SeaHelp News

Tsunami Maretazo in Peru: Tsu-nami – the destructive harbor wave

On December 28, 2024, the tsunami known as the Maretazo hit Peru, causing many boats to capsize with waves up to 4 meters high and destroying port facilities and tourist infrastructure in the center and north of the country. 20 years earlier, at least 231,000 people were killed by the great tsunami in Southeast Asia. But how do tsunamis occur? And above all, what should boat owners bear in mind in the event of an emergency?

It is now 20 years since the great tsunami of December 26, 2004 killed more than 200,000 people in Southeast Asia. The wave was triggered by one of the strongest earthquakes on record. The devastating effect was mainly due to the large volume of water that hit the land per kilometer of coastline, while the wave height was comparatively low, usually only a few meters.

Most recently, the tsunami known as the “Maretazo” caused 4-meter-high waves in Peru, destroying boats and infrastructure in the center and north of the country; about 3,000 fishermen were affected, reported La Nacion, 81 ports on the north and central coast of the country, from Tumbes to San Juan de Marcona, were temporarily closed by the port authority.

The strong waves, which had their full force on the northern beaches near the border with Ecuador, had capsized dozens of boats and yachts, destroyed docks and tourist infrastructure, and left thousands of fishermen without a livelihood.

 

YouTube

Mit dem Laden des Videos akzeptieren Sie die Datenschutzerklärung von YouTube.
Mehr erfahren

Video laden

 

YouTube

Mit dem Laden des Videos akzeptieren Sie die Datenschutzerklärung von YouTube.
Mehr erfahren

Video laden

 

In the case of the Maretazo in Peru, there was a warning, but the height of the waves exceeded the expectations of the authorities

A warning from the Directorate of that strong waves would occur from Wednesday, December 25, and that all necessary measures should be taken to minimize the impact. “We have already had unusual waves in this area, but this was the most devastating, we did not expect anything like it,” La Nacion quoted Jaime Yacila Boulangger, mayor of the province of Contralmirante Villar in Tumbes.

The businesses most affected were those near the beaches of Máncora, Cabo Blanco, El Ñuro, La Caleta and Los Órganos, vacation spots that attract a large number of domestic and foreign tourists in search of fun and relaxation every summer. The sea also hit the town of Lobitos in the province of Talara hard, it was reported. “This wave was generated thousands of kilometers from Peru, off the United States, and is a wave caused by a prolonged wind on the sea surface,” explained Lieutenant Commander Enrique Varea Loayza of the Hydrographic and Navigation Directorate of the Peruvian Navy in the newspaper article.

The mayor of Los Órganos in Piura, Manuel Garrido, was concerned because dozens of fishermen had gone out to sea to prevent their boats from being destroyed by the rough waves. In their desperation, they had gone out to sea to move their boats deeper to prevent the wave from knocking them over, Garrido said. But now at least 80 fishing boats are missing off the coast.

What is – and how does a tsunami actually occur? And what should be done if a tsunami (Jap., literally ‘harbor wave’), formerly called an earthquake wave or earthquake flood, is threatening? A tsunami is initially a sequence of particularly long water waves that are able to spread over very long distances and as such represent a displacement of water or sea as a result of displacement.

Japanese fishermen christened the mysterious wave as “wave in the harbor”, German: Tsu-nami

When it reaches areas of shallow water, the sea is finally compressed and thus piles up on coasts to form several high tidal waves. These carry the water with great force far beyond the shoreline, usually causing great destruction.

The origin of the term tsunami is interesting in this context: it is said to have been coined by Japanese fishermen who returned from fishing and found everything devastated in the harbor (although they had not seen or felt any waves on the open sea) – for this reason they are said to have named these mysterious waves Tsu-nami, literally: “wave in the harbor”.

The earliest known scientific description of this natural event, with an exact analysis of the cause, was provided by the Austrian geoscientist Ferdinand von Hochstetter in 1868 and 1869. That event also involved a tsunami in connection with Peru, the only difference being that these tidal waves were caused by an earthquake in Peru – and had unleashed their destructive power on the east coast of New Zealand and Australia.

Tsunamis often occur as a result of underwater earthquakes or undersea volcanic eruptions.

A tsunami can be caused by an underwater earthquake: tectonic plate movements (so-called subduction zones) cause the water above the earth’s crust to be jerkily raised or lowered. Example: the 2004 tsunami in the Indian Ocean was triggered by a magnitude 9.1 earthquake.

Tsunamis can also be triggered by undersea volcanic eruptions or massive eruptions that plunge into the sea. One of the most famous examples of this is the eruption of Krakatoa in 1883.

Furthermore, (submarine or coastal) landslides can also cause an enormous displacement of water, as happened in Lituya Bay in Alaska, where an earthquake triggered a tsunami in 1958 because millions of cubic meters of rock had fallen from a height of 600 meters into a fjord. The wave of this tsunami is considered to be one of the largest ever. Rare but possible: larger meteorites can also trigger tsunamis when they hit the sea.

In the Atlantic, tsunamis are usually caused by undersea landslides. Off the Canary Islands in particular, volcanic activity or landslides could cause tsunamis at any time. The Lisbon tsunami of 1755 is sadly famous in this context.

