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Pani, Pani Everywhere

Geohazards in Bangladesh - Wed, 10/14/2015 - 07:46

 

House in the middle of the wet fields. During the summer monsoon, it will be an island connected by the bamboo bridge.  In a month it will be connected by dry land

House in the middle of the wet fields. During the summer monsoon, it will be an island connected by the bamboo bridge. In a month it will be connected by dry land.

Six of us headed out on Oct. 8 for Brahmanbaria, northeast of Dhaka. Our target is a large winding abandoned river valley that we believe used to be the course of the Meghna River. Currently, the much smaller Titas River flows northward in the channel. Why would a river in the world’s largest delta flow the wrong way? We think that an earthquake uplifted the Comilla District area to the south. That caused the Meghna River to shift westward to its present channel and the Titas to flow up the old channel. A well drilled in the channel in 2012 shows a layer of muds overlying coarser sands.

The large abandoned channel we hoped to work in is completely flooded.

The large abandoned channel we hoped to work in is completely flooded.

We think the sands represent sediments from the old Meghna and the muds are sediments filling up the channel. We will be using resistivity to image the channel and an auger to first sample and describe the sediments and then to collect samples for dating.

Finding organic matter to date by carbon 14 is rare, so we plan to use a technique called OSL dating. OSL stands for Optically Stimulated Luminescence. Electrons from the radioactivity of all rocks get trapped in defects in quartz grains. However, they

A group of children play in a pond while we try to figure out where to find land dry enough to work in.

A group of children play in a pond while we try to figure out where to find land dry enough to work in.

are so weakly trapped that sunlight can release them. When traveling down the river, the electrons are released and then start accumulating when they are buried. By measuring the light released by the sample when optically stimulated, we can calculate the time since the sample last was exposed to light. By sampling the top of the sands and the bottom of the muds, we can date the time the river switches, or avulsed. The details of the procedure to get an OSL age are pretty complicated, but if this works, we

Our resistivity meter set up in a rice field.  We were able to collect data at the cost of very muddy legs.

Our resistivity meter set up in a rice field. We were able to collect data at the cost of very muddy legs.

will date the earthquake that caused the river avulsion.

This technique is new to me. I helped with some sampling the last time I was here, but I have not been in charge of doing it. I am also more comfortable with the quantitative data from the resistivity than the qualitative geologic descriptions we will make of the sediments. Luckily I have a good team with me, Céline, my postdoc, Matt, my former teaching assistant, and Alamgir, Atik and Basu from Dhaka University. I have spent time in the field with Alamgir and

Spools of the cable we use along where we collected the profile.  We used the slightly raised boundaries between fields for access, to avoid stepping on the crop and to stay a little less muddy.

Spools of the cable we use along where we collected the profile. We used the slightly raised boundaries between fields for access, to avoid stepping on the crop and to stay a little less muddy.

Atik before. Alamgir has conducted his own resistivity surveys. Basu was recommended to me as someone with a lot of experience in describing sediments.

We set out early in the morning for the four-hour drive. However, when we reached the river valley, we found it was almost completely flooded. We walked out on an elevated road and there was pani—the Bangla word for water—everywhere. The abandoned valley is still slightly lower in elevation than the surrounding land. Even that land has the rice fields flooded with shallow water, although the

Céline and Basu examine a core of samples brought up by the auger gouge.

Céline and Basu examine a core of samples brought up by the auger gouge.

boundaries between the fields are above water. But our main target is submerged! In the winter this will be dry land, but we are a month and a half too early. A number of scheduling issues required me to come now, although I knew it was too soon after the monsoon, but I didn’t expect so much of the land to still be flooded. Time to come up with an alternative plan.

For the resistivity, we need long straight stretches of dry land. We decided to

Kids playing soccer on the open field where we did our first auger hole.  The auger was hit by the ball several times.

