<p>There are many factors involved, so this is worth yet another answer. At the end of his/her <a href="https://earthscience.stackexchange.com/a/10880/595">answer</a> <em>aretxabaleta</em> states:</p>

<blockquote>
  <p>In general, the areas near the poles have a negative trend (sea level is dropping, not rising) because of the Glacial Isostatic Adjustment (GIA) as the crust is still rebounding from the previous glaciation. In mid-latitudes, on the other hand the sea level rise rates are maximum</p>
</blockquote>

<p>In those locations however, there is a stronger effect:</p>

<p>The ice masses themselves exert a large gravitational pull on the surrounding water, resulting in a <strong>lowering</strong> of the sea level around those masses (Greenland, Antarctica) when the ice melts.<br />
This may seem counter-intuitive, and is best explained by looking at what happens when the ice masses grow:</p>

<p>The gravitation of the growing mass pulls water towards it. The resulting sea level rise on the edges of the ice mass is therefore <em>larger</em> than the eustatic (global, uniform, across the world) sea level decrease that occurs because of the water moving into the ice. The effect is that near the ice mass, sea level actually rises, and far away it falls faster than 'expected'.</p>

<p>When the ice melts the reverse happens: sea level close to the ice mass will drop, sea level far away will rise more than 'expected'.</p>

<p>To give this some actual numbers:<br />
The eustatic sea level rise corresponding to the melting of the Greenland and West Antarctic ice caps is both approx. 6 meters.<br />
Here in Europe (I live in the Netherlands) however, the Greenland melt would 'only' result in approx. 3 meters rise, because that is relatively close, but the West Antarctic melt would result in something like 8-9 meters extra water.</p>

<p>This picture shows the <em>relative</em> effect calculated for water running of West Antarctica. You should read the numbers as a multiplication factor to apply to amount of sea level rise in the case of a uniform distribution.</p>

<p><a href="https://i.sstatic.net/vlbI8.jpg" rel="noreferrer"><img src="https://i.sstatic.net/vlbI8.jpg" alt="enter image description here"></a></p>

<blockquote>
  <p>Sea level change associated with a uniform thinning of the West Antarctic Ice Sheet (WAIS). Their result, reproduced in Fig. 1(a), was normalized by the eustatic sea level change (i.e. the change computed assuming that the meltwater entered the present-day ocean uniformly). [...] The map shows a peak sea level rise greater than 25 per cent above the eustatic value in the north Pacific and more than 20 per cent above the eustatic in the north Atlantic and Indian Oceans. In addition, the sea level fall is greater than five times the eustatic amplitude in the ocean adjacent to the West Antarctic.</p>
</blockquote>

<p><a href="https://academic.oup.com/gji/article/187/2/729/571441" rel="noreferrer">On the robustness of predictions of sea level fingerprints</a><br />
J. X. Mitrovica, N. Gomez, E. Morrow, C. Hay, K. Latychev, M. E. Tamisiea<br />
14 October 2011<br />
DOI: 10.1111/j.1365-246X.2011.05090.x  </p>

CC BY-SA 3.0
2017-07-30T11:03:19.607Z
This is only in an ocean without currents or rotation. The reality is much difference than that
arkaia
CC BY-SA 3.0
2017-07-30T11:39:58.180Z
@aretxabaleta Of course. I'm naming just another factor to take into account.
Jan Doggen
CC BY-SA 4.0
2019-05-22T10:07:55.347Z
And then again, this effect that I describe here will be *reduced* by the *current* melting as describes in [this answer](https://earthscience.stackexchange.com/a/17019/595)
Jan Doggen
CC BY-SA 3.0
2017-07-29T19:18:20.357Z
2017-07-29T19:18:20.357Z
Jan Doggen
<p>The sea level will rise uniformly due to thermal expansion of the seas, but you are right that glaciers make things more complex. Basically when a massive glacier melts its gravitational pull is redistributed in the ocean. For example if all of the antarctic ice would melt sea levels would rise everywhere, but with a largest rise in the north pole and smallest in the south.</p>

<p>There is also currently rising of the earths crust in areas that were pushed down by the last ice age glaciers. Therefore where the current glaciers melt away earth will gradually be rising. When earth is rising at the ocean floor it forces the water to flow uniformly to everywhere else.</p>

