A powerful 6.8-magnitude earthquake struck Morocco late on Friday night, killing over 2,400 people, as of Monday, according to the country’s Interior Ministry. Morocco’s earthquake monitoring network measured it at 7.0 on the Richter scale.

Though this was Morocco’s strongest earthquake in over a century, historically, it is not among the most powerful.

24/7 Tempo has determined the 20 most powerful earthquakes ever recorded by reviewing data from The United States Geological Survey (USGS). Magnitudes are measured on the Moment Magnitude scale (Mw). The earthquakes considered occurred in the 20th century and after, as any occurring before this time were not able to be standardized to the current scale. For earthquakes that occurred before 1935, when the (now outdated) Richter Scale was developed, magnitude measurements are estimates based on historical seismogram readings.

Click here to see the most powerful earthquakes ever recorded

A few areas of high tectonic activity are responsible for many of the largest earthquakes of all time. About 80% of earthquakes occur in what is called the “Ring of Fire” – a zone around the Pacific Ocean where the Pacific tectonic plate is being subverted (or pushed under) the surrounding plates. Unfortunately, this means that some countries and areas, including Chile, Indonesia, Japan, the Kamchatka Peninsula of Russia, and the Aleutian Islands of Alaska have experienced numerous devastating earthquakes throughout their histories. (Here are ancient civilizations destroyed by natural disasters.)

Earthquakes can destroy whole towns and displace residents – sometimes permanently – as a result of landslides, flooding, and soil liquefaction. They cause millions and sometimes billions of dollars in damage. More often than not, however, the damage caused by an actual quake is minor compared to the death and destruction caused by the massive tsunamis that can form as a result of underwater quakes.