After the resistivity, I was supposed to go to Khulna to join Scott and Scott on repairing the compaction meters. We have two places with sets of wells where we installed optical fibers. A local person uses a device to measure the length of the fibers each week by shining a laser through the fiber. Unfortunately several on the fibers have broken since we installed them. The Scotts will be repairing them, as well as the usual yearly measurements and data collecting. They went to the northern site first – we saw them heading north while the conclave group was heading south. I was going to join them for the southern site, but their work went so much faster than expected that they finished while I was doing resistivity. Thus there was no need for me to go to Khulna before meeting Chris Small for the river work. I spent the two extra days in Dhaka. I had plenty of people to look up that I didn’t expect to have time to meet.
On the first day, Humayun and I went to the US Embassy to meet with people who couldn’t make it to the conclave due to the hartal. Even the US Ambassador was going to meet us when he took guests to a resort in Sylhet. As Humayun and I passed through several layers of security, we ran into the Ambassador on his way out. We chatted for a few minutes and then went on to our meeting. After making it back to the university for lunch, we went to the Geological Survey of Bangladesh, where my main contact has been promoted to Director General. I showed him our results and we discussed collaborations, particularly on GPS. All around the university women were dressed on yellow, orange and red
saris for the first day of Bangla spring. Finally back to the Ambala Inn where I met up with the Scotts and Doug and all of us went to dinner with Chowdhury, my collaborator from the Bangladesh Water Development Board (BWDB). He has gotten us a huge dataset on the water levels in the rivers and in groundwater wells. Well over a million individual measurement. Water is so central to life in Bangladesh that there is an excellent monitoring system in place that we use to determine the amount of water impounded in Bangladesh during the monsoon. It is over 100 billion tons of water.
The next day, we went to BITWA to try to obtain more detailed information about the tide gauges for examining sea level changes. Tide gauges measure the height of the water relative to the land, but here the land is sinking. We put 2 GPS
to monitor the land subsidence next to tide gauges. That will let us separate the sea level rise from the subsidence. The combined effect has Bangladesh worried about land loss and water salinification. We went meet with the wrong person twice before we finally found the correct person, a woman whose sister had been a student of Humayun’s. It will now be straightforward to get the detailed data. The afternoon was spent working with one of the students from the resistivity training. Sojon wanted to go through everything in detail so he knows how to run the system. Fayaz would have joined us, but he was out filming archeological sites with Doug. The two of them have taken the initiative to be leaders among the group. The 10-minute ride back to the Ambala Inn took an hour. An area just north of the
university has been blocked off because of the peaceful protests against the razakers, the groups that collaborated with the Pakistani army during the revolution and helped them in their killings. The Islamist party’s hartals for the release of their leader has lead to a larger movement wanting the death sentence for him and others. It is Occupy Dhaka. It was very strange to see women dressing in colorful clothing yesterday with headbands calling for death for the razakers. Finally, I arrived and waited for Meredith, the last of our party to arrive from NY for the river work. The bad traffic meant she arrived very late. Doug and I had a last dinner together at 11 pm in a local packed restaurant.
Today I am finally on my way to Khulna with Meredith and Humayun, with Babu as our driver, of
course. I am stuck waiting to get on the ferry across the Padma River, formed by the merger of the Ganges and Brahmaputra. Once across, we will be in the more leisurely and relaxing south to meet up with Chris in Khulna.
After returning from Sylhet, I left Dhaka the next morning for Comilla for 4 days to train a group of Dhaka University students and graduates on operating our resistivity imaging system. Many of the conclave people headed out to the Padma River, formed by the joining of the Ganges and Brahmaputra to do sampling for a remote sensing study of the rivers. I will be doing this later in the trip, but had other plans now. The transects of wells that we are drilling provide detailed vertical records of the sediments, but how do we connect the dots when the wells are 3-4 km apart? It turns out we can do it with electricity. Clay and mud has much lower electrical resistivity (or higher conductivity) than sands. The basic technique it to pound two pairs of electrodes (stainless steel rods) into the ground. We then use a car battery to
send a current between one pair and measure the voltage at another pair. The voltage depends on the rock type between the 4 electrodes. For our system, we have 84 electrodes that can be spaced up to 9 m apart and a long cable in 12 sections to connect them. A sophisticated resistivity device then sends current to one pair and measures the voltage at up to 8 other pairs at a time. The device is programed to do measurements with thousands of different combinations. The result is similar to doing and electrical catscan of the earth showing the distribution of sand and mud.
