During the Chilean tsunami of 22 May 1960, precise readings of sea level were digitally recorded every 15 seconds by the La Jolla low-frequency wave instrument. The tsunami remained above background for a week. The record gave a good opportunity to measure the decay of tsunami energy as a function of frequency. Energy is reduced by 1/e about once each half day. The decay is somewhat more rapid at high frequen cies and at high energy densities. The total energy of the tsunami is estimated to be of the order of 3 x 1023 ergs.