Record Dive into the Deep Sea

No man has ever sunk so deep: with their submersible “Trieste”, Swiss oceanographer Jacques Piccard and US naval officer Don Walsh reach the Challenger Deep in the Mariana Trench – 10,910 metres below sea level. A sensation!

The metal sphere into which Piccard and Walsh squeeze themselves on the morning of 23 January is only two metres in diameter. They can barely stand upright. From 8.23 a.m. onwards, they start to descend: their submersible Trieste sinks one metre per second, 18-centimetre-thick steel walls separate them from the water masses of the West Pacific. No one knows for sure whether the submersible can withstand the enormous water pressure.

At 1.06 p.m. the two reach their ambitious goal: the seabed at the lowest point on earth. A column of water weighing more than 170,000 tonnes weighs on them. It is pitch dark down here. Nevertheless, Piccard claims to have spotted a flatfish through a Plexiglas window. Otherwise, there is little going on in the depths: no plants, no schools of fish. After a short stay, the adventurers begin the ascent.

The nerve-racking dive lasts nine and a half hours. When the two reach the top safe and sound, the jubilation is immeasurable. A milestone is reached – Piccard and Walsh throw a container with the American flag into the depths. With their sensational journey, the two will go down in the history of mankind.

Who is this Jacques Piccard?

Scientist, tinkerer and adventurer – all this applies to the Swiss Jacques Piccard. He was born on 28 July 1922 in Brussels. The spirit of discovery was in his cradle: His father Auguste was a physicist and inventor. After Auguste Piccard had set a balloon altitude record in 1931, he devoted himself to exploring the deep sea after the Second World War. His son Jacques jumped on the bandwagon: After studying economics and history, he developed the legendary submersible Trieste together with his father. The US Navy was impressed, financed test dives and bought the boat. Jacques Piccard became a scientific advisor and, against initial resistance from the Americans, managed to get on board for the record-breaking dive to the Challenger Deep. Hard to believe: the Trieste reached its destination at the lowest point on earth. Since this spectacular event, Piccard is on top of everything else: a pioneer of the deep sea!

The seabed

The surface of the oceans glistens in dark blue. It is hard to believe that the seabed lies many kilometres deeper in places and that a spectacular underwater landscape is hidden down there. For the seabed is not as smooth as the bottom of a swimming pool: On the seabed there are high mountains, deep trenches and lava-spewing volcanoes as well as vast plains.

The water of the oceans is not equally deep everywhere. Around the continents lie the shallow shelf seas. Here the seabed slopes gently downwards from the coastline until it reaches a depth of about 200 metres below sea level. The bottom of the shelf seas consists of continental crust. Therefore, it actually belongs to the mainland, even though it is covered by seawater.

Only many kilometres from the coast, on average after 74 kilometres, does the shallow shelf area end with the shelf edge. From this edge, it descends steeply, like a slide, to a depth of about four kilometres. This steep slope forms the transition to the deep sea, where no more light penetrates. That is why no plants grow down there. Only some animal species have been able to adapt to this habitat, despite the hostile conditions

In the midst of the oceans, mountains rise up into the air, the mid-ocean ridges. These underwater mountains stretch over long distances through all the world’s oceans. In some places they rise above sea level as islands. Iceland, for example, lies directly on the mid-Atlantic ridge, the longest mountain range in the world.

Deep trenches also run through the oceans. Most of them are in the Pacific. Among them is the Mariana Trench, the deepest trench in the world. It reaches down to 11,034 metres below sea level. Only two people have ever been down there: The marine explorer Jacques Piccard and his companion Don Walsh on their record-breaking dive in 1960.

Treasures at the bottom of the ocean

Deep down at the bottom of the ocean lie hidden treasures. We are not talking about the sunken booty of predatory seafarers here; we are talking about raw materials found on the ocean floor.

