This visualization, just released from the NOAA Pacific Marine Environmental Laboratory, shows the estimated size of the tsunami — the approximate wave heights that researchers anticipated seeing as the tidal wave traveled across the Pacific basin Friday morning. The largest wave heights, shaded in black, were expected near the earthquake epicenter, just off the coast of Japan. If their models were correct, the wave would decrease in height as it traveled across the deep Pacific, but would also grow taller as it neared coastal areas. According to NOAA, "in general, as the energy of the wave decreases with distance, the near shore heights will also decrease (e.g., coastal Hawaii will not expect heights of that encountered in coastal Japan). A second image provided by NOAA illustrates the depth of the Pacific Ocean floor. Comparing the two, you can see how low wave height tends to correlate with deeper areas of the ocean. An animated view can be seen here.