May 16 - Arriving in Antigua
Noon Position : lat 16 53.5 N: long 62 04.0 W
Course made good: variable
Air temperature @ noon today : 28.8 degrees C
Sea temperature @ noon today : 27.2 degrees C
Wind: Direction: SE , Force 3
Arriving in Antigua
Here we are in the Caribbean! I guess that not many Antarctic ships get to visit these waters, it's certainly a lot different to FIPASS and Stanley. The island of Antigua is about 20 miles long and 5 miles wide. The temperature at the moment is nearing 30 degrees and it is raining. Most of the time, though the sun shines and we are all roasting in this unaccustomed heat. Fortunately we are cooled by the trade winds on most days. The combination of calm seas, good weather and trade winds means that this is a major centre for sailing yachts. We have just missed Antigua Sailing Week, it finished last week, but there are still plenty of sailing ships around as you can see below.
Science and Volcanoes
Having arrived at Saint Johns we picked up the scientific team and headed across the water for Montserrat. This has to be the shortest time to start of cruise ever, 2 hours! Before we started getting muddy we invited the Governor, Minister and head scientist of Montserrat aboard to have a look around this research ship and discuss the things that we would be doing. Steve Sparks, the Principal Scientific Officer has written a short piece to explain the science that we are doing at the moment.
JR123 Exploring the flanks of an active volcano
A major eruption of Soufriere Hills volcano on the island of
Montserrat in the Caribbean took place between 1995 and 2003. More
than half a cubic kilometre of magma has been erupted, making this
one of the most significant volcanic eruptions of the last few
decades. Much of the volcanic material erupted has been transported
into the sea due to large collapses of the volcanic andesite dome
that grew during the eruption. The World’s largest collapse
of a lava dome took place on 12 July 2003 when the entire erupted
material avalanched into the sea over a 5 hour period. (photos 1
& 2) Cruise JR123 of the James Clark Ross aims at finding how
this material is distributed in the ocean, getting new information
about the volcanic history of Montserrat and understanding the
major geological processes that build volcanic islands.
Photo 1. The andesite lava dome of the Soufriere Hills volcano on 31st May 2003. The dome had grown continuously since 29th July 2001and had a height of 1100 metres above sea level and an estimated volume of about 200 million cubic metres of rock. (Image courtesy of Monserrat Volcanic Observatory).
Photo 2. The dome collapsed over a five-hour period on 12th July
2003 forming a major collapse depression (scar) in the volcano.
Almost all the dome and some of the older edifice slid into the
sea. (Image courtesy of MVO).
The distribution of the new submarine deposits around Montserrat
has been successfully established using the ship’s swath
bathymetry system, comparing the new survey to surveys by
colleagues from Paris in 1999 and 2002 (figs 3, 4). Over 30
sediment cores have been collected so far, using the vibrocorer
developed by the British Geological Survey. The new cores and
bathymetry data show that there have been a number of huge
submarine landslides off the coast of Montserrat that can be
related to volcanic activity. The sediment samples will allow the
ages of the landslides and major eruptions of the Soufriere Hills
volcano to be determined. One of the major questions in volcanology
is what happens when hot volcanic flows move from land into the
ocean. JR123 results have established that the hot flows mix
violently with sea-water. During the mixing, coarse fragments and
sand separate from the fine sand and silt to form two separate
types of flow. The coarse material avalanches down the submarine
flanks to form linear ridges of new deposits up to 60 metres thick
and extending about 8 km offshore. The suspension of fine sand,
silt and volcanic dust then travels to distances of at least 30
The cruise also involves a pilot geochemical study of the effects of fine volcanic ash on the chemistry of seawater. The results confirm that volcanic ash is highly reactive and may have a significant influence on ocean chemistry.
Relaxing in the Sunshine
As well as working in the heat we have all managed to have some time off ashore. Antigua supposedly has 365 beaches, one for each day of the year. We haven't managed to visit even a tenth yet, but we've certainly liked the ones we have seen.
Malcom Hart (one of our scientists) has asked if his travelling companion can get his photo onto the web page.....
So, here is Barnaby Bear, from Montpelier Infants School in Plymouth (UK). He has joined the RRS James Clark Ross on cruise123 to Antigua and Montserrat. He wanted to learn about research ships and to visit the town of Plymouth on the island of Montserrat to see the damage caused by the Soufriere Hills volcano. If you enlarge the picture and look carefully you will see the houses of Plymouth in the background.
This is it, my last web page. In a final attempt to out-jolly all other doctors I am paying off in Antigua and the crew will be sailing home without me. Next week the boys will be in the mid-Atlantic and I'm sure there will be a guest editor to tell you what they're up to without me. I will be catching up with them in Portland, when they come alongside in the UK.
I hope that you have all enjoyed this Antarctic season as much as I have.