<p>Also changes in weather systems change the prevailing winds that affect where water will pack, but this effect is much smaller in the long run.</p>

<p>Unfortunately all the predicting maps I found, like this interactive one <a href="http://geology.com/sea-level-rise/" rel="nofollow noreferrer">geology.com</a>, don't take into account these factors.</p>

<p>Some articles for more info: <a href="http://ocean.si.edu/sea-level-rise" rel="nofollow noreferrer">Ocean Portal</a>, <a href="http://e360.yale.edu/features/the_secret_of_sea_level_rise_it_will_vary_greatly_by_region" rel="nofollow noreferrer">Yale</a>.</p>

CC BY-SA 3.0
2017-07-21T11:02:01.660Z
What do you mean by 'gravitational pull' from Antarctic glaciers, and why would the sea level rise be largest at the North Pole? To quantify the impact of post glacial rebound of continental shelf, we must also estimate the subsistence of peripheral bulges. They are often located under sea level and would have a mitigating effect of sea level rise due to melting ice sheets.
user2821
CC BY-SA 3.0
2017-07-21T11:33:05.953Z
Ice sheets do have a gravitational pull. https://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch5s5-5-4-4.html
Communisty
CC BY-SA 3.0
2017-07-21T12:00:54.670Z
Ok, that context! This is a good paper http://www.nature.com/ngeo/journal/v2/n7/abs/ngeo544.html that explains some of the aspects. The regional effects due to rebound is, however, of a larger magnitude.
user2821
CC BY-SA 3.0
2017-07-28T15:15:22.460Z
@Tbb -- Rebound is a very slow process; rebound from the last glaciation is still occurring in northern Eurasia and North America. During the next hundred years or so, the Earth will not have time to respond to the ice that melts in that period. Communisty is correct about melting being non-eustatic. Localized melting (Greenland and Antarctica being "local") will subtly change the shape of the geoid, with the changes being at their greatest well away from the location at which the melt occurred.
David Hammen
CC BY-SA 3.0
2017-07-28T15:15:40.953Z
For example, see [Global geoid and sea level changes due to present‐day ice mass fluctuations](http://onlinelibrary.wiley.com/doi/10.1029/2000JB000011/abstract) (paywalled).
David Hammen
CC BY-SA 3.0
2017-07-29T09:32:48.033Z
@DavidHammen Yes, I agree. I didn't mention the rate and the postglacial rebound is indeed a slow process, by human timescale. Still, the rebound can be much faster than the eustatic sea level change, that is why we get raised beaches along the coast in Canada, Northern Europe and parts of Antarctica. This rebound can be in the range of hundreds of meters since LGM, a much larger magnitude than vertical gravity pull, that usually is estimated to less than a meter. Hence, my comment.
user2821
CC BY-SA 3.0
2017-07-29T09:49:34.453Z
The Milne et al 2009 paper is a very good overview of the processes. The Tamisiea et al 2003 is also a good read on ice mass variations and attraction on the oceans.
user2821
CC BY-SA 4.0
2021-07-12T22:54:29.690Z
@Communisty "if all of the antarctic ice would melt sea levels would rise everywhere," is not correct. Nearest the greatest ice loss (currently Greenland) sea levels FALL. This NASA video based on satellite telemetry shows this - https://www.youtube.com/watch?v=VY_SeZiBcM4
Ken Fabian
CC BY-SA 3.0
2017-07-21T06:36:23.213Z
2017-07-21T09:34:23.820Z
2017-07-21T09:34:23.820Z
Communisty
<p>Sea level rise (SLR) is anything but spatially uniform. The satellite derived SLR rates that you present are a good example of the complexity of the spatial response. 
A good way to explore the spatial characteristics from observations is to use the data from the Permanent Service for Mean Sea Level (<a href="http://www.psmsl.org" rel="noreferrer">PSMSL</a>). They have a good interactive <a href="http://www.psmsl.org/products/trends/" rel="noreferrer">map</a> to investigate global mean sea level trends since 1900. The time limits can be adjusted to see the changes depending on the data you use.
<a href="https://i.sstatic.net/xIz9r.jpg" rel="noreferrer"><img src="https://i.sstatic.net/xIz9r.jpg" alt="PSMSL"></a> Source PSMSL.</p>

