Evidence of Undersea Oil Plumes

[Cees Binkhorst]

REPLY TO: D66 at nic.surfnet.nl

Als je mayonaise maakt voeg je druppelgewijze olie toe en moet je snel
roeren.
Als je het met een hoge druk toevoegt mengt het vanzelf, het kan maar
een  kant op, en dat is weg van de spuitmond en frontaal in het water.
Hier staat dat water alleen al onder een druk van honderden atmosferen.

Groet / Cees

June 2, 2010, 8:19 am
Evidence of Undersea Oil Plumes
By JUSTIN GILLIS AND JOHN COLLINS RUDOLF

Tony Hayward, the chief executive of BP, claimed recently that his
company’s testing has shown “no evidence” that any of the oil in the
Gulf of Mexico is lurking beneath the ocean surface. Oil is lighter than
water, Mr. Hayward explained, and will rise to the top.

Apparently Mr. Hayward is not familiar with the results of a test
conducted in Norway, in which his company took part, that suggested
exactly the opposite would happen when oil was released in very deep
water. A demand has come from Congress that Mr. Hayward explain himself.

In the meantime, university researchers keep adding to the preliminary
body of evidence suggesting that some of the oil — no one knows what
proportion — is dissolving into the water and forming huge plumes of
dispersed oil droplets beneath the surface. This is worrisome because it
raises the possibility that sea life, including commercially important
species of fish, could be exposed to a greater load of toxins than
conventional models of oil spills would suggest.

At least three groups of researchers have now reported evidence for
these undersea plumes of oil droplets. And the government, with little
fanfare, posted a map this week showing the location of one plume, based
on sampling done by a research ship operating under contract to BP. This
would seem to be the most detailed confirmation yet by a federal agency
that the undersea plumes are real.

The first group to report the subsea plumes was led by Samantha Joye of
the University of Georgia and Vernon Asper of the University of Southern
Mississippi, who found several apparent plumes at various ocean depths,
generally stretching west or southwest from the gushing oil well.

Their team has spent much of the past few weeks in the gulf aboard two
different ships, trying to map the plumes, which appear to shift with
undersea currents. The Joye-Asper team is back out this week under a
grant from the National Science Foundation.

Their report was followed last week by an announcement from researchers
at the University of South Florida who found a similar plume stretching
northeast of the leaking well, toward Mobile Bay. And a group at
Louisiana State University has also reported finding similar indications
of oil hovering below the surface.

All of this work is preliminary, and neither the government nor
university researchers have released definitive chemical analyses that
would show what is in the deep water. Lately researchers have begun
pulling up samples from within the plumes that display a visible sheen
and the smell of hydrocarbons. But the main evidence still consists of
unusual readings taken with instruments that are lowered by cable from
ships to the ocean floor.

Passing through a suspected plume, these instruments show huge spikes in
a reading known to oceanographers as C.D.O.M., for colored dissolved
organic matter. Dissolved oil can produce such spikes. It is not the
only substance capable of doing so, but the others are rarely found in
quantity in the deep ocean.

The C.D.O.M. spikes in the suspected plumes are associated with other
anomalies, including a high reading on an instrument that essentially
measures the murkiness of seawater. Dr. Joye explains more of the
technical details in a blog she is writing, and she has posted an
example of what the spikes look like.

In most water samples coming up from the deep, the level of dissolved
oil (assuming that’s what it is) is low and usually cannot be seen with
the naked eye. But that’s not always the case; take a look at the
pictures below. These are from Dr. Joye’s group, which identified a
plume earlier this week that appears to be denser than most of the
others. The experiment was done by a young University of Georgia
researcher named Adam Rivers.

The first filter shown below is essentially a control; it was
photographed after nearly three gallons of clean water from a part of
the ocean above the plume was passed through it.
Samantha Joye, University of Georgia

The next filter was photographed after a similar volume of water from
the plume was passed through. It is visibly oily.

What will turn up in chemical analyses of the water from these suspected
plumes? Various academic groups are racing against one another to
complete such tests, while also worrying about whether scientific
journals will try to block their papers if they release the results
early, as the public interest would seem to warrant. The government and
BP are conducting similar tests, and as noted above, the Environmental
Protection Agency has begun to make public some useful information.

But the test results released so far are still incomplete. The big
question remains: Exactly which toxins are dissolving into the ocean,
and how high are the levels?

http://gulfblog.uga.edu/
Gulf Oil Blog - UGA Department of Marine Sciences

Closing in.
By Samantha Joye | Published: June 1, 2010 6:55am

Closing in

May 31st, 23:58.   Happy Memorial Day.  Today we’ve been trying to trace
the deepwater plume as close as possible to the leaking wellhead.
Finally, after about 14 hours of searching and 5 unsuccessful CTD casts,
we closed in on the source of the plume.  After a very long day, we
finally have this feature well constrained.  We found more visible oil
in the deepwater today – at different sites from yesterday – which
increases our confidence in this finding.

