Field Notes: Drilling for Climate History in Sulawesi, Indonesia

Story kept in the voice of Chris Kelly, as told to Patrick Orenstein. Pictures by Chris Kelly. 
 
Brown Graduate Student Chris Kelly spent the summer of 2015 on the Indonesian island of Sulawesi as part of an international team of researchers using lake sediment cores to study the region's climate history. Led by Brown Professor James Russell, the Lake Towuti Drilling Project sampled ancient sediments from the lakebed, the analysis of which will give researchers new information on the long-term climate dynamics of the tropical western Pacific.

Chris: Collared kingfisher (Todiramphus chloris) near Lake Matano on Sulawesi island, just one example of tremendous regional biodiversity.

Night shift on the barge, showing drill rods (sent down to the lake floor) and rig setup. Pictured to the right is the emergency boat, in the event of an evacuation of the barge.

It’s a tremendously big lake (560 square kilometers!). We did some surface sediment sampling too, to understand modern geochemical and sedimentologic variability across the lake. Pictured here is the winch device from which the grab sampling device was lowered to the lake floor to obtain surface sediment samples. On sunny days, every vista could have been a postcard.

The barge during the day had the benefit of the beautiful view, but with the notable con of hot, humid weather conditions.

Various special creatures were attracted to the barge at night. Pictured here is an endemic water snake to Lake Towuti. The region is a hotspot for endemism; many species found in the lake are found nowhere else in the world.

This past semester Chris graciously agreed to be interviewed about his experiences, and the following is told in his words. 

(For more specific information on the the Towuti Drilling Project, visit the projects's website.)

Some background

This particular lake was identified such that a drilling campaign could recover sediments, and thus a history of environmental change, going back almost a million years. If you only have 10,000 years you’re only looking at one warm time, which is pretty similar to recent climate pre- Anthropocene, the current interglacial [period]. By studying timescales spanning hundreds of thousands of years, scientists can elucidate multiple glacial-interglacial cycles.  For instance, if we probe back something like 800,000 years, this is a timescale on par with the big Antarctic and Greenland drilling operations, the likes of which have given us a really full picture of CO2 history and climate history at high latitudes. A key research question motivating this project is then what’s going on at low latitudes across these same glacial-interglacial cycles, such that we can analyze Earth system responses in the modern tropics, and specifically look at previous warm times that may or may not have behaved similar to this one. 

As pollen, organic molecules, dust, and creatures (their remains), settle through the water column of the lake, year after year, this material piles up as lake bottom sediment. Based on this principle of stratigraphy, the topmost sediment represents the most recent material deposited, getting older as one delves deeper. By thus recovering the sediment, one can recover a history of past environments, as recorded over time. For example, scientists can analyze abundances of pollen washing into the lake to infer vegetational changes in the rainforest surrounding the lake. Similarly, by looking at certain isotopic ratios of leaf waxes synthesized by ancient plants, scientists deduce past precipitation trends, as well as the assemblage of the floral community. These are just a couple examples of the methods by which scientists can use the lake sediment to reconstruct past changes in the lake and its surrounding environment (or, perhaps, region).

This is an incredibly biodiverse hotspot in the modern day, so understanding how that came to be and what might happen to that as we enter a warmer anthropogenic climate state is really important. This means looking at not just climate change but environmental change at the level of a whole ecosystem- information that can be gleaned through Lake Towuti's lake history archive. 


Logistics

The bottom of lake is between 160-200m deep, and so to retrieve sediment we drop down the casing to the bottom and from there actually drill into the lake floor using various push/drilling technologies. 

The drilling work took place on a barge that was docked out in a strategic position in the lake and tethered down with four anchors. Day-to-day life depended on one's current position.  If you were on a day shift drilling, it meant you slept during the night ending at 4 am, got up, drove—through sometimes frantic Indonesian traffic patterns—45 minutes down to the dock, then took another boat ride (another 45 minutes) out to the drill rig to help process cores.