I came to Comilla with 6 trainees, Fayaz, Sojon, Jia, Rabi, Fuad and Paval. During the 4 days, they will work with me to learn to use the system
well enough to be able to carry out these surveys on their own. For the training site, we came to Comilla where to work around the Lamai anticline. It is the westernmost hill sticking up out of the floodplain. To help interpret the structure creating the anticlines, we need to know the dip, or slope, of the folded beds. This has been roughly done from topography, but the exposed topography is partly eroded. We want to image the boundary between the older Pleistocene sediments of the anticline and the younger Holocene sediments that cover them. Both sediments are similar, but the surface exposed during the last glacial period when sea level was 120 m lower has been altered to clay. This should show up as a dipping layer of low resistivity. We will do 4 lines, two on each side of the anticline to image the dipping beds.
Our first day was short because of the time it took to get here. We laid out a short line with 56 electrodes a short distance south of one of the wells that was drilled on the east side of the anticline. The car batteries we took along were not fully charged, so we hooked up Babu’s van to provide more power. That worked well and decided to use the car to run the equipmet the rest of the days. However, that meant the lines had to be where a car could go. Humayun did not join us because his wife has been ill. That meant we didn’t have a GPS to record positions or track where we were. We managed to use the GPS in my camera to get the positions of the line. We moved to our home for the next few days, the Bangladesh Academy for Rural Development or BARD.
The next day we shifted to the west side the next day. Google Earth became our tool for finding sites. With a USB modem we had slow, but continuous internet. We found a set of fields close to the one of our drill sites. We navigated to it by recognizing buildings, mostly gas stations from Google Earth. The fields were fallow, so we could cut across them. Everything was going smoothly. We finished early and I was able to spend the late afternoon teaching the students. That evening we processed the data for both lines. The first one showed the boundary we were looking for to be very shallow. A river had eroded part of the anticline. Thus we were on top of it and not on the flank. Good data, but it didn’t provide us with a slope. The other line had noise problems from a power line, but clearly showed the layer we wanted dipping ~3° to the west. The system was providing hard data.
We still needed a line on the east. We tried our first site, but Babu’s van could not drive to the line location. On to plan B, a country road on the west side. We drove our electrodes into the fields at the base of the road being careful not to disturb the growing vegetables. The data was marred by some power lines, but showed our layer for part of the line. It lined up well with the previous day’s results. For our final day, we need a good line on the east. I picked several candidates on Google Earth. The first was inaccessible, but I quickly found another road and we did it there. Because they were planting rice, the side of the elevated road was not useable. The top turned to not be that good a place. The data was much worse quality than any of the other sites. Still, it gave reasonable results. Humayun and Doug came out, so we interspersed working on the resistivity line with filming. That line competed our work here and the training and we all headed back to Dhaka. The students were trained and we learned how to select good sites.
Now that the hartal was over, we were free to travel as we wished. We also switched film crews. Doug and Diane from Earth Images are independent filmmakers that make PBS specials. They arrived in Dhaka on the morning of Feb 6 during the hartal, so could not travel here. Humayun arranged for them to be picked up by an ambulance, exempt from the hartal, and taken to the Ambala Inn to wait out the strike. That meant they were able to spend the day walking around getting footage of Dhaka without cars, a rarity. Colorful bicycle rickshaws ruled the road. They left Dhaka in the afternoon when the hartal was dying down and arrived at the Shuktara around 11 pm.