Several people have asked me how much methane versus oil is in these
plumes.  We can’t answer that question yet.  But, the plumes are very
much enriched in gas.  After we complete the sample analysis, we’ll be
able to do this calculation.  I’ll try to make some rough calculations
tomorrow to get a feel for the volume and magnitudes we are dealing with.

Three people asked whether we plan to fingerprint the oil from the deep
plumes.  Yes, we will be doing that as it is the only way to concretely
link the plume oil to the oil leaking from the wellhead.

Four others asked whether we are measuring the dissolved inorganic
carbon (DIC) concentration in the plume waters.  Yes, we are measuring
DIC concentration.  In addition, we are measuring the stable carbon
isotopic composition of methane, DIC, oil, and microbial biomass and the
radiocarbon content of methane, oil and particulate organic carbon
(POC).  This way, we can use the unique isotopic signatures of oil and
gas to track these compounds into the microbial food web.

Multiple people have asked about oxygen depletion and whether oxygen
depletion will become a big problem out here.  We do not know the answer
to this question.  Oxygen is depleted but it is not at dangerously low
levels and we don’t know the rate of depletion yet.  We will know this
in a few days.  If oxygen gets too low (less than 2 mg/L), organisms
that can flee or avoid low oxygen waters will do so.  The problem would
be for the organisms that are sessile and cannot flee.

We’ve also gotten a lot of questions about what the surface oil looks
like. Today, we have been within 3 miles of the leaking wellhead.  In
here, the distribution, texture, and extent of surface oil slicks are
extremely variable but there was oil at every site we visited.

In places, there was a thin oily sheen on the water (see figure).  In
other places there were odd-looking ‘pancakes’ of oil floating on the
surface (see figure).  In these same places, there were bizarre orange
and black stringers, some 10’s of cm long, as deep in the water column
as you could see.  These stringers looked like mucous strings but they
were the color of oil.  We don’t know what they are but they are
abundant as far as you can see into the water column.  There are mats of
oil (see figure) and then there are thick ropey sea rows of oil (see
figure).

There were a lot of surface burns today, more than we’ve seen since we
got out here.  When it got dark, you could actually see the flames
reaching high into the air.

We got to enjoy a beautiful sunset tonight and pretty soon the sun will
be rising again.  Before the sun rises, we’ll begin another day of plume
chasing.

Sunset behind a skimmer boat
Posted in None | Comments closed
Trust your senses
By Samantha Joye | Published: May 31, 2010 12:38am

May 30th, 18:00.  One of the strangest things about these deepwater
plumes we’ve been tracking is that we see a strong CDOM signal but
there’s been no visible oil in the deepwater.  That changed today: we
saw oil in the deepwater.  We sampled a station about a mile south of
our previous stations (you can get our position and our ship track on
www.marinetraffic.com, just look for the R/V Walton Smith in the Gulf of
Mexico sector) and we saw the most intense CDOM signals that we’ve seen
so far.  The Pelican cruise sampled near here three weeks ago but the
CDOM signals we are seeing now are much stronger.

CTD profile showing depth (L axis) and relative signals in dissolved
oxygen (high to the R, low to the L), CDOM (low to the L, high to the
R), and beam attenuation (transmissometry; low to the L, high to the R).

In the CTD figure shown here, green is the dissolved oxygen signal, red
is the signal for colored dissolved organic matter (CDOM), and blue is
the transmissometer signal.  The main plume extends from about 1100m to
1300m in the water column.  Though the signals for CDOM and beam
attenuation (transmissometer) are very high, there is only moderate
oxygen depletion.  We hypothesize that this is because this is a
relatively young region of the plume—in other words, the microorganisms
have not had time to break down the organic matter yet.  We’re going to
track the plume to the west to see how far it goes and to see whether
oxygen is depleted more as we get further away from the source (that is,
into an “older” part of the plume).

Seeing these CTD data got everyone pretty excited.  Little did we know
that when we collected the water samples samples from the bottles, we
were in for an even bigger surprise.

We triggered sample collection bottles 300m below the plume, from two
depths within the plume, and from 300m above the plume.  When the water
collected from within the plume was transferred into collection bottles,
we noticed an oil sheen.  You could see it.  Everybody saw it.
Everybody got excited.  Seeing is believing.  Even more, the bottles
from the plume layers smelled strongly of petroleum.  The bottles from
above and below the plume did not.

