Snapshots of dynamic rupture propagation for two other cases. Δτexcess for the large patch is 5.5 MPa, and Δτexcess for the small patches are (a) 16.280 MPa and (b) 16.335 MPa. These examples show the difficulty of controlling the rupture process for the small patches. In case (a), the rupture onset is slightly delayed for the small patches, but once rupture starts, it propagates very rapidly. In case (b), no rupture occurs.