Three-line trigram
Thunder Trigram
震 · Zhen
Thunder is associated here with arousing movement and the image of thunder. Its bottom-to-top binary line pattern is 100 where 1 represents yang and 0 represents yin.
Thunder as a lower or upper trigram
As the lower trigram, Thunder describes the inner or initiating three lines of a hexagram. As the upper trigram, it forms the outer or completing three lines. The meaning of a full hexagram comes from the complete six-line figure and textual tradition, not from simply adding two trigram keywords together.