Dive and Discover : Expedition 1 : Daily Updates

Daily Update: Dive 3518
January 15, 2000
By Dr. Dan Fornari and Dr. Susan Humphris

With the wind at only 10-13 knots and the seas calm, it was a wonderful day to be working at sea. It is especially nice for those of us who live on the East Coast of the US where we hear that it is freezing and has snowed the past few days. Most of us are wearing shorts and t-shirts.

We have seen several pods of pilot whales since we left Guaymas. Each day some of the other local whales visit us. This area is a famous breeding ground for California gray whales. From January to April, these whales travel south from the Bering Sea and Gulf of Alaska to Baja California in order to mate and give birth.

Today, Susan, Dan, Steve, and "Fast" Ed Popowitz (the boat driver) set out in the Avon to identify some of the larger whales. We brought a small hydrophone to record whale sounds. A hydrophone is a microphone that is designed to record sounds while underwater. We got close enough to one of the big whales to identify it as a fin whale, but the whale didn't feel like talking to us. We'll continue our attempts to record whale sounds over the next few days. Check back to see if we're successful!

The routines on the ship are now pretty much established. All the scientists and students know their jobs and have settled into the rhythm of shipboard life. The biologists and microbiologists worked late last night cutting up and photographing the different worms, preserving samples in different chemicals for future analysis back on shore, and freezing other samples for future genetic analysis. The chemists prepared the electrodes for the chemical sensors and installed the science equipment on Alvin.

Dive Summary
On Bottom: 0911 hrs
Off Bottom:1538 hrs.
Maximum Depth: 2003 m

Steve Faluotico piloted today's dive, #3518. Martial Taillefert and Phil Taylor went as observers. Their principal objective was to return to some of the previous vent sites and collect more samples of sulfides, microbes, and worms. (Everybody thought the samples from yesterday's dive were so great, they wanted more!) Martial and Phil also wanted to conduct additional experiments using the Sipper and the chemical sensors. They also planned to repeat some of the measurements to make sure the instruments were working properly. When doing experiments of any kind, it is always important to duplicate the results. The chemical sensors worked well. George Luther, Don Nuzzio, Martial, Liz McCliment and Tim Rozan, all of whom are involved in the electrochemistry work, are happy with the results.

But as often happens when doing science at sea, there were problems and challenges. One problem that still has to be solved is the inability to bring back undisturbed cores of mud. So far Alvin has brought up a few cores, but they have been stirred up. One of the unusual features of the Guaymas Basin is the thick sediment layer covering the seafloor. The hydrothermal fluids flow up through this layer, heating the sediment. Organic matter within the heated sediment breaks down into methane and hydrocarbons (petroleum products). When a core of mud is brought up to the surface, these gases bubble out, disturbing the layering in the sediment. George and his group are thinking of ways to get around this problem so they can make the measurements and perform the experiments they had planned.

A special event capped the end of the dive. This dive was Phil Taylor's first. He emerged from the sub and received the ritual dowsing of chilled seawater.