Last Saturday evening I was banging my head on my keyboard, trying to pull together a coherent post on financial independence: chasing yield, peer-to-peer lending, and church bonds. (Which probably means that it’s really two or three separate posts.) As I was writing, the Civil Defense warning sirens started wailing. So I decided to take a break from the financial topic to write about Hawaii and tsunamis.
Hawaii has been a tsunami target for centuries. The middle of the Pacific Ocean is one of the world’s most remote geographic locations, and tsunamis can get a running start of thousands of miles before rolling across the islands. Tsunamis are usually spawned by earthquakes but can also occur with volcanic eruptions. Unfortunately written records didn’t begin until the late 18th century, so earlier events are derived from oral history.
Unlike tides or waves, tsunamis have a very long wavelength and a very long period, measured in minutes and occurring for several hours. When the waves approach shallow water they’re very low but moving at hundreds of miles an hour, and then they compress against the bottom topography. This causes the wave to pile up and push its tremendous destructive energy ashore. Not only can they approach the islands from any direction, but the wave energy can refract around the shores and ricochet between islands. The result is that a tsunami can assault the islands for as long as six hours, and smaller reflections can occur as late as the next day– long after we’ve let down our guard.
The most destructive tsunamis in Hawaii’s 20th century happened in 1946 and 1960. The first came from a magnitude 7.1 earthquake in the Aleutians and the second came from an 8.3 earthquake off Chile. The first killed over 150 people and caused tremendous damage in Hilo on Hawaii Island. The second one was almost as bad in Hilo, despite the experience of Hilo residents, because since 1946 there had been several tsunami warnings that didn’t actually impact the islands. Many locals ignored the 1960 alert as “crying wolf”, and some even lined the shore to see if anything would really happen. Over 50 years later, the Pacific Tsunami Museum in Hilo is still helping us remember those lessons. Today most of Hilo’s waterfront is still zoned as parkland, designed to absorb some of the next tsunami’s energy before it reaches the town.
20th-century radio managed to warn the islands of the 1946 and 1960 earthquakes, but the problem was predicting the tsunami arrival times and their severity. There were dozens of smaller tsunamis and “false alarms” between the two events because oceanographers lacked the ability to gather the data and to analyze it. That led to a number of open-ocean buoys and other research projects, and computer models gradually improved. However governments and populations are reluctant to spend the necessary money for basic research when the disasters seem to occur so infrequently. By 2001 Hawaii had a rudimentary six-buoy network collecting data for oceanographers to compare to their models.
That all changed in 2004. The Indian Ocean magnitude 9.1 earthquake generated a tsunami over 90 feet high and killed over 230,000 people. It happened during the holiday season and with almost no time to warn people between the earthquake and the tsunami’s arrival. It drove home the need to have a widespread network of many detectors with an automated data-collection and warning system. By 2008 Hawaii’s warning network had 39 DART II buoys sending data (scroll down the linked website for the detailed images & diagrams). The system forms a network near the shores around the Pacific Ocean that automatically detects tsunami-generating events and shifts to continuous data transmission.
So what did all of this technology mean last Saturday night? When the earthquake struck off the coast of western Canada just after 5 PM Hawaii time, it immediately triggered earthquake warnings at the tsunami centers. An information bulletin went out and the centers continued watching. Two hours later the DART buoys captured the pressure pulse of a wave propagating away from the quake and the bulletin elevated to a warning. Arrival was predicted for 10:30 PM. The first warning went out at 7:15 PM and the sirens lit off at 7:45 PM.
My spouse and I were in our Central Oahu home (elevation 450 feet). We have emergency food & water and we were ready for power outages. (HECO’s electric plants are by the shore, almost at sea level.) While I was waiting for more news, I let our daughter and other Mainland family/friends know that we expected to be fine. (Mainland media tends to blow a Hawaii tsunami out of proportion.) Then I started watching Twitter hashtag #tsunami.
