Tsunami Warning Buoy System and an Acoustic Telemetry System for High Current Area Yasuhisa ISHIHARA Marine Technology Center JAMSTEC
Contents 1. Large depth Surface Buoy Mooring TRITONBuoyand GlobalTropical Moored buoy Array 2. JAMSTEC Tsunami Warning buoy System Detail of the Tsunami buoy warning system Father more challenge
1.Large depth Surface Buoy Mooring
JAMSTEC Large depth Surface Buoy Mooring in Tropical Ocean TRITON :1998~ 14 10 1 15 11 7 2 18 16 12 13 8 9 3 4 5 17 6 19 TRITON :2002~2007 m-triton :2008~
Tropical Moored Buoy Array Program: A coordinated, multi-national effort to implement a sustained moored buoy observing system in the global tropics for climate research and forecasting A contribution to the Global Ocean and Global Climate Observing System (GOOS & GCOS)
Indian (2000) Pacific (1984) Atlantic (1997) Japan Japan Brazil Indonesia U.S. France India U.S. China France U.S. ASCLME Contributing Nations A contribution to the Global Ocean and Global Climate Observing System (GOOS & GCOS)
Advantage of surface mooring Wide spectrum of time scale (Hourly ~ Decadal) High data quality are obtained by suitable calibration Variability in time between space are distinguished Real-time data communication between underwater sensors and satellite communication system A contribution to the Global Ocean and Global Climate Observing System (GOOS & GCOS)
2.JAMSTEC Tsunami Warning Buoy System After Japan earthquake at March 11th 2011, JAMSTEC has started to develop a tsunami warning buoy system Tsunami monitoring buoys already exist like the DART system which is developed NOAA in USA and Ina Buoy system which is developed BPPT in Indonesia These systems consist of mooring system with surface float and ocean bottom pressure sensor station. But.
JAMSTEC Tsunami Warning System K hi i f t Kuroshio is famous ocean current as one of the fastest current in the world
JAMSTEC Large depth Surface Buoy Mooring in Tropical Ocean TRITON :1998~ 14 10 1 15 11 7 2 18 16 12 13 8 9 3 4 5 17 6 19 TRITON :2002~2007 m-triton :2008~
Mooring Lines TRITON m-triton TAUT Line Scope (Line length/depth)<1 abt.0.85 SLACK Line Scope (Line length/depth)>1 abt.1.3
Estimation of Scope Alteration.5m), (kgf), Displa acement (x0. f W.R. Lower End(x10m) Line Tension Lift of 3,500 3,000 2,500 2,000 1,500 1,000 500 : Tension below Surface Buoy : Tension below Wire Rope : Tension above Anchor : Displacement of Surface Buoy : Lift of Wire Rope Lower end Water Depth=5,000m Vc = 3kt Vw = 20m/s 0 1.0 1.1 1.2 1.3 1.4 1.5 SCOPE
Comparison of Mooring Characteristics
JAMSTEC Tsunami Warning Buoy System and Acoustic Tl Telemetry System for High Current ta Area (Min. cycle : 10 sec)
JAMSTEC Tsunami Warning Buoy System and Acoustic Telemetry System for High Current Area These systems consist of mooring system with surface float and ocean bottom pressure sensor station The slack mooring system is required at Kuroshio area High accurate water pressure sensor should be used for bottom station An acoustictelemetry telemetry system isrequired for data transmission of water pressure from a bottom station to surface buoy (Planed Min. cycle : 10 sec) Because of slack mooring, beam width of a transducer must be wide over 45 degrees and 1000m length of jacked wire rope are used for mooring line To reduce its transmitting power consumption, the PWM system is applied for transmitting water pressure data
Mooring Calculation result (ab 5 kt at surface) 潮流速度 cm/sec 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 0 knot 0 0 1,000 2,000 3,000 4,000 5,000 ドリフト距離 m 0 0 1,000 2,000 3,000 4,000 5,000 6,000 張力 Kgf 1,000 2,000 水深 m 3,000 1,000 1,000 4,000 水深 m 水深 m 5,000 2,000 2,000 6,000 3,000 3,000
Father more challenge New collaboration with Tohoku university and JAXA has just started Tsunami buoy system is also going to equip thegps acoustic system to observe the drift of the ocean floor This Prototype buoy are going to deployed on next December.
Tsunami buoy system with GPS acoustic ブイ 海中音速情報 変位 海底局
Schematic image of Tsunami buoy and GPS/A SLACK Line Scope (Line length/depth)>1 abt.1.3 45 Pressure data
Block Diagram of proto type buoy Iridium modem GNSS Surface Inductive Modem (SIM) Data logger Position Roll/Pitch JAXA GPS/A Transducer Tohoku University JAMSTEC IMM 1000m Wire Transducer Botom station GPS/A Responder
Target position of prototype buoy
Summary JAMSTEC has started t dto develop the Tsunami warning buoy system The slack mooring system is required at Kuroshio area An acoustic telemetry system is required for data transmission of water pressure from a bottom station to surface buoy Because of slack mooring, beam width of a transducer must be wide over 45 degrees To reduce its transmitting power consumption, the PWM system is applied for transmitting water pressure data Tsunami buoy system is also going to equip the GPS acoustic system to observe the drift of the ocean floor This Prototype buoy are going to deployed on next December.