AL4593 Starboard Observer (Mark Behn) Transcript & Notes:
1630: (X = 26523, Y = 7810, depth = 2855 m, 27º) On the bottom. Heavily sedimented
pillows w/ fissure running perpendicularly to the sub. Pillows appear somewhat
elongated.
1637: Took hand held shot.
1647: Sub is neutrally buoyant.
1652: Maneuvering to take sample.
1654: Arm out, grabbed small piece of crust (Sample 1a)
1656: Switched to basket cam. Mike took handheld photo of sample.
1658: Dropped Sample 1a into basket location 1a.
1659: Mike grabbed another larger pillow and took handheld photo (Sample 1b)
1701: Dropped Sample 1b into basket location 1a.
1702: Switched back to starboard pan & shoot camera.
1703: Heading toward waypoint #2
1705: Moving over pillows. Pillows are elongated w/ some decoration.
1710: Climbing pillows toward waypoint #2. Less sediment as we move higher up the
hill.
1715: More pillows, fewer ornaments, no apparent faulting/fissuring.
1717: Rather than continuing to the top of small seamount to waypoint #2, we decide to
go eastward (~80º) along ridge following a contour.
1723: More sediment on pillows in several large pockets.
1730: (X=26846, Y = 7602, depth = 2827) Stopped to take sample of pillows. Switched
to basket cam.
1731: Mike grabs pillow & takes photo with handheld.
1732: Placed Sample 2 in basket 1B.
1733: Took handheld photo of sampling location
1739: Decided to take second pillow sample in same location. Mike took photo with
handheld (Sample 3) and dropped into Basket 4b.
1741: Switched to starboard pan & shoot and started moving toward waypoint #3.
1747: Continuing straight toward waypoint #3, moving over heavy (nearly continuous)
sediment.
1749: Moving back into outcrop, mostly pillows.
1752: (X=26994, Y = 7627) Flew off small ridge and lost sight of bottom. Rather than
searching for bottom, we will continue straight toward large seamount.
1758: Coming up on west wall of seamount. Can see the bottom. Relatively heavy
sediment, with tallus and some emplaced material. Tallus blocks are 0.5–1 m in
diameter.
1801: (X=27210, Y = 7647) Climbing through tallus that is fairly sediment covered.
1806: (X = 27300, Y = 7659) Moving up tallus slope, made primarily of pillow fragments
but with less sediment than below.
1808: Elongated tallus ridge on starboard side of sub.
1811: (X = 27380, Y = 7671) Tallus/pillow fragments with slightly more sediment.
1816: (X = 27492, Y = 7678, depth = 2696) Tallus/pillow fragments with light sediment
cover.
1818: Moving over larger tallus blocks (1–2 m)
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Dive AL4593
3/19/10
1823: Back in smaller tallus blocks (0.5–1 m)
1824: (X = 27625, Y = 7679, depth = 2614) Move out of tallus and up into outcrop.
Shear wall cut through pillows, can see classic pillow morphology in wall. Mike
switched starboard point & shoot cam to point up to make sure nothing was over
us.
1828: (X = 27642, Y = 7679, depth = 2599) Relatively shear cliff to starboard.
1830: Adjusted starboard pan & shoot back to point forward. Topography is flattening
with some sediment cover.
1832: (X = 27707, Y = 7673, depth = 2593) We are at the western edge of the graben
coming up onto the top of the seamount. Continuous sediment over relatively
large pillows. Stopping to take a sample.
1846: Waited for several minutes, but too much silt was kicked up when we set down to
sample. Ate lunch.
1853: (X = 27796, Y = 7690, depth = 2583) Moving over 2-3 m pillows, with moderate
sediment.
1855: Coming up on crevasse, with shear wall just beyond. Possibly the wall of the
northern wall of the graben. A jumbled sheet flow appears to be flowing down
out of the graben. Sheet flow is mixed with pillows covered by moderate
sediment.
1900: (X = 27831, Y = 7682, depth = 2583) Stopping to take sample of sheet flow.
1902: Took 2 handheld pictures of sheet flow out the window. Switched to basket cam.
1903: Mike picks up piece of sheet flow, takes handheld shot, and placed Sample 4 in
basket 5a.
