November 15, 1995
Location: Bransfield Strait. Sea Beaming/Sea Floor Mapping
Update: Larry Lawver, the Chief Scientist from Texas called me from
the wet lab at 7:00 AM. I was startled from bed and answered the phone on
the first ring. He said, ìAre you awake?î I said ìYesî, mostly out of
surprise and disorientation rather than being awake He said, "We just
brought up a dredge and we have some really interesting stuff. You have
to come down!î
From the excitement in his voice, I knew that something really
intriguing was lying on the back deck. I pulled on some clothes and
boots, grabbed my camera and headed down to the deck. When I got there I
was met by a sea of orange float coats. I felt like I was at an opening
for some big event.
I knew when I had gone to bed that the OSU team had planned a dredge
this morning near one of the suspected hydrothermal vents. I was half
expecting to see some interesting volcanic rocks, or possible a part of a
hydrothermal vent chimney. Instead, on a piece of white map paper are a
collection of fish, sea stars, and worms laying on a piece of paper. It
was like a mini fish market. Everyone on the ship made their way down to
the wet lab, including the Captain and most of the crew. Photos were
taken with the ìcatchî. Everyone was caught up in the excitement. It is
unusual to find living organisms in dredges of the sea floor. Typically
all that is collected by the dredge is rocks.
By 8:00 the scene had calmed down. Since I am the only ìbiologistî
aboard, I happily became responsible for collecting, logging and
preserving the samples. It was great! I really felt comfortable with the
task and thrilled to be given the responsibi lity. I have had a good
educational background and quite a bit of experience working with fresh
water organisms. I felt a bit anxious as we began, because I knew that I
was preserving these specimens for future research, and their might be a
scientist one day cursing or praising our preservation techniques.
This was my first opportunity to work with salt water organisms. What
is parcticularly interesting is that these organisms were collected at a
depth of nearly one mile. Deep water organisms are referred to as benthic
organisms. One of the research ass istants from OSU, Chris Schneller
helped log and preserve all the organisms. After about three hours we had
logged, packaged and preserved 23 specimens.
All of the organisms were deep water species, but none were
specifically hydrothermal based organisms. One characteristic typical of
animals from hydrothermal vents is that their biology is based upon
sulfur. Hydrothermal vent animals smell like hydr ogen sulfide (rotten
eggs) because of the sulfur in their environments.
We collected three fish, worms, sea stars, nematodes and sponges off the
rocks. It was a fantastic experience. Although these animals look
similar to their fresh water relatives, the cold and high pressure
conditions at the sea floor produces some inter esting variations,
parcticularly in the larger organisms.
The gills and internal organs of the fish were void of any color. They
were white with no evidence of red blood within their circulatory system.
I saw no evidence which would indicate the presence of an air bladder.
Buoyancy appeared to be controlle d by fat bladders on the pectoral fins.
The body shape was tubular with a broad flat head. The two largest fish
appeared to be the same species. The third fish was similar in shape to a
tadpole. It had no caudal, or dorsal fins. Itís circular in shap e was
positioned in the middle of the front of the head. The jaw was not a
dominant feature.
The sea stars had most of their appendages severed, although one had
three of the five nearly intact. I have to email one of the Marine
Biologists at the University of Delaware to see if he wants them sent to
him at the completion of the cruise. If he does want them we have to
secure the proper permits to transport them to the US. Other wise, they
will be transported to OSU for their Marine Biologists.
We also sent down a deep submersible still camera. The photos show
some of the small organisms on the rocks on the sea floor. They turned
out extremely well considering the age of the equipment. The last time
photos had been taken with this parcticul ar camera was in 1982. Mark
Wiederspahn from Texas was responsible for its operation on the cruise. In
the first days of the cruise out of Chile, I helped Mark clean and setup
the camera and strobe. Small areas of the metal pressure housing in the
area of the O rings was pitted from rust. There was considerable concern
that the O rings which seal out the water housing might fail. Mark
carefully cleaned all the metal surfaces and replaced the O rings.
