SHOA

CHILEAN NAVY HYDROGRAPHIC AND OCEANOGRAPHIC SERVICE

The commission for the anchoring of 2 prototypes of the System DART 4G begins on September 22, on board of the vessel Cabo de Hornos of the Chilean Navy, with professionals of the Hydrographic and Oceanographic Service of the Navy and technicians of the National Oceanic and Atmospheric Administration (NOAA).

The commission in charge of the new prototypes of the NOAA will run for 11 days. These instruments will allow increasing the protection capacity for the detection of tsunamis from a closer distance with the earthquakes that originate the tsunamis, also providing a source of important and necessary data for the warning centers to detect, predict and warn about these events. This activity takes place within the framework of the Memorandum of Understanding signed by both organisms last July.

These instruments have been initially tested in the State of Oregon, US; however, the final tests will be performed in the Chilean coasts to verify the correct functioning of the technology for the early detection of tsunamis, they will be located closer to the Peru-Chile Trench where the Nazca Plate and the South American Plate converge, area of permanent seismic events due to the subduction between the oceanic and continental plates. Once the system is installed, it is expected to provide the data of the tsunamis generated in the areas nearby the national territory, or in a short distance from the source, in less time than the one currently provided through the System DART II.

To Michael Angove, Director of the Program Tsunami of the NOAA, being able to perform this activity in Chile is mainly due to the trust and professional capacities of the SHOA, as one the most important Warning Centers of the Pacific Trench. “We have had a great relationship with the SHOA, especially in the last 15 years and we are confident, because we know the work they perform, that the Service and in the Chilean Navy have the capacities and experience of the people to deploy and maintain our prototypes”. What is interesting and groundbreaking about this work, according to Angove, is the collaborative aspect with which this activity was developed, in which Chilean scientists also took part, mostly in the determination of the place where the prototypes must be placed.

According to the provided indications by the professionals of the NOAA and the SHOA, during the Press Conference given today, on board of the AGS 61 Cabo de Hornos, the first prototype will be approximately 77 nautical miles from the coast close to Mejillones, almost equidistant from both DART II Chilean buoys already in place, this will allow validating this new sensor comparing the data gathered with the existent buoys. The second will be placed 113 nautical miles from the coast close to Constitución, advancing with the latitudinal coverage towards the tsunamigenic zone in the center-south of the country.

Regarding the characteristics of the System DART 4G, the Director of Engineering at the Pacific Marine Environmental Laboratory (PMEL) of the NOAA, Mr. Christian Meinig, said that the prototypes brought to Chile have the latest technology that exists in the world right now. “The big difference that the equipment has with the previous versions is that the data processing is much faster and it can differentiate if the registered signal is produced by a tsunami or an earthquake.”

The Director of the SHOA, Rear-admiral Mr. Patricio Carrasco, expressed how important it is for the Service and the Navy that the NOAA had decided to jointly work with the professionals and specialists of the SHOA and the vessel Cabo de Hornos. “This is an indication that out work is valued by organisms that are experts on the subject of tsunamis around the world, and we are acknowledged as professionals who contribute to science and knowledge of these complex events.”

Characteristics of the System DART 4G

Recent progress in the sensors, software and energy administration assure the possibility of detection and measurement of tsunamis of close range with an unprecedented resolution.

This new pressure sensor and improved algorithms with Nano resolution installed in the BPR (Bottom Pressure Recorder), will allow the differentiation of a tsunami signal from a “noise” due to an earthquake.

The slowness and loss of communication in real time between the sea bottom (BRP) and the surface (Buoy) have been reduced, while the measurements of the height of a tsunami have improved its resolution.

The 4G version of the DART System have the technology developed by the PMEL of the NOAA, which has been transferred to the private industry in the United States. A first prototype was deployed during 18 months in the United States, at an approximate depth of 900 meters, which allowed recordings of very high sampling rates (40 Hz), from which a detection algorithm was developed, being concordant with the use of batteries of low energy consumption.

The System DART 4G includes improvements in the BPR with a new pressure sensor and software that uses the detection and filtering algorithm for the broadcasting of data such as the tsunami height, while the earthquake reaches its breaking stage.

The new algorithms have been developed from the research of the data of tsunamis of close range and applying the most effective processing techniques.