The timing was the worst I can remember since the history of the 1946 disaster. Tides were high (well, two feet isn’t much by Mainland standards, but that’s very big here) and tsunami would arrive in the dark. Visitor counts this year are setting new records. Saturday night on a Hallowe’en party weekend meant that Waikiki & Ala Moana were packed with people and vehicles. Partyers were in costume and much less than sober. Waikiki visitors & residents were evacuating “vertically” above the second floors of their buildings. Ala Moana Shopping Center was evacuating, as were the rest of Oahu’s coastal areas. Airports were grounding flights as quickly as possible and canceling the rest of the schedule. (Honolulu’s reef runway is at an elevation of about six feet, even before the two-foot tide.) The Marines evacuated Kaneohe Base (1700+ servicemembers & families), and the rest of Kailua & Kaneohe were right behind them. Everyone on the Ewa Plain headed straight upslope to Makakilo community centers and parks. Kahului (Maui) and Hilo residents were evacuating to higher ground. At least 5000 people were in shelters or camping out. By 10 PM police were ordering drivers in traffic jams to abandon their cars on the road and walk uphill.
The greatest concerns were panic and bad driving. A North Shore road was jammed in both directions– one group of residents evacuating south to higher ground, another group driving north to Haleiwa to see the surge. Ambulances made over a dozen calls in traffic accidents before the wave even arrived.
At 10:30 PM the Makapu’u Point buoy showed a drop of three feet followed by a rise of 1.6 feet, which caused some excitement. But then Kahului came in at 1-2 feet and Hilo harbors saw “only” four feet. The waves were surging every 5-10 minutes instead of 30+ minutes, which indicated that the tsunami had less energy and would probably fizzle out. (The first wave is often the smallest and the worst doesn’t happen for another 2-3 waves.) Even then the tsunami energy ricochets around the islands for as long as 24 hours before dissipating, so by 1 AM everyone was a tad burned out. The Civil Defense staff was reluctant to give the all-clear too soon, but did so less than an hour later. Daylight revealed that there was almost no damage throughout the state. It could have been a natural disaster, but the warnings went very well. The evacuation went as quickly as could be expected and the recovery was smooth.
Many Darwin Award nominees “distinguished” themselves that night. There were the usual idiots rushing out to the ends of the piers or standing in the shorebreak with their cell phone cameras– and they were probably sober. I’m sure a number of people had a bit too much to drink and decided to drive anyway (“Because it’s an emergency!”), and I bet almost every driver was “simultaneously” checking their cell phone for the latest updates. People raced to stores to buy the traditional tsunami supplies of rice, bottled water, batteries, and toilet paper. (Because, you know, nobody stores that stuff at home and we might not ever get any more of it after the tsunami.) Several tweets reported fistfights at gas stations. Boaters spent the night at sea, and I doubt that all of them were ready for a sortie. Harbormasters didn’t re-open the piers until after sunrise so the Coast Guard was busy on Sunday morning. A serious vehicle accident took at least one life and injured several more people.
Social media was timely, broadcast media lagged. Twitter’s #tsunami hashtag worked very well (it trended at #2) and locals were updating their Facebook status. There was frequent on-scene reporting from beach webcams and mobile users, too. Local broadcast media was crowdsourced by the audience over 3G networks while the media staff was stuck in traffic, stopped at roadblocks, or filling dead air in the studio. I got faster/better updates from Twitter than from any other source, although it took a while to filter 100x the volume and read through only 1% signal/noise ratio. I’d see a local tweet on the hashtag, and then a couple of minutes later a news anchor would say “This just in from our on-scene reporter…”
Hawaii is well-known for hurricanes, but ironically it’s been over 20 years since Iniki devastated Kauai. There have been several close calls since then, but nothing causing more than gusty winds and heavy rains. The worst natural disasters this decade have been a local earthquake and not one but two tsunamis. The March 2011 Japan tsunami caused some isolated damage here, and this time we were even luckier.
I hope the East Coast recovers from Hurricane Sandy soon. Despite our initial fears about the tsunami, that hurricane was far worse.
The Pacific Disaster Center
Pacific Tsunami Museum
Pacific Tsunami Warning Center
3D Hawaii: Hale Koa Hotel in Waikiki
Lifestyles in military retirement: Living in Hawaii
Good reasons NOT to live in Hawaii
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