Schematic illustration of the earthquake ruptures that have been reported as conjugated fault ruptures. (a) Category 1 earthquakes and (b) category 2 earthquakes. Solid stars indicate the initiation location of the rupture, and gray stars indicate the hypocenter of the secondary rupture. Arrows show the direction of fault motion. Solid lines are fault traces in map view for strike slip earthquakes and in cross-section for thrust earthquakes.