The wave’s water column is around 2.5 miles from top to bottom. This mass of water is hurtling from Chile toward Hawaii at 446 mph. The wave is small when it’s mid-ocean, but it may rise 16 to 33 feet.
Jim Borg’s explanation for why, unlike 1960, Hilo Harbor on the Big Island got through with only minor sloshing. It’s not so much that the tsunami was smaller as it crossed the wide sea, although this is a factor. The key, it says here, was its lack of resonance with the harbor basin and its nearby marine topography, something that the 1960 wave column did have.