NFA Community Forums

NCIS Fanfiction Addiction Forums
It is currently Mon Nov 20, 2017 5:35 am

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 20 posts ] 
Author Message
 Post subject: Exploring our Oceans
PostPosted: Mon Oct 30, 2017 12:27 pm 
Offline
Director
User avatar

Joined: Sun Sep 14, 2008 6:51 am
Posts: 68896
Location: Usually in bed with Gibbs
Title: Gibbs' Gal forever
Name: Patsy
Aliases: pattywatty
Gender: Female
link: My Author Board
link: My Fanfic.net
Flag: Image
I just hope this map stays it's fantastic
http://www.slate.com/articles/technolog ... e_map.html

More from Slate’s series on the future of exploration: Is the ocean the real final frontier, or is manned sea exploration dead? Why are the best meteorites found in Antarctica? Can humans reproduce on interstellar journeys? Why are we still looking for Atlantis? Why do we celebrate the discovery of new species but keep destroying their homes? Who will win the race to claim the melting Arctic—conservationists or profiteers? Why don’t travelers ditch Yelp and Google in favor of wandering? What can exploring Google’s Ngram Viewer teach us about history? How did a 1961 conference jump-start the serious search for extraterrestrial life?

___________________________
Words in this post: 119
_______________________
Image]
ImageImageImage

sig by McMhuirich thank you


Top
 Profile  
 
 Post subject: Re: Exploring our Oceans
PostPosted: Mon Oct 30, 2017 12:37 pm 
Offline
Director
User avatar

Joined: Sun Sep 14, 2008 6:51 am
Posts: 68896
Location: Usually in bed with Gibbs
Title: Gibbs' Gal forever
Name: Patsy
Aliases: pattywatty
Gender: Female
link: My Author Board
link: My Fanfic.net
Flag: Image
For the Victorians the voyage of the Challenger between December 1872 and May 1876 was akin to the Apollo astronauts’ trips to the Moon - it was a journey into the unknown.

It resulted in the birth of oceanography as a multidisciplinary science and created a legacy that is with us today. Watch Howard’s video for details about the significance of its discoveries and legacy; additional information is provided below.

https://www.hmschallenger.net/map

https://www.hmschallenger.net/the-route

Learn about the Route

Portsmouth to Tenerife (stations I to VIII)
From Tenerife to Bermuda (stations 1 to 57B)
From Bermuda to Cape Verde (stations 58 to 94)
From Cape Verde to Fernando de Noronha, Brazil (stations 95 to 113A)
Fernando de Noronha to Cape of Good Hope, South Africa (stations 113B to 140)
Cape of Good Hope to the Kerguelen Islands (stations 141 to 151)
Kerguelen to Fiji (stations 152 to 174D)
Fiji to the Philippines (stations 175 to 205)
The Philippines to Hawaii (stations 206 to 261)
Hawaii to the Magellan Strait, Chile (stations 262 to 312)
Magellan Strait to Ascension Islands, British Overseas Territory (Stations 313 to 343)
Ascension Island back to Portsmouth (stations 344 to 354)

___________________________
Words in this post: 204
_______________________
Image]
ImageImageImage

sig by McMhuirich thank you


Top
 Profile  
 
 Post subject: Re: Exploring our Oceans
PostPosted: Mon Oct 30, 2017 12:40 pm 
Offline
Director
User avatar

Joined: Sun Sep 14, 2008 6:51 am
Posts: 68896
Location: Usually in bed with Gibbs
Title: Gibbs' Gal forever
Name: Patsy
Aliases: pattywatty
Gender: Female
link: My Author Board
link: My Fanfic.net
Flag: Image
The discoveries made on the expedition include the first maps of ocean currents and sea temperatures; the first geological maps of the sea floor; the change with depth from calcareous grey Globigerina ooze to red silicaceous Radiolarian ooze below the calcium carbonate compensation depth (a discovery that relates directly to current concerns of the oceans ability to absorb carbon dioxide); underwater mountain ranges including the Mid-Atlantic Ridge; the deepest part of the world ocean, the Marianas Trench in the Pacific; 1000s of new species but very few living fossils eg sea lilies (crinoids); the concept of bottom-living fish depending upon a rain of organic particles from shallow water; the azoic theory was disproved - animals live at all depths in the oceans; and Huxley’s “Bathybius” in bottom samples was shown to be a precipitate of calcium carbonate reacting with alcohol and not a universal primordial slime of protoplasm.

At the end of the voyage, Wyville Thomson set up an office in Edinburgh to distribute the samples to international experts, to collate all the data, and to oversee the publication of the resulting reports. There are 50 volumes of reports - the last of which was published in 1895. Wyville Thomson died in 1892 and John Murray took over the publication of the final volumes. The volumes contain 1000s of illustrations, including photographs, watercolours, and engravings. Many of the latter illustrate the 4417 new species that were found, which included ca 2900 new species of Radiolarians.

___________________________
Words in this post: 245
_______________________
Image]
ImageImageImage

sig by McMhuirich thank you


Top
 Profile  
 
 Post subject: Re: Exploring our Oceans
PostPosted: Mon Oct 30, 2017 12:43 pm 
Offline
Director
User avatar

Joined: Sun Sep 14, 2008 6:51 am
Posts: 68896
Location: Usually in bed with Gibbs
Title: Gibbs' Gal forever
Name: Patsy
Aliases: pattywatty
Gender: Female
link: My Author Board
link: My Fanfic.net
Flag: Image
https://paleonerdish.wordpress.com/2013 ... anography/

On December 21, 1872 the H.M.S. Challenger sailed from Portsmouth, England, for an epic voyage which would last almost three and a half years. It was the first expedition organized and funded for a specific scientific purpose: to examine the deep-sea floor and answer questions about the ocean environment.

