Dots show epicenters of the earthquakes that caused Tsunamis.

Serious destruction

Moderate destruction

Light destruction

Generally the danger of a tsunami occurring exists where earth- and lake-quakes are possible, in areas where tectonic plates collide with each other, drift past each other or collide, as well as in other areas with geological faults. Mostly beaches and coastlines are affected by tsunamis. In estuaries, however, the wavefront can advance many miles inland. Tsunamis arise from the sudden displacement of gigantic water masses due to earthquakes on the seabed, volcanic eruptions above and under water, landslides or meteorite impacts. About 86 % of all Tsunamis result from so-called seaquakes.

Which regions are mostly affected?

Tsunamis occur most frequently in the Pacific, particularly along the “Pacific Ring of Fire “. This zone is found at the northern edge of the Pacific Plate and refers to the geologically most active fields of the earth. Several times a year, strong earthquakes of at least 7 on the Richter scale result in tsunamis. Japan, for example, is hit by a tsunami at least once a year. From observations of scientists and historical sources, we know today that Tsunamis can occur in all larger seas of the world. Thus, fatal tsunamis occur in geologically less active oceans such as the Atlantic, the Indian Ocean or the Mediterranean as well. Great danger exists in densely populated areas or in vacation areas in which a tsunami can endanger millions of human lives. Indeed Tsunamis occur more seldom in for example the Mediterranean than in the Pacific Ocean, but that is exactly why one must not underestimate or minimize the danger. Looking back to the year 1755 one can see that the tsunami triggered by the earthquake off Lisbon is accountable for the majority of the 70 000 deaths.

The greatest tsunami catastrophes worldwide

About 1000 tsunamis were documented and verified so far but most of the tsunamis were small waves that had caused only minimal damage. Only 10% of the verified tsunamis were of catastrophic dimension due to their destructive force.

The 7.5 magnitude earthquake produced a tsunami that was unusual from the scientific point of view. First of all, it can be stated that the earthquake produced a horizontal movement in which the formation of tsunamis is very rare. Rather, an undersea landslide was responsible for it. In addition, the hardest hit city, Palu, was at the end of a bay, which made the waves higher than expected. The number of deaths is at least 2,256.

One of the most momentous earthquakes in human history with a magnitude of 9.1 caused a tsunami up to 40 meters high that destroyed large parts of the east coast of Japan. Although walls were built in advance to protect against tsunami waves, these were too low in relation to the waves that ultimately hit. Around 18,500 people died in the disaster. One of the greatest consequences is the persistent dangers that exist from the damage to the Fukushima nuclear power plant.

A 7.8 magnitude earthquake off the island of Sumatra triggered a tsunami that hit the Mentawai Islands in particular. The wave reached a height of about three meters and rolled up to 600 meters into the interior of the island. Due to the proximity of the epicenter, the up to three meter high tsunami reached the archipelago after about 10 minutes. According to official figures, around 435 people died.

At 8.8, one of the strongest earthquakes since earthquake records began on that day. Due to the geological mass displacement, the duration of a day was shortened by 1.26 microseconds. The tsunami caused by the quake reached the coastal town of Talcahuano in less than 30 minutes. Around 520 people died as a result of the earthquake and the tsunami that followed.

An earthquake with a magnitude of 8.1 around 180 kilometers southwest of the island state of Samoa triggered a tsunami that reached a height of up to twelve meters. 189 people died in total. Since the earthquake was relatively centrally located in the Pacific, the less dangerous extensions of the tsunami could be felt on almost all coasts of the Pacific Ocean.

The earthquake off the Solomon Islands had a magnitude of 8.1 on the Richter scale. As a result of the quake, Ranongga Island was raised by three meters. The resulting tsunami, which reached a height of up to twelve meters, hit the archipelago by surprise because the distance between the epicenter of the earthquake and the mainland was too short. About 50 people were killed.

A 7.7 magnitude seaquake off the Indonesian island of Java triggered a tsunami that killed 700 people. Despite information about the impending tsunami, the authorities in Indonesia did not issue a tsunami warning to their population. The customers of the A3M tsunami alarm system were warned in good time, so they could get to safety and were unharmed.

