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Drill, Baby Drill! Drilling and filling for the SUGAR seismic shots

Sugar - Fri, 07/31/2015 - 12:14
We are using sound waves to image the subsurface of Georgia along two long transects.  It is like creating a huge x-ray of the geology in the region. Thousands of instruments (termed “Texans”) will record sound waves that are generated from a series of controlled seismic sources (“shots”) that we will set off along the line. 

For the last few weeks, the seismic source team, based at the University of Texas – El Paso, and the drillers have been hard at work drilling twenty-six 60- to 100-foot-deep holes that will contain the explosives used to create the sound waves.  Once the holes are drilled (the first stage of which is termed spudding), emulsion explosives with boosters and caps are carefully installed in the base of the hole and the remaining height is filled in with dirt and gravel (“stemming”). 

Now with the 26 shots drilled and patiently waiting for the electronic signal to blow, all we have left to do is deploy the 2,000 instruments that will record the sound waves … An easy feat for the 50+ scientists, students, and engineers descending on Vidalia, GA over the next few days.  Stay tuned for our progress and adventures as we continue on this epic scientific undertaking.

Natalie Accardo - LDEO

The SUGAR seismic source and science team from left to right:
Steve Harder, Dan Lizarralde, Ashley Nauer, and Galen Kaip
The drill rig set up and drilling a shot on SUGAR Line 2.

Galen Kaip prepares the source charges (white tubes) on the truck bed as
the drillers complete a shot hole.
The source team carefully lowers the prepared seismic charges into the complete shot hole.
Ashley Nauer (red hat) stands waiting with shovel in hand to fill the remaining height of
the hole with sand and gravel.   
The drill team monitors the process of spudding, the very first stage of drilling the
shot hole, for SUGAR line 2.
The source team and drill team push on late into the night to ensure the completion of the
final shot for the entire SUGAR experiment.  

Ramping up for bigger, badder SUGAR Part 2

Sugar - Tue, 07/28/2015 - 23:11
We are in Georgia gearing up for the second phase of field work for the SUGAR project, which will involve collecting seismic refraction data along two profiles spanning eastern Georgia. In the coming weeks, we’ll deploy thousands of small seismometers along county and state roads across the region, which will record sound waves generated by a series of controlled blasts. We can use the sound waves to make pictures of geology beneath the surface. Geological structures beneath Georgia record the most profound events involved in the formation and evolution of the eastern North America continent. In particular, we want to image an ancient suture between Africa and North America that formed when these continents collided to create the supercontinent Pangea, frozen magma bodies from one of the biggest volcanic outpourings in Earth’s history, and continental stretching and thinning that lead to the breakup of Pangea and formation of the Atlantic Ocean.


Map of SUGAR lines, showing two possible locations of the ancient suture (red dotted lines)

We collected similar data in western Georgia last year during the first phase of the SUGAR experiment imaging these same features. During that field program, we deployed 1200 seismometers and set off 11 controlled blasts along a 250-mile-long line, which felt like a big project at the time. But this year, we will go even bigger! In eastern Georgia, we need to span an even larger area to encompass our geological targets. One of the reasons that we need to look at a bigger swath of the earth is that there is a debate about the location of the suture here – it could be as far north as Milledgeville, GA or as far south as Baxley, GA. (In case you are not up on your Georgia geography, those towns are ~100 miles apart). This means longer profiles, more instruments and more blasts! We will deploy a total of 2700 seismometers and detonate 26 blasts along two profiles. The longer profile spans 350 miles from Winder, GA to the Florida-Georgia state line near St Mary’s Georgia. Stay tuned!

Donna Shillington, LDEO 



Stay Tuned for SUGAR 2!!

Sugar - Wed, 07/22/2015 - 21:57
In just a few short weeks a mass of students and scientists will descend on southern Georgia with work boots and sunscreen in hand to take part in the second portion of the SUGAR active source experiment.  Make sure to stay tuned for regular updates on our progress and to learn more about the exciting science that motivates this amazing field expedition!

Smooth Sailing Back to Tasmania

Melting Glaciers-Tracking Their Path - Fri, 05/01/2015 - 10:12
Antarctica, NBP1503 science team

The NBP1503 science team.

After a surprisingly smooth crossing of the Southern Ocean, with favorable winds we arrived back in Hobart, Tasmania. The weather maps show that we just got ahead of another big storm system.

