19 June 2009

Winding down in the Atacama

17 June 2009

Image: The upper skylight entrance of Salon Cave.

Today, the entire team went to Salon Cave once again. The mapping team was wrapping up their work, and the sensor team was there to pull data off sensors and maintain the instruments.

Image: Preparing to enter oneof the lower canyon entrances to Salon Cave. One of the reasons this is such a leaky sieve is because it has three entrances at the lower canyon entrance, and contains a passage that opens up into a series of skylights and open canyon. Credit: Tim Titus.

In discussing the results of the thermal analysis with Tim, I’m getting pretty good at predicting the thermal behavior of each of our study sites. In July 2008, I actually equivocated on Salon Cave. The mapping team had mapped about one-third of this cave as I was deploying sensors, and then I realized it was essentially a big leaky sieve cave, and that it wouldn’t make a good study site. As we later learned, we had around only six true caves, so we had to use some additional sites (i.e., leaky sieve caves) as another study feature -- presumably, a non-cave anomaly or perhaps a new end member entirely. Long story short, prior to Tim running the analysis, I indicated it would be a leaky sieve cave, and it was.

Image: Upper canyon entrance for Salon.

The mapping team finished Salon today. They now have one very small cave segment to map tomorrow and then they are done.

Once we got back to the house, we learned we had two sensor failures from this cave. The sensor team will return to this cave tomorrow and exchange the malfunctioning sensors for working ones. We will then see if we can correct the issues with these instruments so we can use them at some of our other study sites.

When we were looking, we learned one of the sensors was programmed to collect data every minute; as a result, it collected data for only 100 days. The other collected barometric pressure data correctly, but was logging temperature data as -888ยบ F. While this is somewhat of a disappointment, we have been incredibly fortunate, out of 90 Hobo loggers, we have had issues with only two instruments.

Image: One of the skylights within the swiss cheese passage of Salon.

No comments: