1995 ALVIN DIVES (North Cleft, Axial, CoAxial segments) Present filename Dive location ALV2940.GPS COAXIAL (Flow site - extensometer - Chadwick/Meinig) ALV2945.GPS COAXIAL (Source site - Lupton/Jonasson) ALV2946.GPS COAXIAL (Floc site - Delaney/Roe) ALV2947.GPS COAXIAL (Floc site - Holden/Tunnicliffe) ALV2948.GPS COAXIAL (Floc site - Chadwick/Smith) ALV2949.GPS COAXIAL (Floc site - Embley/Lilley) ALV2951.GPS COAXIAL (Floc site - Wright/Holden) ------------------------------------------------------------------------ Notes on all dives: We have used the 1995 navigation as a datum for CoAxial Floc site, CoAxial Source site, and N. Cleft, and all previous Alvin dives in these areas have been shifted to match the 1995 navigation and marker positions. All files have been processed with [chadwick.programs]navskip to eliminate redundant nav records (note this was done on the latlng/alvinxy files looking for redundant xy's ... this eliminates fewer records than just looking at the lat/lngs since the xy's have more resolution). ------------------------------------------------------------------------ Notes on specific Alvin dives: Dive 2943: Surface nav only (one fix per minute). The threshold on the nav box was not set properly so the sub could not hear the 13.5 kHz transponder until they were returning to the surface. Dive 2946: The hard disk on the in-sub computer filled up half way through the dive (due to human error) and so the Alvin data logger stopped logging data. We recovered the in-sub navigation for the 2nd half of the dive from the Alvin video. Dive 2949: Both altimeters stopped working right after the sub got to the bottom on this dive. The microbathymetry files are faked for this dive. Dive 2951: This dive was reconstructed in 4 parts: 1) 09:05-09:36 was replayed with xp 10.0/7.5 (which provided better nav with no shift from the original 8.5/7.5 xp), 2) 09:36-10:51 is original nav (8.5/7.5), 3) 10:51-14:00 is shifted original nav (-9x/-3y) - during this interval they switched to xp 8.5/10.0 while working at HDV vent (a place that can't hear the 7.5) which provided good nav, but with a shift from the rest of the dive, 4) 14:00-14:55 original nav (8.5/7.5). ------------------------------------------------------------------------ Questions?? Contact Bill Chadwick (chadwick@new.pmel.noaa.gov) or Julia Getsiv (getsiv@new.pmel.noaa.gov)