Digging deeper into the last mile

March 11 is right around the corner and will mark the passing of a decade since the Great East Japan tsunami. Tsunamis are on my mind so I’d like to dig a little deeper into the “last mile” problem.

Why is it so difficult to get people out of harm’s way? Two reasons: technology and human behavior. Turn the clock back to 1946 Hawaii. April 1 dawned sparkling clear like most Hawaiian mornings. At 6:30 a.m., people were getting up, having breakfast, heading to school and work, and enjoying the lowered stress of the post-war era.

A colleague and friend, Jeanne Johnston, was 6 years old and in Hilo. She remembers awaking to car horns blaring and grabbing her 4-year-old brother’s hand to go outside and investigate. Ocean debris was scattered around the house. Fortuitously, red ants began attacking her brother’s bare feet, driving them back inside. From the second story of the house, Jeanne watched a surge of water pour in, reaching as high as the clothesline near where they had been standing. To this day, she thanks the ants for saving their lives.

In 1946, there was no tsunami warning system. In Hawaii, no one saw or felt anything that presaged the coming disaster. The tsunami was caused by a M8.6 earthquake centered in the Aleutian Islands more than 2,300 miles from Hilo. Needless to say, no one in Hawaii felt the shaking.

There were seismographs in 1946. The University of California at Berkeley had a network in Northern and Central California, including a station in Ferndale. Caltech had stations that covered the southern part of the State. There were instruments elsewhere in the world including a pair in Hawaii, but earthquake investigations of that era relied on analyzing data after the event. It was often weeks