Microearthquake
(重定向自Microquake)
A microearthquake (or microquake) is a very low intensity earthquake which is 2.0 or less in magnitude. They are very rarely felt beyond 8 km (5 mi) from their epicenter. In addition to having natural tectonic causes, they may also be seen as a result of underground nuclear testing or even large detonations of conventional explosives for producing excavations. They normally cause no damage to life or property, and are very rarely felt by people.