What's Happening Today - Nov. 30

We've been hustling all day with camera tows, rock cores and getting ABE off on its last dive of this expedition. As the data from ABE is processed and analyzed we continually modify our strategy for how to best use the remaining time. The past few ABE dives have suffered slightly from bad acoustics. Basically this means that when ABE is navigating itself on the seafloor using the transponders it sometimes has trouble calculating its position, either because it is too far or close to a baseline between two transponders (it needs a minimum of two transponders to calculate a fix), or because some feature is in the way of the sound path between ABE and a transponder. This latter problem is called acoustic shadowing and it is the nemisis of deep submergence operations and science.

After we recognized that ABE was having problems navigating at the begining of Dive#61 this morning, Dana and Al put their heads together and came up with a new plan and a way to tweak ABE 's navigation systems and software. One good thing about recalling ABE from Dive#61 is that Al and Dana were able to use their system of command codes to abort the mission. This is the first time this has been done on purpose and a great testament to the superb engineering that has gone into ABE.

The ABE group, assisted by the ship's crew, worked like a pit-crew at a motor car race when it came on board so that it could be prepared for another dive in record time - just under 1.5 hours. As I type, ABE is chugging along, doing what it does best - collecting data to produce the best and most detailed maps of the seafloor ever made.

Best Regards,

Dan Fornari

Paul Johnson created this image of the ABE micro-bathymetry map overlaid on the DSL-120A sidescan sonar imagery. The crenulated lobes, seen clearly in the bathymetry and sidescan data and that extend east of the East Pacific Rise axis, are lava flows that erupted at the axis and flowed east down the ridge flank. The red dots are rock core samples that Dan Fornari and Mike Perfit have collected over the years. Having the sonar data will help enormously in interpreting the geochemical data on the lavas.

3-D perspectives of the ABE micro-bathymetry (top) and the DSL-120A sidescan sonar imagery for the East Pacific Rise axis area at 9° 50'N covered in the first image (above). View is to the northwest, North is to the right corner of the image. Paul Johnson created these images.

3-D perspectives of the ABE micro-bathymetry (top) and the DSL-120A sidescan sonar imagery for the East Pacific Rise axis area at 9° 50'N covered in the first image (above). View is to the southwest, North is to the right of the image. Paul Johnson created these images.

Bob Waters, one of the DSOG electrical techs. working on equipment in the Alvin ET shop.

Christina Courcier, one of the SSSG techs., and Tim Logan, the ComET tech., working on the satellite telephone equipment.

Brook Stembridge got some ship driving lessons from Craig Dickson, the 2nd Mate, and Ed 'Catfish' Popowitz, an Able Seaman.

The foam creation made by the students for Dan Fornari and shrunk on today's camera lowering. There are over a dozen beasts of various kinds on there.... thanks to all of you who made this- it will have a special place on my office bookshelf with other cruise memorabilia.

Rod Catanach cleaning the pool.

Tony Tarrantino, one of the Alvin electrical techs., working on equipment for the next diving program in the Alvin ET shop.

The next few photographs are of a curtain folded sheet flow surveyed by the Towed Camera THING on Tow#12 today. They are displayed in the order they were recorded -you can see some of the same features at the edges of successive photos. The two lines on either side of the image are connected to trial rock core heads that Andy Billings made.

This photo and the blow up of the upper left corner shown in the next photo provides a clear indication that this lava flow travelled towards the lower left corner of the image. The 'boomerang' shaped fold in the lava was broken after it solidified and moved with the surface crust slightly causing the kink in the fold.

Blow up of the upper left corner of previous image showing the kinked fold in the lava surface.

A large scarp exposing pillow lava traversed at the end of Camera Tow #11. This feature is about 3 kilometers west of the East Pacific Rise axis near 9° 28'N.

Pillow lava photographed on Camera Tow#11. White ball at upper right is the trial rock corer Andy Billings is testing.

The digital camera we are using can take color photographs too. I've set it on black&white beause we are imaging largely monochromatic features and the also can store more black&white images. In this photo you can see the two core heads Andy Billings is testing as they fly over a collapse feature. A large anemone is hanging on the edge of the collapse at middle left. I've blown up a part of the original image file in the next photograph to show the high quality of the digital imagery.

Blow up of the anemone on the collapse feature edge shown in the previous photo. The monofilament line and the rock core head cut through the top of the image.