Filter after 10L of water from 300m above the plume was passed through
it--there was no visible oil on the filter

Adam Rivers is filtering large volumes of water to collect samples of
messenger RNA from the microbial population.  The water from 800m, which
was 300m above the plume, served as a control.  At 800m depth, there was
no CDOM signal.  Adam filtered 10L of this water and after filtration,
there was no visible oil on the filter.  The filter was white and clean.

Then, Adam filtered 10L of water  collected from within the core of the
CDOM plume, from 1140m water depth.  The plume filter was visibly oily
and the water smelled strongly of petroleum.  This filter has a brown
sheen of oil on it after filtration (see photo).

Filter after 10L of plume water was passed through it -- visible oil!

Seeing oil in this quantity from plume filters is convincing evidence
that the deep waters do in fact contain oil.  The smell of petroleum is
strong in waters from this layer.  The other samples we’ve collected
were from areas with much lower CDOM signals and thus more diluted oil.
  Even at those sites, we have seen small beads of oil on filters but
nothing like the amounts we saw today.

We’re all very excited and eager to better delineate this strong plume
and track it out as far as we can.

Tonight, we’ll be lowering Vernon’s deep sea camera into the strongest
part of the plume.  Who knows what we’ll see there…

Stay tuned for more updates tomorrow.
Posted in None | Comments closed
Heading towards a new grid
By Samantha Joye | Published: May 30, 2010 6:12am

May 30th, 01:00.  Sleep is a luxury at sea.  You don’t want to miss
anything so you better stay awake.  We’re heading towards some new
stations to the North of ground zero and will be doing a hexagonal grid
around ground zero tonight in search of additional plumes.

In the meantime, I’ll answer some questions posed about the blog.

Several folks have asked what we are measuring out here.  My group is
measuring concentrations of dissolved methane, higher alkanes (like
ethane and propane), inorganic carbon, and oxygen; inorganic and
nutrients; oil and colored dissolved organic matter; dissolved organic
carbon; hydrogen sulfide; and major salts.  We measure rates of oxygen
consumption and methane oxidation.  We’re also collecting samples to
determine the concentration of ATP (an indicator of relative microbial
activity) and will do a separate assay to estimate the level of total
microbial activity.  Finally, we collect molecular biological samples to
look for different types of methane oxidizing bacteria.  Adam Rivers,
from the Moran lab at UGA, will be comparing the metatranscriptome from
deepwater plume samples versus samples from control depths that lack
plumes.  Joanna Green from, from the Miller lab at UGA, will be doing
photochemical experiments with plume waters.  The UNC group will conduct
more detailed molecular biological studies of the microbial population
using both DNA and RNA approaches. The USM group is doing more detailed
characterizations of the PAHs and metals in plume samples and the UCSB
scientist on board is characterizing the relative degradation state of
the oil.  We’ve all been pretty busy.

Someone asked whether the deepwater plumes form because of dispersant
use at the wellhead or whether this material is settling down from
surface waters into the deepwater, again because of dispersant.
Considering the plume trajectories, they appear to derive from the
wellhead.  We do not believe they form from the sinking of oil that was
once on the surface.  However, that does not mean the plumes are
generated because of dispersant use.  Quite the contrary, plumes like
these most likely form through natural processes.  At the temperature
and pressure of the reservoir, methane is dissolved in the oil.  When
the fluid is expelled at the seafloor, the methane comes out of solution
in a fairly violent manner.  This gas expulsion likely fractionates the
oil and it is this fractionation that generates the diffuse oil in the
plumes.  This process is described in the NRC (2003) report that is
given on the resources page of the blog.  Please let me know if you’d
like a more detailed description of this.

A couple of people asked whether we are using underwater video to
visualize the plumes.  We have not done this yet but Vernon Asper from
USM has a deep sea camera on board and we’ll be deploying it Sunday
night.  Stay tuned for updates.

Finally someone asked whether there is a “methane cloud” emanating from
the wellhead.  The plumes we’ve found are enriched in methane as well as
higher alkanes.  The dissolved methane concentrations are higher than
we’ve ever seen at comparable depths on previous Gulf of Mexico cruises.
  Some of the methane is almost certainly venting to the atmosphere but
those fluxes have not been quantified yet to my knowledge.  Scientists
on board the R/V Cape Hatteras will be quantifying atmospheric methane
fluxes about two weeks from now.  One of our major goals for this cruise
is to map the methane concentration fields around the wellhead.  We’ve
made good progress towards achieving that goal so far.
Posted in None | Comments closed

A wake of oil and surfing dolphins
By Samantha Joye | Published: May 29, 2010 2:17am

May 28th, 20:00.  Lesson number 1: Never report that things are going
smoothly at sea.  After saying that yesterday, today we encountered some
instrument problems and lost several hours of mapping time.  Not to
worry, we’re back in business now.  We’ve almost constrained the new
plume’s distribution.  We know it’s around 10 miles long and at least 2
miles wide and that the chemistry and size of the plume vary along its
length.  We’ll learn even more in the coming days.

