We are less than a day away from our first study area on the continental shelf in front of the Dibble Glacier. As we approach Antarctica we are starting our science program with a 4500 meter deep CTD and multibeam acquisition. The CTD is used to determine the conductivity, temperature and depth of the ocean, while the multibeam maps large swaths of the seafloor from the ship.
The main goal of our project is to investigate the continental shelf in front of different glaciers along East Antarctica. We want to find out what the water depths and the water properties are in front of these glaciers and ice streams. Deep troughs and connections between the glaciers and the open ocean could allow “warmer” ocean waters to reach the ice front and result potentially in melting of the ice. We are especially interested to compare the situation in front of different glaciers along East Antarctica to better understand the differences between them. Many of these areas are poorly charted, if at all. So we are all excited to discover what is there!
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From left to right: Sampath Rathnavaka, Sumant Jha, Gillean Arnoux, Colton Lynner and Terry Cheiffetz.
We had a smooth trip to Kolkata with our two taxis amazingly staying together through the traffic. After checking in and freshing up, we went out for dinner and found a great Bengali Restaurant filled mostly with Bangladeshis around the corner. Our hotel turned out to be next to an area where Bangladeshis frequently stay, including Humayun previously. In the morning, he and I went for an early morning walk through the park and saw the Queen Victoria Memorial. Circling back past all the cricket players, we passed Fort William, the original British fort here, and joined Doug and Diane for breakfast. Our car arrived and before heading to the Sundarbans, we drove around to get shots of the Hooghly River. Before the 1600s, this was the main course of the Ganges, but since
then it shifted to it present course into Bangladesh. We got some shots from the new bridge before being chased off. Then we headed to the Strand to get close to the river. While we were filming, a funeral procession arrived to scatter ashes of the deceased into the river. Once the Holy Ganges, always the Holy Ganges. We couldn’t have planned it better.
Then, off to the Sundarbans. Where we were going was a lot farther than implied. This is because of a difference in naming. In Bangladesh, the Sundarbans is the National Mangrove Forest. The cultivated areas that previously were forest are not considered the Sundarbans. In India, they are. Thus we entered the Sundarbans after 2.5 hrs, but still had that long to go to meet our boat.
Admittedly, some of the cultivated areas in India still maintain mangroves outside of the embankments, which is not the case in Bangladesh. Continuing on, we reached literally the end of the road and carried our luggage (including a 50 lb. bag of rock samples) down to a ferry that took us to Gosaba. There, we first got a hand rickshaw to get the luggage across the town, then got two motorized rickshaw trucks to cross to the other side of the island. Finally, we were met by a boat that took us across the river to the eco-lodge where we would stay. After a late (4 pm) lunch we went on a sunset boat ride through some tidal channels. The saw and heard lots of bird and at times the channel became so narrow that we had to push branches away to fit through. The
trees here overhang the channels more than in Bangladesh. We would see further differences tomorrow. After finally showering off, we met other people staying at the eco-lodge, started by 4 cousins including Ajoy, who is leading our trip. The lodge is solar powered, so electricity is limited,but the water was refreshingly cool, not cold. We all heard a performance of Bengali Baul music, recognizing some songs from similar experiences across the border. After dinner, we all went for some local rice wine and then a boat ride to see bioluminescent plankton in a small channel. If you wave your hand in the water dots of light flash.
In the morning, we started at 6 am to have enough time before I had to head for the airport. We picked
up food and a cook and permits and a guide and finally were ready to enter the forest. In India, no one is allowed off the boat to step on the forest, nor to stay overnight in the forest, even on a boat. Thus many hotels and lodges have sprung up outside the forest for tourists. Many come simply to party and drink. We are very glad to be using an eco-lodge that is more respectful of the land and the local population.
At 8, we finally entered the national forest. Among the differences from the Bangladesh side we noted were the shorter height of the trees in the more saline water, the lack of sediment in the water, and the extent of bank erosion. Where the eastern Sundarbans is fresher with ample sediment carried by the tides due to its proximity to the Ganges-
Brahmaputra-Meghna River mouth, the western, Indian Sundarbans is more saline and lacks new sediment. Between subsidence and sea level, it is loosing ground. More land is being lost than gained. With the higher salinity, there is also less wildlife. However, there was a tiger sighting this morning. We sailed to the spot, but it was too late, we missed it. Still, we spent 4 hours sailing through tidal channels of different size, eating, and filming. Doug captured the beauty of the Sundarbans and I was interviewed with a great backdrop.
