Natural catastrophes, natural and non-human caused events, influence the lives of people around the world. Earthquakes, volcanos and, as a result, tsunamis occur mainly at the edges of tectonic plates. In Europe or eastern US, we are mostly spared from this. Other countries, e.g. The Pacific countries are much more affected by this.
On this page, the most serious earthquakes, volcanic eruptions and tsunamis of the modern era are listed.
The most severe earthquakes since 1950
Earthquakes are usually caused by shifts of tectonic plates at a depth of 20 to 50 kilometers. If two plates collide against one another, tensions and movements happen, which can lead to devastating damage on the surface of the earth. The adjacent map (source: NASA, DTAM project team) shows the most abundant epicentres of earthquakes, regardless of their strength, and thus clarifies these plate boundaries. Especially on the American west coast and along the Pacific fire ring, there are strikingly frequent earthquakes.
In the most severe earthquakes over the last 60 years, Chile, Alaska (USA) and Indonesia have appeared several times. The column of total damage includes destroyed houses and financial losses. Victims and damage are not included in the tsunamis, which may be caused by the earthquake.
The strongest volcanic eruptions of the past 2000 years
Volcanos also occur mostly in the regions where tectonic plates collide. As a result of the pressure in the interior of the earth, liquid rock (magma) makes its way through the resulting cracks to the earth's surface. If a volcano erupts, lava and rock masses are thrown out to high heights.
The strength of volcanos is measured in a volcanic explosivity index (VEI). Volcanos at a VEI of 8 or above are called supervolcanos, which occure extremely rarely. The last outbreak of a supervolcano took place around 26,500 years ago in New Zealand (volcano Taupo). The strongest values calculated for the last 2000 years achieved a VEI of 7, which nevertheless has enormous proportions. Tephramasses of up to 1000 km³ are thrown at heights above 25 km.
The most disastrous tsunamis of the past 2000 years
As a result of earthquakes and volcanos, not only land masses, but often also water masses move. The more violent the displacement is, the stronger the tsunamis, which are hardly visible in the open sea. But in shallow waters the waves surge to dozens of meters and sometimes cause the most severe damage on landfall.
The largest floodwave measured so far reached a "megatsunami" in 1958 in the Lituya Bay in Alaska. Through a massive rock slop on one side of the fjord a 524 meter high tidal wave on the other side arose. The fjord was however only 3 km wide.
Unlike volcanos and earthquakes, the effects of tsunamis are often spread over large areas. In the most famous tsunami in December 2004 off the coast of Indonesia and Thailand a tidal wave arose and claimed death sacrifices in 17 countries. The wave reached a height of up to 50 meters and even reached the African continent.