Has a tsunami ever hit a hurricane?

11.9.1995

On the night of September 11th, a huge wall of water rushes towards the "Queen Elizabeth 2". The monster wave that approaches the cruise ship over the Newfoundland Bank and finally rolls over it is over thirty meters high. As if by a miracle, passengers and crew survived the natural event almost unharmed. However, the ship is badly damaged.

The "Queen Elizabeth 2" was en route from Southampton to New York. There had been a warning the previous evening. "Today it will be a little stormier," said Captain Ronald Warwick to his passengers. A little later at dinner, dishes flew from the table, the musicians interrupted their playing, and all guests had to go to their booths. Nobody suspected that the foothills of Hurricane Luis were piling up a gigantic wave over the Newfoundland Bank. The shallow water off the coast is already known for its high swell.

The 33 meter high wave hit the ship in the early hours of the morning. "As if we were steering straight into the white cliffs of Dover," Warwick later described the approaching wall of water. According to the crew, the monster wave was a three-sister phenomenon: three huge waves followed each other at an interval of 13 seconds. None of the people on board were harmed. The luxury ship was still fit to drive after the accident, but it was badly damaged.

For scientists, this has proven that monster waves really do exist. For a long time, similar adventure stories were not taken very seriously by seafarers, but now a measuring buoy near the ship provided evidence: The wave that rolled over "Queen Elizabeth 2" was 33 meters high.

Monsters of the sea

It seems to be the year of the monster waves. Only nine months before the collision with the "Queen Elizabeth 2" a single gigantic wave hit a Norwegian oil platform. The 26-meter-high Kaventsmann hit the oil rig on New Year's Eve during a storm on the North Sea. This is proven by the measurements of the automatic shaft measuring system. Up until then, it was believed that waves couldn't get higher than 15 meters. Descriptions of much higher waves were considered a sailor's thread, all ships and drilling rigs were constructed according to a maximum wave height of 15 meters. That should now finally be over. Ships and drilling platforms will have to arm themselves against possible monster waves in the future.

Waves and monster waves

Wind and waves - these two forces of nature are inseparable. Because, unlike the ebb and flow of the tides, waves are generated by the wind. The wind slides over the surface of the water and pushes the water in the process. How high the waves get depends on the strength of the wind and the distances over which the wind whistles across the water.

When the waves hit land on the coasts, they get higher. This is due to the fact that with decreasing water depth there is less and less space for the water, it moves upwards. In shallow water, the wave is braked on the bottom. The corrugated crown, on the other hand, tilts forward without braking and "breaks". The whirling up of the water in the air creates white foam crowns, the spray.

If an extremely strong wind blows across the sea, a storm surge occurs. Storm surges are particularly common in spring and autumn. With their power, they can cause severe flooding and completely change the shape of the coast. The North Sea coast with the German Bight is particularly at risk from storm surges. Because the North Sea is very shallow, the water here can build up very high in a storm.

In addition, there are some particularly steep waves that are much higher than the waves in their vicinity. For a long time, such monster waves or “cavalry men” were considered to be “sailor's yarn”, that is, extremely exaggerated adventure stories by seafarers. However, satellite images and precise measurements can now prove that such monster waves really do exist. They can reach heights of up to 40 meters and are therefore also a serious danger for large ships. How they arise has not yet been clarified exactly. Presumably they are formed by the meeting of slow and fast waves, combined with ocean currents.

Unlike waves and monster waves, tsunami waves develop after earthquakes or volcanic eruptions. Tsunami waves can be devastating: In Japan, after a violent earthquake in March 2011, a ten meter high tsunami rolled over the north coast of the country. Thousands of people fell victim to the disaster.

Tsunami - devastating harbor wave

A wall of water as high as a house rushes towards the coast. The gigantic wave breaks near the shore and carries with it everything that gets in its way. Such giant waves, called tsunamis, can destroy entire coastal regions. Many people have already fallen victim to them. The tsunami catastrophe that devastated the coasts of Indonesia and Thailand in December 2004 is still a terrible memory for many. Likewise the tsunami that hit the east coast of Japan in March 2011 and triggered the nuclear disaster in Fukushima. Because there are so many such giant waves in Japan, the word “tsunami” comes from Japanese. It means "harbor wave" - ​​which sounds quite harmless compared to its destructive power.

A tsunami is usually caused by earthquakes or landslides under water. The movement of the sea floor pushes the surrounding water as it were. A huge wave arises. Far out in the sea, this wave is initially not particularly high, but it can be several hundred km / h fast. It becomes dangerous when such a wave rushes towards the coast. Because the sea is getting shallower and shallower, she lacks the space to evade. The wave is slowed down a bit in the direction of the land, but it piles up many meters high.

