Yesterday we left our first study region with new samples from
the seafloor and a healthy respect for the ocean currents that
can erode sediment deep in the ocean. The samples will be useful
for our research but we had to work for them. The seafloor we
surveyed was heavily eroded and we had to look carefully before
finding sites that were promising enough to sample. Even then we
ran into difficulties getting the sediments back to the ship. We
spent several days surveying the seafloor using instruments on
the ship to identify possible sites for sampling. We looked for
flat areas where we could see layers of sediment below the
seafloor. These layers show up in the echoes from sound pulses
in a type of measurement called seismic reflection (see previous
blog post). Unfortunately much of the region we surveyed has
deep gullies with no sediment layers. Ocean currents have
scoured these regions leaving no sediment for us to core. We
finally located several small areas that had a hint of sediments
and one big pile o