How long would it take to outwalk a tsunami?
The 2011 Japanese earthquake and tsunami proved that walking to higher ground can save your life when a killer wave is headed to shore.
But every minute counts.
To better educate the public on how long it would take to get out of a tidal wave’s deadly reach, the state Department of Natural Resources has created a series of highly detailed maps for Aberdeen, Hoquiam, Cosmopolis, Bellingham, Anacortes and Port Angeles.
The maps illustrate how many minutes it would take to walk to a safe zone from various sections of those cities and towns. Parts of all of those communities are in the projected inundation zone of a tsunami generated by an earthquake on the Cascadia fault, about 50 miles off the Washington coast.
“If you feel an earthquake, that’s your warning and you should evacuate and get to high ground immediately,” said Corina Forson, chief hazards geologist.
However, Forson said, a tsunami can arrive without an earthquake warning. Waves from the 2011 Japanese quake struck California and Oregon several hours after the quake, which wasn’t felt in North America.
The evacuation times are based on a slow walking pace easily maintained by the average adult, according to Daniel Eungard, a tsunami scientist. It equates to about 2.5 miles per hour.
“If you can cross through a cross walk before the (red) hand comes up ... then you are walking faster than this pace,” he said.
In the Aberdeen area, evacuation times range from 10 minutes near Grays Harbor College to 30 minutes at the Home Depot.
Why not just drive, you may ask.
In a major earthquake, utility poles might fall, ground could liquefy, roads could fissure, bridges and buildings might collapse. Walking may be your only way to safety.
The maps also show main and secondary evacuation routes.
The evacuation time estimates are based on LIDAR imaging, surfaces and obstacles.
“This is all taken into account in the modeling process,” Eungard said. He suggested making a practice run, especially if you have children or a disability.
The time estimates begin the moment the ground begins to shake, Forson said.
“If this is a Cascadia subduction zone earthquake, shaking could last five minutes,” she said.
Most of Aberdeen could be evacuated within 40 minutes, according to the map. The estimated arrival time for a wave in Grays Harbor is one hour.
Bellingham and Port Angeles have it easier with most of those cities already in a safe zone. But if you happen to be on Ediz Hook, the spit that forms Port Angeles Harbor, you’ll have to move quickly.
“Must run,” the map states for that area.