The camera and strobe were cleaned and checked. Fresh batteries were
placed in both units. The mechanisms were tested on the deck without
film, and all systems seemed to work properly. Since we had only one
battery for the strobe, there was no prete sting in the water. The photos
from the vent area were the test, and the equipment worked well.
We continued our sea floor mapping for the remainder of the morning and
headed to an intriguing region of the Bransfield Strait near a volcano to
take a core sample of the sediments in a flat basin near the volcano.
Dr. Ben Sloan from the University of Texas and Amelia Shevenell, a
senior at Hamilton College, were again responsible for the coring
operation. The technique for using the corer seams to have been mastered
by the coring crew. A beautiful sediment cor e was retrieved on the first
attempt. Ben and Amelia spent about 6 hours taking samples of the core
for further analysis at their universities.
Ben was hysterical about his post coring encounter with the birds that
fly along with the ship. He described a scene that Hitchcock would have
been hard pressed to imagine. As he tried to shovel the unneeded
sediments overboard using a shovel, the birds flew near miss bombing
missions at him. He could barely get the mud over the side due to what
seemed to be an orchestrated assault.
After a short while Ben decided to take matters into his own hands and
he returned fire on the oncoming bird squadrons using a water hose on
deck. These were savvy foes and they lured his fire toward the side of
the ship. Instead of hitting his troublesome antagonists with the stream
of water, the ocean wind allied with the birds blowing back the steam into
a spray that blew toward to the head of unsuspecting Amelia. What started
out as a simple task of tossing some sediments overboard had evolved into
an Antarctic Elvis and Costello style ship comedy with Ben and Amelia as
its stars.
We left the coring site and set a course for an evening of ZAPS work.
We continued our survey of the sea floor in the area with Captain Joe at
the helm. All of the ships navigators are excellent sailors, but Captain
Joe seems to see the Palmer as an ice yacht rather than an ice breaker.
He thrilled us with a circuitous course through the bergs at sunset. It
was a captivating evening ballet of ice and the light of the setting sun
choreographed by Captain Joe at the helm.
ANNOUNCEMENT: Technically we have been having a bit of trouble with the
servers that we manage the Antarctic Link Project from. As a result, some
of the updates have been a bit slow at being posted. Without the help of
Bob Manthey and Eric Truett man aging the page in the states, it would be
impossible for me to post the updates as efficiently as they have been.
Due to some problems in Cyberspace we would request that you look for
the Antarctic Link Page at one of the following two ULR locations.
http://www.wctc.net/~bmanthey/antarc.htm
or
http://dns.worldweb.net/~etruett/antarctic.htm
These servers are stable sites and as a result you will see more
frequent updates, and hopefully in a about a week photos taken while on
the cruise.
We would also like to create a database of email addresses of those
visiting the web page, so that information about future projects on this
web site can be posted to you as well as opportunities for polar science
curriculum materials. Also, we would like to be able to demonstrate to
NSF and our sponsors the diversity of the audience that has been visiting
our web page.
I look forward to your continued questions, I would appreciate any
comments about the page as well.
QUESTIONS:
WFPHS95: The ocean in the region of the South Scotia Sea and the
Bransfield Strait ranges in depth from about 4500 meters forming deep flat
plains to steep abrupt volcanic mountains and ridges that are at a depth
of about 500 meters below the surface. The sea floor has plains, valleys,
ridges, hills and mountains just like the surface of the earth. The
primary differences is that on the sea floor, the forces of erosion are
very slow, so the features are more stark and rough on the sea floor.
Scientists are able to measure the rate and direction of these deep
ocean plates by using and array of special geographical positioning
Instruments that are anchored to the sea floor. These instruments record
their geographic position using satellit e positioning. A special radio
transmits the instruments position to the scientist. The instruments are
placed on either side of a fault on two opposing plates. The change in
the geographic position of the plates is used to determine the rate and
direc tion of motion. Plates typically move centimeters to tens of
centimeters a year.
From the data that we have, the hydrothermal vents in this area are
miles to tens of miles apart.
The atmospheric pressure here changes hourly. We have had a high of
1005.5 millibars and a low of 948.2 millibars. In a single day it is not
unusual to have a change of 2 to 3% in the air pressure.