The geology that we saw over the hartal changed our drilling plans. Steve Goodbred was excited enough by what he saw to change the day’s well from the flat floodplain to the back of the anticline. He and the Vanderbilt team went there early in the morning with the AMNH film team to get their last shots before heading to Dhaka. That meant the rest of us had to stay away. Most of the group went to the Sylhet anticline outcrops near the cricket stadium and airport. I later learned that they found clear evidence of rivers cutting through the anticline while it was growing. It caused mud deposits from the ponding on one side and gravels from the steeper slope on the other. I was recruited by Doug for an interview and to take him up to the Jaflong area by the Shillong Plateau so he could film that. Nafisa and Mosher stayed with us. After they watched my interview from behind a
wall, our group headed north. At the site where Nano gave us an overview, I repeated his story with a 3D camera rolling. Nafisa, Mosher and I held conversations about the geology while Doug filmed us over and over. We then went over to the Rangapani River where border guards stopped us and informed us that foreigners were not allowed to film there. After some explanation from Nafisa, they call their superiors and we were OKed. The pits we had seen a few days before were now deeper and the miners had uncovered a large tree trunk and exposed boulders up to 6 ft across. We continued our conversations for the camera until the border guards told us it was time for us to go. Doug still tried to get more footage, including outcrops out of site of the guards until they followed and saw us still going. We left peaceably.
All the filming and multiple takes meant there was no time for Jaflong itself. We rushed back to the Sylhet Anticline in time to catch the drilling before it got dark. Since we only had a short ride back to the hotel instead of a 1-2 hr drive, a car full headed to Sylht City for shopping. As it was the last night of the conclave, we had a barbeque on the deck on the roof of one of the bungalows. They barbequed fish and tandoori chicken along with a host of other dishes and a procured bottle of vodka. An excellent end to the meeting.
The next day it was time to head back to Dhaka, stopping at a few of the anticlines from southern Sylhet on the way. As usual, getting everyone out and the cars loaded up took longer than expected. Nano and Ellie decided to stay another day in Sylhet and then go straight to the airport rather than have a day in Dhaka. Our group was shrinking. Jenn and Sanzida had already left early
because of ill relatives. A few people had canceled because of illness. We were down to about a dozen people heading to Dhaka. However, the defections and splitting of the groups the last few days made the field stops less unwieldy and more efficient. On the way south, we had a quick stop at Sreemongal, where a group from Singapore we are collaborating with put in a GPS. Then we saw tea gardens, a sure sign of an anticline. Tea needs well-drained soils and cannot be grown on the floodplains. However, the first tea plants were on flat land. The rising anticline had uplifted some of the floodplain on its flank, another useful observation. Then we entered the Rashidpur anticline proper. Several stops revealed that the dips of the beds were not preserved, limiting the value of the outcrops. We stopped for lunch in a tea garden and continued on to our GPS station and seismometer at a school in Chunarughat. In
2007 when we installed the site, we found the building we originally selected was unsuitable. It was brick made to look like reinforced concrete. We found this site by driving down the main street of the town on a Friday night. We found this school and contacted the headmistress, visiting her at her home on the weekend evening. The next morning we installed the site. Now on this visit, Humayun and I were again pressed into service for filming, along with a Nafisa, Mosher and Fayaz. By the time it was finished, we had to head straight back to Dhaka. Some quick stops at the next anticline revealed it too had poor outcrop. We then hit some of the worst traffic I had ever seen. The highway into Dhaka, never very fast, was at a standstill. Babu, our driver, turned around and led
us through back streets to alternative routes until we found one that was moving. It was almost 10 pm by the time we reached our hotel and officially ended the conclave and part one of my trip. Still it was extremely successful, pulling together the different groups and changing the direction of our research.
Our experience in in Bangladesh in nothing will go as planned, but somehow we are able to get everything done. Living in this ever changing land beset by numerous natural disasters has made Bangladeshis incredibly resilient and adaptable. This was tested over the last few days – and may continue to be over the next weeks – by a hartal. A hartal is a strike in which transportation is shut down. The party calling it sets up roadblocks and attacks cars and buses on the streets. Bicycle rickshaws and the green baby taxis are OK. This one was called by Jamaat-e-Islami, the largest Islamic party. The reason was that their leader was sentenced to life imprisonment for war crimes during the 1971 Independence War. The religious
parties supported remaining part of Pakistan and are accused of helping the Pakistani Army in killings. Estimates are that 3 million people were killed in the war for independence with Hindus and intellectuals particularly targeted. The leader on trial was specifically accused of killing 12 and assisting in the killing of 369 others. The problem is that the Jamaat-e-Islami is part of the opposition coalition and many believe the trials are politically motivated to take down part of the opposition before the elections later this year.