Kids playing soccer on the open field where we did our first auger hole. The auger was hit by the ball several times.

do it west of the valley to try to image the thickness of the entire Holocene (last 10,000 years) section. It should vary because of the folding of the strata from the tectonics. Mapping the thickness will help us to map the position of the buried fold. For augering, we only need a small patch of land to stand on. To find it we headed south towards where the valley was uplifted more and might be drier. Not as ideal as the original location, but possible. The next morning we headed farther south and crossed the river valley. It was drier and we noted some potential augering sites. We continued to a location for resistivity. The six of us set up the >350 m long resistivity line, then Céline, Basu and I headed back to try augering while the resistivity data was collected. The augering proved very difficult. We were very slow describing the core that the auger brought up, and while we were doing it the hole would start to collapse. The muddy sediment was very stiff, and we had to hammer the auger in. We only got to 2.7 m when we stopped, nowhere near the depth we needed. Things were pretty discouraging.

Sea ice bacteria review published

Chasing Microbes in Antarctica - Tue, 10/13/2015 - 12:25

I’m really excited (and relieved) to report that my review on the taxonomy and function of sea ice microbial communities was recently published in the journal Elementa.  The review is part of a series on biological exchange processes at the sea ice interface, by the SCOR working group of the same name (BEPSII).  I’m deeply appreciative of Nadja Steiner, Lisa Miller*, Jaqueline Stefels, and the other senior members of BEPSII for letting (very) junior scientists take such an active role in the working group.  I conceived the review in a foggy haze last year while writing my dissertation, when I assumed that there would be “plenty of time” for that kind of project before starting my postdoc.  Considering that I didn’t even start aggregating the necessary data until I got to Lamont I’m also deeply appreciative of my postdoctoral advisor for supporting this effort…

The review is really half review, half meta-analysis of existing sea ice data.  The first bit, which draws heavily on the introduction to my dissertation, describes some of the history of sea ice microbial ecology (which goes back to at least 1918 for prokaryotes).  From there the review moves into an analysis of the taxonomic composition of the sea ice microbial community, based on existing 16S rRNA gene sequence data, takes a look at patterns of bacterial and primary production in sea ice, and then uses PAPRICA to infer metabolic function for the observed microbial taxa (after 97 years we still don’t have any metagenomes for sea ice – let alone metatranscriptomes – and precious few isolates).

There is a lot of info in this paper but I hope a few big points make it across.  First, we have a massive geographical bias in our sea ice samples.  This is to be expected, but I don’t think we should just accept it as what has to be.  More disconcerting, there has been very little effort to integrate physiological measures in sea ice (such as bacterial production) with analyses of microbial community structure.  A major exception is the work of the Kaartokallio group at the Finnish Environmental Group, but their work has primarily taken place in the Baltic Sea (an excellent system, but very different from the high Arctic and coastal Antarctic).  This all translates into work that needs to be done however, which is a good thing… we are just barely at the point where we can make reasonable hypothesis regarding the functions of these communities.

Taken from Bowman, 2015. Sampling locations for sea ice studies that have collected community structure data (blue), ecological physiology data (red), and both (orange). Note the strong sampling bias, particularly in the Antarctic. The black arrows point to the locations of the two community structure studies (at the time of writing) that we sufficiently deep to actually describe community structure.

Taken from Bowman, 2015. Sampling locations for sea ice studies that have collected community structure data (blue), ecological physiology data (red), and both (green). Note the strong sampling bias, particularly in the Antarctic. The black arrows point to the locations of the two community structure studies (at the time of writing) that we sufficiently deep to actually describe community structure.

*This image of Lisa pops up a lot. If you can identify what, exactly, is going on in this picture I’ll buy you a beer.

Winter Blooms in the Arabian Sea - NASA

Featured News - Tue, 10/13/2015 - 12:00
Lamont's Joaquim Goes and Helga do Rosario Gomes have been studying blooms in the Arabian Sea, where a tiny organism and its tenants have made an unexpected appearance that could harm other marine life that the region depends on for food.

