From: beve@mpl.UCSD.EDU (Beverly Kennedy)
Subject: Precruise Meeting
To: shipsked@ucsd.edu
Date: Tue, 4 Jun 1996 13:22:04 -0700 (PDT)
Cc: beve@mpl.UCSD.EDU (Beverly Kennedy)
Mime-Version: 1.0

Beverly Kennedy
Phone: 619-534-1324
Fax:   619-534-6849
E-Mail: beve@mpl.ucsd.edu
_____________________________________________

Notes for pre-cruise meeting.
from Peter Lonsdale
Leg 4, Valparaiso to Punta Arenas

This leg represents the second half of a 2-leg field program designed to explore the origin and northward growth of the Pacific-Antarctic East Pacific Rise during the early Cenozoic.
The first half was completed Melville in 1994; this second half was originally scheduled for 1995,
but was postponed.
The NSF grant intended to pay for the project expires New Years Eve, 1996, ten days before the leg
begins; we hope to get an extension that will allow us to pay for the leg, and perhaps even for
interpretation of the data it will produce.

Equipment needs"

Primary survey tools will be Seabeam 2000, magnetometer, gravimeter, 3.5kHz profiler and seismic
profiler (analog system with two 80 inch water guns, perhaps with an airgun in reserve for rough
seas).
Of these, my principal concern is about the 3.5kHz profiler.
To be useful, this must use a streamer as its receiver, and I am told that the new streamer now on
Melville is not working or broke.
Will it be repaired or replaced for this expedition?
I want the Seabeam system free of the test wires and other add-ons that produced devastating noise
during the first part of the present expedition.
I would appreciate the vessel being ballasted bow-down, as much as possible, for improved SB
performance into the seas.

Techs and other personnel"

>From STS I need a computer tech, Seabeam engineer, and a res tech who is capable of operating the
profiling systems (as well as looking after the mag, etc).
I understand I will have to find the travel costs of the engineer somewhere in my expired grant
(on-way? round trip?).
At sea data processing will be handled by me and the 4-5 Scripps students aboard.
I expect two or three additional volunteer/watchstanders.
If the Chilean government wishes, we can accommodate and put to work several Chilean participants, but
cannot cover their travel costs.

Miscellaneous

Our only shipping needs will be data returning from Punta Arenas.

I hope our primary ship to shore communications will be by satellite-routed e-mail, and that business
messages using this route will not incur an additional charge.

Our scientific party will be prepared to shift out of their bunks, either ashore or to whatever space
can be made available on Melville, after the first night in Punta Arenas.
I hope the same pattern will prevail at the Valpariso change-over.

I would like to know more about the entry to Punta Arenas.
I had assumed that we would pick up the pilot at dawn Feb 13 at the entrance to the Cockburn Channel
"short-cut" to Punta Arenas (as Melville has done before).
A recent message from Captain Althouse implies that pilots can no longer be picked up at the Cockburn
Channel entrance, so that a 12-16 hour extra diversion to the west entrance of the Straits is
necessary.
If so, when will we pick up the pilot?
Will the schedule need to be adjusted to accommodate this diversion, or will part time or working time
be reduced?


FOR CRUISE PROSPECTUS
Leg 4
Valparaiso to Punta Arenas, Chile/fR

The purpose of this leg is to complete a survey of the conjugate pair of oceanic rifts that initiated
the northern part of the Pacific-Antarctic East Pacific Rise, and of the Pacific-Farallon-Antarctic
triple junction trace that marks the subsequent growth of that rise.
Henry Trough, the western member of the conjugate rift pair, was surveyed by Melville in 1994; the
eastern Hudson Trough and the major structures that intersect it (Humboldt Trough and the Menard,
Vacquier, Raitt and Tula fracture zones) will be principal targets of this survey.

Equipment to be used includes the Seabeam 2000 sonar, magnetometer and gravimeter (throughout the
leg) plus 3.5 kHz and seismic (2X 80" water gun) profilers for 10-15 days.
Sediment thickness in the survey area generally increases southward toward Antarctica.
How much profiling gets done, and how far south the survey extends, will depend on how effective the
profiling systems are in the prevailing sea states.

Foreign clearance will be required only for the Seabeam/magnetics/gravity transits across the coastal
waters of Chile.
The attached track chart assumes entry into the Straits of Magellan via Cockburn Channel, rather than
by the less direct western end of the Straits.

The scientific party will number 10-12, including 3 techs and 4-5 Scripps students, plus possible
Chilean participants.