On Feb 5, there was a hartal called that ran from 6am-6pm. Driving around in our vans was our of the question. Luckily, it was the day to visit outcrops on the Sylhet anticline, where our hotel is. The sites at the airport and cricket stadium
were out of the question. We found out later that there were bombs thrown in Sylhet, although, thankfully, no one was hurt by them. The third area of outcrops we planned to visit were right by our hotel. We walked to the sites situated by the tea gardens and tea factory to see them. They were not the greatest outcrops, but still provided valuable new data and discussions. We returned to the hotel for a late biryani lunch, a step up from the cold packet lunches we’re been having. For the rest of the afternoon, we held discussions around our large poster-sized maps, or relaxed. The Bangladeshi students took advantage of the early night to go into town after the hartal ended. This was also the day that the AMNH team was doing interviews, so we were able to have people walk back and forth to their makeshift studio in one of their rooms.
More serious was when a second day of hartal was called for Feb. 6. The visit of the U.S. Ambassador to Bangladesh to our group was cancelled. But what were we to do now? We were to visit outcrops to the north and one of our drilling sites. After exploring several options, Humayun rented a very small pickup truck. This type of vehicle should be exempt from the hartal. To play it safe, we started our work by continuing along the same small road over the anticline that we walked on the day before. There are no roadblocks on a small country road. We continued the geologic work over the anticline. These young weathered sediments were hard to interpret confidently. However, we did see the dips of the strata switch from towards the south to towards the north
as we went over the crest of the anticline. We crossed where the floodplain sediments lap up against the folded strata. Our excitement about the interactions we are having in the field continues to grow. After completing this part of the drive, we came to a decision point. Would we continue to the main road and risk facing a possible roadblock? Did we want to travel that far on the back of a pickup? In the end, our group split up. The film crew rented a baby taxi and went off to get footage of the countryside. A second group walked back to the road over the anticline to visit more outcrop and pick potential drilling sites. Steve Goodbred was excited enough by what we saw to change tomorrow’s drilling site from the floodplain to the anticline. The interaction
at the conclave was now altering our project plans. It is working. The last group, including myself, continued as planned with the pickup. Not only was there no roadblock, but it was a pleasure to drive through Bangladesh with so few cars on the road and so little traffic. We got to the well site as they reached the maximum depth they could drill. Gas in the sediments impeded the drillers ability to lift the sediments out of the hole. We could see the gas bubbling up. We continued on to Jaintiapur and took a pleasant hike through a new set of outcrops and beautiful views. I personally found the evidence of a long gap in sedimentation 20-30 million years ago puzzling. As darkness fell, we had to leave the solution for another day. But at least the 2-day hartal was over.
Up to now, each group in our Bangladesh project has worked individually on fieldwork in their subject of expertise. Now that our project is now in it’s third year, we decided it was time to get together in the field to integrate our results. A major focus of the project is the interaction of tectonic forces and sedimentary processes. This week, is our opportunity to have experts on each interpreting the same outcops together. We have gathered a group of 9 Americans and 7 Bangladeshis in Sylhet in NE Bangladesh to what we have termed the “conclave”. I guess we have to send up a puff of white smoke if we all agree. Sylhet is an area where the large basement block of the Shillong Plateau and the Dauki Fault that bounds it meets the fold belt of the Burma Arc with its tea garden covered anticlines. It is also has a rapidly subsiding basin being filled with sediments in which the level of the rivers go up and down with sea level. Lots to see through different prisms. On top of the excitement of the conclave, we have a film crew from the American Museum of Natural History with us for the first 6 days to make a video to be shown in the AMNH and other museums about our project and the science we have been working on. After they finish, will we have another film crew from a company that makes PBS documentaries following us.
