The Planetary Society Blog
By Emily Lakdawalla
Borup Fiord Pass Field report: Return to Resolute
Jul. 6, 2006 | 20:41 PDT | Jul. 7 03:41 UTC
Stephen Grasby called this evening from Resolute; the field expedition is over. They've spent the last couple of days continuing the work on the field geology. Today was a good travel day, and the helicopter came to pick them up as planned; the team are all ensconced in the hotel in Resolute, having happily enjoyed showers.
"We flew over the site again in the helicopter and the spring was still flowing pretty steadily," he said. "We didn't see any change at all in the flow rate while we were there."
They have made another interesting observation about the spring. During the days they've been at Borup Fiord Pass, warm summer weather has melted almost all of the winter snow. So the formerly white valley is now brown -- except at the location of the spring's outlet. What gives? Steve explained that as the spring flowed during the (otherwise mostly dry) winter, its waters would freeze at the location of the outlet, building out the outlet. Occasional snow falls would coat the valley and the stream outlet. When the warm weather arrived, all that snow melted first, but the ice formed at the spring outlet will take longer to disappear. "It must start running very early in the season, or maybe run all winter," Steve said. "When the snow started melting, the only place there was still ice was where all the sulfur was."
Steve said that the change has been pretty dramatic during their short stay in the field. He had been looking through his photos this evening, selecting some to send to us (he would have sent them tonight but the wireless access in the hotel wasn't working; he said he'd try to find a hard wire tomorrow). "The first image [from the field site], there we are in waist-deep snow; today there was no snow to be seen."
In addition to being a useful clue to the longevity of the spring, the iciness of the spring outwash could also serve a useful purpose. Both of the attempts to get satellite image data of the field site were clouded out; the next attempts won't take place until July 11 and 16. Bob Pappalardo told me he was very concerned about not getting satellite data of the site for comparison to the spectral data that his student Damhnait Gleeson acquired while she was there on the ground, especially because the melting of the snow and ice was apparently washing all of the sulfur staining away. But, Steve said, "Where the sulfur is, the ice hasn't started melting yet. It's still pretty thick, almost as much as when we got in. Hopefully it'll hold out a couple of days, and we'll get the satellite view."
I hope to have those pictures for you tomorrow!
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