OS34A-01
SCIMPI: A new seafloor observatory system
A new seafloor observatory system design to make subsurface time series measurements of temperature, pressure, and resistivity has been developed. This system, called SCIMPI (Simple Cable Instruments for Measuring Parameters In-situ), incorporates established, modular technology, in a novel way, to capture data from sub-seafloor sensors over long time periods (months to years). For specific uses, the SCIMPI system, once developed, will be a lower-cost alternative (~1/5 the cost) in sedimentary environments to the standard CORKs (Circulation Obviating Retrofit Kits) that currently serve as the backbone of Integrated Ocean Drilling Program (IODP) observatory science. SCIMPI addresses critical infrastructure needs for the IODP. The initial science plan of IODP includes innovative research programs that focus on the study of the seafloor as a dynamic system that dictates the need to install long-term observatories. SCIMPI has three major advantages: (1) the costs associated with the instrument systems are estimated to be significantly less than "traditional" CORK systems with little reduction in the data that can be obtained; (2) the design is simple to configure for many environments, the system is easy to install, and it does not require expensive hole completions; and (3) SCIMPI incorporates already-proven components from industry, which reduces the design and testing costs. The design is based on the use of off-the-shelf, proven components. The pressure, temperature, and resistivity instruments are required to directly characterize site characteristics and changes with time that reflect sub- seabed processes.
OS34A-02 INVITED
AURORA BOREALIS - Development of a New Research Icebreaker with Drilling Capability
Polar research both on land and in the sea cannot achieve the needed progress without novel and state of the art technologies and infrastructure. In addition, we have the obligation to equip the upcoming young and courageous generation of polar researchers with the most modern and safest research platforms the 21st century can provide. This effort will require major investments, both in terms of generating new tools, as well as maintaining and renovating existing infrastructure. There are many different novel tools under development for polar research, we will concentrate on the presently largest one, the planning for a new type of research icebreaker, the AURORA BOREALIS with an all-season capability of operations in permanently ice-covered waters and with the possibility to carry out deep-sea drilling in ice-covered deep-sea basins. AURORA BOREALIS will be the most advanced Polar Research Vessel in the world with a multi-functional role of drilling in deep ocean basins and supporting climate and environmental research and decision support for stakeholder governments for the next 35 to 40 years. The vessel is planned as a large research icebreaker with 44,000 tons displacement and a length of up to 196 m, with about 50 Megawatt propulsion power. Advanced technological features will include azimuth propulsion systems, extensive instrumental and airborne ice- management support, and the routine operation of Remotely Operated Vehicles (ROV) and Autonomous Underwater Vehicles (AUVs) from two moon-pools. An unique feature of this icebreaker will be the drilling rig that will enable sampling of the ocean floor and sub-sea down to 5000 m water depth and 1000 m penetration at the most inhospitable places on earth. The possibility to flexibly equip the ship with laboratory and supply containers, and the variable arrangement of other modular infrastructure (in particular, winches, cranes, etc.), free deck- space, and separate protected deck areas, will allow the planned research vessel to cover the needs of most disciplines in marine research. http://www.eri- aurora-borealis.eu/en/about_aurora_borealis/
OS34A-03
Automatic Quantification of X-ray Computed Tomography Images of Cores: Method and Application to Shimokita Cores (Northeast Coast of Honshu, Japan)