The expedition covered 69,000 miles (about 130.000 km) and gathered data on currents, water chemistry, temperature, bottom deposits and marine life at 362 oceanographic stations. More than 4700 new species of marine animals were discovered during the course of the voyage, many of which were found on the seafloor – an environment that scientists originally believed to be too inhospitable to support life.

http://www.challenger-society.org.uk/Hi ... Expedition

In 1870, Charles Wyville Thomson (right), Professor of Natural History at Edinburgh University, persuaded the Royal Society of London to ask the British Government to furnish one of Her Majesty's ships for a prolonged voyage of exploration across the oceans of the globe. On the 7th December 1872, the expedition put to sea from Sheerness aboard the corvette H.M.S. Challenger.

The vessel was a three-masted square-rigged wooden ship of 2300 tons displacement and some 200 feet in length. She was essentially a sailing ship even though she possessed an engine of 1200 horsepower. It was planned that the ship would be under sail for most of the cruise, using the engine primarily for manoeuvring when conducting scientific observations and deploying heavy gear. All but two of the ship's 17 guns had been removed to make way for purpose-built scientific laboratories and workrooms designed specifically for biological, chemical and physical work. Storage space for all the trawls and dredges was also necessary, together with space for the anticipated sample collection.

___________________________
Words in this post: 299
_______________________
Image]
ImageImageImage

sig by McMhuirich thank you


Top
 Profile  
 
 Post subject: Re: Exploring our Oceans
PostPosted: Mon Oct 30, 2017 12:56 pm 
Offline
Director
User avatar

Joined: Sun Sep 14, 2008 6:51 am
Posts: 68896
Location: Usually in bed with Gibbs
Title: Gibbs' Gal forever
Name: Patsy
Aliases: pattywatty
Gender: Female
link: My Author Board
link: My Fanfic.net
Flag: Image
TIM LE BAS: You often hear that only 15% of the oceans has been mapped. Well, exactly what does mapped mean? And sort of we're trying to say that sort of, we've got the regional, global scale of maps. But the 15% means we've got the slightly higher resolution, the 100 metre resolution of the deep ocean. And so we can actually see that. So when Captain Cook was discovering his land of Australia and places like that, he was looking at the land, and would take profiles from what he could see from a ship.

And he would occasionally take a lead line, which he would lower over the side of the ship to see how deep the water was for safety of his navigation. Now, what we're starting to do is instead of using a lead line and going down thousands of metres into the deep ocean, we're using sonar as a sort of sounding to understand how deep the ocean is. We send down a sonar signal. We measure the time that it takes to go down to the bottom and back up again. And therefore, we can actually see the time it takes, and we know how fast that sonar signal travels. And therefore, we can work out the depth.

So that's a single ping of sonar sound that we use. But now what we start to use is multiple pings, where multiple pings go down at all different angles, all the way from the ship. And each of those individual pings come back, and we receive all those pings, at which we can make a swath of depth soundings. Because we know the angle, and we know the time that they took to come back up. And so therefore, we can build up a set of pings, and we move the ship forward, at which point we can then take more soundings and slowly build up an idea of the depth of the ocean and the shape or the morphology of the sea floor.

And from that morphology, we could start to understand some of the processes that are going on on the sea floor. Now, that's going from a ship. Now, the ship is possibly 3,000, 4,000 metres above the sea floor. And so therefore, our angled beams could only get a certain resolution. Now, what we really want to do is to get down to really fine resolution and actually sort of survey the sea floor at a much higher resolution. And that higher resolution can be achieved if we then send some of our remotely operated vehicles, or maybe an autonomous vehicle, that flies really quite close to the sea floor.

And because it's close to the sea floor, it can then send out, again, the same kind of sonar pings. But because it's much closer, we can actually do things in much higher resolution, and therefore pick up the morphology of the sea floor in much more detail. And this is when we start to detect some of the biological communities of the sea floor and sort of try and work out what's going on there. So life on the sea floor can be maybe determined better rather than the big, regional scale, or even the global scale that we've got. So we've moved from the Captain Cook where he just did the coastline.

We've now gone deeper, and with single beam echo sounders and multi-beam echo sounders, going right down to remotely operated vehicles very close to the sea floor. We've surveyed quite a lot of the sea floor with our multi-beam systems, which covers about 15% of our oceans. And if we want to think about that, that's probably about the size of Africa in terms of coverage of the sea floor. But then when we get into the really high detail, the ROV, the remotely operated vehicle type areas, it is an absolutely tiny amount. A, because it's very, very high resolution, but also it is a very, very new technology, and is only really coming into its own in the last couple of years.

