@article {lindner_bayesian_2023,
	title = {Bayesian regional moment tensor from ocean bottom seismograms recorded in the Lesser Antilles: implications for regional stress field},
	journal = {Geophysical Journal International},
	volume = {233},
	number = {2},
	year = {2023},
	month = {12/2022},
	pages = {1036{\textendash}1054},
	abstract = {Seismic activity in the Lesser Antilles (LA) is characterized by strong regional variability along the arc reflecting the complex subduction setting and history. Although routine seismicity monitoring can rely on an increasing number of island stations, the island-arc setting means that high-resolution monitoring and detailed studies of fault structures require a network of ocean bottom seismometers (OBS). As part of the 2016{\textendash}2017 Volatile recycling at the Lesser Antilles arc (VoiLA) project, we deployed 34 OBS stations in the forearc and backarc. During the deployment time, 381 events were recorded within the subduction zone. In this paper, we perform full-waveform regional moment tensor (RMT) inversions, to gain insight into the stress distribution along the arc and at depth. We developed a novel inversion approach, AmΦB{\textemdash}{\textquoteleft}Amphibious Bayesian{\textquoteright}, taking into account uncertainties associated with OBS deployments. Particularly, the orientation of horizontal components (alignment uncertainty) and the high noise level on them due to ocean microseisms are accounted for using AmΦB. The inversion is conducted using a direct, uniform importance sampling of the fault parameters within a multidimensional tree structure: the uniXtree-sampling algorithm. We show that the alignment of the horizontal OBS components, particularly in high noise level marine environments, influences the obtained source mechanism when using standard least-squares (L2) RMT inversion schemes, resulting in systematic errors in the recovered focal mechanisms including high artificial compensated linear vector dipole (CLVD) contributions. Our Bayesian formulation in AmΦB reduces these CLVD components by nearly 60~per~cent and the aberration of the focal geometry as measured by the Kagan angle by around 40~per~cent relative to a standard L2 inversion. Subsequently, we use AmΦB-RMT to obtain 45 (Mw \&gt; 3.8) regional MT solutions, out of which 39 are new to any existing database. Combining our new results with existing solutions, we subsequently analyse a total of 151 solutions in a focal mechanism classification (FMC) diagram and map them to the regional tectonic setting. We also use our newly compiled RMT database to perform stress tensor inversions along the LA subduction zone. On the plate interface, we observe the typical compressional stress regime of a subduction zone and find evidence for upper-plate strike slip and normal fault behaviour in the north that becomes a near arc-perpendicular extensional stress regime towards the south. A dominant slab perpendicular extensional stress regime is found in the slab at 100{\textendash}200~km beneath the central part of the arc. We interpret this stress condition to be a result of slab pull varying along the arc due to partial slab detachment along previously hypothesized lateral slab tear near Grenada, at the southern end of the LA arc, leading to reactivation of pre-existing structures around the subducted Proto-Caribbean ridge.},
	issn = {0956-540X},
	doi = {10.1093/gji/ggac494},
	url = {https://doi.org/10.1093/gji/ggac494},
	author = {Lindner, Mike and Rietbrock, Andreas and Bie, Lidong and Goes, Saskia and Collier, Jenny and Rychert, Catherine and Harmon, Nicholas and Hicks, Stephen P and Henstock, Tim and the VoiLA working group}
}
@article {cooper_variable_2020,
	title = {Variable water input controls evolution of the Lesser Antilles volcanic arc},
	journal = {Nature},
	volume = {582},
	number = {7813},
	year = {2020},
	note = {Number: 7813 Publisher: Nature Publishing Group},
	month = {jun},
	pages = {525{\textendash}529},
	abstract = {Oceanic lithosphere carries volatiles, notably water, into the mantle through subduction at convergent plate boundaries. This subducted water exercises control on the production of magma, earthquakes, formation of continental crust and mineral resources. Identifying different potential fluid sources (sediments, crust and mantle lithosphere) and tracing fluids from their release to the surface has proved challenging1. Atlantic subduction zones are a valuable endmember when studying this deep water cycle because hydration in Atlantic lithosphere, produced by slow spreading, is expected to be highly non-uniform2. Here, as part of a multi-disciplinary project in the Lesser Antilles volcanic arc3, we studied boron trace element and isotopic fingerprints of melt inclusions. These reveal that serpentine{\textemdash}that is, hydrated mantle rather than crust or sediments{\textemdash}is a dominant supplier of subducted water to the central arc. This serpentine is most likely to reside in a set of major fracture zones subducted beneath the central arc over approximately the past ten million years. The current dehydration of these fracture zones coincides with the~current locations of the highest rates of earthquakes and prominent low shear velocities, whereas the preceding history~of~dehydration is consistent with the locations of~higher volcanic productivity and thicker arc crust. These combined geochemical and geophysical data indicate that the structure and hydration of the subducted plate are directly connected to the evolution of the arc and its associated seismic and volcanic hazards.},
	keywords = {Geochemistry, Geodynamics, Geophysics, seismology, Volcanology},
	issn = {1476-4687},
	doi = {10.1038/s41586-020-2407-5},
	url = {https://www.nature.com/articles/s41586-020-2407-5},
	author = {Cooper, George F. and Macpherson, Colin G. and Blundy, Jon D. and Maunder, Benjamin and Allen, Robert W. and Goes, Saskia and Collier, Jenny S. and Bie, Lidong and Harmon, Nicholas and Hicks, Stephen P. and Iveson, Alexander A. and Prytulak, Julie and Rietbrock, Andreas and Rychert, Catherine A. and Davidson, Jon P.}
}
