Final answer:
Authorities cannot prevent earthquakes but mitigate their impact by constructing earthquake-proof buildings. Earthquake predictions are challenging but valuable for preparation. Larger, less-reinforced structures like gymnasiums and church roofs are more prone to collapse during an earthquake compared to residential homes.
Step-by-step explanation:
The question asks about what authorities do to prevent further earthquakes. While it is not possible to prevent earthquakes, governments and individuals can take steps to minimize the impacts. This includes constructing earthquake-proof buildings with design features such as flexible foundations, reinforced structures, and proper building materials that are resilient to shaking.
The value of earthquake predictions is significant, as they can save lives by giving communities time to prepare. Although precise prediction is currently impossible, efforts such as monitoring animal behavior have been historically noted due to observations such as the exodus of animals from the Greek city of Helice before a massive quake.
Regarding structural failures, roofs of gymnasiums and churches tend to fail more during an earthquake because they often have large open spans and heavy roofs supported by walls that may not be reinforced to withstand seismic forces as well as smaller residential structures.