conference & convention enabling the next generation of networks & services Submarine Cabled Real-time Seafloor Observatory and Subsea Engineering ROV for Observatory Construction Katsuyoshi KAWAGUCHI Japan Agency for Marine-Earth Science and Technology
conference & convention enabling the next generation of networks & services Presenter Profile Katsuyoshi Kawaguchi 1964: Bone in Tokyo 1993: Recived Ph.D in marine science from Tokai University 1993 to 1995: Lecturer, Tokai University 1995 to1996: Post-Doctoral Research staff, University of Hawaii 1996 to 1998: Post-Doctoral Researcher at JAMSTEC 1998 to 2008: Researcher at JAMSTEC 2008-:Principal Scientist / Group Leader Background: Underwater measurement Technology / Underwater Robotics Katsuyoshi KAWAGUCHI Principal Scientist / Group Leader Email: kawak@jamstec.go.jp Tel: (+81) 46-867-9342
conference & convention enabling the next generation of networks & services Submarine Cabled Real-time Seafloor Observatory and Subsea Engineering ROV for Observatory Construction
conference & convention enabling the next generation of networks & services The real-time and long-term monitoring capability on seafloor is essential for understanding and forecasting the earthquake activity and associated phenomenon along tectonic plate and submarine cabled seafloor observation is only approach to be realize the requirements. A lot of earthquakes occurred every year around the Japan Arc, especially under the seafloor.
conference & convention enabling the next generation of networks & services DONET ： (Development of Ocean-floor Network System for Earthquakes and Tsunamis) is a national program to develop an ocean floor network system for earthquakes and tsunamis observation, and has been carried out since 2006.
conference & convention enabling the next generation of networks & services OSAKA YOKOHAMA The Nankai Trough is one of the region with highest concern at present time. In this region, the Mega thrust earthquake and associated tsunami has occurred every 100-150 years.
conference & convention enabling the next generation of networks & services - 250km length of backbone cable system - 5 hub system (Science Node) - 8 observatory interfaces for each hub system - 20 interfaces are reserved for standard DONET observatory - Another 20 interfaces are used for future expansion
conference & convention enabling the next generation of networks & services REQUIREMENTS FOR EARTHQUAKES AND TSUNAMIS OBSERVATION System Requirement High reliability system design to maintain constant (seamless) system operation in the system lifetime of 20years. System Redundancy for the internal system failure or external failures associate with the earthquakes, Mud flows, human activities or abrasions. Replaceable, maintainable and expandable functions for future observatory upgrade and replacement of superannuated system components. Observation Requirement High density deployment of observatories (interval of 15-25km, same as seismic observation network on land)
conference & convention enabling the next generation of networks & services Operation Scenario of DONET Observatory Construction Termination Unit Science Node 20m 10km Extension Cable 20m Observatory
conference & convention Modification of ROV enabling the next generation of networks & services Variable Buoyancy Control System Cable Laying System
conference & convention Requirement for Modification enabling the next generation of networks & services Cable Laying System (Performances Required) Cable Management (Laying and Recovery) Suspend or Resume the Operation (release cable bobbin) Lay on Complex Seafloor Terrain Variable Buoyancy Control System Science Node Installation: 500kg in Air / 180kg in SW Observatory Construction: 250kg in Air / 100kg in SW Extension Cable Laying : 640kg in Air / 220kg in SW
Extension Cable conference & convention enabling the next generation of networks & services -The observatory install 10km radius area center the hub system -Extension cable secure the point to point power distribution and communication channel Outer Diameter ： < 6.5mm, Conductor Resistance:17 Ω /km (Twist 4 copper threads for one conductor) Weight in Air ： < 50kg/km, Weight in Water ： <19kg/km (measured value = 18kg/km in seawater) Breaking Strength ：≧ 100kgf Cross Section and Specification of Extension Cable
Cable Laying System (Cable Management (Laying)) conference & convention enabling the next generation of networks & services Cable Payout System The cable payout system can control the cable payout speed to manage the reasonable cable slack by hydraulic actuator. The slip roller mechanically managed the cable payout tension 30kg maximum. The slip roller set on the hinge mechanism that limit is 60deg lock to lock to follow the cable movement on the bobbin.
(Suspend or Resume the operation) Cable Laying System conference & convention enabling the next generation of networks & services Cable payout system has Clamp Mechanism to Remove/set extension cable from /to slip roller
Cable Laying System (Suspend or Resume the operation) conference & convention enabling the next generation of networks & services The cable bobbin elevator make possible to equip and release the cable bobbin together with 10km length of extension cable in air and water. It is generate 1ton of pulling torque that is good enough to lift the cable bobbin of 650kgf in air. The cable bobbin is fixed to the chasse of cable laying system with the pair of stab rod when operating.
VBCS conference & convention enabling the next generation of networks & services Ballast Tank Control Monitor Pump Servo Valve Filter Add on Equipment :VBCS (Variable Buoyancy Control System)
VBCS conference & convention enabling the next generation of networks & services Consideration of Buoyancy - Total ROV System Weight with 10km extension cable: 5.9 ton in air / neutral in seawater - Extension cable: 18kg/km in seawater - Bobbin: 40kg in seawater Release Bobbin During Laying Operation Touch Down Buoyancy Variation 220 90 0 with VBCS 120 0 0 Adjust Initial Condition 70 0 -50
conference & convention enabling the next generation of networks & services SYSTEM ASSEMBLY TEST Backbone Cable Repeaters Termination Branching Unit Unit Test Facility Science Node Extension Cable Observatory
Backbone cable Laying Operation conference & convention enabling the next generation of networks & services Lading to Cable Ship LWS Cables in Cable Tank Armored Cable Loading BUs Repeaters TUs Cable Landing Operation: Jan 15, 2010
Science Node Installation conference & convention enabling the next generation of networks & services
Observatory Construction conference & convention enabling the next generation of networks & services
Extension Cable Laying Operation conference & convention enabling the next generation of networks & services
2010/3/13 21:46 Off Fukushima 37.6N 141.5E 80km M5.7 2010/3/13 21:46 Off Fukushima 37.6N 141.5E 80km M5.7 conference & convention enabling the next generation of networks & services 21:47 JST DONET A3a Observatory DONET A3a Observatory 10Hz LPF 33-38.905’N 136-36.220’E 2063m 33-38.905’N 136-36.220’E 2063m Pressure Gauge 210 Pa Differential Pressure Gauge Hydrophone 107 Pa Accelerometer Horizontal-1 Accelerometer Horizontal-2 1.6 mm/s 2 Accelerometer Vertical BBS Horizontal-1 BBS Horizontal-2 0.2 mm/s BBS Vertical
conference & convention enabling the next generation of networks & services Conclusions -The DONET is a development program for novel surveillance infrastructure for earthquakes and tsunamis. This is four years program from April 2006 to March 2010. A new observation architecture development, sensing system development, field survey and related technologies development for seafloor observatory construction were discussed and demonstrated in this duration. -The final stage of this program, the construction of network was started January 2010, and successfully launched the first observatory in March 2010. This observatory produce very precise data set that has the quality has never had before
conference & convention enabling the next generation of networks & services Conclusions -In addition, at this moment in time, 19 observatories are waiting in the backyard to deploy on the seafloor near future. These apparatuses are scheduled to be installed to the seafloor and connected to the backbone cable system shortly in the expedition schedule after current year. -The final destination of DONET will be deploy similar or more large scale seafloor earthquakes surveillance system to the other major mega-thrust seismogenic zone around Japan and also the world.
2010 conference & convention enabling the next generation of networks & services The 7th International Conference & Convention on Undersea Telecommunications Pacifico Convention Plaza Yokohama & InterContinental The Grand Yokohama 11 ~ 14 May 2010 www.suboptic.org
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