Day 13, unlucky for some!
James Hammond
The town of Abala.
As we are staying in Mekele I thought we would make use of the facilities, so you are getting two blogs in two days, aren't you lucky!
Firstly I think it is about time that we bring you up to date with our progress and fill you in on some details of what we are doing.
Firstly, I am going to be a little technical - it will help with the later entry, so please bear with me. At each site the seismometer is buried in the ground in a hole about a metre deep; nearby is a bucket containing the battery and all the cables. Leading out of this bucket is the solar panel (to keep the battery charged) and GPS cables (for accurate timing). The solar panel and GPS are located nearby on a wooden post with a clear view of the sky.
By and large the stations have been working well. We have serviced 18 stations and 15 have had no problems. The major problem we are having is that 3 new stations that we deployed in May have software issues. They seem to be working, but the data is corrupted. Our colleagues at SEIS-UK, University of Leicester are working on a solution which hopefully we will have tonight (we visit our last new station tomorrow).
So on to today's developments...
Today was meant to be an easy day, we even allowed ourselves a lie in, only leaving the hotel at 7.30 instead of the usual sunrise. First order of the day was a brief sojourn back into Afar, visiting a town called Abala. About an hour's drive past stunning limestone outcrops we dropped about 1km in elevation and arrived at the site.
A limestone house in Tigray.
The great thing about the limestone is that it falls off the cliffs in rectangular blocks, thus making natural bricks. As a result the houses blend in perfectly with the surroundings. All was well at the station and we left an hour later. The data at this station will be very interesting as the locals reported that they have felt earthquakes in the last month.
So on to our only other station for the day, a two-hour drive back in to the highlands to a town called Semre. This is in the heart of Tigray and thus a stark contrast to Afar. In the past we have had problems with termites at this station so the mood was apprehensive - would we find our solar panel still standing? As we pulled up to the station, located in a secondary school, we saw the panel standing tall, everything looked good. However, we then opened the box containing the cables; it was full to the top with wet mud. In theory, our stations can work submerged in water, but I emphasise the word theory. So, with a heavy heart we tested the battery voltage ... 13.4V.
Unbelievable, it has power! However, chances are the station is not working, water in the connectors. So I connected the palm, the way we communicate with the station, and would you believe that everything was working, and working well!
Locals working in the fields.
We then began the process of digging out the mud, only to find that all our plastic bags, used to cover the cables and battery had disappeared - very strange. Then we saw our cables, almost every one had had the casing completely removed, all that was left was the bare, live wires.
It started to make sense, a rodent had set up house in our box and preceded to feast on everything. The amazing thing is that it stopped every time it got to the bare wires, and so the station was still working. One wrong chew and it would have been game over, for our station and probably the mouse.
A 30 minute job had now become a four hour job. We carefully removed the power, and spent the next few hours changing all the cables, a lot of work. To make matters worse, while digging up the seismometer we came across two scorpions - that makes five for the trip. We left with everything working, and hopefully mouse-proof. A tired, but happy car headed back to Mekele.
Posted on 12 October 2008
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