State of the Planet

News from the Columbia Climate School

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Delays and progress

Our local contractor laying cement for the GPS pad

A couple of long jam-packed days. None of us can believe it’s only been two full days.  We decided to have a late start yesterday morning after the 4AM wakeup and the long drive on top of jetlag.  It wasn’t a problem, as the drillers were not done with the last two wells.  Everything seems to take longer than expected. Any everything needs to be adjusted.  The 10 ft. hole for the GPS pillar could only go to 7 ft., actually 6.5 ft.  But that means the almost 20 ft. frame would be too high for the foundation, so we added a 4 ft. pad with rebar driven into the ground at the corners.  And it turns out we needed the extra height because of the 10 ft. wall around the adjacent building.  Normally GPS columns do not have wide, flat pads because they don’t want any motion from the ground going up and down.  However, we do want to know how the ground moves because our interest is the surface at the compaction wells.  Once again, everything changes from the plan, but works out well.  Bangladesh seems to be a land of improvise.  Someone can always work out a way to get something done.  We lost one of the clips that hold the hacksaw blade; the local metal shop welded a replacement.

Scott Nooner waiting for the ferry with our PVC pipe

The two short wells were not completed overnight yesterday, but last night.  The deep we was still going verrrry slowly, so we stopped when the other wells were done.  790 ft., shorter than 300m (984 ft.), but still the deepest our drillers have ever done.  We couldn’t get started on installing the optical fibers yesterday, but we got ready.  For example, we took the ferry across the Surma River to buy supplies – large buckets to mix the grout and PVC pipe to pour it into the bottom of the well.

A big event was the arrival of Humayun Akhter, Nano Seeber and Ellie Ferguson, our primary Dhaka University collaborator, my long-term collaborator at Lamont and our graduate student.  They had been studying the geology, first across the border in India, then in Bangladesh farther to the east.  They would be arriving at 4, no at 6, no at 7-8, no delay the dinner, they will get here at 9:30.  No space here to list all the causes of the delays, except that one of them was having them stop in Sylhet city to get 6” diameter iron pipes that are not available here.  In any case, they got here and caught up on all our adventures.

Scott D, Scott N., Humayun and Dhiman lowering the fiber from the makeshift spool and bamboo tripod.

Today we really got down to work, and for one day will lots of extra hands.  The wells were cleaned and prepared (the deep well is being cleaned still).  We mixed the grout and poured it down the first well, and it seems to have worked.  We decided on chain as the weight that would be imbedded in the grout.  We lowered it all in with the homemade bamboo tripod and makeshift reel and we got the delicate optical fiber installed.  After the hours of set up, it all went smoothly.  Not so on the second one.  We got stopped partway into the 41m well.  Pulled out and remeasured – the measuring string string would only go 32m.  What to do?  We would put the small PVC pipe back into the hole.  But the thin PVC from yesterday was falling apart, so we replaced it all with the better grade PVC Dhiman and I got today, retaping the connection 10 ft. (with our makeshift connectors.  It cleared the clog!  The second try at lowering the fiber optic cable worked.  Clean everything up for the night and it’s 8:40 PM. Now 24 hours to wait for the grout to harden before we can see it all worked.  Then we can start on the cap that we slightly redesign every day.

My feet (among other parts) covered in bentonite mud.

Oh yeah, and along the way I slipped and fell into the bentonite mud pool for the drillers.  Nothing hurt but my pride. I also looked at the room where the GPS receiver will go.  It’s the former jail cell.  Once we clean away the debris and cobwebs, it will be great.  Iron grate on the window and doors.  Should be completely safe.

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