Submitted by Anonymous on Tue, 08/26/2008 - 19:06
Forums
Kuril Islands Biocomplexity 08

Dr. Etnier,

I was wondering if you and the rest of the KBP team tested different ways to measure the tsunami run-up over the previous summers, before settling on the one you have now?

thanks,

MiaSmile

Mon, 09/08/2008 - 10:48

KBP Team

Yes, they have tested different ways of measuring tsunami run-up.  As with any kind of field-based scientific data collection, we have to strike a balance between the portability of the equipment on the one hand, and the accuracy (how close to "correct" your measurements are) and the precision (how similar repeated measurements of the same thing are) of the data.
 
To return to the example of GPS units, hand-held units are really good at determining your location to within +/- 5 meters.  They are cheap and highly portable.  And they do a good job of telling you where you are (accuracy), but are only so-so when it comes to precision (you could be to the right, left, or up/down) from the stated location.   If we are trying to measure tsunami run-up, the exact location of the a particular wrack-line isn't really all that important.  But the elevation of that wrack-line is important.  So the precision of hand-held GPS units isn't good enough for the tsunami work.
 
At the other extreme, two of our Russian colleagues are using extremely high-precision GPS units to measure shifts in tectonic plates.  Their GPS units can detect movements of less than 1 milimeter!  The drawbacks to this equipment are that it is extremely  expensive, and also very heavy (and therefore not very portable).
 
So in the end, the tsunami team has settled on the nivilier-and-stadia-rod system because it gives them the data they need, but is also inexpensive and relatively easy to lug around across the islands!
 
---Dr. E