One of these raw materials is methane hydrate. This combustible ice is stored on the seabed at a depth of more than 500 metres. It has formed at low temperature and under high pressure from water and methane, which is produced by certain single-celled organisms during metabolism. The estimated deposits of methane hydrate contain over twice as much carbon as all the oil, natural gas and coal reserves on earth. Whether it can contribute to our energy supply in the future, however, is controversial. It is difficult to extract because it decomposes easily at higher temperatures, releasing methane. The danger here is that methane is a greenhouse gas. If too much of it enters the atmosphere, it will affect our climate and temperatures will rise.

At a depth of about 5,000 metres, there is another strange substance at the bottom of the Pacific Ocean: manganese nodules. These black lumps can grow to the size of potatoes, some even to the size of heads of lettuce. They are interesting to humans as a raw material because they contain large amounts of the metals manganese and iron. But the wrinkled structures also contain high amounts of copper, nickel and cobalt – metals that are needed in the electrical industry and for steel production. Whether their extraction is worthwhile still needs to be researched: Although they have a much higher metal concentration than ore mines on land, the mining of manganese nodules is particularly complicated because of the great ocean depths at which they occur.

The world of the oceans

Many secrets still lie dormant in the depths of the oceans. Large parts of the world’s oceans are still completely unexplored. We even know the moon better than the deep sea. What we do know, however: Almost all the water on this earth – 97.5 per cent to be exact – laps in the five oceans.

The largest of all oceans is the Pacific. Its water surface measures a total of 180 million square kilometres! This means that it accounts for about half of all ocean surfaces. At the same time, this world ocean is home to the deepest place on earth: it descends up to 11,034 metres into the Witja Deep in the Mariana Trench, a deep-sea trench in the western Pacific.

The Atlantic Ocean is the second largest ocean. It was formed about 150 million years ago when the primeval continent of Pangaea broke apart. With its 106 million square kilometres, it covers one fifth of the earth’s surface.

Most of the Indian Ocean lies in the southern hemisphere. With an area of just under 75 million square kilometres, it is a good deal smaller than the Atlantic and Pacific Oceans. Its deepest point is called the Diamond Low, which lies 8,047 below sea level.

The Southern Ocean is also called the Southern or Antarctic Ocean. It includes all sea areas south of the 60th parallel in the southern hemisphere. Sailors consider it the stormiest of all seas. Typical of the Southern Ocean are also the large tabular icebergs that float in its waters. They have broken off from the ice shelf that has formed around the Antarctic continent.

Around the North Pole lies the Arctic Ocean, also known as the Arctic Ocean. It is the smallest of the five oceans. About two-thirds of the Arctic Ocean is covered with ice in winter. But its ice cover, like the ice of the Southern Ocean, continues to melt due to global warming.

Even if we live several hundred kilometres away from them: Oceans are of great importance to us. Their currents and the evaporation of seawater have an enormous influence on our weather. A large part of the air we breathe is also produced in the oceans: Algae that live here convert carbon dioxide into oxygen when exposed to sunlight.

Oceanic and continental crust

The earth’s crust is not the same everywhere. The land masses of the Earth consist of continental crust, the ocean floor of oceanic crust. One of the differences is that the continental crust contains mainly silicon and aluminium in addition to oxygen. The oceanic crust, on the other hand, also has a high proportion of magnesium. But that is far from the only difference:

Oceanic crust forms at the bottom of the sea, where magma rises and solidifies along the mid-ocean ridges. As crust constantly grows back here, the two lithosphere plates are pushed outwards. Towards the coasts, the oceanic crust thus becomes older and older. Some of the oldest pieces are around 200 million years old. They lie in the Atlantic off North America and east of the Mariana Trench in the Pacific. However, the oceanic crust, which is about five to eight kilometres thick, does not get any older: because it is heavier than the continental crust, it submerges when it collides and is melted again in the Earth’s interior.

Although the continental crust is lighter, it is thicker than the oceanic crust: on average, it reaches 40 kilometres, under mountains even up to 80 kilometres in depth. When exactly it formed is still a mystery even to scientists. The oldest known rock on Earth provides clues: it was found in northern Canada, is over four billion years old and is probably a remnant of the very first crust.

