All At Sea?
Nearly 80 percent of our planet is covered in water. Marine scientists study the oceans to try to understand the vital importance of this part of our world which we know so little about, yet rely on for our very existence.
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The Science of Oceanography.
Information from the EEA.
This may come as a bit of a surprise, but we know less about the seas on our world than we do about the surface of the moon. The now iconic "Blue Marble" photograph [right] taken from the Apollo 17 mission in 1972, clearly shows the enormity of our oceans. This was the first time people had seen our home planet in its entirety and this image has had a profound effect on how we perceive ourselves and our place in the Universe.
The oceans are so large that some scientists think there could be over 10 million different types of creatures in the sea. The oceans are a vast and complex system of interconnected organisms and environments that cover over 70 percent of the planet, marine scientists study it to try to better understand the importance of this massive part of our world.
Marine biodiversity: life in seas under threat.
Climate change, pollution, acidification, over-exploitation of fish stocks, invasive alien species all threaten life in our seas and consequently the services we obtain from them. It is not only about seafood or a romantic sunset, our oceans are essential to us both ecologically and economically. They regulate our climate, produce oxygen and remove carbon from the atmosphere through processes such as photosynthesis. They are also home to an incredible number of species, with many new ones discovered on a regular basis, living in almost unimaginable settings. The worlds seas and oceans face an unprecedented range of pressures and require urgent action.
The tallest mountain on the earth.
Did you know, that the tallest mountain on the planet is not actually Mt. Everest, which is a measly 8848 m high!
The tallest mountain in the world is in fact Mauna Kea, in Hawaii, which is closer to 9100 m high, you just can’t see most of it as it is under the sea!
To date the Oceans have soaked up around half of the carbon dioxide emissions from the burning of fossil fuels, and that CO2 is gradually acidifying the oceans. This effect is known as Ocean Acidification, and it is very bad news if you live in a shell made from calcium carbonate, as your home will slowly dissolve around you.
Drop an eggshell into a glass of vinegar and leave it over night. What happens to it and why?
The Undersea World
Scuba [Self Contained Underwater Breathing Apparatus]
The aqualung was invented in 1943 by Jacques Cousteau and Emile Gagnan. The aqualung supplies air to the diver, from a compressed air cylinder worn on the back. The whole apparatus is simple, compact, and virtually weightless in water and has undoubtedly revolutionised the exploration of the sea,
In 2010, using modern SCUBA gear, 22 year old Sofia Ponce achieved the incredible feat of diving 190 m down into the open ocean. That is deep, but is nothing compared to the Mariana Trench, home of the Challenger Deep.
Where Is The Deepest Place on Earth?
The Challenger Deep is located in the Western Pacific Ocean near the island
of Guam in the Mariana Trench, is the deepest known location on earth. In
May 2009 a dive by the Nereus submersible robot. Achieved a depth of 10,902
metres (6.8 miles) and makes Nereus the world's deepest-diving vehicle currently
in operation. To accomplish this dive, the vehicle had to sustain pressures
that were 1,000 times that at Earth's surface.
The Nereus is the third vehicle in the world to reach the bottom of the Challenger Deep in the Pacific Ocean. The first was the Bathyscaphe Trieste, which was the the first and only manned submersible to reach the bottom of the trench, carrying two men, U.S. Navy Lieutenant Don Walsh and Swiss engineer Jacques Piccard on January 23, 1960. On 24 March 1995 Kaiko, a Japanese robotic deep-sea probe, made the first unmanned trip to view the trench.
The Virgin Oceanic Expedition
For the first time in history, the deepest trenches in
each of the five oceans will be open to us for surveying, mapping and sampling
from an occupied sub. No current human-occupied subs can dive deeper than 6,500
meters (21,325 feet), so most of the ocean's trenches have only been explored
with robotic vehicles [ROV's] and some trenches not at all.
For the scientists who study the deepest parts of the ocean and the creatures that live there, the crew will be able to give first hand accounts of what is down in the deep. The sub will be able to 'fly' down into each of these trenches, adding detail to existing maps, as well as collecting real-time temperature, water chemistry measurements, high-definition video footage and microbiological samples at known points along the dive path.
No one has yet documented the entire vertical sequence of life in the world's oceans in a single place. This incredible voyage could provide the first complete record of biological diversity from top to bottom in the world's oceans.
- Dive 1. Arctic ocean, Malloy Deep. 5,606m
- Dive 2. Southern Ocean, South Sandwich Trench. 7,235m
- Dive 3. Indian Ocean, Diamantia Trench. 8,047m
- Dive 4. Atlantic Ocean, Puerto Rico Trench. 8,380m
- Dive 5. Pacific Ocean Mariana Trench. 11,034m
Research: The Challenger
Expedition. International Ocean Drilling Program. Jacques cousteau.
