Magnitude 4 earthquakes are generally too small to cause significant damage or be felt by humans, but they can still provide valuable information about the seismicity of a region and can be used to forecast larger events. By monitoring the frequency and distribution of magnitude 4 earthquakes, scientists can identify areas where the stress is building up and the likelihood of a larger earthquake is higher. This information can then be used to issue early warnings and take necessary precautions to mitigate the potential risks.