Hurricane-Like Antarctic Winds May Contribute to Sea Level Rise - Europa Press

Featured News - Tue, 10/13/2015 - 12:00
Hurricane-force winds remove large amounts of snow in Antarctica, which might increase the estimates of how much the frozen continent contributes to sea level rise. Cites research by Lamont-Doherty's Indrani Das.

Horn of Africa Grows Hotter and Drier - Scientific American

Featured News - Tue, 10/13/2015 - 12:00
The Horn of Africa is warming and drying faster now than in the past 2,000 years, says new research into ancient marine sediments found. The findings contradict global climate models, which show that the geopolitically unstable region getting wetter as emissions boost temperatures worldwide, says Lamont's Peter DeMenocal.

Nicolas Young: 2015 Blavatnik Awards for Post-Doctoral Scientists - New York Academy of Sciences

Featured News - Tue, 10/13/2015 - 09:48
Lamont-Doherty's Nicolas Young was named a winner of the 2015 Blavatnik Regional Awards, given to post-doctoral scientists and affiliated with the New York Academy of Sciences. “These talented young scientists will continue to foster innovation and new discoveries for years to come,” said Len Blavatnik, head of the Blavatnik Family Foundation.

Bangladesh and India, Too

Geohazards in Bangladesh - Tue, 10/13/2015 - 07:44
Standing in front of the 240-foot tall Qutub Minar, which dates from the 1200s.

Standing in front of the 240-foot tall Qutub Minar, which dates from the 1200s.

I am heading back to Bangladesh, but this time I am stopping in New Delhi before heading to Bengal (West Bengal and Bangladesh). It is the first time that I will be in a part of India that is not adjacent to Bangladesh. Several of us are meeting there to plan for a new project that will span Bangladesh to India to Myanmar. I arrived a few hours before Nano Seeber and Paul Betka and used the time to get a new Indian SIM for my phone. After meeting up, we headed to the guesthouse of the Ministry of Earth Sciences, where we will be staying. If only the U.S. had a cabinet level department for earth sciences. It was difficult to find at night without a Hindi speaker, but we managed.

Over the next few days we had meetings about the project, but also some time for sightseeing, while

The inscription on the Iron Pillar, still unrusted despite being 1600 years old. It mentions Chandragupta's conquest of Bengal.

The inscription on the Iron Pillar, still unrusted despite being 1600 years old. It mentions Chandragupta’s conquest of Bengal.

discussing the project in the car. Most of our meals were vegetarian, and Gandhi’s birthday, which occurred while we were there, is celebrated by eating vegetarian. When two more scientists arrived from Singapore, we started the day by visiting the Qutub Minar, dating back to the 1200s and the arrival of the Muslim Delhi Sultanate, followed by the Mughal Empire in the 1500s. In the Quwwat-ul-Islam mosque, there is the famous Iron Pillar originally erected by Chandragupta in the 4th century, probably at Patna, and brought here much later. Near the beginning of the inscription it says: “in battle with the Vanga countries, he kneaded (and turned) back with (his) breast the enemies who, uniting together came against (him).” Vanga is Bengal, now split into West Bengal in India and Bangladesh.

The massive South Gate entrance to the Taj Mahal complex.

The massive South Gate entrance to the Taj Mahal complex.

 

After mostly finishing discussions, the others decided to take a day trip to Agra to see the Taj Mahal. I was able to change my flight to Kolkata to the following morning and joined them, continuing to talk science on the 4-hour drive. We had to buy the expensive tickets at 750 rupees rather than the 10 rupees the Indians were paying. However, the premium ticket lets us bypass the long lines. The Taj Mahal is the tomb of Mumtaz Mahal,

The Taj Mahal. You can see its enormous size from the line of people waiting to get inside standing on the pedestal. The line completely circled the tomb on this holiday weekend.