Once the equipment is stored away and the samples are loaded off, we will all head back to our offices and labs to further process and analyze our data and eventually put all the results together.

Taking a 4,000-Meter-Deep Profile of Antarctic Waters

Melting Glaciers-Tracking Their Path - Mon, 04/27/2015 - 10:47
NB Palmer, West Antarctica, CTD system

The CTD system is lowered over the side from the NB Palmer. It measures temperature, salinity, and oxygen with depth.

In addition to understanding potential pathways for “warmer” circumpolar deep water to reach the ice shelf, we are also measuring what the structure and properties of the water column are and determining if there is already warmer water on or near the continental shelf that could already interact with the glaciers of East Antarctica today.

To measure water properties, we are using an instrument that can be lowered through the water column that measures conductivity, from which we calculate the salinity of the water, temperature, pressure (i.e. water depth), oxygen, and fluorescence, which is an indicator for phytoplankton or algae in the water. This system is called a CTD for short.

This system can also take water samples from different depths that can be used for further analysis or for calibration and verification of the sensors. When we lower this system in deep water, e.g. 4000 meters, (about 2.5 miles), the measurements take over three hours.

We have measured the water properties at 42 different locations during our expedition and will analyze the results carefully when we are back.

Follow @FrankatSea for additional updates and images from the Southern Ocean.

Mapping the Seafloor

Melting Glaciers-Tracking Their Path - Mon, 04/20/2015 - 11:53
In addition to depth, we can identify many features in the high-resolution multibeam data that we produce. Most of the seafloor near the shelf break (where the water is between 300 and 500 meters deep) is covered with these irregular furrows that are created when large icebergs are grounded here.

In addition to depth, we can identify many features in the high-resolution multibeam data that we produce. Most of the seafloor near the shelf break (where the water is between 300 and 500 meters deep) is covered with these irregular furrows that are created when large icebergs are grounded here.

One of the goals of this expedition is to investigate if water from the Southern Ocean with temperatures above the melting point of glaciers could reach the glaciers in East Antarctica, and if there are any obstacles on the seafloor of the shelf that impact the ability of such water to reach the glaciers and ice streams.

The continental shelf in our study areas along the East Antarctic margin has been mapped in the past, but the existing data are very sparse and have many gaps. However, it is important to know the actual water depth of the continental shelf if we want to understand if water from the Southern Ocean with temperatures above the melting point could reach any glaciers and ice streams in this part of Antarctica.

We use a multibeam echosounder system installed on the Nathaniel Palmer to map the depth of a wide swath of the seafloor along our ship track. Access to the continental shelf is often limited by dense ice cover, but using the multibeam, we have managed to determine detailed depths in several areas. We will later analyze the depth data together with measurements of water column properties that will tell us exactly how deep the “warmer” Southern Ocean water is.

Follow @FrankatSea for additional updates and images from the Southern Ocean.

In the Ice

Melting Glaciers-Tracking Their Path - Fri, 04/10/2015 - 09:12
 The Nathaniel B. Palmer steaming through dense sea ice cover.

Some examples of the sea ice that we have encountered so far. Top left: bands of grease ice. Top right: small pancake ice merged together. Bottom left: larger pancake ice; bottom right: our ship, the Nathaniel B. Palmer, steaming through dense sea ice cover.

Several days ago we reached our main work areas along the margin of East Antarctica. Our expedition is relatively late in the season and the seas around Antarctica are starting to freeze. While the abundance of sea ice makes it more difficult to get to all of our research areas, the different shapes and forms of newly forming sea ice are a great visual experience. We also have a group of Australian scientists aboard the Palmer who are studying sea ice and sea ice formation using an unmanned aerial system or drone, so they are especially pleased by our icy experience.

Follow @FrankatSea for additional updates and images from the Southern Ocean.

Closing in on Antarctica

Melting Glaciers-Tracking Their Path - Mon, 04/06/2015 - 11:29
During our transit south to Antarctica we deployed seven ARGO floats (yellow device in picture) for the University of Washington. They drift with the currents in the oceans, measure profiles of salinity and temperature and send those via satellite to researchers on land. They are part of an international effort to better monitor the conditions of the oceans.

During our transit south to Antarctica we deployed seven ARGO floats (yellow device in picture) for the University of Washington. They drift with the currents in the oceans, measure profiles of salinity and temperature and send those via satellite to researchers on land. They are part of an international effort to better monitor the conditions of the oceans.

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!

Follow @FrankatSea for additional updates and images from the Southern Ocean.