An earthquake in the Indian Ocean off the island of Sumatra with a magnitude of 9.3 on the Richter scale caused one of the worst tsunami disasters in history. More than 280,000 people (including many Europeans) were killed in eight Asian countries (notably Indonesia / Sumatra, Sri Lanka, India, Thailand, Myanmar, Maldives, Malaysia and Bangladesh). The tidal wave even reached East and Southeast Africa several thousand kilometers away. There were also victims in Somalia, Tanzania, Kenya, South Africa, Madagascar and the Seychelles.

A large, devastating earthquake struck northwestern Turkey, causing a local tsunami in the Marmara Bay. This happened along the northern Anatolian fracture zone. The epicenter was in the Gulf of Izmir. According to official estimates, around 17,000 people lost their lives and thousands were injured.

A seaquake triggered a tidal wave on the north coast of Papua New Guinea, in which 2,000 people lost their lives.

A 26 meter high wave flooded the Flores Islands and injured around 1,000 people. There were no fatalities.

A 10 meter high tidal wave killed around 180 people on the Pacific coast of Nicaragua. The epicenter was 120 km off the coast.

More than 5,000 people were killed in a tsunami in the Philippines.

An earthquake off Alaska triggered a tsunami that claimed 122 lives on the entire west coast of Alaska and the United States. The property damage amounted to approximately $ 100 million.

In Hawaii, the first warning system enabled an entire place to be evacuated in time. Nevertheless, 61 people died on the island. In Chile, the origin of the tsunami, 1,000 people were killed by an eleven meter high wave.

A landslide in Lituya Bay in Alaska caused a tsunami that towered up to 520 meters in the narrow fjord-like bay opposite. Because the area was barely populated there were no fatalities.

The last earthquake in the Aegean Sea between Greece and Turkey that triggered a tsunami was that near the southwest coast of the island of Amorgos, 53 people died, 100 were injured and hundreds of houses were destroyed. The waves were particularly high on the south coast of Amorgos and on the north coast of the island of Astypalaea. At these two places the reported heights were 20 and 25 m respectively.

In Alaska, a tidal wave tears a lighthouse into the sea. The five-man crew dies. After 3,700km the wave reaches Hawaii and kills 159 people.

A 20-meter-high wave off the coast of Japan claimed 3,000 lives.

The city of Messina in Italy was almost completely destroyed by an earthquake and the tsunami that followed. More than 75,000 people were killed.

500 to 1,500 people died in a tidal wave that struck the coasts of Colombia and Ecuador.

Tens of thousands of Japanese were caught by a 23-meter wave during religious celebrations. The so-called Saraiko tsunami claimed 26,000 lives.

One of the largest volcanic eruptions occurred on the island of Krakatau in Indonesia. The eruption of the volcano, which sank almost two thirds of the island, triggered a 35 meter high tidal wave. 36,000 people died. The tsunami made itself felt on the coast of Great Britain with a rise in sea level of half a meter. The air pressure wave created by the explosion circled the earth seven times.

The Portuguese capital Lisbon and its inhabitants were particularly hard hit by an earthquake in the eastern Atlantic. Two thirds of the city was destroyed by a fire that broke out as a result of the earthquake. People sought protection from the flames on the banks of the Tagus River and were caught by waves as high as a house. 60,000 people lost their lives. The waves were still noticed in Ireland and across the Atlantic in the Lesser Antilles. On Madeira’s coasts, the waves were still 15 meters high.

A devastating earthquake was triggered by an underground eruption of the Colombo volcano, the crater of which lies in the sea to the northwest of the island of Santorini. A devastating tsunami was observed on the island of Ios, in the north of Santorini, and waves up to 16 m high were reported.

The first tsunami documented by eyewitnesses occurred in Lake Lucerne in Switzerland. The wave, up to 4 meters high, caused considerable damage in the city of Lucerne. The cause was landslides that were triggered by an earthquake centered in Unterwalden in central Switzerland. Allegedly eight people died in the earthquake.

The coasts of the entire eastern Mediterranean were inundated by tidal waves up to 60 meters high. The wave, caused by a volcanic explosion on Santorini, a Greek island in the Aegean Sea, is believed to be responsible for the extinction of the Minoan culture.