<p>From their website:</p>

<blockquote>
  <p>The latest IPCC report, published in 2013, finds that "It is very likely that the mean rate of global averaged sea level rise was 1.7 [1.5 to 1.9] mm/yr between 1901 and 2010, 2.0 [1.7 to 2.3] mm/yr between 1971 and 2010 and 3.2 [2.8 to 3.6] mm/yr between 1993 and 2010. Tide-gauge and satellite altimeter data are consistent regarding the higher rate of the latter period" (<a href="http://www.climatechange2013.org" rel="noreferrer">www.climatechange2013.org</a>). </p>
</blockquote>

<p>That rate is the global AVERAGE but it varies a lot spatially. No location on Earth needs to have this average value (some will). In some places, sea level is rising by more than the global average while in others it is decreasing. There are many causes to for these local differences in sea level. </p>

<p>The regional differences are caused by changes in many variables. For instance, there wind patterns change in annual and decadal scales. As wind changes, wind-driven ocean currents are modified, which modify sea level slopes (e.g., Gulf Stream causes sea elevations gradients). Temperature changes in the oceans are also spatially variable resulting in steric sea level changes (local difference in density and volume change). Additionally, with ice sheets melt, there are changes in pressure over the crust modifying sea level. Other very local effects such as earthquakes, groundwater extraction, and subsidence of the land will cause apparent change of sea level at that location. </p>

<p>In general, the areas near the poles have a negative trend (sea level is dropping, not rising) because of the Glacial Isostatic Adjustment (<a href="http://www.psmsl.org/train_and_info/geo_signals/gia/" rel="noreferrer">GIA</a>) as the crust is still rebounding from the previous glaciation. In mid-latitudes, on the other hand the sea level rise rates are maximum. Of course, there are local effects because of many of the forcings mentioned above.</p>

CC BY-SA 3.0
2017-07-21T13:53:34.930Z
Is there any strong relationship between tidal variation and places that will experience more sea level rise?  From the map you show, it appears that the two are inversely related in many places.
f.thorpe
CC BY-SA 3.0
2017-07-21T15:02:48.700Z
@farrenthorpe, as far I know, there isn't a strong relationship connecting tidal amplitude and slr. There is a very small connection because with more water elevation, you might have less tidal dissipation and then larger tidal amplitudes, but the changes are tiny except in very coastal regions where the tidal amplitude versus water depth is large.
arkaia
CC BY-SA 3.0
2017-07-27T18:40:57.063Z
Why wouldn't there be an average rise in sea levels all around the world?  Let's forget about winds and whatever but why not?  It has to be in the ball park unless there is an ocean damn somewhere I haven't heard about.  What about land, continents rising or falling.  Has anyone taken this into consideration?  And when I think of putting ice cubes INTO my drink that raises the level of my drink far more than when those ice cubes melt.
stormy
CC BY-SA 3.0
2017-07-27T18:43:53.010Z
And don't you find it interesting that sea levels only seem to be rising where the largest population and development has occurred?  Or maybe where the most measuring devices are found?  Or where there is the largest pressure to FIND sea level rise?
stormy
CC BY-SA 3.0
2017-07-29T19:24:58.520Z
@stormy You should take a better look at your drink, or drink less.
Jan Doggen
CC BY-SA 3.0
2017-07-21T12:41:55.797Z
2017-07-21T15:09:25.410Z
2017-07-21T15:09:25.410Z
arkaia
<p>Sea level rise from melting glaciers will not be uniformly distributed across the globe.  However, it isn't clear to me what places will have the most and least extreme changes in sea level rise.  I had previously thought that, in general, tropical latitudes would have the least sea level rise, and the polar regions would have the most sea level rise.  However, when I view <a href="https://upload.wikimedia.org/wikipedia/commons/5/5e/M2_tidal_constituent.jpg" rel="noreferrer">this map</a> of tidal variation, and also consider the change in mass on the land (<a href="https://earthscience.stackexchange.com/questions/9607/dataset-for-expected-sea-level-rise-in-case-of-massive-meltdowns-greenland-anta">when the glacier melts</a>), it appears that sea-level rise will be complex.  I've seen <a href="http://www.soest.hawaii.edu/coasts/sealevel/MSL_Map_MERGED_Global_IB_RWT_NoGIA_Adjust.png" rel="noreferrer">this image</a> of recent sea level change, but I don't think a change of several meters would continue to follow this trend.  </p>