And the area we've covered now is probably only about, on a global scale, comparatively, about the size of Tasmania or something even smaller than that. This is really quite a small area. So there's loads more to do. It's really quite exciting to think about what we've got still to discover down on the sea floor. We've probably been to most places on our planet. But the deep sea has got all kinds of different life. It's got interesting minerals that could be used for industry and also sort of-- there are other things down there that we don't even know about yet. It is a world of discovery.
I make maps so that we can then go and find maybe places that have interesting changes in depths and different morphology to see the processes that are going on.

http://theconversation.com/just-how-lit ... loor-32751

http://www.nature.com/news/gravity-map- ... es-1.16048

___________________________
Words in this post: 845
_______________________
Image]
ImageImageImage

sig by McMhuirich thank you


Top
 Profile  
 
 Post subject: Re: Exploring our Oceans
PostPosted: Wed Nov 01, 2017 9:38 am 
Offline
Director
User avatar

Joined: Sun Sep 14, 2008 6:51 am
Posts: 68896
Location: Usually in bed with Gibbs
Title: Gibbs' Gal forever
Name: Patsy
Aliases: pattywatty
Gender: Female
link: My Author Board
link: My Fanfic.net
Flag: Image
"Mobilis in mobili’ is a Latin phrase which means ‘moving in a changing environment’.

And that’s the theme of this week. We will be looking at how the oceans are moving around our planet.

Now when I saw this I thought of Season 15 and how everyone is "moving".

___________________________
Words in this post: 49
_______________________
Image]
ImageImageImage

sig by McMhuirich thank you


Top
 Profile  
 
 Post subject: Re: Exploring our Oceans
PostPosted: Fri Nov 03, 2017 12:24 pm 
Offline
Director
User avatar

Joined: Sun Sep 14, 2008 6:51 am
Posts: 68896
Location: Usually in bed with Gibbs
Title: Gibbs' Gal forever
Name: Patsy
Aliases: pattywatty
Gender: Female
link: My Author Board
link: My Fanfic.net
Flag: Image
Angular momentum can also be observed when watching ice-skaters spin. As they bring their arms and legs in closer to their core, they spin faster. Opening their arms out slows them down.
In the northern hemisphere moving objects are deflected to the right, whereas in the southern hemisphere they are deflected to the left. The magnitude of this apparent Coriolis force which we use to account for the deflection is dependent on the distance from the equator (so latitude), and it is zero at the equator and increases towards the poles.

http://stratus.ssec.wisc.edu/courses/gg ... iolis.html

___________________________
Words in this post: 100
_______________________
Image]
ImageImageImage

sig by McMhuirich thank you


Top
 Profile  
 
 Post subject: Re: Exploring our Oceans
PostPosted: Fri Nov 03, 2017 12:28 pm 
Offline
Director
User avatar

Joined: Sun Sep 14, 2008 6:51 am
Posts: 68896
Location: Usually in bed with Gibbs
Title: Gibbs' Gal forever
Name: Patsy
Aliases: pattywatty
Gender: Female
link: My Author Board
link: My Fanfic.net
Flag: Image
Tides

The sea level drops and then comes back again. But does it drop the same amount every single day? Over the course of a month, you can see that that's not the case in this plot I'm showing you here. You can see that the sea level's got times when it varies a lot and times where it varies relatively a little. So it's not just a straight cycle, there's something else going on. Now you may have heard that the tides are driven by the gravitational pull of the moon and that's partially true.

If you imagine Earth surrounded by a thin layer of water and the moon orbiting the earth, you end up with a bulge of water pulled by the gravitational attraction of the moon, in a bulge, and it's aligned with the moon. There's also a bulge on the opposite side of the Earth, as well, in line with the moon, but that's a bit higher level than we're going to talk about here. But think about that bulge. Now the earth orbits once every 24 hours so every 24 hours, every location on the earth will go through this bulge twice. One in the bulge facing the moon and one in the bulge on the opposite side.

And that gives you two high tides that you might have heard of a day. But that's not the whole story. The moon is not the only thing that's causing the water to move on the earth. There's other things out there that have gravitational pull. For example, the sun. Now the sun's much further away from the earth, 93 million miles, but it's very much bigger. Well, what that means is the gravitational pull of the water is about half that from the moon. But it also creates a bulge in line with the sun and also, a bulge on the other side of the earth.

But the earth orbits the sun once a year, but the moon is orbiting the earth once a month so it's how those two bulges interact that gives us the variation. When the bulge from the sun and the bulge from the moon are aligned, we get the maximum tides. About seven days later, the bulge caused by the gravitational pull from the moon and the gravitational pull from the sun are at 90 degrees. They partially cancel out and that's a minimum tide. Another seven days or so on and they're back in line again, so we get the maximum tides. And then another seven days on again, we're back to these minimum tides.

Now when the two bulges are lined up, we call those spring tides. And when the two bulges are at 90 degrees to each other, we call them neap tides. Now the system I've just talked about is if you have a planet Earth theoretically covered with a thin layer of water. But we know, theoretically, that's rubbish. The earth has got continent. It's got land. It's got all sorts of things in the way. So these bulges don't stay in line with the moon and the sun, they get deflected by the continents as they drift around the planet in what we call kelvin waves. But how these two bulges interact is what makes this spring neap cycle.

Now the other interesting thing about the tides is they're not the only two variations that are going on. The axis of the earth is wobbling slightly. The axis of the moon is wobbling slightly. The so-called declination, the angle of the moon to the equator, is changing as well. And all of these cycles add up to make the tide vary over the course of a week, over the course of a month, a year, and even decades. What's really interesting is some species of animals have tuned in their lifestyles to the way the water level varies because of tidal variation.