Sunrise...Sunset...Sunrise...Sunset...

The ENAM Seismic Experiment - Sun, 04/05/2015 - 03:46
A compilation of sunrise and sunset photos aboard the R/V Endeavor. 

Day 3 sunset

Day 4 sunset

There is a bizarre foggy mist across the entire surface of the ocean.

This was a huge cargo vessel off in the distance. I know it isn't a sunrise or sunset but its a sweet pic.

Day 6 sunrise with a storm front in the distance.

Panorama of Day 6 sunrise.

Porthole sunset with my refection.

First bit of sunset color directly off the bow of the Endeavor.

about 20mins later....





Terry Cheiffetz




Go Endeavor Go! Nighttime Adventures...

The ENAM Seismic Experiment - Sun, 04/05/2015 - 02:25
A unique low light vantage point of the Endeavor

A look at all the instrumentation on the bridge of the R/V Endeavor. 

The full moon as it shines over the ocean water! Creepy!

The OBS retrieval at night! One of the crew members installed a light at the end of the hook to aid in the equipment capturing process. 


This picture was take from the bridge of the Endeavor. It is the Quantum of the Seas cruise ship at ~0300 during an OBS retrieval. 
This picture is ~2 miles away from the Quantum of the Sea cruise ship and is as close as the Endeavor can legally pass another large ocean vessel under maritime law. The bright celestial object overhead is Jupiter.

This photo shows the Endeavor docked at port just before we embarked on this high seas adventure. The first evening we went to a chinese restaurant called 7 moons. By the time we arrived back at the shipyard the gate had been pulled shut and appeared to be locked and was topped with plenty of barbed wire. After some deep thought our highly intelligent group realized that it was pulled closed and all we had to do was roll it open haha. There is a geophysicists joke embedded in that experience. 

This is the WHOI crew carefully bringing the OBS back onto the ship. Hard hats and life preservers are required when on deck during retrieval operations. The OBS in this photo is hanging down beneath the orange apparatus.  

As the Endeavor aligns itself with the OBS in the ocean currents at night the WHOI crew get in position to capture the Ocean Bottom Seismometer. 


After a successful OBS capture the WHOI crew quickly disassembles the OBS and prepares it to be stacked with the other equipment that is strongly secured to the surface of the deck. 

This shows the spotlight at night. It is used to help orient the ship alongside the OBS in the pitch black darkness of the night at sea. We have also thankfully had the full moon over the last few days to assist us in finding the OBS once it pops up to the surface.

This lovely burry image is the spot light as it tracks the OBS. The spotlight is extremely useful once the OBS is within several ship lengths of distance. 


The OBS is starting to get closer now....

Full moon over a perfect OBS recovery.

Hammock in the middle of the night!

You can really get a good feel for spotting the OBS at night in this picture. It is obviously a ship length or two off the starboard bow. 





Terry Cheiffetz







  

Survival Suits to the Rescue!

The ENAM Seismic Experiment - Sat, 04/04/2015 - 16:20
Before the R/V Endeavor embarks on its research voyage the new crew/scientists get to enjoy the challenge of a mock sinking scenario where they have ~2mins to jump out of their shoes and wiggle into these fashionable lobster costumes.  

Dr. Maureen Long and one of the crew members race each other to safety!

Graduate Student intern Colton Lynner is almost unrecognizable once the survival suit is fully on. Only the last troublesome step up zipping up to go before full emersion can take place. 

Graduate Student intern Terry Cheiffetz struggles with the final zipper step as well. 

Dr. Maggie Benoit looks like she wants to really know how to put on the survival gear in case of emergency or... she can't believe she has to participate in these fun shenanigans.


The final product appears to be both fashionable and comfortable. We would interview the model in this photo but he declined to comment....hopefully next years model will have a mouth hole haha!



Living Quarters aboard the Endeavor

The ENAM Seismic Experiment - Sat, 04/04/2015 - 04:03
This is what the state rooms look like for the research scientists on the Endeavor. That lovely extra piece of wood wedged in on the top and bottom bunks help prevent us from falling out of bed in the middle of the night if the ship rolls more than expected.


Using the restroom at sea can be challenging at times...... especially when the seas unexpectedly turn on you while you are trying to take a shower. It is basically an unexplainable balancing act.


This lovely area is where we gather for three amazing meals a day and get an opportunity to socialize with some of the various crew members aboard the ship.