<p>How will sea level rise be distributed across the globe?</p>

CC BY-SA 4.0
2021-07-12T03:41:03.810Z
l[andmass and ocean topography](https://earthobservatory.sg/faq-on-earth-sciences/why-will-sea-level-rise-not-be-same-everywhere) prevents sea level from rising and falling evenly and uniformly throughout the world. For Example, any water going towards the Central American land bridge would have to be flushed up and down, towards the bottom of South America and up towards the north pole and Greenland.
[![](https://i.sstatic.net/pa1Sm.png)](https://i.sstatic.net/pa1Sm.png)
or it could flow into bays. this occurs in many parts of the globe. heightened Ocean topography can cause water to
Tardy
CC BY-SA 4.0
2021-07-12T03:41:31.357Z
There are many more reasons too.
Tardy
<climate-change><oceanography><sea-level><glaciology><tides>
How will sea level rise be distributed across the globe?
f.thorpe
# How will sea level rise be distributed across the globe?

(Asked by: username_0 on 2017-07-21)

Sea level rise from melting glaciers will not be uniformly distributed across the globe. However, it isn't clear to me what places will have the most and least extreme changes in sea level rise. I had previously thought that, in general, tropical latitudes would have the least sea level rise, and the polar regions would have the most sea level rise. However, when I view [this map](https://upload.wikimedia.org/wikipedia/commons/5/5e/M2_tidal_constituent.jpg) of tidal variation, and also consider the change in mass on the land ([when the glacier melts](https://earthscience.stackexchange.com/questions/9607/dataset-for-expected-sea-level-rise-in-case-of-massive-meltdowns-greenland-anta)), it appears that sea-level rise will be complex. I've seen [this image](http://www.soest.hawaii.edu/coasts/sealevel/MSL_Map_MERGED_Global_IB_RWT_NoGIA_Adjust.png) of recent sea level change, but I don't think a change of several meters would continue to follow this trend.

How will sea level rise be distributed across the globe?

**Tags:** climate-change, oceanography, sea-level, glaciology, tides

> **Comments:**
> **username_1**: l[andmass and ocean topography](https://earthobservatory.sg/faq-on-earth-sciences/why-will-sea-level-rise-not-be-same-everywhere) prevents sea level from rising and falling evenly and uniformly throughout the world. For Example, any water going towards the Central American land bridge would have to be flushed up and down, towards the bottom of South America and up towards the north pole and Greenland. [![](https://i.sstatic.net/pa1Sm.png)](https://i.sstatic.net/pa1Sm.png) or it could flow into bays. this occurs in many parts of the globe. heightened Ocean topography can cause water to  
> **username_1**: There are many more reasons too.  

---

## 3 answers

### Answer by username_3 on 2017-07-21. Score: 8 | Accepted answer

Sea level rise (SLR) is anything but spatially uniform. The satellite derived SLR rates that you present are a good example of the complexity of the spatial response.
A good way to explore the spatial characteristics from observations is to use the data from the Permanent Service for Mean Sea Level ([PSMSL](http://www.psmsl.org)). They have a good interactive [map](http://www.psmsl.org/products/trends/) to investigate global mean sea level trends since 1900. The time limits can be adjusted to see the changes depending on the data you use.
[![PSMSL](https://i.sstatic.net/xIz9r.jpg)](https://i.sstatic.net/xIz9r.jpg) Source PSMSL.

From their website:

> The latest IPCC report, published in 2013, finds that "It is very likely that the mean rate of global averaged sea level rise was 1.7 [1.5 to 1.9] mm/yr between 1901 and 2010, 2.0 [1.7 to 2.3] mm/yr between 1971 and 2010 and 3.2 [2.8 to 3.6] mm/yr between 1993 and 2010. Tide-gauge and satellite altimeter data are consistent regarding the higher rate of the latter period" ([www.climatechange2013.org](http://www.climatechange2013.org)).

