Daniel Possee
Leg 2 is well and truly underway now and if you read Ben’s last post then you’ll already know that we intend to pick up 34 ocean bottom seismometers (OBS) from all around the Lesser Antilles. This Leg sees some changes to the Science party with Nick, Lidong, Steve and Dan joining in Guadeloupe. The OBS recovery efforts are led by the DEPAS (German Pool of Amphibious Seismic Instruments) and SIO (Scripps Institute of Oceanography) technicians Henning, Maria, Mark and Sean who also join the ship. With just 10 days at sea on this, the second of three legs, everyone is thrown straight into their duties with the first OBS recovery scheduled just six hours after leaving port.
For anyone who hasn’t been involved in an OBS recoveries before then you should know they are a tense affair. Leaving something on the sea floor and hoping that you can retrieve it a year later is a risky venture. With this in mind, the first recovery was met with a lot of nervous scientists, all with arms, fingers, legs and toes crossed, knowing that it would set the tone for the remainder of the expedition.
To everyone’s relief, the first recovery was a success, the release mechanism activated allowing the OBS to rise to the surface and the eagle-eyed spotters on the bridge quickly located it upon surfacing. Some deft manoeuvring of the ship and the OBS was soon being winched onto deck. This whole process takes about 1-2 hours depending on the water depth, which increases up to 5,000 m for some of the OBS!
With the first OBS onboard we now OBS hop our way down towards Grenada, then back up to Antigua and Barbuda before making port again in Guadeloupe and, with a bit of luck, a deck load of OBS instruments!