The correct statement about the earthquake is:
The earthquake was caused by plates moving together. It released a lot of energy, but the observer did not see much damage.
This is because earthquakes at convergent boundaries typically involve tectonic plates moving towards each other, often leading to significant energy release. High magnitude indicates a lot of energy was released, while low intensity suggests that the effects were not strongly felt or did not cause much damage in the observed area, which can occur due to factors like depth of the earthquake or distance from the epicenter.