X-ray computed tomography (CT) of rock core provides nondestructive cross-sectional or three-dimensional core representations from the attenuation of electromagnetic radiation. Attenuation depends on the density and the atomic constituents of the rock material that is scanned. Since it has the potential to non-invasively measure phase distribution and species concentration, X-ray CT offers significant advantages to characterize both heterogeneous and apparently homogeneous lithologies. In particular, once empirically calibrated into 3D density images, this scanning technique is useful in the observation of density variation. In this paper, I present a procedure from which information contained in the 3D images can be quantitatively extracted and turned into very-high resolution core logs and core image logs including (1) the radial and angular distributions of density values, (2) the histogram of distribution of the density and its related statistical parameters (average, 10- 25- 50, 75 and 90 percentiles, and width at half maximum), and (3) the volume, the average density and the mass contribution of three core fractions defined by two user-defined density thresholds (voids and vugs < 1.01 g/cc <e; damaged core material < 1.25 g/cc < non-damaged core material). In turn, these quantitative outputs (1) allow the recognition of bedding and sedimentary features, as well as natural and coring-induced fractures, (2) provide a high-resolution bulk density core log, and (3) provide quantitative estimates of core voids and core damaged zones that can further be used to characterize core quality and core disturbance, and apply, where appropriate, volume correction on core physical properties (gamma-ray attenuation density, magnetic susceptibility, natural gamma radiation, non-contact electrical resistivity, P-wave velocity) acquired via Multi- Sensors Core loggers (MSCL). The procedure is illustrated on core data (XR-CT images, continuous MSCL physical properties and discrete Moisture and Density measurements) from the Hole C9001C drilled off-shore Shimokita (northeast coast of Honshu, Japan) during the shake-down cruise (08-11/2006) of the scientific drilling vessel, Chikyu. http://pgaillot.ifrance.com/CTscan/indexctscan.html
OS34A-04
Long Term Borehole Monitoring System For NanTroSEIZE 3.5 km Riser Hole: Requirements And Specifications
Most of the large earthquakes (magnitude greater than 8.0) observed in Japan fall into the subduction plate- boundary category. Based on the results of previous Nankai Trough research efforts, further research opportunities have been proposed under the umbrella of the IODP scientific drilling proposal 603 (NanTroSEIZE: Nankai Trough Seismogenic Zone Experiment) ranked as the top level proposal in IODP. IODP proposal 603 not only proposes drilling, coring and geological analysis, and geophysical logging, but also mandates that a long- term borehole monitoring system be installed into two deep riser holes at about 3,500 m and about 6,000 m below sea floor (mbsf), where we expect to encounter the mega-splay and the locked region of mega thrust fault, respectively. The first riser target (NT2-03 site) is expected to drill through five potential splay faults above 3,500 mbsf. We plan to install sensors to monitor strain, tilt and optionally pore pressure for crustal deformation at and between splay faults, to monitor seismometer array for micro and slow earthquakes detection and for seismic microstructures, and to monitor pore pressure and temperature for hydrologic state change at the fault during interseismic period. The major technical features to develop the deep ocean borehole observatory for NT2-03A are mainly as follows; 1) high temperature (125E#8249;C), 2) long life (5 years), 3) deployment (15,000 psi wellhead system, deep well, retrieval, perforation, packer, mechanical shock), 4) coupling to formation (cement, clamp), 5) multi level monitoring (against 5 spray faults), 6) multi purpose monitoring (seismic, geodetic, hydrogeologic), 7) low power consumption, 8) real time monitoring (connecting to sea bed cable), 9) accurate synchronization, 10) wide frequency range / high dynamic range ADC, 11) down sizing (installing into 9-5/8hcasing with tubing), 12) system redundancy (fault tolerant). We started to develop an experimental prototype (EXP) for field test using the borehole on land from 2007, and plan to carry out the field test in 2009. The objectives of EXP are to collect real data to determine if the system works as designed and to identify all unseen problems in the design. The implementation phase will be followed to improve the system based on the field test results, upgrade the design, and produce the Engineering Prototype (ENP) to be installed in NT2-03A in 2011.