Thanks to those who have emailed me questions in response to the blog.
Several people have asked whether we are doing experiments related to
the dispersants being used out here to break up the oil.  We are not
measuring dispersant concentrations, but several scientists on board are
examining the potential impacts of dispersants on microbial activity and
microbial community structure.  So we’ll have information about
dispersant effects, we hope, but we will not be measuring dispersant
concentrations.

Someone asked if the plume reported by the University of South Florida
(USF) researchers is the same one we found.  No, the plume we found is
to the W of the spill site while the USF plume is to the NE.  From the
description the USF researchers provided, the NE plume has two
similarities to the plume we discovered: a CDOM signature and invisible
– to the eye at least – oil.  But, the USF plume is moving the opposite
direction (NE vs. SW) and the USF plume appears to be larger (22 miles
long and 6 miles wide) and it spans a broader depth range (from just
below the surface to 1100m water depth) than the plume we are presently
tracking.

The USF researchers fear the plume will reach De Soto canyon, where it
could be upwelled onto the shelf and negatively impact fisheries.  While
this is an obvious concern, I think it’s too early to predict where the
USF plume might end up.  The plumes we are studying seem to be very
dynamic, that is, they are moving around.  The USF plume may be
similarly dynamic so the key is to keep track of where it’s going, to
understand it’s chemistry, and to understand how it’s behaving.

We did 14 CTD casts in the last 24 hours and we’re pretty saturated with
samples at the moment.  We’re transiting to the North to search for some
plumes there and then late Saturday we’ll be back on the West side of
the spill site, further constraining the dimensions of this new plume.
When we started this transit, the wake of the ship was brown with
oil…can’t say that I’ve ever seen anything like that before.

While we are transiting, we’re analyzing samples to determine methane
and dissolved inorganic carbon concentrations.  Chassidy Mann, lab
assistant extraordinaire, is working at the gas chromatograph analyzing
many of these samples.

Perhaps the highlight of everyone’s day was when we broke out of the
surface oil slick and entered beautiful blue, crystal clear Gulf of
Mexico surface water.  There, we were joined by a pod of Spinner
Dolphins who kept everyone entertained for half an hour by “surfing” the
bow wave of the ship doing acrobatic spins and flips in the air.  Seeing
these dolphins swimming and jumping made me forget about the oil spill
for just a little while.

An airborne dolphin!
Posted in None | Comments closed

Day three in the city of ships
By Samantha Joye | Published: May 28, 2010 5:32am

City of ships
May 28th, 01:00. Today we saw some new things around the area. A fleet
of skimmer ships was doing a surface burn to reduce the size of an oil
slick. We were a couple of miles away from the burn but the large cloud
of black smoke caught everyone’s eye. I’m still amazed by the ‘city of
ships’ around the spill site. The rigs drilling the relief wells and the
‘siphon’ ship (large ship to the left in photo), as well as many support
vessels are visible in this shot.

Burning off surface oil
Our sampling and general operations are going very smoothly. We ran CTD
profiles all through Wednesday night and Thursday morning, thanks to the
efforts of Vernon Asper from the University of Southern Mississippi. We
tracked the ‘new’ plume along a S/SW line by doing CTD casts about every
half mile. The main plume features were fairly consistent along the line
can concentrations of CDOM decreased with distance from the spill site.

Around 10AM Thursday morning, we moved slightly to the North and found
another very interesting plume that was different from the previous one.
The second plume contained less CDOM but exhibited more oxygen
depletion. Perhaps this plume is older than the other one? The oxygen
concentrations are not low enough to harm animal life but they are
substantially lower (by ~25%) than the waters outside the plume at
similar depths. Methane concentrations in this feature are the highest
we’ve measured anywhere so far during this cruise.

CTD rosette and surface oil sheen
This is an extensive plume. We’ve been tracking it now for approximately
7 miles and both the CDOM signal as well as oxygen depletion are strong
and they co-vary. The samples with oxygen depletion also contain high
concentrations of methane. Our hypothesis is that methane oxidation and
CDOM degradation are driving oxygen consumption. We will be testing this
hypothesis directly by measuring methane oxidation rates and oxygen
consumption rates. Back at the UGA lab, we’ll be doing experiments to
determine what factors regulate methane oxidation rates in these samples.

