December 5, 1999

Dave DeMaster and Sue Boehme prepare a kasten core.

We shuffed into the galley at about 11:45pm for "midrats," the midnight meal for the moonlighters on the graveyard shift. People have been getting some sleep, but the days are blurring into sequences of coring activities and the quick summer transitions from day to night and back to day. Most everyone his still in pretty good spirits, although fatigue has shortened a few tempers. Lab experiments and the competition for who gets what cores and at what time, relative to the precious moments of sleep time, have lead to the odd snit and black look. Humour will out in most cases and a spirit of friendly competition between watches has emerged. We have all struggled against the swell and against very soft, soupy and juicy sediments to obtain good boxcores. This seems to be the least forgiving and the success of a watch is increasingly measured according to the whim of Miss Penelope. At least with the megacores, there is a chance of getting at least 2 out of 8, or better odds. With the boxcore, it is all or nothing. The watches compare notes at hand off time.

Trent Sanamo adjusts the shackles on a kasten core.

This night, we were 50% for boxcores: two beauties, one complete miss and one aborted mess of mud on the deck. The megacoring went well with one scratch and one success: 9 out of 12 tubes coming up roses. By lunch there was still one sampling tube unclaimed! This stuff is like gold...

We had a little variety to the rotation of box and megacores. At each station, 1-2 kasten cores are deployed. The kasten core is perhaps the most simple and straightforward of the three type being deployed on this cruise. It is essentially a 3 metre stainless steel channel, with a series of removable panels on one side. At one end there is a detachable "bit" with bevelled edges for cutting into sediment; this has two trap doors which swing shut when the core is pulled from the sediment. At the other end, a shackle assembly with a series of lead weights provides the push to send the core 2-3 metres deep into the seabed. Another set of lead weights is attached by ropes and extends to the bit in order to stabilize the core when it strikes the sediment: countering the top heavy force.

Liz Galley prepares samples from a megacore in the aquarium lab.