Deep Diving. Virgin Oceanic
Why is the Challenger Deep so deep?
The earth's crust isn't one solid piece of rock, it's really pretty thin, like the shell of an egg is compared to the size of the egg. In fact, it's made up of huge plates of thin crust that "float" on the molten rock of the earth's mantle. While floating around on the mantle the edges of these plates slide past each other, bump into each other, and sometimes even crash. The oceanic crust is much heavier than the continental crust so when the plates crash into each other, the oceanic plate plunges downward toward the molten mantle, while the lighter, continental plate rides up over the top. The forces driving the two plates together are incredibly strong, and so the underlying oceanic plate (the subducted plate) creates a trench where it drags the edge of the continental crust down as it descends underneath. This is what's happening on the bottom of the Pacific Ocean off the Marianas islands. The really deep part of the ocean is in the bottom of the trench created by the subducting ocean crust.
Biotechnological research might be able to produce organisms that can be grown specifically for their high energy characteristics to make biofuels, eating pollution and other applications.
Fluorescence found in
Bahamian brain coral, pictured
above. May provide new
A Biological Treasure Chest.
Natural chemicals made by undersea snails, algae and bacteria, are very different than those from up here on the surface. The sea has already given up some of its secrets. Scientists have made a new antibiotic from a fungus, two closely related compounds from a sponge that can treat cancer, and a neurotoxin from a small sea snail that is a thousand times stronger than most common painkillers.
Scientists at Plymouth Marine Laboratory are active in the area
of marine biotechnology, looking for sustainable solutions from the sea that
will be of benefit to society. Marine biotechnology is a rapidly growing
sector that includes a wide range of disciplines to develop alternative products
from the sea.
The Carbon Trust is working with PML to find a formula for cultivating biofuel from algae. The aim of the project is to look at thousands of different algae to find one which will be able to produce a substance similar to vegetable oil, to make biofuel which could then lead to large scale commercial production.
The ultimate aim of the project is to reduce our reliance on fossil fuels and provide a viable alternative to land-crop biofuels.
Algae is a variety of aquatic organisms that have no stems or leaves, but can mostly be classified as plants as they go through Photosynthesis.
Algae were among the first organisms on the planet, and their signatures have been found in rocks 1.2 billion years old, but they could be even older.
Land plants evolved from green algae about 500 million years ago
Atmospheric CO2 produced by burning of fossil fuels, is thought to be largely responsible for current warming. However, scientists have known for some time that the gas also goes through natural cycles. By far most of the world's mobile carbon is stored in the oceans - 40 trillion metric tons, or 15 times more than in air, soil and water combined. But how this vast marine reservoir interacts with the atmosphere has been a subject of debate for the last 25 years.
The study indicates what many scientists have long suspected, but could not prove: sometimes the oceans can release massive amounts of CO2 into the air as they overturn. The upwelling and release of this carbon dioxide matches well with rapid warming and rises in atmospheric CO2 shown in glacial ice cores from Antarctica and other far-flung records. The researchers believe that largely as a result of these episodes, CO2 in the atmosphere went from 190 parts per million (ppm) during glacial times to about 270 ppm, and remained at that level until recently. A similar but much more rapid rise, to 380 ppm, has taken place since the Industrial Revolution - most of it in the last few decades. Both rises almost certainly affected climate warming.
Eureka! So that’s what floats my boat.
2200 years ago the mathematician Archimedes famously leapt out of the bath exclaiming 'eureka!' which means I have found it in ancient Greek. And what he found is still with us today, the Archimedes Principle states that “A solid object placed in a fluid, will be immersed until the weight of the solid is equal to the weight of the fluid displaced.” Which is why your weight of water spills out of a full bath when you get in to it.
It is this principle that allows
us to float boats that weigh eighty thousand tons on water, and lead to the
development of early flying machines. Archimedes
- born 287 BC in Syracuse (Sicily). He is widely considered to be one of
the greatest mathematicians of all time.
Research: Archimedes Principle, laws of buoyancy, burning
mirrors, super tanker.
The Archimedes’ principle
The upward force on an object totally or partially submerged in a fluid
is equal to the weight of fluid displaced by the object. When an object
is immersed in a liquid, it is buoyed up by a force equal to the weight
of the liquid displaced. There are two forces acting on the object. The
weight of the object acting downwards pushing it down and the buoyant
force acting upwards pulling it up. The net result is an outcome or resultant
of the strength of the two forces. In the case of a floating ship, the
weight of the volume of water displaced is always greater than the ship’s
weight, hence it sails [caution! if water enters inside to the brim,
it sinks due to the increased strength of the force (weight) pushing
Sound Navigation And Ranging.
