Global warming's next surprise: Saltier beaches

August 11, 2016, New Jersey Institute of Technology

Batches of sand from a beach on the Delaware Bay are yielding insights into the powerful impact of temperature rise and evaporation along the shore that are in turn challenging long-held assumptions about what causes beach salinity to fluctuate in coastal zones that support a rich network of sea creatures and plants.

The findings have implications for the migration and survival of invertebrates such as mussels and crabs as global warming drives temperatures higher.

A first major study of the effects of evaporation on the flow of subsurface water and salinity, or , in the beach intertidal zone - the section of the beach between the low and high tide marks - is being published today in Scientific Reports.

The study, by New Jersey Institute of Technology's Center for Natural Resources Development (CNRDP) and led by two environmental engineers and a coastal geologist, shows that sediments from some sections of Slaughter Beach in Delaware have salt concentrations four times as high as the ocean water that washes over them. The finding came as a surprise.

The nearshore seawater the team measured had salt concentrations of 25 grams per liter (g/L), leading the researchers to expect that the subsurface water in areas of the beach it infiltrated would have similar or even lower levels as seawater mixes with inland groundwater in this zone. However, they discovered that the average salinity in the upper intertidal zone - the high tide line - was 60 g/L, with some values reaching as high as 100.

"These elevated levels can only be caused by evaporation, as there is no other mechanism for increasing the salt in pore water - the water trapped between the grains of sediment," said Xiaolong Geng, a postdoctoral fellow at NJIT and the principal author of the study, noting that the rates of evaporation - and salinity - are thus mainly determined by temperature and relative humidity, while tide and wave flows dilute a beach's salt content.

"Previous studies have identified seawater as the primary source of salinity in coastal aquifer systems, thereby concluding that seawater infiltration always increases pore-water salinity by seawater-groundwater mixing dynamics," said Michel Boufadel, director of the CNRDP, who is also an author of the study. "Based on what we learned, we think this finding should alter the way water management in coastal areas is conducted."

The team analyzed nearly 400 sediment samples collected during the sequential phases of a complete tidal cycle, from day to night, on seven discontinuous days.

The intertidal, or littoral, zone, is a dynamic habitat, washed by seawater at high tide and uncovered at low tide, that is favored by crabs, mussels and sea anemones, the birds and sea mammals that feed on them, and plants such as kelp. Many of these animals burrow in the beach to find food and to seek protection from predators and the action of waves, and are in near constant contact with pore water.

The researchers have developed models that show that increases in temperature associated with global warming will not only make inland locations more salty, but would also create drastically different pattern of pore water salinity that will have implications for animals and plants in the intertidal zone.

"Evaporation is an important driver of underground water flow and salinity gradients, and animals such as mussels and crabs are affected by changes in . If the concentrations are too high or too low, they will move away," noted Geng.

Nancy Jackson, a professor of coastal geomorphology in the Department of Chemistry and Environmental Science and the study's third author, collected the beach samples from Slaughter Beach and provided interpretations of pore water dynamics.

Explore further: Researchers study reactions that occur when groundwater, saltwater meet in coastal aquifers

More information: Xiaolong Geng et al, Evidence of salt accumulation in beach intertidal zone due to evaporation, Scientific Reports (2016). DOI: 10.1038/srep31486

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10 comments

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antigoracle
1.8 / 5 (10) Aug 11, 2016
LOL
First it was the WARMING oceans would absorb more CO2 and become acidic and now, surprise, it is getting saltier.
The AGW Cult, there is no limit to the shit they can make up, that BILLIONS of your tax dollars can't buy.
Captain Stumpy
4 / 5 (8) Aug 12, 2016
become acidic
if only there was some way we could measure, experiment, test, validate and model this in a constrained way to remove bias while determining facts so that we could know WTF was actually happening... why, we could build upon that knowledge and maybe change the world

http://science.sc...37.short

http://eprints.un...3120.pdf

http://www.annual...com&

https://scholar.g...dt=0%2C4

and now ... it is getting saltier
if only there was a way to check this and actually see what is happening like above
http://ieeexplore...3D942551
entrance
2.3 / 5 (6) Aug 12, 2016
The problem is that there are too many people on this earth. I am ready to help.
antialias_physorg
4.4 / 5 (7) Aug 12, 2016
The problem is that there are too many people on this earth. I am ready to help.

Should we alert a suicide prevention team?
LifeBasedLogic
Aug 15, 2016
This comment has been removed by a moderator.
Maggnus
4.3 / 5 (6) Aug 15, 2016
The problem is that there are too many people on this earth. I am ready to help.

Should we alert a suicide prevention team?


What???
Come again??
What???

How can you have the audacity to state something as suicide as even truthfully real
when YOU SAID,

"I do not believe life is truth"?

What is wrong with your brain?

You said it, now stick to it and pretend you are not alive and keep your mouth shut if it doesn't agree with your previous comments.

I think he said shut up! Hard to tell, he surrounds everything with gobbly-gook.
humy
5 / 5 (4) Aug 16, 2016
LOL
First it was the WARMING oceans would absorb more CO2 ....

antigoracle

No you complete moron; Any climate scientist would and does claim it isn't the WARMING of the oceans that would cause more CO2 to be absorbed into them but rather the greater concentration of ATMOSPHERIC CO2 that would cause greater CO2 absorption CO2 into the oceans assuming this wouldn't be more than offset (and it probably wouldn't in the long run) by the CO2 released from the oceans to the atmosphere because of the increase in ocean temperature from global warming. Just like any climate scientists or physicist would tell you, it is just vary basic physics that, just like with most gasses, solubility of CO2 in water goes DOWN, not UP with increase in temperature.

http://www.engine...148.html

Please stop your science-ignorant straw men.
BongThePuffin
Aug 16, 2016
This comment has been removed by a moderator.
abecedarian
1 / 5 (4) Aug 16, 2016
Out of curiosity, what's the possibility this increase could be caused by 'road salt', finding it's way to the beaches?
Maggnus
4.2 / 5 (5) Aug 17, 2016
Out of curiosity, what's the possibility this increase could be caused by 'road salt', finding it's way to the beaches?

None.

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