The Mosquito, aptly named for its titanium needles that penetrate the sediments on the seafloor, was deployed during VISIONS'11 at Southern Hydrate Ridge. It has been in place for over a year now and will be recovered during VISIONS'12 Leg 1. The instrument was designed by UW Professor, Evan Solomon, to measure the rate at which fluids move through the sediment over a specied length of time.
How does it work?
The Mosquito uses osmotic pumps called OsmoSamplers and a tracer injection device to continuously measure fluid flow rates and solute fluxes at multiple depths below the seafloor. The OsmoSampler pump is the "heart" of the Mosquito and consists of two chambers – one filled with distilled water and the other with saturated saline solution. A small diameter Teflon coil is filled with de-gassed distilled water and then connected to the distilled water chamber. The osmostic pressure drives a net flow of distilled water across the membranes to the saturated saline chamber, and continuously pulls distilled water though the Teflon tubing and samples in situ pore fluids in the sediment at the other end. After recover, the tubing is divded into sections of appropriate length for chemical analyses and desired temporal resolution.