What is the theory of plate tectonics?
The theory According to the theory of plate tectonics, which is generally accepted today, the outer crust of the earth consists of seven large and a number of significantly smaller plates, which reach a depth of around 100 kilometers. However, these do not float on the glowing interior of the earth, as is often assumed.
How can you explain an earthquake in bullet points?
Earthquakes are particularly common at plate boundaries. When two plates rub against each other, tension builds up. At some point this tension is so great that it is released with a jerk. Where the jerk takes place, the earth trembles.
What do people have to do with earthquakes?
Causes of earthquakes in general Earthquakes are caused by a sudden release of stress along fractures in the earth’s crust. Due to the constant movement of the tectonic plates, stress builds up in the rock strata on either side of a fracture.
What are earthquakes and how do they occur?
Most damaging earthquakes have a tectonic origin. Earthquakes are caused by sudden displacement along a fracture surface in the earth’s crust and the resulting release of accumulated elastic energy. These fracture zones are mainly found at plate boundaries.
How does an earthquake happen?
Due to convection currents in the Earth’s interior, the plates move, drift apart or collide. If the friction of the plates causes the pressure to become too great, or if two plates wedge into one another, a rupture occurs and the stresses are discharged in an earthquake.
How does an earthquake happen?
If the earth’s crust can no longer withstand the tension, it discharges itself with a violent jolt, an earthquake – initially inside the earth. The force spreads in the form of waves (similar to waves in water) and reaches the sea or earth floor in a matter of seconds.
How long does an earthquake last?
In the case of strong earthquakes, depending on the type and size of the rupture process and the subsoil, the duration of the tremor can range from a few seconds (for around magnitude 6) to more than five minutes (for magnitude 9 and stronger).
What is a strong earthquake?
Earthquake: From magnitude 5 it becomes dangerous From magnitude 3 or 3.5 residents in populated areas feel the earthquake. From strength 5 you have to reckon with damage. In the table below you can learn more about the effects of the different magnitudes on the Richter scale.
What is the name of the spot where an earthquake is strongest?
The science that deals with earthquakes is called seismology. With one exception, the ten strongest earthquakes measured since 1900 all occurred in the subduction zone around the Pacific, the so-called Pacific Ring of Fire (see list below).
Where are the strongest earthquakes?
Strongest earthquakes worldwide by magnitude 19 on the Richter scaleChile (1960)9.5Prince William Sound, Alaska (1964)9.2West coast of North Sumatra (2004)9.1Japan, east of Honshu (2011)9.19 •
Where were the worst earthquakes?
Infographic: The ten worst earthquakes in the last 100 years Country Strength1 Chile 9.52 Alaska 9.23 Indonesia 9.14 Japan 9.06
Where was the last big earthquake?
Since 1950, 28 earthquakes with a minimum magnitude of 7 have occurred in Chile, the last on September 17, 2015, with a magnitude of 8.3.
When was the last major earthquake in Germany?
The last major earthquake in Germany took place in the Rhineland on the night of April 13, 1992. A magnitude 5.9 earthquake shook the ground in Heinsberg/Roermond (NL). One person died and the damage caused was estimated at 250 million DM.
When was the last major earthquake in San Francisco?
When the earth shook in San Francisco on April 18, 1906 and largely destroyed the city, this was one of the greatest natural disasters of all time in the USA.
How many earthquakes are there in Japan each year?
In Japan, the earth trembles around 5,000 times a year. The country lies on the Pacific Ring of Fire – where continental plates collide, causing volcanoes to erupt and the earth to tremble. The worst earthquake happened in 2011, it had consequences for the whole world. Shortly after the earthquake on September 11
Why are there so many earthquakes in Japan?
Earthquakes are common in Japan. This is caused by movements of the tectonic plates in the lithosphere, which meet in the vicinity of Japan. The Japan Trench is one of the consequences of subduction. In particular, there is concern about an earthquake in Tokyo.
How did the 2011 Japan tsunami occur?
So did the tsunami that hit the east coast of Japan in March 2011 and triggered the Fukushima nuclear disaster. A tsunami is usually caused by earthquakes or landslides under water. The movement of the seabed pushes the surrounding water, so to speak. A huge wave arises.
How often are there earthquakes in Germany?
In northern Germany there are almost no significant tremors. Most registered earthquakes are concentrated in the Upper Rhine Valley, the Lower Rhine Bay, the Swabian Jura and the Vogtland. Several hundred earthquakes are measured in Germany every year.
How many earthquakes are there per year?
How many earthquakes occur worldwide each year? Very strong earthquakes with magnitudes over eight occur worldwide on average once a year. Earthquakes with a magnitude of between seven and eight occur on average 15 times a year.
When was the earthquake in Friuli?
40 years ago: The devastating earthquake in Friuli in 1976. The magnitude 6.5 earthquake was the most momentous natural disaster in Italy in the second half of the 20th century. The epicenter (46.25°N, 13.22°E) was southeast of Gemona, the focus depth was 15 km.
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