Sept. 16, 2005
Jim Cowen Another busy dive day. Today we went down to check on our equipment
and verify that there was indeed positive fluid flow from the borehole
1026B. Historically, this hole has been over-pressured (for years).
This hole was refitted with a new CORK observatory a year ago at the
same time that our other target holes, 1301 A and B, were drilled and
fitted with their own CORK observatories; we had expected both 1301 A
and B to be over-pressured too. An over-pressured hole produces
(discharges) fluids if the hole is opened at the seafloor; an
under-pressured hole would ‘suck’ ocean into the hole. As it turns
out, much to our surprise, consternation and puzzlement, all of the
holes are currently ‘sucking’. This turn of events has been
frustrating, but that is sometimes the way of science, especially
exploratory science. However, it has also been challenging and the
experienced and talented group of hydrogeologists (Andy Fisher, Keir
Becker, Earl Davis), geochemists (Hans Jannasch, Don Nuzzio), and
microbial geochemists (Jim Cowen, Brian Glazer) have come together to
try to work out the puzzle and find technical solutions over the short
and long term to continue to access the deep subsurface fluids. The
non-stop conversations and animated debates have been exhilarating…and
we think productive, as we have settled on a new strategy for
tomorrow’s dive. We need to verify that 1026B has stopped producing
from just some or all of the fluid delivery lines at this hole. We
have come up with a combo-sampling method that makes the best out of a
very challenging sampling situation. Doug Pargett, Samuel Hulme, Jamie
Becker and Mike Cole all pitched in to help construct and prepare
different aspect of tomorrow’s sampling gear. Meanwhile Kevin McCarthy
copied previous dives videos so we could carefully review key aspects
of the 1026B’s CORK structure. It is now midnight, but we’ll be ready
for tomorrow morning’s dive.
During todays dive we also made a 2 km transit over the seafloor. It
was amazing to those of us who have dove many times just how many
animals were living on the seafloor. These include sea cucumbers ,
brittle stars, feather duster worms, giant orange anemones, several
octopi and many, many strange almost clear holothurian-like organisms
(no one on board knows exactly what they are—we are not that kind of
biologist!), as well as innumerable zooplankton (crustaceans, medusa,
siphonophores, and planktonic annelids-worms) up in the water column. |