Near-field tsunami formation is detailed by means of mode summations using point moment tensor sources with a spherically symmetric, self-gravitating, and elastic earth. Snapshots of vertical sea surface motion calculated within 200 km and 1000 s of an event typically show an initial tsunami pulse slowly grow and then evolve into dispersed wave trains. The general point moment tensor used here produces frequency dependent tsunami radiation patterns of azimuthal degree ?2. Pure dip and strike slip sources, however, create waves that are symmetric or antisymmetric about the epicenter. With a moment of 1020 Nm and a rise time of 25 s, these sources generate initial tsunami pulses 40 km wide buried 10 km beneath an ocean 4 km deep. Maximum dip slip and strike tsunami amplitudes of 209 and 56 cm occur 10 km from the epicenter, 75 s after the start of nucleation. Tsunami from deeper earthquakes are smaller, broader, and slower to develop because they are depleted of high frequencies. In general, characteristics of tsunamis developing in this dynamic model contradict static concepts which base tsunami formation on permanent deformations of an otherwise rigid seafloor supporting incompressible water. I find that the permanent strain state of the seafloor is not important in tsunami generation because it is defined by frequencies well below the range of interest (100--2000 s).