So some animals can vary their breeding cycle and feeding to when the tides are at maximum and when their tides are at minimum. Now tides are a really amazing feature and happen virtually all over the world. Some places in the world get two high tides a day. Some places in the world, because of the way these cycles interact, get only one tide a day. But the tides are not the thing responsible for controlling the climate on the planet. For that, we have to look at the larger scale ocean currents.

___________________________
Words in this post: 751
_______________________
Image]
ImageImageImage

sig by McMhuirich thank you


Top
 Profile  
 
 Post subject: Re: Exploring our Oceans
PostPosted: Sun Nov 05, 2017 10:37 am 
Offline
Director
User avatar

Joined: Sun Sep 14, 2008 6:51 am
Posts: 68896
Location: Usually in bed with Gibbs
Title: Gibbs' Gal forever
Name: Patsy
Aliases: pattywatty
Gender: Female
link: My Author Board
link: My Fanfic.net
Flag: Image
In general the saltier water is denser so sits below the fresher water which is less dense. The temperature differences depend on the temperature of the river water which is colder than the oceans in the winter but is a similar temperature to the oceans in the summer months. The relationship between saltiness, temperature and density is a complicated, non-linear one but in an estuary, as we have seen in the video, the dominant control on density is the salinity of the water. Colder fresh water flowing in from the land flows over the top of warmer saltier seawater and is mixed up in the estuary as the tide comes in and out.
In solution mining, wells are erected over salt beds or domes (deposits of salt forced up out of the earth by tectonic pressure) and water is injected to dissolve the salt. Then the salt solution, or brine, is pumped out and taken to a plant for evaporation. At the plant, the brine is treated to remove minerals and pumped into vacuum pans, sealed containers in which the brine is boiled and then evaporated until the salt is left behind. Then it is dried and refined. Depending on the type of salt it will be, iodine and an anti-clumping agent are added to the salt. Most table salt is produced this way.

When solution mines are located near chemical plants, they are called brine wells, and the salt is used for chemical production. After the salt is removed from a salt mine, the empty room often stores other substances, like natural gas or industrial wastes.

Salt is harvested through solar evaporation from seawater or salt lakes. Wind and the sun evaporate the water from shallow pools, leaving the salt behind. It is usually harvested once a year when the salt reaches a specific thickness. After harvest, the salt is washed, drained, cleaned and refined. This is the purest way to harvest salt, often resulting in nearly 100 percent sodium chloride. Only areas with low annual rainfall and high evaporation rates -- Mediterranean countries and Australia, for example -- can have successful solar evaporation plants. Usually machines perform this harvest, but in some areas it is still done by hand.

___________________________
Words in this post: 371
_______________________
Image]
ImageImageImage

sig by McMhuirich thank you


Top
 Profile  
 
 Post subject: Re: Exploring our Oceans
PostPosted: Sun Nov 05, 2017 10:38 am 
Offline
Director
User avatar

Joined: Sun Sep 14, 2008 6:51 am
Posts: 68896
Location: Usually in bed with Gibbs
Title: Gibbs' Gal forever
Name: Patsy
Aliases: pattywatty
Gender: Female
link: My Author Board
link: My Fanfic.net
Flag: Image
on average, seawater contains something like 35 grams of salt for every litre of water. And if we evaporate that water, we find we have salt crystals. it was the Romans that actually worked out how to evaporate tasty salt crystals from seawater to get rid of the chalky calcium carbonate and the really bitter magnesium salts that are the minor components of seawater and produce crystals which we can sprinkle on our food. So every element that is present on this planet, in the solar system indeed, is present in seawater at some concentration. At the higher end, we have chloride, which is present at 19 grams in every litre of seawater. And we can measure this relatively easily by titrating the chloride against chemicals to work out what the concentration is.

___________________________
Words in this post: 133
_______________________
Image]
ImageImageImage

sig by McMhuirich thank you


Top
 Profile  
 
 Post subject: Re: Exploring our Oceans
PostPosted: Sun Nov 05, 2017 10:43 am 
Offline
Director
User avatar

Joined: Sun Sep 14, 2008 6:51 am
Posts: 68896
Location: Usually in bed with Gibbs
Title: Gibbs' Gal forever
Name: Patsy
Aliases: pattywatty
Gender: Female
link: My Author Board
link: My Fanfic.net
Flag: Image
The salt comes from weathering and volcanic activity. The oceans formed very early on in Earth history, as soon as water comes into contact with rock then weathering processes start - these leach (dissolve) the soluble elements preferentially out of the rock (sodium, calcium, magnesium, potassium etc). There isn’t very much chlorine or sulphur in rocks but there is lots in volcanic gases and it readily dissolves in water in the atmosphere to form chloride and sulphate that rains into the ocean. If these processes go on for billions of years we get salty oceans.

Where evaporation outweighs precipitation, surface seawater will become more salty. Local seawater salinity is also enhanced if there aren’t many rivers nearby, and/or if the basin is restricted, as the high salinity seawater can’t mix very well with seawater of normal salinity in this case. The Red Sea is a good example and has an average salinity of 40. Eventually high salinity water from restricted basins does escape and enter global circulation. Higher and lower salinity waters are still recognisable a long way from their source due to slow ocean mixing.

The reason river water is fresh is also due to evaporation. When water evaporates from the ocean surface, the salts don’t evaporate with it. It’s this freshwater that eventually ends up in rivers. That’s why we end up with a totally different balance of salts in rivers and oceans.
What is the difference between land and sea salt?

