The crust of the Earth comprises of seven large lithospheric plates and several smaller plates. These places move towards each other, apart or even past each other. Earthquakes are caused due to the sudden release of stress along the faults in the crust of the earth. Paul Favret mentions that the continuous motion of tectonic plates leads to a steady build-up of pressure in the rock strata on both of the sides of a fault, till the stress becomes too much and gets released in sudden, jerky movements. The resulting waves of seismic energy propagate through the ground and over the surface, causing the shakes perceived as earthquakes.
Not all countries are equally impacted by earthquakes. There are several regions in the world that are more likely to face earthquakes than others, here are some of them:
- China: This is a seismically active country with the world’s largest population. China has experienced more than 150 earthquakes from 1900 to 2016, and a lot of them took place in the southwest region of the country which has a pretty mountainous terrain. Fortunately, some of the least populous provinces of the country are located in this region, including Yunnan, Tibet, Qinghai, Xinjiang Sichuan and Gansu. The harsh climate and rugged terrain of these regions are not conducive to supporting high populations.
- Indonesia: More than a hundred earthquakes with considerable magnitude took place in this country between 1900 and 2016. The location of Indonesia on the Ring of Fire is one of the key reasons for the high frequency of earthquakes here. Most of the earthquakes in the world happen in the Ring of Fire, which features a shoe-shaped area of about 40,000 square km. The submarine or surface volcanic eruptions, as well as the movement of tectonic plates in the area, have triggered several earthquakes that have impacted Indonesia over the centuries.
- Iran: This Middle Eastern country is also located in an area of high seismic activity. Iran lies in the region where the Eurasian and Arabian tectonic plates meet. One of the youngest mountain ranges of the world, the Zagros, developed in the area owing to the subduction of the Arabian place under the Iranian plate. As Iran is located collision zone of the different plates, earthquakes are inevitable in this country. Moreover, the seismic zone encompasses most of the country, is spread over an area that is 1600 kilometers long and 400 kilometers wide.
Geologists are the experts who study the mechanics of earthquake behavior for the purpose of developing an understanding of where and when earthquakes are most likely to happen. They make use of radiocarbon dating and other methods to learn the age of pre-existing layers affected by ancient earthquakes, and also the new layers deposited after the earthquakes. This helps them to constrain a fault’s earthquake history. Paul Favret has an academic background in geology, which helps him to better understand earthquakes and their causes.