Sonar can be used to locate the bottom of the sea, which is handy if you don’t want to crash your boat! It works like this; a sound pulse is sent out from the bottom of the boat and is timed on its return, and then, using a simple equation we can work out the distance between the bottom feeders and us. We multiply the speed of sound in water, [approximately 1.5 kilometres per second] by half the time the signal takes to return to the sender, easy! Ancient mariners used a very long knotted rope with a heavy lead weight on the end to take 'soundings' and by counting the knots they could work out how far the bottom was from the boat.
What an echo sounder does is send high frequency sound waves (outside the range of human hearing) through the water down to the ocean bottom. Sound waves will travel through water, even faster than they travel through the air, and bounce off solid objects, such as the ocean bottom. The echo sounder measures precisely how long it takes for the sound waves to be returned to the surface and determines the depth based on the rate of return. These soundings are plotted on a graph by a computer to make an "echo map" of the ocean bottom.
The speed of sound in air is 343 meters per second. This equates to 1236 kilometres per hour. Amazingly sound travels 4.3 times faster in water at 1484 meters per second, about 5347 kilometres per hour. Which incidentally is much, much, much faster than the common snail, who moves at a mind numbingly slow 0.048 kilometres per hour.
Why does sound do that?
The reason sound travels faster in a liquid is because sound is a vibration of kinetic energy passed from molecule to molecule. The closer the molecules are to each other and the tighter their bonds, the less time it takes for them to pass the sound to each other and the faster sound can travel. So it's easier for sound waves to go through liquids than through gases because the molecules are closer together and more tightly bonded in liquids [sound will travel faster still through a solid for the same reason]
The first analytical determination of the speed of sound was given by Isaac Newton in the Principia Mathematica 1687.
Feature article: Tidal Power. Feature company: Marine Current Turbines.
Increasingly we are looking at clean renewable energy sources,
and the sea has huge tidal power within it, but until now it has not been
practical to harness that power. There is a lot of interest in the power
industries for off shore wind farms, wave power, tidal barrages and tidal
turbines. The idea is not a new one. Over forty years ago the French La Rance
Tidal Barrage was the world's first tidal power station, in Brittany,
France. It opened on the 26th November 1966. Recently a British company Marine
Current Turbines installed the World’s first offshore tidal current
powered turbine 'SeaGen' in Northern Ireland in 2008.
SeaGen is sited in Strangford Lough a large (150km2) shallow tidal inlet situated on the east coast of Northern Ireland, which connects through a deep narrow channel to the North Sea. The tidal flow creates strong currents in the narrow channel which is the ideal site for the 1.2MW tidal turbine,which has delivered its two millionth unit of electricity into the UK electricity grid. It is now operating 24 hours, seven days a week.
If we could harness all the potential tidal power around the UK's coastline it would supply badly needed electricity to the National Grid, without a carbon emission in sight!
Why bother with all that Sea Power, it seems
like a lot of hassle. Why can't we just use oil, natural gas and coal?
Well what happens when you burn oil, coal and natural gas? These are known as ‘fossil fuels’, because they are literally the fossilised remains of animals and plants that lived millions of years ago, and had, until he beginning of the Industrial Revolution around 1850, remained safely buried in the ground.
To make coal, you need trees, swamps and plenty of time. Most of the world’s black coal was created between 360 and 290 million years ago in a period known, appropriately, as the Carboniferous.
Making oil is a more delicate process. Oil was formed from the dead bodies of tiny sea creatures, but these bodies had to be trapped, preserved, and cooked to exactly the right temperatures and pressures. That’s why oil is found in far fewer places than coal.
Since fossil fuels used to be alive, they are all made up of forms of carbon. Thus burning fossil fuels produces carbon dioxide.
The reason fossil fuels are so important to the climate change story is that they involve releasing carbon that had been buried for hundreds of millions of years, and really that is where it should have stayed.
The requirement for new and renewable energy technologies is being driven by the worlds needs to reduce greenhouse gas emissions in conjunction with the increasing global energy demands. Innovative British company Marine Current Turbines have come up with a worlds first. SeaGen which is the world's only commercially operational tidal turbine: feeding 10MegaWatt hours per tide into the UK grid
Marine Current Turbines Ltd has been involved with tidal energy technology development since the early 1990’s, initially with the Loch Linhe turbine and more recently with SeaFlow located near Lynmouth, North Devon. SeaGen is the name given to the 1.2MW tidal energy convertor that was installed in Strangford Lough in April 2008. Sea Generation Ltd is the project company which is a wholly owned subsidiary of Marine Current Turbines Ltd. SeaGen has been licensed for a maximum installed duration of 5 years. Marine Current Turbines Ltd have been operating the 300kW Seaflow tidal energy system at Lynmouth, Devon since May 2003 and are recognised as being one of the worlds leading tidal energy system developers.
SeaGen - the world's first commercially operational tidal turbine: feeding 10MWh per tide into the UK grid
The Environment Tabs are currently under development
[this section is under development]