The Taj Mahal. You can see its enormous size from the line of people waiting to get inside standing on the pedestal. The line completely circled the tomb on this holiday weekend.

the beloved wife of Shah Jahan, the Mughal Emperor. It was built over 17 years from 1631-1648. She died in childbirth of her 14th child. He was buried there as well when he died in 1668, after being overthrown by his son. I have seen many pictures but was not expecting how enormous the structure is. The entire place is beautiful and enormous with flanking buildings, gardens and gateways. I kept wondering about the cost of building it and how many man-years of India’s peasants financed it. Perhaps this excess was why this was the peak of the Mughal Empire. Within a 100 years, the British were

The entrance to the Red Fort at Agra, a seat of the Mughal Emperors, and still used as by the Indian military.

The entrance to the Red Fort at Agra, a seat of the Mughal Emperors, and still used as by the Indian military.

taking over. Afterwards we went to Agra Fort, which is similarly gigantic, and another seat of the Mughals. There are palaces and a throne inside the red fort with views of the Taj. There are 30 buildings left, the rest having been leveled by the British to erect barracks for their troops. We didn’t get back to our hotel until 11.

I left early the next morning for Kolkata, the British Indian capital until 1911, when they moved it to Delhi. It was done to punish the Bengalis for opposing the

Standing next to a window in the Agra Fort with a view of the Taj Mahal farther down the Yamuna River.

Standing next to a window in the Agra Fort with a view of the Taj Mahal farther down the Yamuna River.

splitting of the Bengal Presidency into more manageable size, which would have cut Bengal in two. I spent the day at Calcutta University then headed back to the airport to fly to Dhaka. At my usual hotel, I met up with Jenn Pickering, a student at Vanderbilt University, and Céline Grall, my postdoc. They were teaching a short course at Dhaka University. I spent the next few days in multiple meetings and making arrangements for a week of fieldwork. It will be good to get out into the countryside.

DSCN4598

A highly decorated marble palace inside the Agra Fort. It has a beautiful fountain built into the floor.

 

Severe Drought Threatens Millions of Ethiopians - RFI

Featured News - Mon, 10/12/2015 - 12:00
Recent figures reveal that the number of Ethiopians in need of food has risen sharply because of the lack of rain, combined with the El Nino weather phenomenon. A new study involving Lamont-Doherty's Peter deMenocal suggests that the region is growing drier.

Anatomy of an ‘Ice Station’

TRACES of Change in the Arctic - Sun, 10/11/2015 - 19:58
Moving equipment on and off the Healy for sampling requires organization. (photo T. Kenna)

Moving equipment on and off the Healy for sampling requires organization and creativity. (photo T. Kenna)

Completing an ‘Ice Station’ means collecting samples over a wide range of Arctic water and ice conditions. Each station means a major orchestration of people and resources. The teams gather, equipment is assembled, and the trek off the ship begins. After the first off ship exodus the sample teams are well practiced in moving equipment and setting up work areas so as not to interfere with the other stations. There is no shortage of space so spreading out is not a challenge!

Sampling on the ice also means being aware of your environment. A required component is the Polar Bear watch. Fortunately we have not seen a polar bear when out on the ice.

Sampling on the ice also means being aware of the environment,  requiring a polar bear watch. Fortunately the team has not seen a polar bear when out on the ice. (Photo T. Kenna)

Collecting a wide range of samples at multiple Arctic locations allows GEOTRACES to get an integrated look at the trace elements moving through the Arctic ocean ecosystem, and to better understand how these elements connect to the larger global ocean. Each is carefully collected. Whether the elements are ‘contaminants’ or essential nutrients there is a specific protocol in order to quantify the inputs without ‘dirtying’ the sample. It may seem odd to think of ‘dirtying’ something we label a contaminant, but in order to fully understand the concentrations and methods of transport for each element, every sample is handled with the same amount of care.

The following photo essay showcases the various ice/water sampling stations and reviews what is being collected at each.

