Installation of a tide gauge at Toamasina Installation of a tide gauge at Toamasina


Installation of a tide gauge at Toamasina


From 22 to 26 March 2010, SHOM installed a permanent tide gauge at Toamasina (Madagascar) during a stopover by the hydro-oceanography ship, Beautemps-Beaupré in this port. The installation was carried out within the infrastructures constructed with the support of the UN-ISDR (International Strategy for Disaster Reduction) by the Madagascar Meteorology Authorities and the tidal observatory will be managed by this organisation.

This installation on the east coast of Madagascarwas undertaken as part of the French contribution to the tsunami warning system in the Indian Oceaninitiated in 2005. This initiative is coordinated by Météo France. It is the third installation operated by SHOM for this programme and the first for the benefit of a foreign country after the tide gauge installations at La Réunion in October 2007 and in Mayottein November 2008. 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 Toamasina tide gauge transmits its data via the Meteosat satellites and now contributes to the network of tide gauges that supply 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. The data from the Toamasina tide gauge are currently on line on the IOC Internet website (, which is therefore supplying virtually real-time data on the height of water at Toamasina every minute.

This action contributes to the efforts of consolidation of the 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 and the measurement of cyclone surges) this tide gauge is now the only one in service in Madagascar and presents an issue for the monitoring of sea levels in this part of the Indian Ocean. This difficulty is studied as part of the worldwide programme GLOSS (Global Sea Level Observing System).

Source : SHOM