Everyone is doing their individual fieldwork before or after the conclave. Several of us arrived in Bangladesh just before the conclave, while others drove over from their fieldwork in western Bangladesh and two crossed the border from studying the Shillong Plateau in India. We all arrived and filled all of the rooms in the Shuktara Nature Retreat. For our first day, we headed to the Patheria Anticline with the Madhabkundu Waterfall. While the waterfall was spectacular, if took most of the day to get there. Pulling out maps after breakfast, we spent time discussing the region, slowed by the filming. Then the drivers took a wrong turn that took us and hour out of our water plus another ½ hour to double back via a faster road. It was 2:30 by the time we got there and almost 3:00 when we finally reached the falls. While there were great outcrops, we only had a hour there before having to start back. It was too late to visit our second stop and quite late before our cranky group got back to the resort for dinner. Overall, a disastrous first day.
Having gotten our bad day out of the way early, we had nowhere to go but up. And it did. We headed north toward the border with India and the Shillong Plateau. At the first stop we got an overview and our first view of the 2000 m high mountain and the geology while standing on one of the folds that mark the frontal area of the Dauki thrust fault. Then we went on to the Rangapani River where the large boulders are washed down from the plateau. There is a huge industry in Bangladesh mining rocks and gravel from the rivers along the border. Bangladesh has a shortage of rock that can be used in construction, particularly making concrete. The Indian border is clearly marked by the presence of rocks. On the Bangladeshi side they have all been stripped away and they are digging
pits to mine the rocks from the older river sediments. This results in beautiful exposure of the sediment layers and we scrabbled around in a pit while the workers mined the rocks around us. After a brief stop at the border crossing where trucks bearing rocks enter Bangladesh, we went to Jaflong, where the mining industry is even larger. The amazing thing about Jaflong is that besides being an industrial site with rock mining and noisy rock crushers, it is also a tourist site where people come to see the mountain. There are tourist kiosks, snack stands and guides mixed in with the industry. For us, there were also outcrops of the older strata from before the uplift of the Plateau. Our final stop was a visit to our GPS and seismometer station at Jalfong. Humayun and I were filmed explaining our work there while the others visited the geology exposed on the side of the hill we were on.
Day 3 was an exciting trip up the Shari River. We rented three wooden country boats and sailed up the river, crossing through exposures of sediments of various ages. The originally horizontal layers of strata have been deformed from the tectonics. The dip of the sediments started at 38° then increased to nearly vertical before decreasing back to ~45°. This folding is due to the sediments riding over structures beneath, possibly a fault. We also saw that the oldest sediments were marine and the seceding layers went to estuarine and then fluvial (rivers) due to the increasing amount of sediments coming from the Himalaya. Our boats traveled together and occasionally leap frogged from outcrop to outcrop. Chris Paola, our river specialist, also noted changes in the shape of the river indicating active tectonics. Our group of specialists is coalescing into a team. Meanwhile, we passed other teams of people dredging the sand and gravel from the river bottom using buckets into their boats.
Monday:The morning briefing room was filled with layers of engineers and technicians from the civilian side, matched with pilots, navigators and air support staff from the Air National Guard side. Spanning the middle were the two Systems Project Office (S.P.O.) representatives. Adding new instrumentation and equipment to any aircraft requires intense scrutiny, but on a military plane there are extra rounds of reviews and sign offs required, and it is the S.P.O. office that is responsible for overseeing this final testing and approval. Specialists at avionics (aircraft electrical systems) and aerodynamics (air interaction and flow meeting the aircraft/pod) the first part of the week was theirs as they observed, measured, questioned and weighed equipment as it was installed in the aircraft, and prepared to monitor the in-air operation of the pod for turbulence, and potential aircraft/equipment interference.
The IcePod team arrived at Stratton Air Force Base with a carefully planned schedule of equipment installation and flight-testing. One day of install followed by two days of S.P.O. testing and then five additional days available for our own flight maneuvers to test the full potential of the pod and instruments. Inside the airport hanger crates of electrical wiring, connectors, tools and supplies were piled around aircraft 21094 the LC130 labeled ‘Raven Gang’ that was selected for the test flight. The biggest item on the floor was the 700 lb. crate containing the IcePod. The plan was to finalize the installation of the 350 lb.avionics (AV) rack located inside the plane, and then move straight to installing the arm and hanging the pod. By close of business Monday the goal was that the S.P.O. ground tests to ensure all the equipment was functional could be completed.