Snow Samples: The snow collected at this station is being used in part to determine the presence/absence of contamination related to the March 11, 2011 Fukushima event.

Tim Kenna collecting a snow sample. The sample area is generally 1 or 2 square meters and collected down to the ice. (Photo B. Schmoker)

Tim Kenna collecting a snow sample. The sample area is generally 1 or 2 square meters , with the snow collected down to the ice surface below and carefully bagged. (Photo B. Schmoker)

Both the snow samples and the ice core sections will be analyzed and examined along with the information collected from seawater, suspended particulates, and bottom sediments, in order to better understand the influence of processes specific to the Arctic on the transport and distribution of several anthropogenic radionuclides.

Bagging up the snow from the snow station. Each sample is labeled by quadrant of ice collected. (Photo B. Schmoker)

Lamont’s Tim Kenna (r) and Wright State University graduate student Alison Agather (l) bag up snow. Each sample is carefully bagged and labeled by quadrant of ice collected. (Photo B. Schmoker)

Ice core samples: The ice cores are sections of sea ice, and again are being collected to determine the presence/absence of contamination related to Fukushima. In general the samplers were able to obtain 1.5 – 2 meters of ice in the cores.

Section of sea ice core collected by drilling into the ice. (Photo Cory Mendenhall, USCG)

Section of sea ice core collected by drilling into the ice. As the cores are collected they are photographed, labeled by sections, and ice properties were measured in situ prior to being taken back to the labs. (Photo Cory Mendenhall, USCG)

Melt Ponds: Surface melt ponds form on the sea ice in the long says of the Arctic summer. The warmth of the sun creates ponds that sit on top of the ice. The water collected in these ponds carries different properties than the either the sea ice from which it melted, or the ocean water from which the sea ice formed. Most often these ponds have a frozen surface layer that needs to be drilled through before water is pumped out for collection.

Surface Melt Pond Team collecting water sample. (Photo T. Kenna)

Surface Melt Pond Team collecting water sample. (Photo T. Kenna)

Beryllium-7 (7Be) Samples: Produced in the atmosphere when cosmic rays collide with nitrogen atoms, 7Be is constantly being added to the surface of the water, and therefore is a great surface water tracer.  With its very short half-life, ~ 53 days, 7Be can be used to track water parcel circulation as it moves between surface and deep water (which has no significant source of the 7Be isotope). The surface water pulls the 7Be with it as it moves down deeper into the ocean, allowing us to track and time the mixing process.

Pumping water through the hole drilled by auger. (photo B. Schmoker)

The Beryllium team first uses a gas powered auger to create a hole for a pump and a CTD instrument (used to measure salinity, temperature and depth)  to fit through. They then pump water through the hole for collection. Because beryllium is in very small amounts they pump thousands of liters of water from 3 or 4 depths. Each is pumped through big cartridges that absorb the Be. (photo B. Schmoker)

Dirty Ice Samples:  The dirty ice work is more opportunistic, and therefore is not be part of each ice station. If dirty ice is spotted it will be sampled, and while it may not be part of each ice station, it is part of the overall GEOTRACES protocol. While most of the stations sample for quantification, i.e. grams of sediment/ml ice, the dirty ice samples are used more for characterization, i.e. composition or mineralogy.  For Tim’s work the collection of dirty ice is used to look at sediments originating from continental shelves bordering the Arctic, with the goal of evaluating or characterizing dirty ice as a transport vector for anthropogenic radionuclides.

Tim sampling dirty ice. (photo C. Mendenhall).

Tim sampling dirty ice with a pick and bucket. (photo C. Mendenhall).

Minimal Processing of the samples collected at the stations will occur on the Healy. The snow and Ice gets melted and the seawater acidified. The focus of the trip is to collect as much material as possible. There will be plenty of time for processing when  the researchers are back at their home institutions.

Margie Turrin is blogging for Tim Kenna, who is reporting from the field as part of the Arctic GEOTRACES, a National Science Foundation-funded project.

