Date: 3/21/96 5:48 PM
From: Diane Baxter
Hi, Darlene! Here's a sample of the reports sent in weekly from SIO research vessels and printed in the SIO-wide newsletter. Do you think these would be of interest to teachers/students? db
R/V MELVILLE, Weekly Report - Boomerang Leg 6, Southeast Indian Ridge, March 12-19, 1996: Our survey and sampling efforts during the first half of this past week concentrated on a small, approximately 80 km wide and previously unknown microplate just to the south of the Amsterdam-St. Paul hotspot platform. Its boundaries are formed by a textbook propagating rift, with at least 2 episodes of propagation, and another spreading center illustrating various stages of demise - between these spreading centers is a complex zone of rotated and sheared crust. We collected 15 dredge and waxcores, on-average every 12 km along the spreading boundaries. These should yield considerable insight into both the variability of shallow-level magmatic processes along these ridges and deeper-seated mantle interactions between mid-ocean ridge and hotspot flow. On Thursday, we had a major power failure due to a blown panel in the electrical system. The tireless work of those in the engine department in bringing about a bypass operation revived power 24 hours later, and about 36 hours after the initial failure, we were back to doing science. We were very fortunate that the winds and seas were light during our time adrift.
During the latter part of the week, we surveyed two ridge segments on the Amsterdam-St. Paul platform. Completed patterns of reflective seafloor and magnetic anomalies reflect the complicated patterns of crustal generation here. Today, we collected 7 samples and came up empty on two waxcores on these spreading centers. This past week also marked the anniversary of the first sighting of Amsterdam Island, on March 18, 1552, by Elcano and the small party which completed Magellan's famous voyage. Fittingly, we've gained the company of three Amsterdam albatrosses, a species discovered only in 1983, when 8 breed pairs were known. Tonight we celebrate hump day and look forward to continued smooth sailing and exciting surveys and sampling. (Kevin Johnson/Dan Scheirer)
The section below (also included in the weekly newsletter) is used to plot the ships' courses and keep people posted on which ships are in and out of port. I don't know if it would be of interest to students or teachers, but it's easy to get and share. db
CRUISE MAP INDEX/AREA/ CH SCI/INSTITUTION/ PORTS DAYS/AGENCY/ DATES PURPOSE/ PROPOSAL NO./ STATUS/CLEAR CAPTAIN/CHIEF ENGINEER/STS TECH
R/V MELVILLE
22 Feb IN3-7/ 42-32S 77-91E/ Johnson, K./SOEST/ Fremantle 59/NSF/F 15 Apr SB,dredging, mag, grav OCE94-15948 Port Hedland France E.Buck/O.Ames/G.Pillard