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Into the swing of things

Since being at sea, the time has flown by and we now find ourselves five days into the cruise. I am now fully into the swing of things, although it did take a few days to adjust. All the days seem to have merged, and it feels like this week has been one long busy day!

Over the first day or so, we sailed north from Trinidad, to the west of the island arc past Grenada, St. Vincent, St. Lucia and Martinique. On this stretch, the DEPAS team deployed 4 OBS, and the SCRIPPS team deployed 1 OBS in the Grenada Trough and the back arc. The sea was amazingly flat in the Caribbean sea but as we crossed the arc between Martinique and Dominica and reached the Atlantic side, the swell picked up a little. This resulted in a day of feeling pretty queasy and a little bit useless, but after a nights sleep I felt much better and was able to move around without feeling bad. On the Atlantic side, we turned south, deploying another 8 OBS, in the trench, along the forearc and the Tobago Trough.

DEAPS OBS deployment (left) and SCRIPPS OBS (right). The two instruments look very different. The white arm on the SCRIPPS instrument releases the green ball when it hits the seabed and records lower frequencies than the other
type.

Yesterday we turned north again and passed through the Grenadines (series of smaller volcanic islands north of Grenada). Here, we carried out a swath survey of Kick ’em Jenny (a submarine volcano located 8km north of Grenada). This is the only currently active submarine volcano in the Lesser Antilles, although it is also the most active volcano in the arc. The depth to the top of the crater has remained constant at 180-190m for sometime, but there was reported unrest and two eruptions in July 2015 so we wanted to carry out a bathymetric study to sea if the edifice had changed from the last time it was imaged. As a volcanologist, the survey was very exciting for me to see and I cant wait until we process the new data. We are now back into the flow of deploying OBS with a few very busy days for the DEPAS team coming up.

Diamond Island (left) and Ronde (right) at dawn. Kick em’ Jenny lies beneath the water here.

I wasn’t sure what I would be doing whilst onboard and on watch. Most of the time, my job is to check the status of the monitors in the main lab. Here, we can assess and adjust the deep water swath, the shallow water multibeam, the single beam echosounder, the sub bottom profiler, the magnetometer (when deployed between OBS stations), as well as keeping up to date with the ships location and schedule for the day. The time when I am not on watch mainly involves eating; there is so much good food available, it is very hard to say no to three large meals a day. Today, because its Saturday, there are morning cakes and curry for dinner. All the eating has led me to brave the treadmill in the gym, which was made more interesting by the swell!

Lots of monitors in the main lab to keep an eye on.

I have been surprised at how little wildlife there has been at sea and I have only spotted the odd sea bird diving for fish. However it is still great to get out on deck, particularly when the sun is rising and setting.

Caribbean sunset