Say a major earthquake is taking place by a town in the Mediterranean area. It destroys various buildings and what not. How would the ordinary person - visiting peasant, craftsman - react to this?
Would earthquakes or similar occurrences be completely unheard of? Would everyone simply declare it to be 'another one of those punishments from God'? If so, would they pray harder or follow it up with riots?
No medieval historian could possibly say - if anyone posits an answer that is more than a quote from a single source in geography and time, they would be selling you land you should not buy.
All evidence is from 'chronicles', chronicles whose objective is moral and not testimony to any fears except the consequences of those same morals. Other than a basic dread and fear for life, family and friends, we will never know.