SCIMPI: A New Seafloor Observatory System

Abstract

The Simple Cabled Instrument for Measuring Properties In Situ (SCIMPI) is a proposed new long-term seafloor observatory system for sub-seafloor studies. The SCIMPI sensors, initially proposed, include temperature sensors, resistivity sensors, and pore pressure transducers. The design easily accommodates integration of other sensors (e.g., geophones, X-ray fluorescence, spectrophotometry). SCIMPI can be deployed autonomously with a battery and data module for 1-2 year deployments or connected to a seafloor fiber optic cable for real time data streaming. Applications include the study of subseafloor hydrological and deep biosphere studies; pore pressure measurements for hazards assessments; long-term temperature measurements; and earthquake monitoring. Potential near-term SCIMPI sites include Monterey Bay, Cascadia Margin and the Gulf of Mexico. In Monterey Bay, SCIMPI is proposed to be part of the Monterey Accelerated Research System (MARS) cabled observatory. On Cascadia Margin, SCIMPIs are proposed to be part of a cabled observatory, and are specifically targeted for a location called Hydrate Ridge. Hydrate Ridge studies are focused on understanding the mechanisms, rates, and extent of methane hydrate formation in this area. SCIMPIs at Hydrate Ridge will measure temperature, pore pressure, electrical resistivity, and micro-seismicity. The proposed plan is to install SCIMPIs by the IODP and then link the SCIMPI observatories into the Regional Cabled Observatory in the ORION program. Potential Gulf of Mexico sites are in the deep water environments where overpressures have been observed in shallowly buried, loose sand deposits.

Reanalysis ofin situpermeability measurements in the Barbados décollement

“…Thus, even significant disturbance of the surrounding formation during borehole installation such as occurred at Hole 949C and filling the casing with mud as was done at Hole 948D did not affect the validity of the long-term pressure measurements. These results bode well for the potential use in long-term pressure monitoring of simple systems installed in uncased holes relying on formation collapse around the sensors (Moran et al 2006). Design issues for high frequency pressure records may differ from those required for longer-term averages.…”

Nature and Extent of the Deep Biosphere

“…Elsewhere, sampling devices are placed into drill holes or squeezed into casing and allowed to incubate in place in order to sample indigenous microbes. So-called CORKs or SCIMPIs (Davis et al 1992;Moran et al 2006) are used in the seafloor and parallel the multi-level samplers (Smith et al 1991;Lehman et al 2004), in situ flow cells (Nielsen et al 2006), and flow through in situ reactors (FTISR) (Lehman 2007) used in the continental subsurface. Hybrids of these technologies and ingenious smaller systems that are deployed using clever means by which to sample microbes and chemistry include passive gas samplers (Spalding and Watson 2006), U-tube systems (Freifeld et al 2005), and the ever-changing osmosampler (Orcutt et al 2010).…”

Submarine Mass Movements and Their Consequences

“…The ODP and IODP have installed a series of observatory systems within boreholes, but these are designed for deeper reservoirs/faults zones. Substantial modifications and engineering development is underway (Moran et al 2006) for the required measurements and monitoring in shallow sediments.…”