For more on the GEOTRACES program, visit the website here.

The Horn Of Africa Is Rapidly Drying Due to Climate Change - International Business Times

Featured News - Fri, 10/09/2015 - 15:32
The already arid countries of Djibouti, Ethiopia and Somalia are becoming even drier at an unusually fast pace, threatening to deepen drought, famine and instability, a new study by Lamont-Doherty's Peter DeMenocal and former post-doc Jessica Tierney finds.

Scientists Predict Drier Horn of Africa as Climate Warms - Reuters

Featured News - Fri, 10/09/2015 - 14:56
The Horn of Africa is becoming drier in step with global warming, researchers said on Friday, contradicting some climate models predicting rainier weather patterns in politically challenged region. Cites research by Lamont's Peter DeMenocal and former post-doc Jessica Tierney.

Ocean Sediments Suggest Dry Future for Horn of Africa - Nature

Featured News - Fri, 10/09/2015 - 12:00
The Horn of Africa is growing drier, threatening food security for millions of people — and this change is driven by global warming, according to an analysis from Lamont-Doherty's Peter deMenocal.

American Graduate Day: Glaciologist Robin Bell - WNET

Featured News - Fri, 10/09/2015 - 12:00
Lamont-Doherty's Robin Bell talks with WNET for American Graduate Day about her work on glaciers, the IcePod project and what inspired her to become a scientist.

The Tsunami that Engulfed an Island - BBC

Featured News - Wed, 10/07/2015 - 10:47
About 73,000 years ago a volcano collapsed. Its force generated a wave that engulfed an island over 30 miles away. Cites research by Lamont-Doherty's Ricardo Ramalho and Gisela Winckler.

Ancient Mega Tsunami Hurled Boulders Nearly as High as the Eiffel Tower - Washington Post

Featured News - Mon, 10/05/2015 - 12:00
The evidence hinges on the nature of the boulders, which are composed of rock types that "exclusively crop out on the cliff faces and lower slopes of the plateau, implying a source at considerably lower elevations," the authors write. Richard Ramalho worked on the study at Lamont-Doherty.

Ancient Skyscraper-High Tsunami Prompts Worries about Current Risk - Scientific American

Featured News - Mon, 10/05/2015 - 12:00
"Most of these fairly young oceanic volcanoes—such as in the Azores and the Canary Islands and Hawaii—are incredibly high and steep, so the potential energy for a collapse to happen again is there,"said Richard Ramalho, who worked on the study at Lamont-Doherty Earth Observatory.

800-Foot Tsunami Once Heaved Truck-Sized Boulders Onto a High Plateau - PBS NOVA

Featured News - Mon, 10/05/2015 - 12:00
Geologists have concluded that 73,000 years ago, a tsunami six times taller than the wave that hit Japan in 2011 struck off the coast of West Africa, in the Cape Verde islands. Cites work by Gisela Winckler and Ricardo Ramalho.

Uptick in Huge Wildfires Tied to Warming - Discovery

Featured News - Mon, 10/05/2015 - 12:00
Catastrophic wildfires in the West are burning land more violently and more frequently in recent years than at any point on record. Lamont-Doherty's Park Williams explains how this year’s big fires have corresponded with higher temperatures.

California Once Had a 2,000-Year-Long Dry Spell - Discovery

Featured News - Fri, 10/02/2015 - 12:45
Lamont-Doherty scientists Linda Heusser and Jonathan Nichols used ancient pollen to look at Southern California's changing ecology through time and discovered a series of mega-droughts thousands of years ago.

NYC Subway System Prepares for Hurricane Joaquin - Wall Street Journal

Featured News - Fri, 10/02/2015 - 12:44
With Hurricane Joaquin headed northward in the Atlantic, the Wall Street Journal looked at how prepared the New York City subway system is to handle another major storm. The Journal spoke with Lamont-Doherty's Adam Sobel.

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