When the rocks break, the earthquake occurs. Does hydraulic fracturing cause earthquakes. These activities include the filling of reservoirs behind dams for water supplies and hydroelectric energy production; extraction of groundwater, oil, or gas; underground injection of water for geothermal energy production; and underground injection of wastewater from the oil and gas industry[4].

Major earthquakes, greater than magnitude 7, happen more than once per month. American Geosciences Institute. See how they stick. The shaking that results is what we call an earthquake. Why do earthquakes happen? This fact sheet illustrates information on the frequency of earthquakes of various magnitudes, along with details on the effects of earthquakes and the equivalent energy release. This fact has been exploited as a means to enforce the global nuclear test ban, because no nuclear warhead can be detonated on earth without producing such seismic waves. Movement of tectonic plates has formed large mountain ranges like the Himalayas and the Andes. It measured a 9.6 on the Richter Scale. Permission granted for reproduction for non-commercial uses. After a while, the rocks break because of all the pressure that's built up. Walls in some houses may crack and windows break. This causes shock waves to shake the surface of the Earth in the form of an earthquake. These explosions, however, don't cause very strong seismic waves. Over 90% of earthquakes – including almost all of the largest and most destructive ones – happen at or near so-called plate boundaries, where the 15 or so major subdivisions (“plates”) of the Earth’s crust and uppermost mantle move towards, alongside, or away from each other[1]. These explosions may be set off to break rock while making tunnels for roads, railroads, subways, or mines. They can cause huge waves in the ocean called tsunamis. The circum‐Pacific belt (also called the Rim of Fire) follows the rim of the Pacific Ocean and hosts over 80 percent of the world's shallow and medium‐depth earthquakes and 100 percent of the deep earthquakes. 6.0 - Stuff will fall off of shelves. The plate boundaries are shown in red; the grey, yellow, and white circles show the 485 earthquakes with a magnitude greater than 5.5 that were recorded in 2018. Most of the plates’ movement is focused at these boundaries, so large earthquakes far away from these boundaries are much less common. But this slipping doesn’t happen easily – rocks are stiff, rough, and under a lot of pressure from rocks around and above them. Earthquakes are usually caused when rock underground suddenly breaks along a fault.
On average, Magnitude 2 and smaller earthquakes occur several hundred times a day world wide.