Alvin 3362

23 February 1999
Pilot: D. Foster
Port: Cindy Van Dover
Stbd: Eric Bergmanis

TIME DEPTH HDG Observations
0842 1052 094 Maggie Spin
0849 End Maggie Spins
0942 Approaching bottom; broken, platey lobates
0959 2582 032 On bottom, took sample of collapse edge from lobate
1012 Finished sampling, heading toward Rehu Marka; over lobates
1013 2583 080 Budded lobates morphing almost to pillows; older stuff with fractures then elongate pillows and back into budded lobates
1015 2580 083 Lobate flow; some hydrothermal sediment in very small pockets
1017 Still older lobate with dandelions
1018 Solitary pillows among lobates; dense dead serpulid tubes, anemones increasing
1019 Small mussel patches; Alvin dive wt; all among dead serpulids, some stalked barnacles; where there are mussels, they are ~25% dead
1022 Continuing through dead serpulids and; no mussels or serpulids, no Phymorhynchus or brachyurans
1023 Dense orange anemones, more fish; serpulids absent, barnacles absent
1025 Still in inactive vent field at x/y for Rehu Marka; heading to WP3
1027 To heading of due N, for WP3; budded lobate turning to pillow with dense anemones, occasional fish, occasional galatheid.
1028 Anemone bed with abundant Phymorhynchus and their egg capsules; back into serpulid area. Continuous coverage of vent-like system since 10:19 am. Live barnacles, mussels. Live serpulids here.
1030 2580 004 Over dense barnacle bushes; mussel patches 50% dead; no clams in sight, purple cucumbers
1031 Extensive bed of dead and dying mussels, dirty barnacles; with very local patches of aactive diffuse flow and "healthier"-looking mussels. This place looks more alive than Animal Farm, but not by much. Oasis is by far the more active of the three main biology sites on this dive series. Buddha's Place beats them all, but was not sampled effectively (1 sample only).
1039 2581 000 Small patch of mussels with shimmering water, with dead mussels adjacent.
1041 2581 Sampling at Rehu Marka Site 1. X = 1180, Y = 243. T in mussels = 9.5C. Live, happy mussels have byssal attachments; dead and dying mussels lack byssal threads and lie next to each other as a single layer rather than as a mound. Ophiuroids among the live mussels. Took 3 pots, 1 scoop box from here. (One pot didn't work.) CLVD now on stbd dive through remainder of dive.
1155 8 m away from black smoker x 1170 y 254
1158 Looking for more mussel patches. Some live clams in the area
1206 2581 Setting up at Rehu Marka Site 2. X = 1149, Y = 276. T in mussels 5.5C.
1220 Pot 1 taken; setting up for second pot.
1229 Pot 2 and 3, Site 2 taken
1232 Scoop sample site (very close to pots i.e., 1-2 m). T in mussels 9.2 C.
1318 Scoop sample without scoop/ using manips, 1-2 mussels at a time
1325 Looking for tubeworms at smoker. No luck; decide to do geology since all pots are used and scoop is lost at back of basket. Two mussel bins remain empty.
1327 2581 093 Over biology still. Anemones. Lobates with local collapses.
1329 Local collapses -3-4 m across, with anemones around top margin but not on floor
1330 326 Course to WP4. Anemone density drops; at edge of field
1331 2585 326 Fractured lobate with dense anemones
1333 Anemones, with understory of small dense grey anemones on lobate flow; crossing fiber optic cable of Japanese expt.
1334 Contact? Fingered margin. Lobates onto lobates. Anemones on both old and new flow in equal densities.
1345 2583 259 Sample near WP4; anemone field; heading to WP5
1349 Anemone field, lobate flow.
1350 Broken old lobates with Phymorhynchus, dandelions; with local collapses
1351 Larger collapse network ­ big enough for Alvin
1352 Out of dense anemone field; abundant dandelions
1353 Lobate flow
1357 2583 345 Sampling.
1405 2582 090 Heading to WP6
1407 2581 093 Over lobates with local collapses.
1408 Large collapse region with pillars; rubble in bottom. Flow layers in walls
1413 2586 092 Lobates with high relief giving way to pillows
1414 Robust pillows
1420 2587 085 Into big pillows with buds
1427 Sampling complete
1428 2582 090 Lobates with solitary pillows; very local hydrothermal staining, spaghetti
1431 2588 088 Budded lobates morphing occasionally to pillows
1433 2591 087 Contact? Sediment cover heavier.
1445 2594 Finished sampling pillow bud; changing course to 230 to connect contact
1447 2594 236 Climbing lobates
1448 2598 Over pillows then to budded lobates with considerable relief.
1452 2591 230 Climbing a pillow ridge
1456 2589 Turning to 250; over heavily-dusted lobate
1459 2579 250 Contact with over-drapes onto glassier flow
1500 Last sample; maggie spin at 1000 m.