http://www.pbs.org/cringely/pulpit/pulpit20041230.html
PBS: I, Cringely -- The Pulpit
How to Build a Global Internet Tsunami Warning System in a Month
By Robert X. Cringely
A friend of mine is missing in southern Asia.
She isn't missing in the sense that anyone saw her swept away by this
week's horrible tsunami, but she and her entire family haven't been heard
from, either so of course, I am worried. That worry makes real for me a
disaster of such horrific proportions that without a personal connection,
it simply can't be real to most of us. By the time all the bodies have been
counted and estimated, probably 100,000 people will have died. If cholera
follows, as it tends to in that part of the world, another 40,000 or more
could follow. That's a lot of people, 140,000 -- enough people that we
ought to do something to make sure it doesn't happen again. So of course,
there is lots of talk about tsunami warning systems and global cooperation,
but I think that's just going about solving the problem the wrong way. We
don't need governments and huge sensor arrays to warn people on the beach
about the next huge wave approaching at 400 miles-per-hour. Thanks to the
Internet, we can probably do it by ourselves.
Here's the problem with big multi-government warning systems. First, we
have a disaster. Then, we have a conference on the disaster, then plans are
proposed, money is appropriated, and three to five years later, a test
system is ready. It isn't the final system, of course, but it still
involves vast sensor arrays both above and below the surface of the ocean,
satellite communication, and a big honking computer down in the bowels of
the Department of Commerce or maybe at NASA. That's just the detection
part. The warning part involves multilateral discussions with a dozen
nations, a treaty, more satellite communication, several computer networks,
several television and radio networks, and possibly a system of emergency
transmitters. Ten years, a few million dollars and we're ready.
We can't rely on governments to do this kind of work anymore. They just
take too darned long and spend too much money for what you get. Besides,
since governments are almost totally reactive, what they'll build is a
warning system for precisely the tsunami we just had -- a tsunami bigger
than any in that region since the eruption of Krakatoa in 1883. One could
argue (and some experts probably will) that it might even be a waste of
money to build a warning system for a disaster that might not happen for
another 121 years.
What we need is a tsunami warning system not just for parts of Asia, but
for anywhere in the world that might be subject to such conditions. And
that decision about what beaches to protect ought to come not from
Washington, D.C., or Jakarta, or any other capital city, but from the beach
people, themselves. If you are concerned about a giant tidal wave taking
out your village, it might be a good idea to build your own warning system,
you retired engineer, you Radio Shack manager, you harbor master, you radio
amateur, you nerd with a suntan.
It can be done.
The Tsunami Warning System (TWS) in the Pacific Ocean shows us how such a
warning system can be run with the cooperation of 26 countries. Maybe we
can do the same thing, just without all that cooperation. TWS is based on
crunching two kinds of data -- seismic activity and changes in sea level
measured by tide gauges. Most tsunamis begin with an earthquake, the
severity and epicenter of which can tell a lot about whether a tsunami is
likely, how strong it will be, and in what direction it is likely to go.
From the TWS, the first warning is based purely on such seismic data. But
once the big wave starts rolling it will have an effect on the level of the
sea, itself, which is routinely monitored by weather stations of many
types. This additional data gives a better idea of how bad the wave is
really going to be, so in the TWS system, it is used to justify expanding
the warning to other communities beyond those warned purely on the basis of
seismic data.
Depending on where the originating earthquake is, the tsunami can be
minutes or hours from crashing into a beach. This week's wave took about 90
minutes to reach Sri Lanka, just over 600 miles from the epicenter. That
not only means the wave was traveling at over 400 miles-per-hour, it also
means that had a warning system been in place, there would easily have been
time to get the people who were affected in Sri Lanka to higher ground.
So to start, we need raw seismic data. If you take a look at the fourth of
this week's links, you'll see that plenty of such data are available.
Thanks to the Pacific Northwest Seismograph Network, here is one place
where you can find real time data from 199 seismographs around the world.
There are also links to a dozen regional operations that consolidate such
data. The data is available. Tide gauge data is available, too, though
there is less of it, and aggregation will
