The oceans are the heart of our planet, but we know more about Venus

The Guardian, in an Editorial on 7th August 2015, states: The tentative identification of a scrap of wing washed up on the Indian Ocean island of Réunion as part of the missing Malaysia Airlines flight M370 is a reminder of a paradox of scientific investment and capacity. Humans have identified and pinpointed the fabric of Beagle 2, a probe not much bigger than a dustbin lid, lost for more than 11 years on the plains of Mars, always more than 60m km (37m miles) away. But so far they have not found a giant Boeing 777 lost 16 months ago in an ocean crossed by mariners for a thousand years. The oceans are the last unexplored region of the planet.

Oceanographers have complained for decades that the topography of the planet Venus — shrouded in a dense atmosphere raining sulphuric acid on to a terrain hot enough to melt lead — is better mapped than most of the surface of the blue planet Earth.

There are reasons, many of them understandable. Oceanography begins with expensive hardware in the form of specially designed or modified ships that must spend weeks in all weathers on any mission, and these ships have to be supported by submersibles that can operate under unimaginable pressures and with sensors that can “see” at depths reached by no light at all.

But the ocean is vast and the area so far visited by submersibles is tiny: perhaps about the size of London. For most of the history of exploration, navigators and navies alike have been interested in the islands, reefs and coastlines washed by the sea, but only in the late 20th century did anyone become aware that the longest continuous mountain range on Earth — 65,000km (40,000 miles) long — lay far below the waves.

The ocean is by far the oldest feature of the planet, far older than any of the granite continents, but unexpectedly the basalt ocean floor is far younger, and continuously being renewed by processes that no one knew anything about until the mid-1960s, nor even witnessed until the mid-80s.

The sea is the birthplace of all life on Earth. Every feature of all animal, plant and reptile life on land has evolutionary origins in the saline depths half-a-billion years ago, and the sea still represents the greatest single living space on the only planet known to be home to any life at all. Yet marine biologists have been able to examine at first hand only a tiny fraction of this living space, again, mostly around reefs and coasts. Orbiting satellites provide a picture of sorts, but one oceanographer likes to compare this to working out what a picnic blanket tells you about the grass and twigs underneath.

The ocean is the origin of the planet’s rainfall, the distributor of its heat and the arbiter of its climate. A distinguished scientist once calculated that the Gulf Stream delivered the thermal energy of 27,000 power stations, to keep Britain 5°C warmer than its latitude might dictate.

The sea is the most important thing on Earth, and the exquisitely thin but vast layer of the ocean where water and atmosphere meet is where the most vital processes take place. But almost the entire ocean surface is now polluted with plastic wastes. One 2015 study calculated that 8m tonnes of plastic waste flow from the land to the sea every year.

The life beneath it is being hunted or fished to near-extinction: the count of whales, dolphins, sharks, rays and turtles has fallen by 75% and some species, such as the so-called common skate, have been reduced by 99%.
Greenhouse gas emissions from human industry are making the seas ever more acidic, bad news for the corals and shellfish that have evolved to exploit the precise chemistry of the seas, and probably for many of the fish that depend on the reefs and mollusc beds.

Deep-sea oil-drilling threatens one kind of pollution; deep-sea mining — for cobalt, manganese, gold and silver – could make things worse.

There are new and ambitious attempts to create automaton observatories to monitor the seas and map the current. They have evocative names like Argo and represent new ways to observe what is going on either in the top 2000 metres or the deep-sea bed, but they are only a beginning, and funding for such science has always been precarious.

The European Science Foundation earlier this century floated a carefully drafted proposal for 10 maritime nations to share a state-of-the-art drilling ship, icebreaker and floating laboratory called Aurora Borealis to explore the Antarctic and Arctic Oceans, and the bedrock beneath, but it may never be launched. Politicians see no votes in oceanography.

We care about lives lost at sea, yet all life, and all civilisation, depends on the sea. But how much do we know about it?

Source: The Guardian, 7th August 2015. For the full text, see http://www.theguardian.com/commentisfree/2015/aug/07/guardian-view-on-ocean-science-care-more-and-invest-more

 

Source: DSCOVR : NASA-NOAA Deep Space Climate Observatory

Source: DSCOVR : NASA-NOAA Deep Space Climate Observatory

 

Marinet asks: You are looking at a planet in the solar system. Which planet is it? And, how have you arrived at your answer?

 

Marinet replies: It is of course the Ocean planet, Earth. And you know, because over 70% of its surface is covered by ocean. The oceans are the origin of all life, the engine that controls the climate, the source of more biodiversity than in the terrestrial realm, and essence of our existence. Yes, time to stop for a moment and to think.


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