Maggie has about a million movies to choose from. They are an ancient technology called VHS used a long, long time ago....


The science deck is the room where all the magic happens. Everything from running the burn sequences on the OBS's to recalculating the surfacing locations due to variable ocean currents occurs here. The amount of technology on the Endeavor is impressive.



Terry Cheiffetz





R/V Endeavor taking on water!!!

The ENAM Seismic Experiment - Sat, 04/04/2015 - 01:45
Short Video of the waves  crashing up onto the deck of the Endeavor


This 20 second video clip show just how dangerous life at sea can be! As the Endeavor rolls from one side to the next there is little to no warning as waves crash up and over onto the deck. Thankfully I was able to escape up the stairs to a somewhat dryer deck where the mist from the cresting waves and the wind were the only things able to assault my senses. The dangers out in the open on the ship at night are only multiplied by these variables.

Since the ship travels at ~10 kts between each OBS waypoint which can produce transit times as long as 12 hours and the weather isn't alway dreary the interns have a fair share of free time on the ship to explore around and lounge about.  

Checking to see if the internet wants to semi-work. I think Sampath knows he is in this picture.


Dr. Maureen Long creating a short cut to the relocated OBS equipment.


(Terry- I found two hammocks up on top of the ship perfect for some afternoon chill time haha. It also serves as a perfect vantage point when trying to find the OBS's when they reach the surface because the wave height and reflection of the sun off the water make it difficult to spot at times.)


Terry Cheiffetz


EN554 2015 Graduate Student Interns

The ENAM Seismic Experiment - Fri, 04/03/2015 - 17:24
The 2015 Graduate Interns aboard the R/V Endeavor


From left to right: Sampath Rathnavaka, Sumant Jha, Gillean Arnoux, Colton Lynner and Terry Cheiffetz.

After days of rough seas we all managed to gather up on the deck to take a group photo. The five of us are proud to be on the Research Vessel Endeavor and to finally have our sea legs. The Endeavor works around the clock out at sea and we worked in pairs on the following shift schedule, 0800-1600. 1600-2400, and 2400-0800. Each group had a PI in charge of their shift. The WHOI team was primarily in control of the extraction of the OBS in the rough seas due to the danger on deck and the sensitivity of the equipment.

The WHOI crew capturing an OBS in rough seas just prior to sunset.


Terry Cheiffetz

A high seas adventure! The ups and downs of an OBS retrieval.

The ENAM Seismic Experiment - Fri, 04/03/2015 - 14:50
April 3, 2015
EN554

A short video of an OBS retrieval on the R/V Endeavor
*WARNING* This video video contains a lot of ups, downs and what have you's. Viewing
is not recommended for the land based geoscientist!


This is a short video showing the Endeavor orienting itself alongside the OBS before the WHOI crew pulls it out of the water. It is clearly visible that both waves and weather play a major role when trying to retrieve the equipment from the ocean. 

A high resolution photo of the OBS on the starboard side of the endeavor
Sampath Rathnavaka (left) and Terry Cheiffetz (right)
Graduate student interns are excited to locate the OBS on the surface after waiting over an hour as the instrument made its transit through the water column.  


It is only a matter of time before your feet get soaking wet out on the deck. The ocean only likes to do this though if you are wearing tennis shoes instead of waterproof boots!


Its a mechanical sea turtle!


Terry Cheiffetz


Indian Sundarban

Geohazards in Bangladesh - Mon, 03/30/2015 - 13:34
Standing in front of the gates to the Queen Victoria Memorial in Kolkata

Standing in front of the gates to the Queen Victoria Memorial in Kolkata

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

A funeral procession arrived to scatter ashes in the Hooghly (Ganges) while we were filming

A funeral procession arrived to scatter ashes in the Hooghly (Ganges) while we were filming

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.

Humayun and Diane on the ferry - before it got crowded.

Humayun and Diane on the ferry – before it got crowded.

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

Doug and Diane following me on their motorized rickshaw truck across Gosaba Island

Doug and Diane following me on their motorized rickshaw truck across Gosaba Island

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

A monkey hangs out near the forest station where we picked up our guide.

A monkey hangs out near the forest station where we picked up our guide.

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-

Doug balancing his camera and his breakfast of puri and dal on the Elmar, our boat for the day

Doug balancing his camera and his breakfast of puri and dal on the Elmar, our boat for the day

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.