1906: Moving toward waypoint #3. Switched back to starboard pan & shoot.
1913: (X = 27843, Y = 7686, depth = 2572) Climbing up a series of steep fault steps.
Each step has similar characteristics – a 4+ m crevasse followed by a sheer wall
and then flat area of pillows at the top.
1917: (X = 27930, Y = 7705) Coming out of graben into pillows with sediment pockets.
1918: Moving over jumbled sheet flow, possible same sheet flow as the first one we saw.
1919: Moving into more pillows, sheet flow disappears off to starboard. Pillows are 1-3
m and show no distinct elongation direction, sediment is collected in pockets.
1923: (X = 28012, Y = 7707, depth = 2557) Stopped to take a sample just shy of
waypoint #3. Switched to basket cam.
1926: Mike took pillow sample, took photo, and placed Sample 5 in basket 5b. Switched
back to starboard pan & shoot cam.
1928: Heading south toward waypoint #4.
1933: Crossing sheet flow.
1934: (X = 28030, Y = 7649) Lost bottom as we came over large scarp. Altimeter shows
the scarp to be ~18 m.
1940: Bottom coming back into view. ~1m pillows with sediment in pockets, in places
pockets are rather large.
1943: Arrived at waypoint #4. Moderate to high sedimentation (greater sedimentation
than in area with sheet flow).
1945: (X = 28080, Y = 7448, depth = 2583) Landed to take sample at base of graben.
Switched to basket cam. Mike took pillow sample, took photo, and placed
Sample 6 in basket 2b.
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Dive AL4593
3/19/10
1950: Heading south toward waypoint #5. Switched back to starboard pan & shoot cam.
1954: (X = 28069, Y = 7395) Pillows with small fissures running through them.
1955: More fissures cutting pillows. Crevasses are ≥ 5 m deep.
1958: Continuing through fissures. Sediment in pockets in pillows. Some pillows are
cracked open.
2000: (X = 28043, Y = 7265, depth = 2566) Reached southern graben wall. Going up
wall, which exposes nice cross-section of pillows.
2002: At top of wall and moving over flat sedimented pillows.
2004: Coming up pillow slope, moving over a series of steps with some tallus at the base
of each step.
2006: (X = 28009, Y = 7117) Crossing fissure and reaching wall that exposes more
pillows in cross section.
2007: Reach top of wall.
2009: Large fissure (~4 steps up from base of graben).
2011: Moving over relatively flat well sedimented pillows.
2013: Moving over fissures, coming up on another wall.
2015: (X = 27972, Y = 6900, depth = 2533) Stopped to take sample. Switched to basket
cam.
2020: Mike took large pillow sample, took photo and placed Sample 7 in basket 3b.
Switched back to starboard pan & shoot cam.
2025: Heading south toward waypoint #6.
2032: Coming up on large wall. Lost overlays on all cameras. Mike reset cameras to get
overlays back.
2034: (X = 27951, Y = 6839, depth = 2509) Cleared wall and moving over pillows.
2035: Lost bottom. Rather than descending we decided to fly straight for waypoint #6.
2043: Changed course to 180º to reach ridge with waypoint #6 faster.
2050: Coming up on bottom.
2051: (X = 27866, Y = 6344, depth = 2547) Tallus slope made of pillow fragments (~0.5
m in size).
2054: (X = 27866, Y = 6326, depth = 2544) Scarp exposing pillows. Rising up along
fault wall. Lost camera overlays again.
2058: (X = 27862, Y = 6328, depth = 2520) Coming up over top of wall onto waypoint
#6 ridge. Stopped to take sample. Mike takes pillow sample, takes photo, and
places Sample 8 in basket 4a. Switched basketcam on and off to watch Mike
drop sample in basket.
2103: Rather than continuing to waypoint #7 we decide to go northeast to valley between
seamount and outer wall.
2110: Moved straight out to center of graben and then dropping straight down.
2113: (X = 27967, Y = 6514, depth = 2569). Landed at base of graben in pillows with
some sediment. Mike took 2 pillow samples and took photos. Both Sample 9 &
10 were placed in basket 3a. Switched basket cam on and off while sampling.
Sample 10 was larger than Sample 9.
2120: Dive finished. Heading to the surface.
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