A S
Given the size of this project, and the remote area you are working in, it must
attract a lot of attention. Are there
any concerns by area residents about
the project? What do the local communities
think about your research?
S W
We have received a lot of attention not
only from national and local media, but also from those living near the lake. The locals were particularly surprised
to see huge cranes and other heavy equipment being transported through
their villages to the project’s dock, where the gear was assembled into
a working drilling barge. The confused locals thought that this equipment
was owned by PT Vale Indonesia, a nickel-mining company operating
nearby, which has often had a contentious relationship with the locals.
Unfortunately for us, the words “drilling” and “project” also carry with them
negative connotations.
Within days after the project began, false rumors about our intentions
started to spread widely. Some people that we met thought that we were
going to do oil and gas exploration. Others were deeply concerned about
the potential environmental impacts of the project; many asked us if a
Lapindo-like mudflow disaster could happen because of our project.1 The culmination was a demonstration staged by approximately 100 local
residents and NGOs two weeks into the project. We listened to them, answered
their questions, and worked hard to explain what the TDP really is.
We were quite surprised with the moves against our scientific project,
as Dr. Russell and Prof. Bijaksana had already held a meeting with the subdistrict
head and local leaders two months prior to the start of the drilling.
In addition, the district chief had known about this project since 2012, when
it was still in the planning stage, but the information did not trickle down to
area residents. The fact that 2015 was a busy year in politics, with elections
of the district chief and village leaders looming, also added another
complex dimension.
We had already planned on doing outreach during our stay in Sulawesi,
but the miscommunication with area residents forced us to go all out
and work harder in conducting such activities. We held many meetings with
various stakeholders: local leaders, government officials, local house
of representative members, as well as representatives from NGOs. We also
visited many elementary and high schools. In addition, we facilitated visits
to our barge by government officials and locals alike, including school
children, so that they may have a better understanding about our work. By
the end, we were elated to learn that most locals had favorable views
toward our project; many of them even expressed their open support.
E T
Regarding the drilling process itself,
how long are the individual cores you are extracting from the lake bed?
What condition do you extract them in (wet/dry, hard/soft, etc.)? And what
will you do with this material next in order to study the samples collected?
S W
We hope to drill the sediment all
the way down to the top of the bedrock. Lake Towuti’s water depth
is approximately
200 meters, and the sediment underlying the water and
overlying the bedrock has a depth of about 180 meters. To perform the
drilling, we have to connect a bunch of five-meter-long drilling rods or pipes.
When the actual drilling or coring equipment is lowered down through
the inside of these rods, it brings along with it a three-meter section of plastic
core liner. The drilled core sediment is captured in the core liner, and is
prevented from falling back down by a core catcher when lifted up.
Once the liner is out on the drilling barge, scientists cut it into smaller
pieces (maximum length: 1.5 meters), put end-caps on both ends of the liners,
and label them. Visual inspection suggests that the drilled wet sediments
inside the core liners consist of different facies (for example bodies of rock
with specified characteristics representing a certain type of depositional
environment), just as we had predicted before. We are able to see claydominated
materials, sand-dominated materials, gravel-dominated layers,
peat layers, as well as tephras (volcanic
ash layers). The labeled sediment cores are
then brought to the shore during our shift change, which happens twice a
day. The cores are logged for magnetic susceptibility and other physical
characteristics using a logger that we brought from Brown University and
then temporarily stored in our field laboratory. We also sieve the sediment
left in the core catcher and analyze these tiny samples under a microscope.
The cores are currently on their way to the U.S. National Lacustrine Core
Repository in Minnesota, where the scientists involved in the project will
split them open into two halves during the core-splitting and sampling party
later this year. The working halves will be photographed and logged for
various physical characteristics using more sophisticated equipment and
finally sub-sampled to be analyzed further by different scientists in their
respective laboratories. Meanwhile, the archived cores will stay untouched
in the repository in Minnesota.
E T
In our correspondence and previous meetings, you mentioned that the core samples you collect from Lake Towuti
will provide up to 800,000 years of climate history. Can you explain more specifically how this climate knowledge
is extracted from the sample? What sciences are involved in such processes of paleoclimatology?
S W
Paleoclimatology is the study of changes in climate taken on the scale
of the entire Earth’s history. Humans started systematically collecting rainfall data from rain gauges and temperature data from thermometers only in the
past few centuries. To obtain climate data from ancient times, we can use a variety of proxy methods borrowed
from the Earth and Life Sciences that can tell us the amount of rainfall or temperature over a certain region
during a certain period in the past. The physical, biological,
and chemical characteristics of Lake Towuti’s sediment offer us clues of ancient climate history, which may
help us understand the overall pattern of climate change and assist
us in predicting how the climate might
change in the future. For example, clay mineralogy may inform us of the
types of materials that eroded easily and entered the lake, especially when the rainfall amount was high. During periods when the titanium level
in Lake Towuti was higher than usual, for instance, we may deduce that
those were relatively wet periods. Using pollens extracted from the sediment, then observed and counted under the microscope, we can learn
about the types of plants that were living in the lake’s catchment area.
Based on our pollen and leaf-wax carbon isotope analyses on the twelve-meter sediment cores from the 2010 expedition, we know that savannah was the dominant ecosystem in the area
surrounding the lake between 33,000 and 16,000 years ago, during the last
ice age. This indicates that the climate was much drier at that time. We hope
to obtain environmental and climatic information further back in time using
the longer drill cores from the TDP. One of our goals is to test whether
the climate in the region was also dry during previous ice ages, and if so, why.