Hawaii experiences a tsunami.
27 February 2010
I've always been fascinated by tsunamis and I have always wanted to
experience one first hand. Obviously I don't want to get caught
in a huge tsunami but I think viewing a moderate tsunami from a safe
location would be fascinating. I've spent a lot of time studying how
tsunamis work. I've also seen plenty of pictures and footage of
tsunamis. Unfortunately, most footage focuses on the drama rather
than trying to give a realistic sense of what it is actually like.
Tsunamis are nothing like the giant waves seen in the movies.
Living in Hawaii it might seem that my chances of experiencing a
tsunami are pretty good. So far though, I haven't seen anything.
Living at 2000 feet above sea level, we're not exactly in a tsunami
threat area. I spend plenty of time at the beach but tsunamis are
surprisingly rare and elusive.
My brother woke us up at 5am on Saturday. He lives in Colorado where
it was already 8am. The 8.8 earthquake in Chile had happened twelve
hours before then but I'm guessing that he was just hearing the news.
The tsunami wasn't due to arrive in Hawaii for another six hours. We
still had plenty of time.
The first thing I did, once giving up on trying to go back to sleep,
was check the internet for information. The NOAA has buoys all across
the ocean that can detect tsunamis. I managed to find the raw,
real-time data from those buoys. More importantly, I found the
tsunami measurements
for cities along the coast of South America. The
highest wave there, in the first city hit by the tsunami, was 7.7
feet. In the very next city, it was only 4.2 feet.
I'm not a tsunami expert but I know tsunamis don't get larger as they
cross thousand miles of open ocean. It was fairly obvious to me that
the wave wasn't going to be a major threat to Hawaii. It looked like
no more than six feet at the absolute highest and probably more likely
to be less than a foot by the time it reached Hawaii. Watching the
news though, they made it sound like it was going to be gigantic.
That's what happens on an otherwise slow news day.
Hawaii civil defense started sounding the tsunami warning sirens at
6am. The sirens went off every hour at first then every half hour.
It's amazing how well we can here the sirens from way up on the coffee
farm even though we're several miles away from the coast. I've been
surfing when the sirens were being tested and they are painfully loud
when you're right next to them. Kind of scary too when you're out in
the water. I had to reassure some tourists that it was only a test, no
need to panic.
After breakfast and watching the news for a bit, I decided to continue
my day as originally scheduled. I had a farmer workshop scheduled and
even though most people decided to not show up, we did still have
some. Too bad there weren't more people because it was a great
workshop.
The workshop ended right before 11am and the tsunami was scheduled to
arrive at 11:26am. I had my camera and my goal was to find my way down
to the beach. I knew that would be difficult because they had
evacuated all the low lying areas and closed all the roads. I
understand how powerful and dangerous the ocean can be so I wasn't
looking to put myself in harms way but I also understand how tsunamis
work so I knew there would be plenty of safe viewing places. All I
needed to do was get past the road blocks and overzealous cops.
It required some four wheel driving and a good personal contact but I
managed to find my way to the ocean. We stopped up high first, about
1000 feet above sea level, right as the first reports of the tsunami
were being announced. The reporters said they could see some abnormal
current changes, as if the tide was going in and out, but that was
about it. From where we were I couldn't see a thing. So we headed the
rest of the way down to the ocean. Here's what we saw when we got
there:
Nothing. Just another beautiful, calm day at the beach. There are a
few places, like inside a bay or along a coastal canal, where the
tsunami was channeled and focused enough that people could see some
unusual currents. Out at the ocean though, there was nothing. If we
looked real hard we could maybe see the sea level changing slightly but
it was so minor that it could have just been our imagination. The
regular waves were as calm and steady as ever.
Of course I realize that a false alarm like this doesn't mean that the
next alarm will also be harmless. In fact, the next time there might
not even be an alarm. Back in September 2009, there was a submarine
earthquake near Samoa that generated a tsunami. There was a tsunami
warning put out for Hawaii but they never sounded the tsunami sirens.
A few hours after issuing the warning, they canceled it. Hearing that
it was canceled, I went back to work instead of heading to the ocean.
It wasn't until later that I saw pictures showing that the tsunami had
arrived anyways.
It's hard to tell from the pictures but that's a good six feet of
tsunami height, measured trough to crest. Yet even at six feet it was
harmless with no injuries and only very minor property damage.
The February 27, 2010 tsunami
wasn't even half that and in most places it was only a few
inches. If they had been predicting a six foot tsunami there would
have been all sorts of hype and panic yet when it happened without
warning, it was no big deal at all.
Again, I realize that just because the Samoa tsunami was harmless
doesn't mean that the next tsunami will be harmless. It is amazingly
difficult, I'd even say impossible, to accurately predict how large a
tsunami will be. Predicting it's arrival time is fairly simple, that's
just the speed of sound through water. Predicting the wave height
though, that is highly dependent on the shape of the coastline and the
local off shore topography.
A tsunami can be funneled and compressed as it enters a bay so there
can be large changes in water height yet just around the corner it may
not be visible at all. Because of that, the only way to be super-safe
is to evacuate everybody. I just sometimes wish I could decide for
myself how super-safe I need to be rather than relying on civil defense
and the press to decide for me.
Oh well, I'll consider this whole thing a learning experience. It was
quite interesting to see how everyone would react. Some people became
quite nervous by the whole thing while others continued to operate
logically. More importantly, now I know how to find my way to the
ocean even if all the roads are closed.
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