We were set back almost before we started. Rack pieces tightly matched to the curve of the plane body needed realigning, electrical connections needed adjusting, and by 7 p.m., the arm that would hold the pod was just being connected. Adjusted plans were agreed upon with an early morning return to add the pod and complete the ground check in the a.m. with a S.P.O. flight in the p.m. Snow was predicted over the evening but for flight the weather looked promising.
Tuesday: The morning briefing covered plans for a 10 a.m. flight time, which quickly slipped to a noon decision on the possibility of an afternoon flight. With the 500-700 foot cloud base predicted to rise to 1500 feet in the afternoon, this was not unwelcome news. In the hangar, electricians and engineers worked with thick ropes of cables taming them into place, floor pieces were notched and the pod support arm and special door secured in anticipation of hanging the pod, but delays continued. Before noon, a no-flight decision for the day was reached, as work continued at a slow but steady pace to prepare for to pod. The hope was that the ground testing could be completed before the close of day and Wednesday morning would bring the first round of flight testing.
By mid-afternoon, the pod was moved into place and fastened to the arm. The first S.P.O. concern was that the pod weight be within the approved limit of 400 lbs. Airport hangars have scales for weighing pallets of equipment but for this application a high degree of accuracy was needed. The first attempt showed a more accurate set of scales was needed. Each instrument, bracket, and set of cables added weight to the pod, so locating, calibrating and lowering the pod onto an accurate set of scales provided a few tense moments until the weight was established and S.P.O. clearance for test flights was provided.
Test Flights included turbulence testing for laminar (smooth) airflow done by installing tapered lines on the pod ends with sections of string inset to demonstrate airflow – 174 sections of string were added like a lion’s mane to the pod, and extending back behind the domed door. Exterior accelerometers were added to detect and monitor vibration on the pod as the group approached a 9 p.m. close to the workday. No matter what the status of the work the plane would be released from the hangar first thing in the a.m.
Wednesday: The weather dictated the day; socked in conditions with poor visibility meant no flights. S.P.O. ground testing was completed, but flying would be pushed off another day.
Thursday: High winds and driving rain arrived during the night with the morning briefing noting that although there was a high cloud ceiling and 3000-mile visibility, 25 mph winds and turbulence would keep us grounded early in the morning, but a 10 a.m. reassessment might allow a flight later in the day. Updates during the morning cited extreme turbulence for other flights forcing additional postponements. Mid-afternoon a decision was made to take up a minimal team to complete day one of inflight S.P.O. testing. On the runway engines are fired up, first 3 then 4 then 2 and 1, ready to go, but a problem with the Auxiliary Power Unit forced the mission to abort. Cancellation, and another day gone. As we headed out for the night we were warned that the APU issue could down the plane for up to two days.
Friday The hope is for at least one flight for this week, but we worry about the news on the APU. The morning briefing notes the APU seems to be holding and the first IcePod flight is a go! The plane is prepped; we are loaded onboard. Engine 3-4-2-1 fired up and we launch down the runway only to squeal to a stop. The domed door over the pod shows as not secure. The door is re-secured. A second attempt to move down the runway ends with the same results. Support is brought on-board and the door is reinforced for take off attempt #3.
10:56 a.m. we are up! The pod is deployed, lowering flawlessly. We begin the test flight at 5000 feet but lower to 2500 feet to move under the weather. The plan includes sets of cloverleaf maneuvers banked at 30 degrees to test GPS and lasers. The turns feel steep, and the ride is bumpy but after all the waiting we are happy to be in the air. There is no electromagnetic interference between the pod equipment and the aircraft, and the exterior accelerometers show a smooth ride for the pod. Test flight #1 for S.P.O. is complete, and everyone can head home for the weekend with a sense of accomplishment. In a week that seemed filled with adages (schedules are subject to change, everything hangs on the weather, anything that can go wrong will go wrong) at least we ended with …anything good is worth waiting for!
For more on the IcePod project see: http://www.ldeo.columbia.edu/res/pi/icepod/