SENAT
Report n° 117 (2007-2008) by M. Roland COURTEAU, Senator (for the parliament office for the evaluation of scientific and technological choices) - Appendix to the minutes of the 7 December 2007 session
Disponible au format Acrobat (21 Moctets)
b) In the Caribbean
In the Caribbean, the commitment of France to set up a warning system runs up against numerous obstacles: not only has the public only recently been made aware of the tsunami risk, but the existing measuring devices are not suited to the setting up of an effective tsunami warning system. In addition, due to the lack of both political will at the national level and a specific budget to fund their actions, those scientific organizations representing France in the ICG/Caribbean-TWS enjoy little room for manoeuvre.
The civil protection authorities have only very recently taken into consideration the tsunami risk. Although the tsunami risk is certainly familiar, up until now, it has not been considered a priority due to the difficulties already encountered in dealing with those risks that are most present in the collective conscience (cyclones, earthquakes, volcanic eruptions).
During your rapporteur's visit to Martinique, he was struck by the poor preparation of this département with regard to natural geophysical risks. 56 ( * ) Indeed, even though Martinique is exposed to a high earthquake risk, most buildings do not meet the seismic-safety standards, while the population remains unreceptive to information and public-awareness campaigns. For instance, your rapporteur learned that in the event of an earthquake comparable in magnitude to that of 1839 57 ( * ) , the prefecture, most fire stations and the island's hospitals would be the first buildings destroyed, thereby seriously hampering the subsequent relief effort. Likewise, the volcanic and seismic observatories in Martinique and Guadeloupe do not meet the safety standards.
France's active participation in the ICG/Caribbean-TWS is also hindered by the fact that the measuring devices are not suited to the technical demands of a tsunami warning system.
Martinique is equipped with two tide gauges: one in Fort-de-France belonging to SHOM and one installed in Le Prêcheur by the departmental council, which is also expected to install a third tide gauge on the Atlantic coast.
In Guadeloupe, there are 5 tide gauges, one of which belongs to SHOM, with the remaining 4 being managed by the OVSG ("Volcanic and Seismological Observatory of Guadeloupe"). 58 ( * ) The regional council should fund a sixth tide gauge planned for Les Saintes.
Nevertheless, none of the tide gauges transmit their data in real-time and neither SHOM nor IPGP has the necessary funds to bring them updated and cover the cost of transmissions. What's more, SHOM has no local antenna in the West Indies. As a result, no SHOM specialist attends meetings held by the working subgroup on devices for measuring sea level within the framework of the ICG/Caribbean-TWS.
IPGP, via its two observatories, is responsible for monitoring the seismicity of the French West Indies. However, its seismic network needs to be modernized, particularly with regard to data transmission which is currently carried out by radio and therefore incompatible with the demands of an effective tsunami warning system.
The director of the OVSM ("Volcanic and Seismological Observatory of Martinique") has been chosen as the National Contact for the ICG/Caribbean-TWS, because of the fundamental role that the seismic network is supposed to play in the tsunami warning system. Nevertheless, since the OVSM is not on-call 24 hours a day, 7 days a week, the Météo France centre in Martinique has been put in charge of receiving the warning messages issued by PTWC and then transmitting them to the prefect.
During your rapporteur's visit to Martinique to evaluate France's involvement in the setting up of a tsunami warning system for the Caribbean, he was shocked to see France discard its international responsibilities by assigning them to scientific organizations that, for want of any precise ministerial orders, not only have difficulty in acting, but also cannot legitimately represent France.
Today, the silence of the French government forces IPGP to alone define, via the OVSM, the orientation of France's contribution to the warning system. Considering the lack of political support and the limited means at its disposal, the OVSM, expecting the University of Puerto Rico to eventually be chosen as the regional warning centre, has chosen to limit France's involvement to the sharing of tide gauge and seismological data with the other ICG/Caribbean-TWS member states.
To this end, the OVSM has mobilized the GEOSCOPE network and built bridges with SHOM. In addition, OVSM's actions have allowed for a real raising of awareness among public authorities and local players with regard to the tsunami risk, which is now included in the "West Indies-Guiana Risk Club" working group, which gathers together the various partners involved in the monitoring and management of natural risks.
Nevertheless, your rapporteur considers that only the government can legitimately decide French policy. In addition, only the French government has (or should have) a global view of the various negotiations currently under way in all four basins, allowing it to make the most pertinent decisions. Also, your rapporteur would like to point out that France could become the regional tsunami warning centre in the Caribbean, if CEA were to assume this responsibility in the Mediterranean.
During his visit to Martinique, your rapporteur learned that the then Minister of the Overseas Territories had instructed the prefect to set up a specialized emergency plan modeled after the French Polynesian plan. Your rapporteur recognizes that a plan for the organization of emergency prior to a warning being given is, in fact, indispensable for ensuring the population's protection. However, this request cannot be satisfied without first obtaining the necessary information for the elaboration of such a plan.
Indeed, the organization of emergency assistance measures will vary according to the time delay available (before the arrival of the tsunami) to the civil-protection services; establishing this reaction time requires an excellent understanding of those zones liable to provoke a tsunami.
In addition, the measures to be carried out depend on the tsunami-vulnerability of the concerned coasts. Your rapporteur would like to point out that BRGM has been assigned with carrying out just such a study by the Ministry of Ecology. However, due to the lack of a precise bathymetry near the coasts, the results are not sufficiently reliable to be used for the elaboration of a specialized emergency plan.
* 56 France's overseas départements are exposed to a host of natural hazards besides geophysical risks such as cyclones or those linked to heavy rains such as landslides and inundations. However, considering the subject of this study, your rapporteur has chosen to focus his attention on those natural hazards liable to generate a tsunami: namely, earthquakes and collapsing volcanoes.
* 57 Martinique's last devastating earthquake dates back to 1839 and statistics on earthquake occurrency suggest that the next earthquake is imminent.
* 58 The tsunami of 13 July 2003 caused by the collapsing dome of the Montserrat volcano caused some damage in Guadeloupe and served as a reminder of this island's vulnerability to tsunamis. Therefore, in 2004, the Ministry of Overseas Territories financed the installation of 4 tide gauges to continuously monitor variations in sea level, in order to analyze the site effects and propagation times of an eventual tsunami on Guadeloupe's coasts.