In addition to earthquakes and landslides, volcanic eruptions can also trigger a tsunami. For example, the Krakatau eruption in 1883 caused a tidal wave nearly 40 meters high.

A tsunami does not hit the coast without warning: First of all, the water runs wider than usual onto the beach and remains there for a few minutes. After that, the running water retreats extremely far, the sea floor becomes visible. Finally the white head of the tsunami appears on the horizon, which is approaching the coast at breakneck speed. Anyone who notices such signs should go to higher places without hesitation in order to escape the giant wave.

Tsunamis are particularly common on the northwestern edge of the Pacific Plate. There, observation stations also warn the inhabitants of the coast. To predict a tsunami, they measure the seaquakes in the ocean. Since the earthquake waves are faster than the waves of the water, they always have a head start on the tsunami. That is why a warning is possible the earlier the further the seaquake is from the coast.

The world of the oceans

To this day, many secrets 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. But what we do know: Almost all of the water on earth - 97.5 percent to be precise - ripples in the five oceans.

The largest of all oceans is that Pacific. Its water surface measures a total of 180 million square kilometers! It makes up about half of all ocean areas. At the same time, the deepest point on earth is located in this ocean: it descends up to 11,034 meters into the Vitja Depth in the Mariana Trench, a deep-sea trench in the western Pacific.

The Atlantic is the second largest ocean. It was formed about 150 million years ago when the supercontinent Pangea broke up. With its 106 million square kilometers, it covers a fifth of the earth's surface.

The Indian ocean is mostly in the southern hemisphere. With an area of ​​almost 75 million square kilometers, it is a good deal smaller than the Atlantic and Pacific. Its deepest point is called Diamantina Depth, which is 8,047 below sea level.

The Southern Ocean is also called the Southern or Antarctic Ocean. It includes all marine areas south of the 60th parallel in the southern hemisphere. It is considered by seafarers to be the stormiest of all seas. The large tabular icebergs floating in its water are also typical of the Southern Ocean. They broke off the ice shelf that formed around the Antarctic continent.

That's all around the North Pole Arctic Oceanalso 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. However, like the ice in the Southern Ocean, its ice cover continues to melt as a result of global warming.

Even if we live a few hundred kilometers away from them, oceans are very important to us. Their currents and the evaporation of sea water have an enormous influence on our weather. A large part of the air we breathe is also created in the world's oceans: algae that live here convert carbon dioxide into oxygen when exposed to sunlight.

15.4.1912

The passenger ship “Titanic” sinks on the night of April 14th to 15th, 1912. A few hours earlier, the Titanic rammed an iceberg in the North Atlantic. Around 1,500 people died in the shipwreck. Around 700 are saved, most of them women and children.

It is the first voyage of the “unsinkable” luxury liner Titanic. The massive ship leaves the port of Southampton in southern England on April 10th. The destination is New York, there are 2,200 people on board. At this point, none of them suspects that for many it will be their last trip. Just four days later, on April 14th, the Titanic's last hour struck. At around 11:40 p.m. the lookout Frederick Fleet sounds the alarm: "Iceberg directly ahead!"

The Titanic tries to turn away quickly, but the iceberg is already too close. At full speed, the Titanic rams the colossus of ice. The front five of the sixteen watertight compartments are slashed open and overflow. The prow of the Titanic dips further and further into the water. The first lifeboat is launched three quarters of an hour after midnight. But there are far too few boats - after all, the Titanic was considered unsinkable. At 2:20 a.m., the ship's hull can no longer withstand the forces of the water and breaks apart. The Titanic sinks, its wreck hits the seabed at a depth of almost 4,000 meters. 1,500 people are killed in the shipwreck in the North Atlantic, including Captain Edward John Smith.

The survivors in the lifeboats will be picked up about two hours after the sinking of the British liner RMS Carpathia, which calls into New York on April 17.

Iceberg alert

Two years after the sinking of the Titanic, the "International Ice Patrol" was founded in 1914. 16 countries that operate shipping in the North Atlantic have joined forces to form this reconnaissance force. Their mission: to prevent accidents with icebergs.

From Newfoundland, the Ice Patrol regularly flies over the North Atlantic to locate and observe icebergs. It is particularly busy here between January and July: 40,000 icebergs break off Greenland's glaciers every year and drift out to sea. There they are a danger to ships and drilling platforms. That is why the experts of the Ice Patrol try to predict the course of the ice giants. And with great success: since the ice patrol came into existence, no more accidents have occurred in this area.