We seismologists at the UW have had an exciting past couple of weeks. The episodic tremor and slip event that we expect about every 14 months came a few months early this year! At http://www.pnsn.org/tremor/, you can see the map of the movement of tremor for yourself. I highly recommend that in "Overlay Options," you select "Color vs. time" to see how the tremor has moved.
This year, it started south of Olympia and slowly moved north. We watched it progress and sat around, biting our nails, asking ourselves, "Is this a false alarm or is this it?" After it held strong for over a week and crept north toward our seismic arrays, we decided that it was probably the real thing, and we went out to activate our seismometers.
Now, last year, catching the tremor episode was easy. Our seismometers were installed in plenty of time, and the batteries had plenty of juice, so no special effort was required.
This year, though, the batteries had been out in the field for a long time, and they were pretty low on power. Also, we'd had to return the actual seismometers to IRIS, the NSF-funded resource for seismometers. Luckily, they'd managed to get us some spare seismometers this summer. So we had two challenges: (1) We had to put the seismometers back out - the easy part. (2) We had to make sure each site had a working set of batteries - the hard part. See, these batteries are rather specialized and very expensive; we couldn't afford to buy anymore. So we did a not-so-fun activity: we pulled good batteries out of sites that weren't important, and we put them into sites that were important. Now these batteries are about 16 pounds each, and we have 5 per site. These sites can be pretty far back in the woods, because if they're too easy to find and get to, people vandalize them. In some sites, we had to take out all five batteries, and in others, we had to replace five batteries. You do the math. It was hard work!
Luckily, it was all worth it. The tremor kept rumbling on northward, and we got the last stations hooked up the same day that the tremor reached our seismic arrays. Whew! Now we just wait another week or two for the tremor to totally pass by, and then we go collect all our great new data.
Jonathan was kind enough to join us in this effort, and he was an excellent field assistant. He was great at hauling those heavy batteries. Plus, one station wouldn't have gotten running if it weren't for him: We had a site that was vandalized, and the vandals had cut the lead that connected the battery to the power cord. Lucky for me, Jonathan knew that we could just strip the wire and wrap it around the battery lead. Not as elegant as an intact power cord, but it worked!
Jonathan also took a lot of pictures. There are a ton of them so I'll put this behind a cut. Here's a little preview:

( Click here for more! )
This year, it started south of Olympia and slowly moved north. We watched it progress and sat around, biting our nails, asking ourselves, "Is this a false alarm or is this it?" After it held strong for over a week and crept north toward our seismic arrays, we decided that it was probably the real thing, and we went out to activate our seismometers.
Now, last year, catching the tremor episode was easy. Our seismometers were installed in plenty of time, and the batteries had plenty of juice, so no special effort was required.
This year, though, the batteries had been out in the field for a long time, and they were pretty low on power. Also, we'd had to return the actual seismometers to IRIS, the NSF-funded resource for seismometers. Luckily, they'd managed to get us some spare seismometers this summer. So we had two challenges: (1) We had to put the seismometers back out - the easy part. (2) We had to make sure each site had a working set of batteries - the hard part. See, these batteries are rather specialized and very expensive; we couldn't afford to buy anymore. So we did a not-so-fun activity: we pulled good batteries out of sites that weren't important, and we put them into sites that were important. Now these batteries are about 16 pounds each, and we have 5 per site. These sites can be pretty far back in the woods, because if they're too easy to find and get to, people vandalize them. In some sites, we had to take out all five batteries, and in others, we had to replace five batteries. You do the math. It was hard work!
Luckily, it was all worth it. The tremor kept rumbling on northward, and we got the last stations hooked up the same day that the tremor reached our seismic arrays. Whew! Now we just wait another week or two for the tremor to totally pass by, and then we go collect all our great new data.
Jonathan was kind enough to join us in this effort, and he was an excellent field assistant. He was great at hauling those heavy batteries. Plus, one station wouldn't have gotten running if it weren't for him: We had a site that was vandalized, and the vandals had cut the lead that connected the battery to the power cord. Lucky for me, Jonathan knew that we could just strip the wire and wrap it around the battery lead. Not as elegant as an intact power cord, but it worked!
Jonathan also took a lot of pictures. There are a ton of them so I'll put this behind a cut. Here's a little preview:

( Click here for more! )
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