Today was our last day for collecting seismic data. The streamer
stayed in the water until 18:00, the Knudsen is still "chirping", and the
multibeam will stay on until we reach the Economic Exclusion Zone of the
Falkland Islands. We are now heading home with an estimated return date
to Punta Arenas on the night of October 21st.
I approach this entry with some trepidation as the scientific adventure
is changing course, we are moving from collecting data to interpreting
data. Many individuals are writing the research cruise report and in six
days new friends will say goodbye and return to their individual worlds
off the vessel.
Yesterday produced a mini snow storm, as if the Scotia Sea is sorry to
see us leave. Even through the snow, work continued, but now all gear is
stowed and we are cruising at 10 knots, heading for port.
But until we dock, there is still knowledge to learn, and today I
learned a bit more about physical geology and plate reconstruction
modeling. Once again, the teacher was being schooled by the students.
Both Bud and Kory took turns in drawing me pictures, and using computer
modeling to remind me of some basic geological features of the earth and
her crusty plates.
Go back, way back how about 190 million years to Gondwana, and think
about how the earth has changed, how the plates have moved, and how they
are still moving. That was my lesson today, and it was fascinating.
Kory drew me a great picture to explain spreading zones subduction, and
magnetic reversals. Bud then jumped in and used an amazing partial freeware program called GPlates. We talked about the oldest minerals on the
planet: zircons from the Jack Hills in Australia at approximately 4.3
billion years old, to the oldest rocks, acastia gneiss, from the
Northwest Territories in Canada.
I was also reminded that I still have questions, and one in particular:
Why does the earth's polarity switch? There is recorded data of 40
million years and no switching, then switching in intervals of three
million years, so what causes this phenomena?
I am pondering these thoughts as the sun peaks through and I see a
glimpse of blue.
I have also been reminded that many of the facts I refer to in my
journals come from the amazing minds on this scientific cruise, but that
the dates might not be exact. For me, the knowledge base in this vessel
is astounding even if some of my numbers might be off by a few million