14 October, 1997

14 October 97

REGIONAL WEATHER SUMMARY...Fine weather will persist about the McMurdo area today as an high pressure area dominates the Ross Ice Shelf.

TODAY and TONIGHT...Mostly cloudy.

Visibility: Unrestricted.

Wind (knots): Northeast 10 to 15.

High -08C/+18F. Lowest Wind-chill -26C/-15F

Low -14C/+07F Lowest Wind-chill -28C/-18F

WEDNESDAY...Mostly cloudy.

Visibility: Unrestricted.

Wind (knots): Northeast 10 to 15.

High -12C/+10F. Lowest Wind-chill -28C/-18F

SCOTT BASE 24HR TEMPERATURE FORECAST

High Today -10 Low Tonight -20.

YESTERDAY'S EXTREMES - 13 October, 1997

Maximum Temperature: -6C/+21F

Minimum Temperature: -9C/+16F

Peak Wind: 58 KNOTS

Lowest wind chill: -36

We took advantage of the gorgeous weather today to go to Little Razorback Island near Cape Evans. A drilling crew made several holes in the ice and set up a hut to prepare the site for the divers. As we drove along in the track vehicle (Spryte) we passed the long narrow tongue of the Mt. Erebus floating glacier that I spoke of in the 11 October journal entry.

The dive site itself is located such that Ross Island's active volcano, Mt. Erebus, looms in the background. A pair of huge Weddell Seals had surfaced through cracks in the ice near Little Razorback and were lying on the ice. We were able to get close enough without disturbing them so that we could take a few pictures. After the holes were drilled and the hut was in place we had lunch.

The hut was positioned directly above one of the holes so that the divers may enter and leave the water from inside. It was possible to look down into the hole and see the animals on the ocean floor. The water was a beautiful deep blue color and crystal clear. Starfish, isopods, sea urchins, and Parbolasia worms are members of this benthic community which could be clearly seen from the surface 82 feet away.

The Parbolasia were fascinating to watch. They are scavengers which my get up to 6 feet in length and are members of a group of organisms called Nemertea. These are simpler organisms than the earthworms we are so familiar with. Their bodies are not divided into segments lack a coelom.

Things to ponder:

1. Find out more about nemertine worms from a book on invertebrate zoology or from the internet.

2. What is a coelom?

3. What are isopods?

4. Where do benthic organisms live?