Overhanging rooks and slumps reveal the much larger amount of erosion and land loss in the Indian Sundarban

Overhanging rooks and slumps reveal the much larger amount of erosion and land loss in the Indian Sundarban

An egret stands tall at the bank of a channel

An egret stands tall at the bank of a channel

A small shrine in the Sundarban to Bon Bibi, the Hindu goddess of forests and streams - and protector from tigers

A small shrine in the Sundarban to Bon Bibi, the Hindu goddess of forests and streams – and protector from tigers

A monitor lizard

A monitor lizard enters a pond

On Our Way: Avoiding the Storm

Melting Glaciers-Tracking Their Path - Mon, 03/30/2015 - 10:24
Map showing the planned track of our expedition with the modifications made due to the storm systems. Our main study areas are on the continental shelf in front of some major East Antarctic glaciers.

Map showing the planned track of our expedition with the modifications made due to the storm systems. Our main study areas are on the continental shelf in front of some major East Antarctic glaciers.

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.

Follow @FrankatSea for additional updates and images from the Southern Ocean.

Geology and Filming in Mizoram

Geohazards in Bangladesh - Fri, 03/27/2015 - 14:08
The landslide that blocks the route to the airport requiring us to take a smaller, longer, bad road instead.

The landslide that blocks the route to the airport requiring us to take a smaller, longer, bad road instead.

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 temporary bridge over a river replacing the one that collapsed from an overweight truck last fall.  There is a new solid bridge being built just to the left. This is also along the route to the airport.

The temporary bridge over a river replacing the one that collapsed from an overweight truck last fall. There is a new solid bridge being built just to the left. This is also along the route to the airport.

 

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.

A small boat sailing up a scenic river in Mizoram.

A small boat sailing up a scenic river in Mizoram.

 

 

 

 

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

Humayun examining crossbeds in a sanstone outcrop

Humayun examining crossbeds in a sanstone outcrop

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

A view down the street in Kolasib in northern Mizoram

A view down the street in Kolasib in northern Mizoram

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

A little Mizo girl sweeping the street in front of her family's shop

A little Mizo girl sweeping the street in front of her family’s shop

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.

Landscape showing the scars of the traditional jum agriculture practice of burning to clear land for planting.

Landscape showing the scars of the traditional jum agriculture practice of burning to clear land for planting.

Doug Prose filming Nano, Paul and Humayun at an outcrop

Doug Prose filming Nano, Paul and Humayun at an outcrop

Sun setting over the hills of Mizoram

Sun setting over the hills of Mizoram

Mapping Faults Hidden below Lake Malawi

northern_malawi_new

Map of northern Lake Malawi showing major faults along the lake

The lakes along the Great African Rift Valley are among the largest fresh water lakes in the world. They lie in depressions created by slow stretching and thinning of the east African continent over millions of years. Many of the essential geological structures that enable the continent to tear and produce earthquakes are hidden within the Earth below these lakes. Lake Malawi (Nyasa) is the southernmost of these Great Rift Valley lakes and represents one of the youngest segments of the East African Rift System today. The lake is a whopping 550 km long and up to 70 km wide and surrounded by three countries : Mozambique to the southeast, Tanzania to the northeast, and Malawi to the west.

Jim Gaherty and colleagues leave port in Chipoka, Malawi aboard the R/V Ndunduma to deploy "lake" bottom seismometers

James Gaherty and colleagues leave port in Chipoka, Malawi aboard the R/V Ndunduma to deploy “lake” bottom seismometers

To image geologic structures and record earthquakes beneath northern Lake Malawi, our science team is undertaking a major “marine” seismic study as a part of the NSF-funded SEGMeNT (Study of Extension and maGmatism in Malawi aNd Tanzania) project. This part of the project involves generating sound waves using a towed array of “air guns” and recording the sound waves on a 1500-m-long cable filled with pressure sensors and an array of seismic stations deployed both onshore and on the lake bottom. The scientific and technical staff for this part of the project come from Lamont-Doherty Earth Observatory of Columbia University, Syracuse University, the Malawi Geological Survey Department, the Geological Survey of Tanzania, Aarhus University and Scripps Institution of Oceanography.

The M/V Katundu in port in Nkhata Bay, Malawi.

The M/V Katundu in port in Nkhata Bay, Malawi.