Salt that is found on the land can come from evaporated ancient oceans, for instance, in the south of Spain today, there are large deposits of gypsum and salt that formed during a period of time known as the Messinian Salinity Crisis. During this period, several kilometres of seawater evaporated from cut-off basins, and left behind a series of minerals, including halite (rock salt) in thick layers. This salt would have been in similar concentrations to the salt in the oceans today.

However, there are other sources of salt on the land. The photographs of volcanoes on this site are incredible. It is run by a team of volcanologists who travel the world and photograph volcanic activity. In Dallol, there are vast salt lakes that are formed in a completely different way. Here, the groundwater is heated from below, as the plates are pulling apart in the region, and the magma is close to the surface, hence the series of Great Lakes and volcanoes throughout the Rift Valley.

When this water is heated, it dissolves a wide range of minerals in the pore waters, and brings them up to the surface. When they reach the surface they cool, and the salt in the waters returns to its crystalline form. Because this salty water is effectively “erupted” at high temperatures, it forms a variety of unusual, and often very short-lived geological features, such as the “hornitoes” seen in some of these photos. The end result is a region very rich in salt, which has been mined for several centuries. The colours in the photographs come from a range of accessory minerals that are also dissolved by the hot waters.

___________________________
Words in this post: 522
_______________________
Image]
ImageImageImage

sig by McMhuirich thank you


Top
 Profile  
 
 Post subject: Re: Exploring our Oceans
PostPosted: Tue Nov 07, 2017 10:17 am 
Offline
Director
User avatar

Joined: Sun Sep 14, 2008 6:51 am
Posts: 68896
Location: Usually in bed with Gibbs
Title: Gibbs' Gal forever
Name: Patsy
Aliases: pattywatty
Gender: Female
link: My Author Board
link: My Fanfic.net
Flag: Image
:gah:
We Know that rivers contain only a tiny fraction of salt compared to the waters of the ocean.

Before we go on to investigate what else accounts for the difference, let’s take some time to think about:

How much salt is there in one cubic metre of seawater?
How much salt is there in the entire volume of seawater in the oceans?
If all the water in the oceans evaporated, how deep would the layer of salt left on the seafloor be?

And you wonder why I can't sleep at night. ;D

___________________________
Words in this post: 109
_______________________
Image]
ImageImageImage

sig by McMhuirich thank you


Top
 Profile  
 
 Post subject: Re: Exploring our Oceans
PostPosted: Tue Nov 07, 2017 10:22 am 
Offline
Director
User avatar

Joined: Sun Sep 14, 2008 6:51 am
Posts: 68896
Location: Usually in bed with Gibbs
Title: Gibbs' Gal forever
Name: Patsy
Aliases: pattywatty
Gender: Female
link: My Author Board
link: My Fanfic.net
Flag: Image
There is, on average, 35 g of salt in every litre (L) of seawater
• The volume of water in the oceans is V = 1.34 × 1018 m3
(A cube with 1 km sides contains 109 m3
, so that is 1.34 billion cubic kilometres)
• The oceans cover a surface area of A = 3.58 x 1014 m2
(A square kilometre contains one million square metres (1 km2 = 106 m2) so the surface area of the Oceans is 3.58 x 108 km2 or 358 million square kilometres.)
• Note that the official figure from National Oceanic and Atmospheric Administration(NOAA) is 361,900,000 km² - our calculations are approximations and the Earth is not
perfectly spherical. That figure is accurate to within 0.1% (100,000 km2) – equivalent to the area of Iceland.

Q1: How much salt is there in one cubic metre of seawater?
Given that there are 35 g of salt in 1 litre, this means there are 35 x 1000 = 35000 g or 35 kg
per cubic meter. This is usually written as a concentration, 35 kg m-3
The recommended daily intake is approximately 5g per person, so one litre provides a week’s
supply of salt.

Q2: Then how much salt is there in the entire volume of seawater?
Now that we have the concentration, we can simply multiply this by the volume of the oceans.
Mass of the salt in all the oceans, M = concentration x V = 35 x 1.34 x 1018 = 4.69 x 1019 kg

To two decimal places of accuracy, M = 4.7 x 1019 kg or approximately 50 million billion tonnes
of salt.

Q3: If all the water evaporated, how thick would the layer of salt be
on the ocean floor?
The density of salt, ρ = 2.16 g cm-3 (grams per cubic centimetre)
Scientists use Greek letters as a shorthand for physical properties, and ρ (the letter rho, pronounced ‘ro’ to rhyme with ‘toe’) is often used for density.
There are one million cubic centimetres in a cubic metre and 1000 grams in a kilogram, so to express the density of salt in SI units we need to multiply by 106 and divide by 1000.This gives ρ = 2.16 x 106 / 1000 = 2.16 x 103 kg/m-3 or just over 2 tonnes per cubic metre.
Density = mass / volume
We can rearrange this formula to find the volume of salt: volume = mass/density, so V = M/ρ = 4.7 x 1019 / 2.16 x 103 = 2.176 x 1016 m3
To the correct significant figures, the volume of salt is then 2.2 x 1016 m3 or 22 million cubic kilometres.
Now this volume has to spread over the total area of the oceans, A = 3.58 x 1014 m2, using theformula depth = volume / area = 2.2 x 1016 / 3.58 x 1014 = 61.45 m.
So the depth of salt would be approximately 61 m.
This is clearly not realistic, as the thickness would vary in proportion with ocean depth. The layer of salt would be thicker at the deepest parts, very thin near the shoreline and could obviously never be more than the original sea level. In the far future, our sun will heat up as it ages and the Earth’s atmosphere and oceans will boil away into space, so all the water will evaporate and leave a thick layer of salts on the ocean floor. Don’t panic – this will not happen for another few billion years!
Note that rock salt (halite) formed when ancient lakes and seas evaporated.

