Also in this section...

Introduction

Equipment on board

Cruise science

Equipment and instruments



Equipment and instruments

In order to carry out the scientific investigations, RRS Charles Darwin is carrying some expensive and highly specialised equipment.

Bathymetry

In the marine environment, the best way to get an idea of what the seafloor looks like is to use sound instead of light to build up an image of the seafloor. The team aboard Darwin will use an instrument called the EM12 Multibeam which is mounted on the hull of the ship to bounce sound waves off the seabed. The reflected soundwaves are recorded and used to construct an image of the seafloor.

Water chemistry

As well as magma, mid ocean ridges commonly expel hot, mineral-rich fluids through hydrothermal vents. The vent fluids are very different in composition and temperature from the surrounding seawater, so by using a CTD (Conductivity-Temperature-Depth) instrument which measures the physical properties of seawater, the location of hydrothermal plumes can be detected.
Another instrument used to "sniff out" hydrothermal plumes is the Pacific Marine Environment Laboratory's Miniature Autonomous Plume Recorder, known as a PMEL MAPR for short. This instrument records temperature, pressure and optical data from seawater and is attached to the dredge (see below) as it descends to the seafloor.

Rock samples

A key part of the scientific investigation involves taking samples of the rocks that make up the Carlsberg Ridge. As the ridge is between 2500m and 3500m below the surface of the ocean, it's not an easy job! A weighted dredge is lowered over the side of the ship on a cable, and pieces of rock are scraped up from the seabed. Biology samples are also taken with this instrument.

Another piece of equipment, a rock chipper, may also be used to bring up rock samples from the seafloor. The picture on the bottom left shows a rock chipper being lowered over the side of the ship.



© CDSP 2003