Moon suffering from Quakes.

Research has discovered that the moon is Seismically Active after all.

Seismometers were deployed on the moon by the various Apollo missions that landed there during the 1970's and it is data from these that has shown the moon quakes. Apparently there are four types of Quake found on the moon, 1) Deep quakes caused by tidal affects (gravity pulling on the lunar rocks), 2) Vibrations caused by meteor impacts, 3) Thermal quakes, caused by sudden expansion of the rocks when the sun shines onto them and 4) Shallow quakes. I

t is these Shallow Quakes that are causing a problem, the source of them is unknown and they can apparently reach a level of 5.5 on the Richter Scale. The other problem found is the length of the moon quakes. On Earth a quakes lasts a very short period of time, on the moon quakes can last for more than 10 minutes. This is possibly long enough to cause problems in the buildings that will be used to house the astronauts when they return to the moon.

More details at: http://science.nasa.gov/headlines/y2006/15mar_moonquakes.htm?list855910