The focus of the earthquake is eighty miles from our city. 這次地震的震源在距我市八十英里的地方。
A possible mechanism for the generation of deep focus earthquakes is faulting caused by olivine undergoing a phase transition into a spinel structure. 發生深層震源地震的機制可能是由於橄欖石經歷了到針狀結構的相變而產生的斷層作用。