ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • seafloor observatory  (3)
Collection
Years
  • 1
    Publication Date: 2021-06-07
    Description: Methane-rich fluid vents have been widely observed and associated to active faults in the Sea of Marmara, along the submerged portion of the North Ana- tolian Fault (NAF). Episodic gas seepage also occurs in the Izmit Gulf, along the NAF segment that ruptured during the 1999 Izmit earthquake. This site is thus a unique area to test the hypothesis on the relation between strike-slip deforma- tion, seismic activity and gas expulsion within an active fault zone. A long-term multi-parametric experiment can be an effective way to study the irregular dy- namics of gas emission from seafloor and to understand its possible relation with seismic activity. A benthic seafloor observatory (SN-4) was deployed in the Izmit Gulf in 2009 using the R/V Urania as a demonstration mission in the framework of the EC ES- ONET (European Seas Observatory NETwork) project. Instrumental redundancy and specific cross-correlation of data from different sensors, proves to be funda- mental to distinguish actual seepage events from other signals related to ocean- ographic behaviour or even sensor biases. The observatory was equipped with a three component broad-band seismometer, a CTD with turbidity meter, two methane detectors, an oxygen sensor and a current-meter. All sensors installed on the observatory were managed by dedicated low-power electronics, which can manage a wide set of data streams with quite different sampling rates. A unique reference time, set by a central high-precision clock, is used to tag each datum. After six months of continuous monitoring, SN-4 was recovered in March 2010 in order to download the data and replace the batteries for a further six month mission period and finally recovered in October 2010. The data analysis clearly shows frequent degassing events, recorded as methane anomalies in seawater and as high-frequency short-duration signals recorded by the seismometer.. The time series of other oceanographic parameters (tempera- ture, oxygen concentration, turbidity and salinity) shows patterns that seem to be linked to both local gas seepage and to the circulation of water masses in the Gulf of Izmit. A comparative analysis of the various observables and their mutual correlation, can be a key tool to understand actual degassing events along the NAF. This analysis is first attempt in finding possible correlations be
    Description: Published
    Description: Cadiz, Spain
    Description: 3A. Ambiente Marino
    Description: restricted
    Keywords: seafloor observatory ; methane seepage ; multi-parametric ; 03. Hydrosphere::03.04. Chemical and biological::03.04.06. Hydrothermal systems ; 03. Hydrosphere::03.04. Chemical and biological::03.04.08. Instruments and techniques ; 04. Solid Earth::04.06. Seismology::04.06.06. Surveys, measurements, and monitoring ; 04. Solid Earth::04.06. Seismology::04.06.10. Instruments and techniques
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: Extended abstract
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2017-04-04
    Description: During the cruise of the Italian research vessel URANIA on August 2007, a new tsunami detector was successfully deployed at 3200 b. s. l. in the Gulf of Cadiz, Portugal. The new detector is installed on board the multi-parameter abyssal observatory GEOSTAR. This activity is a task of NEAREST EC Project (http://nearest.bo.ismar.cnr.it/ ). Among other tasks, the NEAREST project will produce and test the basic parts of an operational prototype of a near field tsunami warning system. The warning system includes an onshore warning centre based on the seismic and tide gauges monitoring networks which are already operating in the area of Gulf of Cadiz and connected in real time with many warning receiving shore stations, a buoy equipped with meteostation and two way acoustic and satellite links, and the tsunami detector installed on board GEOSTAR. The warning centre is in charge of collecting, integrating, and evaluating data recorded at sea. In the observatory at the sea bottom, data are recorded and processed by the tsunami detector which includes a pressure sensor, a seismometer and two accelerometers. The observatory communicates acoustically with a surface buoy in two-way mode. The buoy is equipped with meteo station and GPS and it is connected to the shore station via satellite dual-link. The prototype is designed to operate in tsunami generation areas for detection-warning purpose as well as for scientific measurements during long term monitoring. The pressure data are processed in real time on the sea floor observatory by a tsunami detection algorithm able to detect small tsunami waves, less than one centimetre, in a very noisy environment. At the same time the seismic data are analysed using a STA/LTA algorithm. The tsunami detector sends a near real time automatic alert message when a seismic or a pressure signal exceeds a selectable threshold indicating a strong local earthquake or a tsunami wave event. After the detection of an event, the seafloor observatory will start sending updated pressure data to the shore station. Our objective is to combine a novel approach to the tsunami warning problem, with a study of the coupling between the water column perturbations and sea floor motion, together with the long term monitoring of geophysical, geochemical and oceanographic parameters.
    Description: Published
    Description: Vienna
    Description: 1.8. Osservazioni di geofisica ambientale
    Description: open
    Keywords: tsunami detection ; tsunami warning ; seafloor observatory ; multiparameter ; 04. Solid Earth::04.06. Seismology::04.06.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: Oral presentation
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2020-02-24
    Description: Off East Sicily (at 2100 m depth, 25 km off the harbour of Catania) a prototype of a cabled deep-sea observatory (NEMO-SN1) was set up and has been operational in real-time since 2005 (the cabled deep-sea multi-parameter station SN1, equipped with geophysical and environmental sensors and the cabled NEMO-OνDE, equipped with 4 broadband hydrophones). The Western Ionian Sea is one of the node sites for the upcoming European permanent underwater network (EMSO). Within the activities of the EC project ESONET-NoE some demonstration missions have been funded. The LIDO-DM (Listening to the Deep Ocean-Demonstration Mission) is one of these and is re- lated to two sites, East Sicily and Iberian Margin (Gulf of Cadiz), the main aims being geo-hazards monitoring and warning (seismic, tsunami, and volcanic) and bio-acoustics. The LIDO-DM East Sicily installation represents a fur- ther major step within ESONET-NoE, resulting in a fully integrated system for multidisciplinary deep-sea science, capable to transmit and distribute data in real time to the scientific community and to the general public. LIDO-DM East Sicily hosts a large number of sensors aimed at monitoring and studying oceanographic and environmental parameters (by means of CTD, ADCP, 3-C single point current meter, turbidity meter), geophysical phenomena (low frequency hydrophones, accelerometer, gravity meter, vector and scalar magnetometers, seismometer, abso- lute and differential pressure gauges), ocean noise monitoring and identification and tracking of biological acoustic sources in deep sea. The latter will be performed using two tetrahedral arrays of 4 hydrophones, located at a relative distance of about 5 km, and at about 25 km from the shore. The whole system will be connected and powered from shore, by means of the electro-optical cable net installed at the East Sicily Site Infrastructure, and synchronised with GPS. Sensors data sampling is performed underwater and transmitted via optical fibre link, with optimal S/N ratio for all signals. This will also permit real-time data acquisition, analysis and distribution on-shore. Innova- tive electronics for the off-shore data acquisition and transmission systems has been designed, built and tested. A dedicated computing and networking infrastructure for data acquisition, storage and distribution through the internet has been also created. The deployment and connection of the deep sea structures will be performed using the dedicated ROV and Deep Sea Shuttle handling facilities (PEGASO, owned by INGV and INFN). LIDO-DM constitutes the enhancement of the Western Ionian site in view of the EMSO Research Infrastructure.
    Description: Published
    Description: Vienna
    Description: 1.8. Osservazioni di geofisica ambientale
    Description: open
    Keywords: ESONET ; seafloor observatory ; cabled observatory ; 03. Hydrosphere::03.01. General::03.01.08. Instruments and techniques
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: Abstract
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...