propagationthe transmission or spreading of a wave or signal through a mediumThe propagation of seismic waves through the Earth provides data about its internal structure.NoteThe propagation of seismic waves through the Earth provides data about its internal structure.Elon.io is an online learning platformWe have an entire course teaching IELTS Vocabulary — Band 7+ grammar and vocabulary.Start learning IELTS Vocabulary — Band 7+ now