Where plates collide

When two vehicles collide, their sheet metal is crumpled together. Something similar happens when two plates of the earth’s crust collide. Then their rock is pushed together and very slowly folded into enormous creases – this is how fold mountains are formed. What the crumple zone is in a car accident, the mountain range is in a plate collision – except that a car accident takes place in a fraction of a second, whereas a plate collision takes many millions of years.

In such a crash, the rock of the lighter plate pushes upwards, the heavier one sinks into the depths. This process is called subduction, and the area where the plate dives is called a subduction zone. Along these zones there are often deep gullies, which is why they are easy to recognise. The deepest of these is the Mariana Trench in the Pacific Ocean. This deep ocean channel is located where the Pacific Plate dips below the Philippine Plate.

The further the earth’s crustal plate disappears into the earth’s interior, the hotter it gets. The rock melts and magma forms in the depths. The growing pressure can force it upwards again. Where it reaches the earth’s surface, volcanoes spew lava and ash. There are whole chains of such volcanoes around the Pacific Plate, for example in Indonesia. Because one volcano follows another here, this plate boundary is also called the “Pacific Ring of Fire”.

Not only do volcanoes erupt at such plate edges. Often, the earth also shakes because the plate movement causes enormous pressure and growing tensions. As soon as these are discharged, quakes shake the earth’s surface. In Japan, for example, three plates meet at once: the Pacific, the Philippine and the Eurasian. This is why Japan is so often hit by violent earthquakes.

Altitude record

The Swiss physicist Auguste Piccard and his assistant Paul Kipfer set off on a risky high-altitude flight in the night of 27 May: In a gas balloon they constructed themselves, they reached a flight altitude of over 15 kilometres after a short time. 17 hours later, after a dramatic flight, the balloon and its crew landed unharmed on a glacier in Austria.

Provisions for two days and oxygen for about 20 hours: Thus equipped, the aviation pioneers Piccard and Kipfer shoot up to the sky at 3.56 am. The starting point for their “suicide mission”, a meadow in Augsburg, is carefully chosen: Piccard does not want to land in water and Augsburg is about the same distance from all seas. There are also steady winds over the city.

The self-built aluminium sphere in which Piccard and Kipfer are squeezed has a diameter of only 2.10 metres. It is equipped with all kinds of measuring instruments. The two researchers want to explore the cosmic and radioactive radiation in the stratosphere. They have already made one failed launch attempt, but this time it seems to work: Just half an hour after take-off, they fly up more than 15 kilometres. At around 8 a.m. they break the altitude record: a whole 15,785 metres above the ground, they are the first people to see the curvature of the earth with their own eyes. But up there it gets unbearably hot: the temperature in the aluminium capsule measures almost 41 degrees Celsius. They have forgotten their water supplies. Tormented by thirst, they lick the condensation off the wall of the sphere.

Around noon, the flight pioneers want to land, but the gas valve won’t open: A line has become tangled. For hours the wind carries the balloon across the Alps. Finally the vehicle sinks. In the evening, at exactly 9 p.m., they finally have ground under their feet again: on a glacier near Obergurgl in the Ötztal valley, they land hard on a snowfield. Only in the morning can a rescue team save the balloonists. They are the heroes of this day!

Between hope and fear

In his logbook, Auguste Piccard describes the adventurous balloon flight and the failed attempts to land:

10.10 a.m.: You cannot pull the valve line. We are prisoners of the air. Condemned to wait until 2 or 3 or 4 o’clock. Then we come down.

10.25 a.m.: 39 degrees; upper body completely undressed. Heat so bearable.

2.08 p.m.: Inconceivable that the balloon does not want to sink.

As the Alps approach: The sight is overwhelming in and of itself. I have never seen such an abundance of mountains. The clouds surrounding the mountains add to the splendour. Everyone has already seen them, from below. Now we see them from above.

17.50 hrs: We only have four hours of oxygen left in the pressure bottle.

6.48 p.m.: Why, why aren’t we falling?

7.34 p.m.: It’s incomprehensible that we’re not sinking yet.

20.29 hrs: We won’t suffocate, but high mountains!

9 pm: Landing