Paolo Favali & Laura Beranzoli

Transcription

1 Seafloor observatories, Benefits for the Marine & Earth Sciences and Synergies Paolo Favali & Laura Beranzoli Istituto Nazionale di Geofisica e Vulcanologia, Italy

2 What are Seafloor observatories? Unmanned, multi-sensor platforms with long-term operative life and with different configurations related to the communications and power: 1) Autonomous: stand stand-alonealone configuration, battery packs and limited capacity of data transmission (e.g., data capsules or acoustic link from the surface) 2) Acoustically linked linked: communication by acoustics to an infrastructure (e.g., moored buoy, another observatory) 3) Cabled: power power supply and real-time data transmission (e.g., retired, dedicated or shared cables devoted to other scientific activities) Favali & Beranzoli, 2006

3 What do Seafloor Observatories need for? To study the Earth as an integrated system: geo- biohydro-sphere To provide long time series for the study of multiple, interrelated processes to highlight temporal scale and variability of the phenomena Illuminating the Hidden Planet. The future of Seafloor Observatory Science, NRC - National Research Council, National Academy Press, Washington D.C., 2000

4 The Ocean Margins are punctuated by corals, mounds, vents and canyons with emissions to the sea and atmosphere Methane Gas/Fluid Emissions Deep Corals Mud volcanoes Methane Hydrates Geohazards - Earthquakes, Slides and Tsunamis require instantaneous real-time response Tsunami Slide Turbidite Earthquake

5 Scientific Themes Role of the Ocean in Climate Dynamics of oceanic lithosphere and Imaging Earth s interior Fluids and Life in the Ocean Crust Coastal ocean processes Turbulent mixing and Biophysical interactions Ecosystem dynamics and Biodiversity

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7 Single-frame acoustically linked observatory MODUS GEOSTAR GEophysical and Oceanographic STation for Abyssal Research GEOSTAR GEOSTAR buoy Beranzoli et al., 1998; Beranzoli, Favali & Smriglio (eds.), Dev. Mar. Tech., 12, Elsevier, 2002; Favali et al, 2006b; Favali & Beranzoli, 2006; 2009b

8 Platform GEOSTAR SN-1 SN-3 SN-4 Overall dimensions (m) (L x W x H) 3.50 x 3.50 x x 2.90 x x 2.90 x x 2.00 x SEAFLOOR OBSERVATORIES SINGLE-FRAME (GEOSTAR-class) Weight (kn) (in air) Weight (kn) (in water) Depth rated (m) GMM 1.50 x 1.50 x MABEL 2.90 x 2.90 x (SN-2) 2.90 GEOSTAR SN-3 SN-4 SN-1 MABEL (SN-2) Favali et al., 2006b; Favali & Beranzoli, 2006; 2009b GMM

9 Seafloor Observatory Network EC Projects ASSEM ( ) Shallow-water Corinth Gulf 400 & 42 m w.d. Rolin et al., 2005 Marinaro et al., 2004; 2006 Shore station Radio link Satellite link BUOY ORION-GEOSTAR 3 ( ) Deep-water South. Tyrrhenian Sea Marsili volcanic seamount 3300 m w.d. MODUS Vertical Acoustic link Favali & Beranzoli, 2006 Favali et al., 2006b SATELLITE NODES Horizontal Acoustic link GEOSTAR

10 Single-frame cabled observatory NEMO-SN1 Favali et al, 2006a; Migneco et al., 2006

11 Seafloor Experiments ( ) 26 deployment & recovery successful operations down to > 3300 m w.d. Weddell Sea (1874 m w.d.) Dec.05-Dec.08 >300 Gbytes (binary data), equivalent to >3600 days of operation (>10 years) Offshore Ustica (2000 m w.d.) Sep.00-Apr.01 Marsili Volcano (3320 m w.d.) Dec.03-Apr.04 Jun.04-May 05 Offshore Panarea (23 m w.d.) Mag.08-on Adriatic Sea (44 m w.d.) Aug.-Sep.98 Patras Gulf (40 m w.d.) Apr.-Jul.04 Sep.04-Jan.05 Corinth Gulf (400 m w.d.) Apr-Nov 04 GEOSTAR SN-1 ORION Node 3 (SN-3) ORION Node 4 (SN-4) GMM MABEL (SN-2) PEGASO EGU 2009 SSP18/EG12/CL64/GMPV23/TS9.3 Beyond 2013 in - The the future Sagres of European Plateau scientific (Portugal) drilling Offshore Catania (2105 m w.d.) Oct.02-May 03 Real time (cabled) Jan.05-Apr.08 GEOSTAR 85-km offshore Cape St. Vincent at 3200-m w.d. (Aug.07 Aug.08)

12 Distributed acoustic linked observatory Distributed cabled observatory

13 Type of installation for seafloor observatory equipment Burial (partial or total) On the seafloor ORION (SN4) H2O Borehole OSN-1

14 OSN - Ocean Seismic Network (USA) Orcutt & Stephen, 1993; Stephen, 1998; Collins et al., 2001; 2002; Stephen et al., 2992; Sutherland et al., 2004

15 NEREID (Japan) Suyehiro et al., 2002; Araki et al., 2004; Shinohara et al., 2006

16 MACHO (Taiwan) Favali & Beranzoli, 2009a

17 North East Pacific Time-series Undersea Networked Experiment NEPTUNE Stage 1 MARS Monterey Accelerated Research System