How do you think that some salt mines are found in mountainous regions, such as near Salzberg in Germany?
:gah: another sleepless night :lol2:

___________________________
Words in this post: 637
_______________________
Image]
ImageImageImage

sig by McMhuirich thank you


Top
 Profile  
 
 Post subject: Re: Exploring our Oceans
PostPosted: Tue Nov 07, 2017 10:30 am 
Offline
Director
User avatar

Joined: Sun Sep 14, 2008 6:51 am
Posts: 68896
Location: Usually in bed with Gibbs
Title: Gibbs' Gal forever
Name: Patsy
Aliases: pattywatty
Gender: Female
link: My Author Board
link: My Fanfic.net
Flag: Image
A 10 litre bucket of seawater contains 350g of salt
The oceans cover 70% of the surface of the earth
The area of the oceans is 3.58 x 108 km2 or about 360 million square kilometres. How does that compare with your home country?
There are about 50 million billion tonnes of salt in the whole ocean. How does that compare to the amount of rubbish dumped into landfill sites annually?
The volume of the total amount of salt in the ocean is 2.2 x 1016 m3 If that was a cube, how large would it be? How would it compare to Mount Everest?
If all of the water was evaporated out of the oceans and the remaining salt was spread evenly over the sea floor, the salt would be about 61 metres thick. How does that compare to the average depth of the oceans?

___________________________
Words in this post: 145
_______________________
Image]
ImageImageImage

sig by McMhuirich thank you


Top
 Profile  
 
 Post subject: Re: Exploring our Oceans
PostPosted: Tue Nov 07, 2017 1:11 pm 
Offline
Director
User avatar

Joined: Sun Sep 14, 2008 6:51 am
Posts: 68896
Location: Usually in bed with Gibbs
Title: Gibbs' Gal forever
Name: Patsy
Aliases: pattywatty
Gender: Female
link: My Author Board
link: My Fanfic.net
Flag: Image
Why are differences in density important?
Much of our knowledge about how the deep oceans circulate is based on measuring the various parameters of the water column, and one of the most important instruments used by oceanographers is called a “CTD”. This piece of scientific equipment measures the conductivity (C) and temperature (T) of the seawater, and pressure to derive the depth (D) of the seawater.

A CTD measurement in the upper few hundred metres of the eastern north Atlantic would show a trend of warm salty water towards cooler and fresher water properties. At about 1000 m depth one would again measure relatively warm salty water which had formed in the Mediterranean Sea and then travelled through the Strait of Gibraltar. On reaching the maximum ocean depth of over 4000 m, the water would show cooler temperatures and salinities lower than Mediterranean waters but still relatively salty. So where did this deeper water come from?

In the polar regions such as the Arctic, the water is cold enough for the ocean to freeze. As the ice crystals develop and coalesce, a very salty residue is left behind. This is called ‘brine rejection’. Adding salt means that the water increases in density and the water sinks until there is no denser water beneath it. This means that the cold and salty water in the North East Atlantic Ocean is actually from the Arctic!

The sinking water displaces water beneath and ‘pulls’ new surface water to the deep water formation location, in this way large scale horizontal currents are set up. Over long periods of time the density differences have set up what is called the global thermohaline circulation (working like a huge conveyor belt system).

https://www.sciencelearn.org.nz/resourc ... an-density

___________________________
Words in this post: 294
_______________________
Image]
ImageImageImage

sig by McMhuirich thank you


Top
 Profile  
 
 Post subject: Re: Exploring our Oceans
PostPosted: Tue Nov 07, 2017 1:36 pm 
Offline
Director
User avatar

Joined: Sun Sep 14, 2008 6:51 am
Posts: 68896
Location: Usually in bed with Gibbs
Title: Gibbs' Gal forever
Name: Patsy
Aliases: pattywatty
Gender: Female
link: My Author Board
link: My Fanfic.net
Flag: Image
https://svs.gsfc.nasa.gov/vis/a000000/a ... r_iPod.m4v

http://www.gov.scot/Publications/2011/03/16182005/25

___________________________
Words in this post: 16
_______________________
Image]
ImageImageImage

sig by McMhuirich thank you


Top
 Profile  
 
 Post subject: Re: Exploring our Oceans
PostPosted: Thu Nov 09, 2017 11:25 am 
Offline
Director
User avatar

Joined: Sun Sep 14, 2008 6:51 am
Posts: 68896
Location: Usually in bed with Gibbs
Title: Gibbs' Gal forever
Name: Patsy
Aliases: pattywatty
Gender: Female
link: My Author Board
link: My Fanfic.net
Flag: Image
So now let's think about hydrothermal inputs to the ocean. And let's start with something that's un-reactive, a noble gas, helium. Helium is present everywhere on this planet, in the atmosphere, and the ocean, and it comes in two forms. There's the helium 4 isotope, which is formed from radioactive decay and is the dominant form. And then a minor component is the helium 3 isotope that was present right at the start of planetary formation and is being captured in the interior of the planet and is present at high concentrations in the magma inside the planet.

