Ƙirƙirar wani nau'i mai mahimmanci na wannan jumla An yi girgizar ƙasa a yankin kudancin Appalachian Seismic Zone (SASZ).
Tabbas, mafi rikitarwa na jumla shine "An girgizar ƙasa ta samo asali ne daga Kudancin Appalachian Seismic Zone (SASZ), daga cikin yankuna masu girgizar ƙasa a kudu maso gabashin Amurka kuma wanda ke iya samar da girgizar ƙasa mai ƙarfi, kaɗan daga cikinsu suna haifar da lalacewa. "