18 Taiwan

19 Cabled Ocean Bottom Observatories (Japan) a) JMA Omaezaki System (1978) b) JMA Off-Boso System (1985) c) ERI Off-Ito City System (1994) d) NIED Hiratsuka System (1995) e) ERI Off Sanriku Seismic Network (1995) JAMSTEC: A) Real Time Deep Sea Floor Observatory Off Hatsushima Island in Sagami Bay (1993) B) Long-Term Deep Sea Floor Observatory Off Muroto Peninsula (1997) C) Long-Term Deep Sea Floor Observatory Off Kushiro-Tokachi (1999) EGU 2009 SSP18/EG12/CL64/GMPV23/TS9.3 Beyond Favali The future & Beranzoli, of European 2006 scientific drilling

20 DONET - Dense Ocean floor Network system for Earthquakes and Tsunamis (JAMSTEC, JAPAN) Sensors over 20 Seismometers 20 Pressure gauges

21 EMSO, a Research Infrastructure of the ESFRI Roadmap (European Strategy Forum on Research Infrastructures), is an European-scale network of seafloor observatories (cabled & acoustically linked), for long-term monitoring of environmental processes related to ecosystem life and evolution, global changes and geo-hazards Azores Porcupine Nordic Sea Iberian Margin Arctic Ligurian Sea Eastern Sicily Norwegian Margin Black Sea Marmara Hellenic 11 network nodes corresponding to key-sites proposed by ESONET EC projects Favali & Beranzoli, 2009a

22 EMSO Iberian Margin site Acoustically linked observatory NEAREST EC Project ( ) 2009) Integrated observation from NEAR shore sources of Tsunamis: towards an early warning system Portugal Gulf of Cadiz 85 km off-shore 3200 m w.d. GEOSTAR M L =4.7 Gulf of Cadiz (Jan. 11, 2008) SISM ACC APG (raw data) ( nearest.bo.ismar.cnr.it/)

23 INGV EMSO Eastern Sicily node NEMO-SN1 The 1 st real-time cabled seafloor observatory in EUROPE Z Optical sensors E Electronic vessels N M w =8.6 off-shore Sumatra (March 28, 2005) Favali et al, 2006a; Migneco et al., 2006

24 Benefits for Marine and Earth Sciences

25 Scientific payload of GEOSTAR-class observatories Geophysical sensors: Broad-band three comp. seismometer Three comp. accelerometer Magnetometers (vectorial & scalar) Gravity meter Hydrophones (geophysical & bio-acoustic applications) Pressure sensors (absolute & differential pressure gauges) Tiltmeter + Gyro Physical Oceanographic sensors: ADCP (acoustic doppler current profiler) Single-point three comp. current meter CTD (conductivity, temperature vs depth) Transmissometer & Turbidity meter Nuclear spectrometer Geochemical sensors: Gas sensors (e.g., H 2 S, CH 4, O 2 ) Automatic chemical analyser (ph, eh) Automatic water sampler (48 bottles, off-line) Unique time reference High precision clock (stability ) Favali et al., 2006b; Favali & Beranzoli, 2006; 2009b

26 D POTT Potential Temp Potential temperature SCAN Density SCAN CTD SeaBird The geochemical data, suggest that gas and radionuclides in BBL seawater, deriving from Earth degassing and diffusion from sediments, can be useful tracers to distinguish water masses of different origin and benthic residence times EOW (Eastern Overflow Water) Interpretative model He/He (x 10 ) air mantle 3 He/ 4 He vs He/Ne upper water (T and S peaks) bottom water (lower T and S) radiogenic He/Ne RAS-500 Remote Autom. Sampler inl WW (Western Water) oscillating interface bnl seafloor RADIONUCLUDES Etiope et al., 2006

27 EC-ASSEM ( ) Corinth Gulf (42 m w.d.; April 04-Jan. 05) Marinaro et al., 2004; 2006

28 EM Lithospheric depth GEOSTAR-class deep seafloor observatories provided long timeseries of magnetic data Estimates of: lithosphere depth (LD in km) from Geomagnetic Deep Sounding and Magneto Variational Gradient Sounding (MVGS) seafloor conductivity (σ in S/m) from MVGS GEOSTAR1: LD = 80 km σ = 0.01 S/m GEOSTAR3: LD = 20 km σ = 1 S/m De Santis et al., 2007; 2009 GEOSTAR2: LD = 40 km σ = 0.1 S/m

29 Southern Tyrrhenian seismic tomography (velocity anomalies) Montuori et al.., 2007

30 NEMO-SN1 cabled observatory seismicity recorded only off-shore Tyrrhenian Sea Etna Calabria Ionian Sea SN-1 Malta Escarpment Deep Ionian Basin Sgroi et al., 2007

31 NEMO-SN1 cabled observatory (Eastern Sicily) OνDE acoustic array (INFN-Univ. Pavia) hydrophones electronics housing % of slots with sperm whale sounds per day Daily acoustic contacts with sperm whales (September-December 2005)

32 Synergies Instrumented boreholes could be profitably interoperated with the seafloor observatories: to provide sub-seafloor measurements as integration of seafloor ones to share sea operation logistics and infrastructures (e.g., vessels, underwater vehicles, underwater cables and communication systems)

33 Chikyu deep-sea drilling vessel

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35 Thank you for your attention Paolo Favali: Laura Beranzoli: