Significant Impact of Hydrothermalism on the Biogeochemical Signature of Sinking and Sedimented Particles in the Lau Basin
| Type | : | ACL |
|---|---|---|
| Nature | : | Production scientifique |
| Au bénéfice du Laboratoire | : | Oui |
| Statut de publication | : | Publié |
| Année de publication | : | 2023 |
| Auteurs (10) | : | TILLIETTE Chloé GAZEAU Frederic CHAVAGNAC Valérie LEBLOND Nathalie MONTANES Maryline LEBLANC K SCHMIDT S CHARRIÈRE Bruno BHAIRY Nagib GUIEU Cecile |
| Revue scientifique | : | Journal of Geophysical Research-Oceans |
| Volume | : | 128 |
| Fascicule | : | 12 |
| Pages | : | |
| DOI | : | 10.1029/2023JC019828 |
| URL | : | https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2023JC019828 |
| Abstract | : | Abstract Iron (Fe) is an essential micronutrient for diazotrophs, which are abundant in the Western Tropical South Pacific Ocean (WTSP). Their success depends on the numerous trace metals, particularly Fe, released from shallow hydrothermal vents along the Tonga Arc. This study aimed to explore the spatio-temporal impact of hydrothermal fluids on particulate trace metal concentrations and biological activity. To identify the composition of sinking particles across a wide area of the WTSP, we deployed sediment traps at various depths, both close and further west of the Tonga Arc. Seafloor sediments were cored at these deployment sites, including at a remote location in the South Pacific Gyre. The sinking particles were composed of a large amount of biological material (up to 88 mg d−1), indicative of the high productivity of the region. A significant portion of this material (∼21 ± 12 wt.\%) was lithogenic of hydrothermal origin, as revealed through Al-Fe-Mn tracing. The sinking material showed similar patterns between lithogenic and biogenic fractions, indicating that hydrothermal input within the photic layer triggered surface production. A hydrothermal fingerprint was suggested in the sediments due to the high sedimentation rates (>47 cm kyr−1) and the presence of large, heterogeneous, metal-rich particles. The presence of nearby active deep hydrothermal sources was suspected near the Lau Ridge due to the large particle size (1–976 μm) and the significant excess of Fe and Mn (2–20 wt.\%). Overall, this study revealed that hydrothermal sources have a significant influence on the biogeochemical signature of particles in the region. |
| Mots-clés | : | hydrothermal impacts, biological production, composition of sinking and sedimented material, trace metals, Tonga volcanic arc, western tropical south Pacific ocean |
| Commentaire | : | e2023JC019828 2023JC019828 |
| Tags | : | - |
| Fichier attaché | : | - |
| Citation | : |
Tilliette C, Gazeau F, Chavagnac V, Leblond N, Montanes M, Leblanc K, Schmidt S, Charrière B, Bhairy N, Guieu C (2023) Significant Impact of Hydrothermalism on the Biogeochemical Signature of Sinking and Sedimented Particles in the Lau Basin. J Geophys Res-Oceans 128 | doi: 10.1029/2023JC019828
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