 

YouTube

Mit dem Laden des Videos akzeptieren Sie die Datenschutzerklärung von YouTube.
Mehr erfahren

Video laden

(©) NASA Video animation: formation of a tsunami

Modern research indicates that the main cause of this earthquake was faulting in the seafloor along the Mid-Atlantic Ridge tectonic plate boundary. The earthquake had triggered a tsunami that produced waves about six meters high in Lisbon and waves as high as 20 meters in Cádiz, Spain.

Tsunamis can also occur in the Mediterranean, for example as a result of earthquakes.

Anyone who thinks that tsunamis can only occur in the world’s oceans is mistaken. The powerful tidal waves can also occur in the Mediterranean region, for example due to earthquake, as there are potentially dangerous subduction zones in the Aegean Sea, the Tyrrhenian Sea and the Hellenic Arc, an island arc structure in the eastern Mediterranean that was formed by the subduction of the African Plate under the Aegean Plate.

The 1908 tsunami in Messina, Italy, was caused by such an earthquake. Another example is the 1979 earthquake on the Montenegrin coast, which also triggered a tsunami that carried away entire houses over a 15-kilometer stretch of coastline.

Tsunamis also occur in the North Sea, albeit very rarely, but they are possible due to landslides. A historical example of this is the Storegga landslide off the coast of Norway about 8,000 years ago.

What should you do as a boat owner if a tsunami threatens? First of all, you should of course pay attention to all early warning systems: tsunami warnings often come via radio stations, weather reports or special skipper or weather apps. The sooner you receive the information, the more time you have to prepare.

Skippers should make sure that they have enough fuel, secure their boats and equipment, and check their safety equipment: are the life jackets ready for use? Are there radios on board? They should also make sure that they have enough drinking water and food on board.

Analyzing your location is especially important when a tsunami is looming.

In this context, particular importance is attached to a location analysis. If the boat is in a marina or at a (coastal) anchorage, it should be borne in mind that boats in the harbor or in shallow anchorages are extremely vulnerable. This is where the force of the tsunami will be strongest. So should you take your boat out to sea if you still have enough time? The clear answer is yes.

The reason for this is that tsunami waves have long wavelengths (often several kilometers) and, above all, low wave heights at sea. Their destructive force only develops near the coast due to the wave build-up; the swell becomes a destructive surge here. Or to put it another way: the water masses pile up only due to the gradual shallowing of the water, the resulting reduction in propagation speed and thus the wavelengths, which must lead to an increase in the amplitudes of the water masses.

If, in addition, the coast is shaped like a bay, then there is also a lateral superimposition or focusing of the water masses. The wave heights are usually less than one meter on the open sea and are not dangerous for ships due to the large wavelengths. It is only when approaching the coast, especially in shallow bays, that the water masses can then pile up to over ten meters, and in extreme cases to more than 30 to 50 meters.

How far out should you go by boat? You should head for a depth of at least 50 to 100 meters. The deeper the better, to minimize the effects of the formation of high, steep surf. However, it should be noted that strong currents and chaotic wave movements can still occur in deep water during a tsunami, which can be potentially dangerous. It is also important to pay attention to any unforeseen changes in the tsunami pattern.

Keep a sufficient distance from the coast and never enter the harbor, advises the GFZ

When at sea, it is recommended to keep a safe distance from the coast and under no circumstances to enter the harbor, advises the German Research Centre for Geosciences (GFZ) in Potsdam.

Further advice from the GFZ in the event of a tsunami includes observing information and warnings from local authorities and passing them on to other people in the area.

When on land, the GFZ recommends fleeing to elevated places as far from the coast as possible on foot, as drivers fleeing in panic often cause traffic jams. In the case of very short advance warning, it may be safer to seek refuge in a stable, newer building on one of the highest floors, rather than trying to flee inland. Express reference is made to the danger of further, possibly higher waves after the first tidal wave has subsided.

So-called inland tsunamis can also form on lakes

It is interesting to note that tsunamis do not only occur in the world’s oceans, but that so-called inland tsunamis can also form in lakes. Inland tsunamis are caused either by earthquakes or by landslides that reach the lake surface or occur below the water surface.

Several tsunami events have been recorded in Switzerland in historical documents or in sediment deposits, such as the Tauredunum event of 563. At that time, a landslide occurred at the eastern end of Lake Geneva. This triggered a 13-meter-high tsunami. Similar inland tsunamis are known to have occurred in Lake Lucerne (1601 and 1687) and Lake Lauerz (1806).

A relatively small one, triggered by a landslide in a flooded open-cast mine, washed an excursion boat onto the opposite shore of Lake Concordiasee in the municipality of Seeland in Saxony-Anhalt, Germany, in 2009.

SeaHelp Service
Für tagesaktuelle Kraftstoffpreise
bitte hier klicken!
SeaHelp Service

Push Service & Newsletter

Advertising

SeaHelp Neueste Artikel

SeaHelp

Coronavirus Current

[ulc id="30297" taxs="576" posts_per_page="-1" order_by="title" order="ASC" cols="1" layout_style="minimal"]
SeaHelp News

Related Posts