Generally we had a crew on the day shift who were drilling and crew on the night shift drilling, and then you had some people in a nearby, land-based lab doing the paleomagnetic analysis, sending it through a semi-automated machine that measures magnetic susceptibility (how magnetic the minerals are) and recording the lengths of core sections more properly. I was mostly in the lab, but when I was on shift, I was on the night shift, which meant you tried to sleep during the day in the hotel and then got up at 4 pm, ate a small breakfast in the hotel, and then took the car ride down and boat ride out. 


On shift

The drillers did the actual drilling for us, so for the scientists, work on the barge mostly revolved around core processing. They’d bring a core up and immediately you had to decide whether it was a success. Do we have three meters of core brought up? If the answer was no, then we would go back and wait for the next core to come on deck. If it was a success, though, then we would work as fast as possible to get the core labeled, to get end caps and electrical tape on it, cut it in half, confirm all the measurements, make sure everything’s labeled properly, mass everything, and then put it in a little storage area. Generally, even though that sounds relatively simple, it would take 10 or 15 minutes, and in those 10 or 15 minutes another core would come up. The drillers got competitive too, so they were trying to go as fast as reasonably possible and beat whatever the last shift’s record was. They would drill like hell while we sometimes struggled to keep up.  

The drillers were an absolute hoot because they’re these charismatic dudes who used to be in fracking or the petroleum industry and are now working for a company called DOSECC [Drilling, Observation and Sampling of the Earths Continental Crust] with a bunch of scientists like me.  DOSECC is the company that lake drilling projects like this one normally contract to do the drilling.

Sometimes, shifts were stressful especially since you can imagine that being in one of Earth's predominant convection zones, thunderstorms would come up out of nowhere. We were out there at night for some pretty tempestuous times, with just sheets and sheets of rain

You saw a lot of cool stuff on night shift because the massive lights that ringed the barge attracted all these little fish, and water snakes would swim up to the barge, which were apparently poisonous but we never tried to test that out. Sometimes bats or birds would come and circle around the lights, confused. As someone who appreciates biodiversity, it was totally wild, and most nights were a treat. 

I make this sound like it was a smooth process, but construction equipment would break down left and right—sometimes quite normal when dealing with equipment of this ilk. We had hydraulic issues with the drilling rig and at one point even had a part shipped to us from Texas while we were there. These times were stressful for those project decision-makers most affected.  

A couple of times between storms there were these hatches of beetles that would just cover the barge, to the point that you couldn’t actually see the deck for the black beetles. In hindsight I think it has to do with the lunar cycle. This was when the rig was down, so we were doing other kinds of research like collecting soil samples, such that it was just the drillers out manning the barge. Judging from the pictures, the drillers would have to shut themselves in the cabin while they got barraged by these thousands and thousands of insects. You’d see the aftermath and it would just be hordes of these things dead. The drillers would get the pressure washer and just have to mow these things down and force them off. It sounds absolutely nightmarish- guys getting pelted on the face, having to run away from all these bugs and shut themselves in. 


The weather and exercise on Sulawesi

It wasn’t as oppressively hot as a lot of people would think; often it was in the 70s or 80s. Don’t get me wrong—it was humid, but we have our dog days even up here on the East coast. You could still run sometimes, but not at noon because of the tropical sun, so I would run in the morning. 

One time I was running up this little hill that overlooked Lake Matano, another lake, which was nearer to the research lab, and I looked out ahead of me at this beautiful landscape, and I look to my left and see what I thought at first was a stray dog or something, this mesoscale, meso-build black animal with big brown hind limbs. As I ran closer, this “dog” (which ends up not being a dog) sits up on its hind limbs and looks out at me, and clear as day I swear to you this was an ape. This was a big ape, too, and this ape’s eyes shot piercing at me just to say, “Hey, I’m intelligent too.” As soon as I got closer it ambled back a little bit, and finally when it could tell I was right about even with it on the road it turned, and scampered back into the forest. ∎