Installation of a tide gauge in Mayotte for the tsunami warning system in the Indian Ocean
From 9 to 24 November 2008, two technicians from SHOM went to Mayottein order to install the 31st permanent tide gauge of the sea level observation network (RONIM) at Dzaoudzi. The new instrument measures the height of the water along the Issouf-Ali jetty at Dzaoudzi and transmits these data in real time. For this installation, SHOM received technical support from its local partner: the Direction de l'Equipement de Mayotte
This installation was provided as part of the French contribution to the tsunami warning system in the Indian Oceaninitiated in 2005; this initiative is directed by the French meteorological office. It is the second installation operated by SHOM in this context after the first was installed at La Réunion in October 2007.
Installation of the tsunami warning system in the Indian Oceanwas carried out under the aegis of the UNESCO Intergovernmental Oceanographic Commission (IOC), and results from the event on 26 December 2004. The tide gauges transmit their data to the regional warning centres and contribute to the warning system by confirming the existence of a tsunami. They make it possible, especially when a severe seismic event occurs, to confirm the arrival of a wave in the regions or countries which are potentially on the alert. In this context, the data from the tide gauge at Dzaoudzi are currently on line at the IOC Internet website, which is therefore supplying virtually real-time data on the height of water at Dzaoudzi every minute. This is already contributing to the efforts to set up an operational system to warn of the risk of a tsunami in the Indian Ocean. In addition, it also contributes to a better understanding of the tsunami phenomena by providing data for modelling aimed at prevention.
Besides its benefit for a tsunami warning and many other applications (such as tide prediction), it is worth remembering that this site contributes to the worldwide GLOSS programme on monitoring sea levels (GLOSS station No. 96), which falls within the scope of the climate warming problem. Data from Dzaoudzi will therefore also be available in GLOSS and in REFMAR. The installation of this new instrument will therefore make it possible to resume the acquisition of sea level measurements at Dzaoudzi, and to continue the historical series that has already been formed.