Now, helium 3 is so light that once it escapes from the magma into the ocean, it'll get into the atmosphere and it'll actually get out into space. And so it's not retained by the planet. It just transits through and it's very useful for us, therefore, as a tracer of these processes in the ocean. So the ocean circulation into the magma mines the heat from the magma and it mines the helium 3 from the magma. And therefore, when the vents erupt on the sea floor, they're enriched in the helium 3 isotope, and we can therefore trace this plume of water many thousands of kilometres right the way across the ocean.

So it's a very useful tracer, an inert tracer of our hydrothermal inputs to the ocean. So we've seen that hydrothermal vents are enriched in trace metals and in hydrogen sulphide. And if you think about the element iron, we know that vent flues are enriched something like a million times over background seawater levels. So we're going to pass over to Will who is going to tell us about what happens when iron is supplied to the deep ocean, what is the fate of that iron, and where does it go in the ocean.

Now, compared to sodium and chloride, iron is only a tiny fraction of the seawater's composition, but it's essential for us to understand because plants that photosynthesize in the surface ocean need this iron. This is an essential nutrient for the photosynthetic process. Iron has a very short residence time in the oceans, too-- just a few tens of years compared to the millions of years the sodium and chloride may hang around. A huge amount of iron enters the ocean from hydrothermal vents. But as it does so, this iron enters an ocean which is comparatively cold, alkali and oxygenated compared to deep within the crust where it was once formed.

And consequently all this iron re-precipitates as sulphide and oxide minerals that form the iconic chimney structures and black smoke that we see emitting from the mid-ocean ridges. Now until recently, we believe these sediments forming locally around hydrothermal systems effectively trapped all of the iron circulating through the crust for these hydrothermal fluids. However new research indicates that a tiny fraction of this iron may, in fact, enter the ocean and be transported for thousands of kilometres within the deep ocean basins. Because iron is so scarce in the ocean, even a tiny fraction of iron circulating through the hydrothermal fluids, if this enters the ocean, for example, one millionth, it could have a big impact on the oceanic budget of iron.

And in fact what, we observe in the ocean is iron has a patchy distribution. So unlike sodium and chloride, we find iron in different concentrations in different parts of the oceans. And this reflects the different sources and removal processes in the oceans. Iron enters the ocean from a number of different sources. It's blown in from the continents as dust settling out of the atmosphere and dissolving in the surface ocean. It's also dissolved from sediments deposited on the continental margins. And as we've seen today, it leaks from hydrothermal vents on the sea bed. And the rivers, too, contribute an important fraction of iron that enters the ocean.

And all these sources form an important part of the oceanic iron inventory, and as scientists we seek to understand the importance of these different sources and how they might vary through time and in space, because this is essential if we want to understand the distribution of life living in our oceans.

___________________________
Words in this post: 706
_______________________
Image]
ImageImageImage

sig by McMhuirich thank you


Top
 Profile  
 
 Post subject: Re: Exploring our Oceans
PostPosted: Fri Nov 10, 2017 10:02 am 
Offline
Director
User avatar

Joined: Sun Sep 14, 2008 6:51 am
Posts: 68896
Location: Usually in bed with Gibbs
Title: Gibbs' Gal forever
Name: Patsy
Aliases: pattywatty
Gender: Female
link: My Author Board
link: My Fanfic.net
Flag: Image
in southern South Africa, north of Port Elizabeth, on the site of Grassridge, where some fossilised oysters, their age is based on the fossil, Plio-Pleistocene, that's about 1 to 5 million years old. The elevation is around 235 metre above present day 0. So the question we have is how did the sea came at this level? Did sea level rise, or did the continent uplifted, or what is the balance between the two?

This oyster bed raised some oyster that are in place, so they have been fossilising in living position, such as this one. Where the two valves of the oysters are still together and showing up. So this indicate that the oyster has been fossilising in the living position-- such as this one. So there is the two valves. The larger one is the bottom one, and then the final one go on top. So the animal was living here. And what's characterised many of the fossils is the shells are very thick and large. And they are three, five-- up to five centimetre thick. And that suggests that oyster was living under stress condition.

And it has to produce a lot of calcium carbonate, and more during at-- more during the day, and this of less during the night. And then in between the shells there is this fine, muddy, sandy material that suggest some very low energy environment. This oyster has the two valves still in place. And on the valve and on many of the fossil, we can see there is no trace of epibiont of animal boring the shell. The shells are very thick. Here are the growing layers of the-- in the fossils. And in between the matrix is this greenish, sandy mud that indicate an environment with low energy, such as an estuary.

Global sea level is known to have fluctuated by several hundreds of meters over the past 100 million years as indicated by marine fossils preserved at various elevations on the continents. However, the exact amplitude of these sea-level changes is uncertain and, in reality, a discrepancy of about 200 m exists between different models.

Here, strontium isotope stratigraphy is used to date fossils from marine environments preserved at relatively high elevations (150 to 350 m above present-day sea level) along the southern coast of South Africa. The Strontium isotope composition of the ocean is known to have changed through time, as measured from marine fossils (shark teeth, sea urchins, corals etc…) of different ages that record the strontium isotope composition of the seawater in which they were living. Using the global curve of strontium in the ocean through time, we can therefore tell what is the age of an unknown marine fossil. We can tell whether a fossil is 1 Million years old, 5 Million years old or even 50 million years old.

