Let me tell you about a rather cool study that came out of expedition #SO292, out in the #Coral #Sea. One of the things we wanted to understand better was what happens on the slope of platforms formed by the growth of #reefs (carbonate platforms)... and ho... there is so much going on there. There are submarine cliffs, and canyons, sediment waves and things that live in the deep.
It is the type of #science that takes a team and a big ship to opens our understanding.
New paper!
With me and colb. from expedition #SO292. From the Queensland Plateau, we present to you - a new type of ( #Mesophotic ) #Halimeda #bioherm, one that possibly got its shape by #storms.
https://link.springer.com/article/10.1007/s00338-024-02500-0
Morphology, internal structure, and in situ facies distribution of mesophotic Halimeda bioherms from the Queensland Plateau (NE Australia) are presented based on hydroacoustic and oceanographic data, seafloor observations, and discrete sediment sampling carried out during RV SONNE cruise SO292 in 2022. Halimeda buildups consist of cone-like mounds up to 500 m in diameter and 3–10 m high, with gentle slopes (2°–5° on the top of Tregrosse Bank). Bioherms occur in water depths of 10–70 m, with most bioherm between 50 and 65 m. Their internal structure consists of aggrading low-amplitude reflections at the core of the bioherm interfingering with high-amplitude reflections to the flanks. Surface facies distribution displays one to four facies belts, from distal to proximal: Halimeda rudstone, Halimeda rudstone with living plants, Halimeda rudstone with coralgal debris, and coralgal boundstone (when present, occupied the top of the bioherms). It is proposed that the alternation of two key processes contributes to the formation of these bioherms: (1) in situ accumulation of Halimeda debris and (2) episodic dismantling of the mesophotic coralgal boundstone at the centre of the bioherm by severe storms. These storms may dismantle the mesophotic reef and export coralgal rubble to the flanks. Flanks may be recolonized by Halimeda during fair-weather periods. Due to their different geomorphic expressions, complex internal structure, and surficial facies distribution, we suggest that the buildups of the Queensland Plateau represent a new Halimeda bioherm morphotype, distinct from previously described bioherms on the adjacent Great Barrier Reef and elsewhere globally.
Dr. Or M. Bialik