That rate is the global AVERAGE but it varies a lot spatially. No location on Earth needs to have this average value (some will). In some places, sea level is rising by more than the global average while in others it is decreasing. There are many causes to for these local differences in sea level.

The regional differences are caused by changes in many variables. For instance, there wind patterns change in annual and decadal scales. As wind changes, wind-driven ocean currents are modified, which modify sea level slopes (e.g., Gulf Stream causes sea elevations gradients). Temperature changes in the oceans are also spatially variable resulting in steric sea level changes (local difference in density and volume change). Additionally, with ice sheets melt, there are changes in pressure over the crust modifying sea level. Other very local effects such as earthquakes, groundwater extraction, and subsidence of the land will cause apparent change of sea level at that location.

In general, the areas near the poles have a negative trend (sea level is dropping, not rising) because of the Glacial Isostatic Adjustment ([GIA](http://www.psmsl.org/train_and_info/geo_signals/gia/)) as the crust is still rebounding from the previous glaciation. In mid-latitudes, on the other hand the sea level rise rates are maximum. Of course, there are local effects because of many of the forcings mentioned above.

> **Comments:**
> **username_0**: Is there any strong relationship between tidal variation and places that will experience more sea level rise?  From the map you show, it appears that the two are inversely related in many places.  
> **username_3**: @farrenthorpe, as far I know, there isn't a strong relationship connecting tidal amplitude and slr. There is a very small connection because with more water elevation, you might have less tidal dissipation and then larger tidal amplitudes, but the changes are tiny except in very coastal regions where the tidal amplitude versus water depth is large.  
> **username_8**: Why wouldn't there be an average rise in sea levels all around the world?  Let's forget about winds and whatever but why not?  It has to be in the ball park unless there is an ocean damn somewhere I haven't heard about.  What about land, continents rising or falling.  Has anyone taken this into consideration?  And when I think of putting ice cubes INTO my drink that raises the level of my drink far more than when those ice cubes melt.  
> **username_8**: And don't you find it interesting that sea levels only seem to be rising where the largest population and development has occurred?  Or maybe where the most measuring devices are found?  Or where there is the largest pressure to FIND sea level rise?  
> **username_2**: @username_8 You should take a better look at your drink, or drink less.  

---

### Answer by username_2 on 2017-07-29. Score: 10

There are many factors involved, so this is worth yet another answer. At the end of his/her [answer](https://earthscience.stackexchange.com/a/10880/595) *aretxabaleta* states:

> In general, the areas near the poles have a negative trend (sea level is dropping, not rising) because of the Glacial Isostatic Adjustment (GIA) as the crust is still rebounding from the previous glaciation. In mid-latitudes, on the other hand the sea level rise rates are maximum

In those locations however, there is a stronger effect:

The ice masses themselves exert a large gravitational pull on the surrounding water, resulting in a **lowering** of the sea level around those masses (Greenland, Antarctica) when the ice melts.  
This may seem counter-intuitive, and is best explained by looking at what happens when the ice masses grow:

The gravitation of the growing mass pulls water towards it. The resulting sea level rise on the edges of the ice mass is therefore *larger* than the eustatic (global, uniform, across the world) sea level decrease that occurs because of the water moving into the ice. The effect is that near the ice mass, sea level actually rises, and far away it falls faster than 'expected'.

When the ice melts the reverse happens: sea level close to the ice mass will drop, sea level far away will rise more than 'expected'.

To give this some actual numbers:  
The eustatic sea level rise corresponding to the melting of the Greenland and West Antarctic ice caps is both approx. 6 meters.  
Here in Europe (I live in the Netherlands) however, the Greenland melt would 'only' result in approx. 3 meters rise, because that is relatively close, but the West Antarctic melt would result in something like 8-9 meters extra water.

This picture shows the *relative* effect calculated for water running of West Antarctica. You should read the numbers as a multiplication factor to apply to amount of sea level rise in the case of a uniform distribution.

[![enter image description here](https://i.sstatic.net/vlbI8.jpg)](https://i.sstatic.net/vlbI8.jpg)

> Sea level change associated with a uniform thinning of the West Antarctic Ice Sheet (WAIS). Their result, reproduced in Fig. 1(a), was normalized by the eustatic sea level change (i.e. the change computed assuming that the meltwater entered the present-day ocean uniformly). [...] The map shows a peak sea level rise greater than 25 per cent above the eustatic value in the north Pacific and more than 20 per cent above the eustatic in the north Atlantic and Indian Oceans. In addition, the sea level fall is greater than five times the eustatic amplitude in the ocean adjacent to the West Antarctic.