Marine seismic studies like ours are routinely done in the oceans using scientific equipment and research vessels outfitted specially for these purposes. Collecting comparable data in a great lake in Africa requires creative repurposing of available vessels and adaption of scientific equipment. To deploy and recover seismometers on the lake floor, Jim Gaherty and team used a small research vessel (R/V Ndunduma) operated by Malawi Fisheries Department. Deck space is limited, requiring efficient packing and multiple trips to deploy 34 seismometers in the lake with a boom normally used for dragging fishing nets. For the seismic imaging component, we transformed a large container ship (M/V Katundu) into a seismic research vessel. Containers were placed on the deck that house our scientific “lab,” a workshop for repairing science equipment, a storage space for extra gear and miscellaneous items, and an accommodation container with 8 bunks to sleep some of the science party. We have also added large spool for the seismic streamer, generators and compressors to drive the seismic sound source, and a large metal arm (termed “the ironing board”) for towing the seismic source. Using non-standard ships, equipment and data collection procedures requires a team with technical expertise and ingenuity, and happily we have that in spades.

We are now slowing steaming across beautiful Lake Malawi in the M/V Katundu acquiring fantastic data as we go …

Donna Shillington and Natalie Accardo, M/V Katundu, 22 March 2015

Adapting to the Unexpected

Wide Ocean, Tiny Creatures - Tue, 03/24/2015 - 10:30

I grew up outside of Chicago and I wasn’t a Boy Scout, so sometimes I feel like I missed out on learning the type of practical—albeit rarely used—skills that would have garnered merit badges. As I mentioned before, I’m hopeless with navigation. I could probably build a fire, but it would take a lot of matches. I don’t know how to whittle. Upon reflection, fire and navigation aside, now that I’m nearing the conclusion of my fourth research expedition at sea, I think I have amassed a few badge-worthy tricks.

The island country of Niue seen through my porthole.

The island country of Niue seen through my porthole.

I can plumb a filter rig like I was born holding Tygon tubing. For example, in my lab space on this ship I had to snake the tube to the vacuum pump through the ceiling, across the floor and up a table leg. And last week I devised a spill-proof method for siphoning 20 liters of radioactive waste into a storage container, no heavy lifting required. You’d be hard pressed to find any Boy Scouts with merit badges for hazardous materials handling. Finally, I can tie a bowline knot with my eyes closed. Of all these obscure, oceanographer skills I’ve acquired, I’m perhaps most proud of this one.

The bowline knot is considered the king of the basic maritime knots; simple but strong, and no matter how hard you pull it’s always a cinch to untie. I use a bowline to secure the rope of our plankton net to the ship each time Andi and I fish for Trichodesmium. If we lose the net to the ocean, that means no more Tricho, and no more Tricho means no more experiments. No more experiments and I might as well walk the plank. I’d bet all of my samples on the security of that knot, but no matter prune-y my hands are, it’s easy to untie when I’m exhausted during clean up at the end of the day.

The bowline knot is a practical trick to ensure the safety of an essential piece of equipment, but I also think it serves as a symbol of life as a scientist on the high seas: strength and mutability. On this cruise in particular, I’ve come to appreciate that when you’re at sea for two months, mutability is key.

For example, when I sailed away from New Caledonia in February I wrote that I wouldn’t see solid ground again until I returned to port in Papeete, Tahiti on April 3. Yet, when I woke up on Saturday morning I smelled land. It was like rain on soil—specific and unmistakable. Sure enough, when I climbed out of my bunk and made my way to my porthole, I was greeted by the sight of one of the smallest countries on the planet: the coral atoll of Niue, population 1,611. Niue is barely three times the size of Manhattan, and it’s completely isolated in the Pacific. However, a crew member of the Atalante injured his knee, and an eight hour detour to the island brought us to the nearest hospital.

Preparing the Zodiac to transport the injured crew member to land.

Preparing the Zodiac to transport the injured crew member to land.

Even though we were within swimming distance from the shores of the island and hours away from our planned cruise trajectory, the labs on the Atalante were still a flurry of activity as scientists sampled water and set up experiments, creating a makeshift station out of what would have otherwise been a floating hospital waiting room.

We’re back on track now, steaming full throttle towards our final long duration station of the voyage. If the volcanoes, tropical cyclones and surprise visits to land of the previous month and a half are any indication, we should still be ready to adapt to the unexpected. I still haven’t had to whittle at sea, but I’ve got two weeks left on the South Pacific, and you never know what might happen.

Follow @kylefrischkorn and the @DyhrmanLab on Twitter for more frequent updates from the OUTPACE cruise.

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