saturated public opinion with the apparent myth that rising seas are all about AGW.

Agreed.

And just to illustrate the above with an unrelated comment blurted out on Sunday by a very nice person and very knowledgable on matters gardening, yet extremely ignorant in matters climate, but that believes that working outdoors empowers him to be an authority on climate, and that has a very popular radio show.

We are experiencing a cold snap (we are in winter after all) due to winds from Antartica that brought snow in many places that had not seen snow for decades. At the same time we had several bush fires that kept the fire brigade rather busy.
The comment? SNOW AND BUSH FIRE !!! AND THEY SAY THERE IS NO GLOBAL WARMING !!!

The outburst aimed at appealing to emotions is just an example of what really drives this fraud, fanned by well meaning ignoramus who see in this story a string of anti values that fits their preconceived view of the world. The bad guys pollute, the good guys denounce and scream.

And the idea is actually true at many levels, however the very valid and true levels where this applies, are neglected and fly under the radar because the false hypothesis of CO2 driven global warming fraud covers all the other very valid and now secondary pollution cases.

The cold snap caused by winds from Antartica ... and the bushfires caused by a mentally ill person who lit them intentionally ...

Save our children future! Stop all subsidies to anything relating to global warming or climate change. The biggest con ever invented.

PS
500 million dollars for "climate change" to the Pacific Islands.
Can someone venture how it will be spent and who will benefit?

[RaymondR]

I think that sea level is definitely rising, I have not run aground for at least five years now. Rising sea levels must be the only reason.