[On the robustness of predictions of sea level fingerprints](https://academic.oup.com/gji/article/187/2/729/571441)  
J. X. Mitrovica, N. Gomez, E. Morrow, C. Hay, K. Latychev, M. E. Tamisiea  
14 October 2011  
DOI: 10.1111/j.1365-246X.2011.05090.x

> **Comments:**
> **username_3**: This is only in an ocean without currents or rotation. The reality is much difference than that  
> **username_2**: @aretxabaleta Of course. I'm naming just another factor to take into account.  
> **username_2**: And then again, this effect that I describe here will be *reduced* by the *current* melting as describes in [this answer](https://earthscience.stackexchange.com/a/17019/595)  

---

### Answer by username_4 on 2017-07-21. Score: 5

The sea level will rise uniformly due to thermal expansion of the seas, but you are right that glaciers make things more complex. Basically when a massive glacier melts its gravitational pull is redistributed in the ocean. For example if all of the antarctic ice would melt sea levels would rise everywhere, but with a largest rise in the north pole and smallest in the south.

There is also currently rising of the earths crust in areas that were pushed down by the last ice age glaciers. Therefore where the current glaciers melt away earth will gradually be rising. When earth is rising at the ocean floor it forces the water to flow uniformly to everywhere else.

Also changes in weather systems change the prevailing winds that affect where water will pack, but this effect is much smaller in the long run.

Unfortunately all the predicting maps I found, like this interactive one [geology.com](http://geology.com/sea-level-rise/), don't take into account these factors.

Some articles for more info: [Ocean Portal](http://ocean.si.edu/sea-level-rise), [Yale](http://e360.yale.edu/features/the_secret_of_sea_level_rise_it_will_vary_greatly_by_region).

> **Comments:**
> **username_5**: What do you mean by 'gravitational pull' from Antarctic glaciers, and why would the sea level rise be largest at the North Pole? To quantify the impact of post glacial rebound of continental shelf, we must also estimate the subsistence of peripheral bulges. They are often located under sea level and would have a mitigating effect of sea level rise due to melting ice sheets.  
> **username_4**: Ice sheets do have a gravitational pull. https://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch5s5-5-4-4.html  
> **username_5**: Ok, that context! This is a good paper http://www.nature.com/ngeo/journal/v2/n7/abs/ngeo544.html that explains some of the aspects. The regional effects due to rebound is, however, of a larger magnitude.  
> **username_6**: @Tbb -- Rebound is a very slow process; rebound from the last glaciation is still occurring in northern Eurasia and North America. During the next hundred years or so, the Earth will not have time to respond to the ice that melts in that period. username_4 is correct about melting being non-eustatic. Localized melting (Greenland and Antarctica being "local") will subtly change the shape of the geoid, with the changes being at their greatest well away from the location at which the melt occurred.  
> **username_6**: For example, see [Global geoid and sea level changes due to present‐day ice mass fluctuations](http://onlinelibrary.wiley.com/doi/10.1029/2000JB000011/abstract) (paywalled).  
> **username_5**: @username_6 Yes, I agree. I didn't mention the rate and the postglacial rebound is indeed a slow process, by human timescale. Still, the rebound can be much faster than the eustatic sea level change, that is why we get raised beaches along the coast in Canada, Northern Europe and parts of Antarctica. This rebound can be in the range of hundreds of meters since LGM, a much larger magnitude than vertical gravity pull, that usually is estimated to less than a meter. Hence, my comment.  
> **username_5**: The Milne et al 2009 paper is a very good overview of the processes. The Tamisiea et al 2003 is also a good read on ice mass variations and attraction on the oceans.  
> **username_7**: @username_4 "if all of the antarctic ice would melt sea levels would rise everywhere," is not correct. Nearest the greatest ice loss (currently Greenland) sea levels FALL. This NASA video based on satellite telemetry shows this - https://www.youtube.com/watch?v=VY_SeZiBcM4  

---

