The recent earthquake in Chile has caused scientists at the Pacific Tsunami Warning Center in Hawaii to reexamine their computer models. While the Chilean earthquake did produce a tsunami, its most devastating effects were local and quick – mostly along the Chilean coast and nearby islands. Even though this was a monster quake (Richter 8.8) the feared tsunami that might hit Hawaii was miniscule compared to the South Asian tsunami that killed a quarter of a million people on Boxing Day 2004 as far away as Africa.
Computer models are relatively new tools used in many science related fields, like engineering, weather forecasting and of course climate change forecasting. Models always need to be tweaked to accommodate all known variables and then need to be back tested against actual events to see how the models performed. That process is ongoing, continuing toward bringing the model closer to reality because the science is never settled, the probabilities are just shifted.