Dearest Anais,

A storm approaches

Today is the third day in a row that we have been unable to launch ALVIN or Jason because it was too rough and the wind was blowing too hard. So naturally we are a bit frustrated.

The only thing we have been able to do is to collect water samples. Water...hmmm. You would think that to collect water all you'd do is throw a bucket over the side and retrieve it--we are not, after all, lacking for water out here. But no, the water freaks are not satisfied with that. Instead over the side goes this complicated contraption that collects many different samples at different depths and also measures the temperature and other properties.

The Nova crew

That's because ocean water is actually rather complex-- think of it as soup. Of course it contains a lot of salt. In fact it has several different kinds of salt, most of which you are not familiar with since we don't use them. To make matters more complicated, you can't actually see these other chemicals in water for the same reason you can't see the salt in water--the stuff is dissolved. There are also some things in ocean water that you never dreamed of. For example, there is a minuscule amount of gold in sea water! Basically, sea water contains a little bit of almost everything.

Stowed for the storm

You might be wondering where all the stuff in sea water comes from. The answer is land. All the water that falls as rain carries dirt, gravel, garbage--everything you have seen being carried in a river and stream or down the street when it rains--ends up in the ocean. Things are taken out of the ocean too. For example, animals with shells make their shells out of a chemical called calcium carbonate, which they get out of sea water. So if there were no calcium carbonate in water, there would be no animals with shells.

Actually, it is not completely true that the ocean gets everything from land. It also gets some chemicals from the vents that we are studying. Now that I think about it, tons of dust from outer space also lands in the ocean every day. But that's another story...To return to the vents, the hot water that comes out of them carries all sorts of weird stuff, including chemicals that bacteria eat. The water that comes out of the vents disperses in the ocean as smoke from a fire disperses in the air. So one of the important reasons that we take lots of samples of water and measure temperature is to find the clouds of vent water, which in turn helps us find the vents themselves.

Margaret Carruthers

Okay, that's enough about water for one night. Perhaps this will give you something to think about next time you drink a glass of water.

Love, Papa