To accomplish as much as we can during this 2-week cruise, we’re doing
around-the-clock operations on the ship. We do mapping CTD casts at
night to characterize the plume’s distribution and variability. During
the day, we collect water samples for various analyses. On Saturday,
we’re picking up a sediment sampling instrument called a “grab sampler”
and will then add sediment sampling to our list of operations. Never a
dull moment out here!
Posted in None | Comments closed

The migrating undersea plume
By Samantha Joye | Published: May 27, 2010 1:16am

May 26th, 20:00:  Earlier today, we sent the CTD down at a site where
two CDOM rich layers were documented during the Pelican cruise.  We did
three casts and unfortunately, saw only very weak signals and had
nothing to get excited about.  Around 3PM, we discussed the possibility
that the plume had moved, which we all found interesting.  So, we looked
at the data from an instrument called an Acoustic Doppler Current
Profiler (or ACDP for short) to see which way the water was moving at
depth.  We observed that the water was moving to the North so we moved
about a mile due North and dropped the CTD into the water for cast
number four.
tarry oil slick

Surface slick
Around 16:00, we spotted the top of the plume at about 800m water depth.
  Everyone got pretty excited.  But, little did we know that we’d soon
be even more excited!  The plume had not only moved North but it was
somewhat different than it was two weeks ago during the Pelican cruise.

The plume was located between 800m and 1300m in the water column and
there appeared to be three distinct layers.  The sensor signal for
colored dissolved organic showed a robust increase in signal between 800
and 900m; then increased by about five times between 1000 and 1200m;
and, between 1200 and 1300m, the signal doubled again.  In these same
depth ranges, the signal from the transmissometer also increased,
suggesting a different suite of particles in the water between these
different depths.

Rig drilling a relief well
We tripped Niskin bottles within each of the unique CDOM layers and at
about 1400m, which was roughly 100m below the peak signal from the CDOM
sensor.  We got the samples on deck and collected samples for methane
concentration analysis and oxygen respiration rate assays.  Those
samples are being run right now and we can’t wait to see the data.  We
also collected several other types of samples, including samples for oil
analysis, but we won’t have those data until about two weeks after we
get back from the cruise.  For now, we’ll have to be satisfied knowing
that there is a good bit of methane in the water!

We’ll be doing CTD casts most of the night to characterize the plume’s
current distribution.  But will only be collecting one more set of water
samples tonight.  It’s been a long day and most people need to get a
little bit of sleep.
Posted in None | Comments closed

Expedition departure
By Samantha Joye | Published: May 26, 2010 7:29pm
The Walton Smith departed Gulfport at 8PM on May 25.  The science party
consists of microbiologists, geologists and biogeochemists from the
University of Georgia, the University of North Carolina (Chapel Hill),
the University of California (Santa Barbara) and the University of
Southern Mississippi and Justin Gillis, a journalist.

Our objective is to conduct a comprehensive, interdisciplinary study of
the deepwater plumes that were discovered on the Pelican cruise two
weeks ago .  We will be further documenting the plume’s distribution as
well as measuring microbial  activity and a suite of geochemical
constituents.

We arrived at the spill site around 6AM.  There’s a lot of oil on the
surface to the N-NE of the spill site.  The smell of oil and gas is
strong. I expected to see a lot of ships in the area but I was amazed by
the density of ships: there are ships everywhere, as far as you can see.
  We began to cruise a line to the SW in search of the plume discovered
on the Pelican cruise.  We turned on the chirp sonar system around 8AM
but the plume appears to be acoustically transparent — or maybe it has
moved?  At about 9:30, we decided to do a profile with the sensors to
“see” what the water column looks like.
CTD in the water

CTD rosette in the water
We use an instrument called a “CTD rosette” to characterize the water
column and collect water samples from specific depths. The CTD rosette
contains an instrument with sensors that quantify temperature, salinity,
depth, chlorophyll (an indicator of phytoplankton biomass), colored
dissolved organic matter (“CDOM,” which includes oil), and
transmissometer (which essentially detects particles in the water). The
rosette also contains special bottles for collecting water at a specific
depth.  We trigger the bottles at depths where we see interesting
signals in the CDOM, and we use the water for measuring  methane gas
concentration and oxygen consumption rates on board the ship.  We’re
also collecting samples for analysis of oil, basic geochemistry,
nutrients, and microbiology; those samples will be analyzed back at the
UGA laboratory.

The CTD is in the water now so we should have our first samples soon!

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