Do you know what is a moonquake exactly? It’s just like the earthquake on earth but normally they last longer. The longest earthquake was just lasting less than 2 minutes but most of the shallow moonquake can last more than 10 minutes! 
Just another question is raised. What is a shallow moonquake? There are at least four types of moonquakes. According to NASA, they are
- Deep moonquake
- Vibrations from the impact of meteorites
- Thermal quakes
- Shallow moonquakes
Deep moonquake is happened about 700KM below the surface of moon and most probably caused by tides. Thermal quakes are caused by the expansion of the frigid crust when first illuminated by the morning sun after two weeks of deep-freeze lunar night. Shallow moonquakes are only happened 20KM or 30KM below the moon, thus, it’s the most dangerous. 
According to NASA, between 1972 and 1977, the Apollo seismic network saw twenty-eight of them; a few “registered up to 5.5 on the Richter scale,” says Neal. A magnitude 5 quake on Earth is energetic enough to move heavy furniture and crack plaster.
The scientists are not sure about the cause of the shallow moonquakes as well as the place where they happen. They have to know this as the lunar bases must be built on the safest spots. They are going to implement 10 to 12 seismometers around the whole moon to find the safest spots.