OS34A-05
Core-log Integration as a Tool for Improving Depth Resolution
Geophysical, geochemical, petrologic, and structural geology data collected from both recovered cores and logged in holes drilled into the seafloor have been used to make many significant advances in our understanding of both the ocean crust and overlying sediments. However, in seafloor drilling operations, especially those in crustal rocks, the recovery of cores is generally incomplete and depths of recovered core pieces are assigned with some uncertainty. Assigning some arbitrary piece depth within a core, such as the shallowest possible depths for recovered core pieces, is a quick but less than optimal method of determining in situ depth. We have integrated physical property data from the recovered core and logged in the open hole to determine a new depth record for core pieces at IODP Hole 1256D, which is our first opportunity to study a section of intact, in situ upper ocean crust drilled down to gabbro. The re-interpreted piece depths will be important to high-resolution studies incorporating both core sample and logging data at this site. Our method will be of general use to IODP researchers wishing to better resolve core piece depths, and to others engaged studies that rely on oceanic and continental drilling. Our method is also rapid, requires little subjective input, and is applicable to any core-log integration problem where sufficient data have been collected in both the open hole and from the recovered core.
OS34A-06
The Distributed Thermal Perturbation Sensor: A New Tool for In Situ Estimation of Formation Thermal Properties and Geothermal Heat Flux
Variations in geothermal heat flux provide a window into a diverse array of geological processes including plate tectonics and crustal fluid circulation. The Distributed Thermal Perturbation Sensor (DTPS) is a novel device that can simultaneously determine formation thermal properties and heat flux in situ. The device consists of a fiber- optic distributed temperature sensor (DTS) and a heat trace cable installed along the axis of a borehole. To operate the DTPS, the sensor is backfilled into a borehole and the disturbed thermal field is allowed to dissipate. A baseline temperature profile is subsequently recorded. Next, the heat trace cable is used to provide constant heating along the borehole and the thermal transient is recorded. DTS monitoring continues after heating concludes during the ensuing cool-down phase. To obtain in situ estimates for thermal properties and heat flux, simple conductive or conductive-convective models can be used to interpret the data. Given the 1 meter spatial resolution of the DTS - the DTPS provides thermal property and heat flux estimates at similar spatial resolution. To date, the DTPS has been deployed at three continental sites: (1) in the Amargosa Valley, Amargosa, NV, USA, to characterize groundwater flow through fractured volcanic tuffs, (2) in a deep permafrost boring within an Archean mafic volcanic belt at the High Lake Project Site (67°22"N, 110°50"W), Nunavut, Canada, and (3) as part of the monitoring program at CO2SINK, a carbon geosequestration experiment being conducted in Ketzin, Germany. The authors present results from these three sites and discuss potential modalities for future deployment in suboceanic environments.
OS34A-07
Real-time Science and Educational Collaboration Online from the Indian Ocean
During Summer of 2007, scientists and students (via the web) jointly participated in research during the Ninety East Ridge Expedition (cruise KNOX06RR) . Staff organizers from Joint Oceanographic Institutions" JOI Learning and the Integrated Ocean Drilling Program planned and implemented an interactive website to allow students to directly participate with scientists during the site survey aboard the R/V Roger Revelle. Dr. Will Sager and middle school teacher Rory Wilson collaborated daily during the scientific expedition with science team, ship crew and students. From the outset, students were involved and helped to guide the program; this included coming up with the website name and initial design work. Communication with students included the website, individual and group emails and video conferences with student groups. Seven secondary schools from the USA, Europe, India and Thailand participated actively in the project from June to August. Students viewed daily updates on the website, sent in answers for weekly science challenge questions, and interacted with scientists and crew. Student participants learned about navigation, geophysics and petrology, as well as ship operations and technology. Students and educators tracked the expedition's progress in a multi-media environment. Website statistics were recorded; participation began well and increased during the expedition as more people became engaged with the website. All of the crew and scientists wrote self-profiles to help students learn about the range of ocean careers; several of the scientists and graduate students on board wrote or co- authored website articles for students. During this presentation, we will explore and review the major features of the outreach program using the Sea90e website to demonstrate how this real-time interaction engages students in science learning. We will discuss the benefits of collaboration for science and education in our "classroom at sea." http://www.joilearning.org/sea90e