Publications scientifiques

The COAST-HF_Marel-Iroise station is a scientific floating platform in the Ifremer in situ test site of Sainte Anne du Portzic equipped with various sensors to monitor the local metocean conditions (Trasch Martin, 2023). It provides a rich array of input data for field campaign on mooring line tension of this station, both with and without the presence of biofouling.

In this study, alternatively to the megathrust, we identify upper-plate normal faults orthogonal to the trench as a possible tsunami source along the Lesser Antilles subduction zone. The Morne Piton fault system is such a trench-perpendicular upper crustal fault at the latitude of Guadeloupe.

In the context of climate change, height and frequency variations in extreme sea levels (ESLs) are studied using deterministic and probabilistic approaches. However, this type of approach does not highlight the dynamic effects (waves, currents) generated by metocean events (storms, cyclones, long swells, and tsunamis) beyond their effects on sea levels. In particular, ESL estimates are calculated by considering the main determining physical factors but cannot include all the effects of these factors. Ultimately, this can lead to confusion between ESL and hazard.

Understanding and precisely dating the sedimentological imprint of storm-induced back-barrier washover deposits is challenging, even more so in macro-tidal environments. Indeed, in such a situation, significant storms may not lead to any washover deposits, for instance if they occurred during low tide. To tackle this challenge, we propose a method based on crossing sedimentology, historical impacts from archives and weather-marine data, together with dating, statistics and modeling technique.

The storm surge is the non-tidal component of coastal sea-level. It responds to the atmosphere both through the direct effect of atmospheric pressure on the sea-surface, and through Ekman transport induced by wind-stress. Tide gauges have been used to measure the sea-level in coastal cities for centuries, with many records dating back to the 19th-century or even further, at times when direct pressure observations were scarce.

Dans ce numéro spécial, une collaboration de l'Association des amis du marégraphe de Marseille et de l'AFT, le lecteur pourra, lui-même, se faire une idée, aussi scientifique que précise, du phénomène. En effet, l'élévation de plus en plus rapide du niveau moyen de la mer est un des indicateurs des changements climatiques anthropiques. Ce numéro aborde donc, grâce à un panel de spécialistes, les techniques de la mesure, du marégraphe aux méthodes spatiales et GNSS puis les corrections de ces mesures pour les rendre indépendantes des mouvements terrestres.

In this study, we estimate the absolute vertical land motions at three tidal stations with collocated Global Navigation Satellite System (GNSS) receivers over French Polynesia during the period 2007–2020, and obtain, as ancillary results, estimates of the absolute changes in sea level at the same locations. To verify our processing approach to determining vertical motion, we first modeled vertical motion at the International GNSS Service (IGS) THTI station located in the capital island of Tahiti and compared our estimate with previous independent determinations, with a good agreement.

In this data paper, the sea level time series at Socoa (Saint-Jean-de-Luz, southwestern France) is extended through a data archaeology exercise. We conducted a comprehensive study of national and local archives to catalogue water level records stored in ledgers (handwritten record books) and charts (marigrams from mechanical float gauges), along with other associated documents (metadata). A dedicated effort was undertaken to preserve more than 2000 documents by archiving them in digital formats.

A first characterization of greenhouse gases had been carried out to study their role and impact in a productive transitional coastal system of the southern Portugal – Ria Formosa lagoon. To this purpose, the partial pressure of CO₂ (pCO₂) and the concentration of dissolved CH₄ and N₂O have been measured. Two surveys were carried out during 2020, at low tide under typical conditions of Spring (March) and end of Summer (October).