After completing our work, we briefly visited an observation post, we took a short cut through an interior channel in Gosaba Island, dropped off our guide, and crossed the channel to our car. Three hours later, I arrived here at the airport to start my journey home. It was an intense, yet calm 48 hours in West Bengal, the third leg of three very different pieces of this trip.
We are now aboard the R/V Palmer and on our way to East Antarctica. Due to two storms in our direct way we are heading west first to go around the storms and we’ll then head south on their backside. After passing the 200 mile zone off of Australia we turned some of the instruments on that collect data constantly while ship is under way. These instruments measure properties including surface water temperature, water depth, gravity, and weather data. In addition to their specific scientific missions research ships like the Palmer are also floating observatories that collect important data from remote areas of the world.
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Humayun Akhter, my main collaborator in Bangladesh, joined me at the airport and we flew together to Kolkata. We spent the night at a nondescript hotel near the airport. The next morning, we met up with film makers Doug Prose and Diane LaMacchia in the airport and all flew together to Aizawl, the capital of Mizoram state in NE India. Doug and Diane have funding from NSF to expand the 5-min YouTube video they made about our project two years ago (https://www.youtube.com/watch?v=WTETuqJPygs) to a ½ hour TV special. Their previous films have been shown on PBS.
The Sumatra subduction zone, source of the 2004 earthquake and tsunami, continues to the north where it encounters the Ganges-Brahmaputra Delta. The 15-20 kilometer thick delta sediments are folded and faulted as they enter the subduction zone. Because of the huge amounts of sediments, this is the only subduction zone whose front is subaerial – entirely exposed on land. In Bangladesh we can see the beginning of this process. Here in Mizoram, farther east, the former delta sediments are folded up into a very hilly terrain. The steep slopes are subject to frequent landslides. One that started last October has moved again and blocks the main road from the airport to the city of Aizawl. As a result, we had to take a longer, slower, bumpier and dustier road to get to the city.
We met up with Nano Seeber and Paul Betka from Lamont at breakfast. They have been doing geologic mapping the region and returned to Aizawl late the night before. We spent the day circling the city and visiting outcrops, many ones I had seen my last time here. We had several interesting discussions on differences of interpretation of the strata. I had visited most of these outcrops before, but it was the first time for Humayun. At the end of the day we were joined by
Vineet Gahalaut from the mainland, as the rest of India is considered here. The people here look Asian and the Mizo language is a tonal language in the Tibeto-Burmese family. Plus, almost all Mizo are Christian. Mizoram is part of India, but also distinct, like many of the other states in NE India. Part of the sense of separation is that the 7 NE states are only connected to the rest of India by the narrow 23 km (14 mi.) Siliguri Corridor between Bangladesh and Nepal – the chicken neck. We spent the evening talking with Vineet about future joint projects in this region.
The next day we were joined by Victor Ralte, our partner from Mizoram University, who became a proud father of a fourth daughter last week. We all headed north, visiting geological sites and filming
beautiful vistas, dropping Vineet off at the airport and continuing on to Kolasib, a small town about 70 km north as the crow flies, but probably twice that on the windy roads of Mizoram. We stayed in Hotel Cloud 9. I had been told since I was a child that I was always off on Cloud 9 and now I was actually here. However, the electricity wasn’t for the first few hours, so showers were cold, but the dinner was hot.
The next day we headed still farther north to see some complex faulting associated with the growth of the anticlines – the hills of folded strata. As we examined each outcrop, it was also clear that we were passing through several kilometers of rocks in which the environment that were deposited in shallowed from the inner continental shelf (10s of
meters water depth) to the tidal zone to estuaries like the present Sundarbans to fully fluvial (river). This represents the ancient Brahmaputra Delta passing across this area as it grew southwards. That several kilometers of sediments were deposited while the environment only shallowed by 10s of meters indicates that there was a lot of subsidence to make space for the sediments. I will have to model this when I return.
Stopping for a beautiful sunset over the hills, we finished heading back to Aizawl for a last dinner together. In my room as it turned out since the restaurant closed for some repairs. The six of us ate a mixture of American, Indian, Chinese and Mizo food with plates dishes and ourselves filling all available surfaces. Today, a quick stop at Mizoram University and then back to Kolkata for my last leg before home.