The Grassridge locality in the video is special because oysters are largely predominant and very little other fossil types have been found. Moreover in this outcrop some of the oysters are preserved in living position, which indicate in-situ conditions.

Pristine fossils are collected and taken back to the lab. Mass spectrometry analyses were undertaken at the MIT Radiogenic Isotope Laboratory. The strontium isotope results date the oysters bed at Grassridge being 1 to 5 million years old, depending on the amount of possible subsequent contamination by fresh water.

The next phase of Bastien’s research involves a world-class and state of the art facility; the Centre for High Resolution Transmission Electron Microscopy at Nelson Mandela University. This work aims to identify which part of the fossil material is unaltered and thus most robust to date.

The new data indicate at least two episodes of marine transgression (where sea level rises relative to the land), during the Oligocene-Miocene (33.9 to 5 million years ago), and again during the Pliocene-Pleistocene (5 million years to 12,000 years ago).

All of this aside, if we assume that the subcontinent of southern Africa has not moved up and down during the period between which the oysters were deposited at Grassridge (5-1 Ma), and when some of the first prehistoric humans colonized the now submerged continental shelf south of South Africa, (150 m below present-day sea level over the last 100 thousand years) this study suggests maximum amplitudes of sea-level change of up to 400 m. Such large fluctuations in sea level change must have impacted on early human occupation.

___________________________
Words in this post: 738
_______________________
Image]
ImageImageImage

sig by McMhuirich thank you


Top
 Profile  
 
 Post subject: Re: Exploring our Oceans
PostPosted: Mon Nov 13, 2017 11:15 am 
Offline
Director
User avatar

Joined: Sun Sep 14, 2008 6:51 am
Posts: 68896
Location: Usually in bed with Gibbs
Title: Gibbs' Gal forever
Name: Patsy
Aliases: pattywatty
Gender: Female
link: My Author Board
link: My Fanfic.net
Flag: Image
he concern about noise pollution in the marine environment has increased dramatically in recent years as it has become evident just how much anthropogenic (human-made) sound is entering the marine environment through shipping, seismic exploration of the oceans, coastal development (such as ports) and even recreational activities (like jetskis etc.).

The reason this is of concern is that it has become evident over the past 10+ years that whales and dolphins can really be considered ‘acoustic creatures’ as they rely on sound for every aspect of their life: for finding food, for navigation, and also for communication and finding mates. However, understanding exactly how cetaceans hear and how sound affects them is not easy as cetaceans can rarely be studied in a controlled, experimental environment. Thus anatomical studies of cetacean ears have played an important role in our understanding of how cetaceans have adapted to hearing under water, what frequencies they can hear, and how sounds affect them.

Sonic Sea is an award-winning 2016 documentary about the impact of anthropogenic noise on marine wildlife. You can watch the trailer for free online. This is an ongoing area of research; military sonar operations have been linked to four stranding cases of beaked whales worldwide, but this is only a very small proportion of strandings that occur globally for a variety of reasons.

The Discovery of Sound in the Sea website has a wide range of information on this subject and you can also listen to underwater sounds created by marine animals, human activities, and natural phenomena in the audio galleries of the site.

It’s also not just large animals like cetaceans that are affected by the noises that we make: invertebrates that play a vital role in ecosystems and dwell in marine sediments can also be affected, altering the way they interact with the environment and the wider ecosystem. A link to a study by University of Southampton researchers is given at the bottom of this step for learners who would like some more advanced material.

© University of Southampton 2017

___________________________
Words in this post: 340
_______________________
Image]
ImageImageImage

sig by McMhuirich thank you


Top
 Profile  
 
 Post subject: Re: Exploring our Oceans
PostPosted: Tue Nov 14, 2017 12:20 pm 
Offline
Director
User avatar

Joined: Sun Sep 14, 2008 6:51 am
Posts: 68896
Location: Usually in bed with Gibbs
Title: Gibbs' Gal forever
Name: Patsy
Aliases: pattywatty
Gender: Female
link: My Author Board
link: My Fanfic.net
Flag: Image
In the deep sea, there are four major variables we have to consider-- salinity, which remains remarkably constant; temperature, of course, which varies from about minus 1. 5 up to 400 degrees Celsius; and oxygen is also very variable, from essentially full oxygen in certain areas down to relatively low oxygens and even hypoxic regions-- that's low-oxygen regions. But possibly the most important variable-- physical variable-- within the deep sea is pressure. And pressure increases 1 atmosphere per 10 metres. And so this turns out to be the longest single environmental gradient on Earth. The other important feature is the availability of food for animals to survive in the deep sea.

The top 200 metres of the water column is called the euphotic zone, where there is usually sufficient sunlight for microscopic algae, known as phytoplankton, to grow through photosynthesis.

But faint sunlight reachers much deeper, through the dysphotic zone (or twilight zone) between 200m and 1000m deep. Many deep-sea species in the dysphotic zone have evolved very large eyes to detect shadows cast by prey in the faint downwelling of light of that zone.

Beyond 1000 metres lies the deeper aphotic zone (or midnight zone), where no light from the Sun ever reaches - but some species still create light from bioluminescence.

___________________________
Words in this post: 213
_______________________
Image]
ImageImageImage

sig by McMhuirich thank you


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 20 posts ] 

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group