20th-century strain accumulation on the Lesser Antilles megathrust based on coral microatolls

Philibosian, B.; Feuillet, Nathalie; Jacques, Éric; Accardo, Jennifer Weil; Mériaux, Anne-Sophie; Guihou, Abel; Anglade, A.

doi:10.1016/j.epsl.2021.117343

Cited by 9 publications

(17 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Interestingly, we also note that the slab is found about 50 km below both eastern Barbuda and La Désirade islands, which share similar maximum elevations for their LIG shorelines. The corresponding seismogenic zone would hence extend below the Moho (Figure 5), as proposed by previous studies based on seismicity (Bie et al, 2020;Laigle et al, 2013;Ruiz et al, 2013) and coral microatolls (Philibosian et al, 2022;Weil-Accardo et al, 2016).…”

Section: Downdip Limit Of the Seismogenic Zonesupporting

confidence: 69%

“…The study of coral microatolls in Antigua documents RSL changes westward of Barbuda. Submergence rates inferred from one sampled microatoll indicate a drastic decrease around 1980 from 9 mm/yr to at most 2 mm/yr, perhaps due to a change in location or degree of megathrust coupling (Philibosian et al., 2022). Thus, for the last several decades, eastern Barbuda seems to have submerged faster than its westward neighboring island, in agreement with the expected trench‐perpendicular deformation pattern.…”

Section: Discussionmentioning

confidence: 99%

“…Microatolls, which are massive corals living in the intertidal zone with upward growth limited by the annual lowest tide, are the highest corals in a modern reef. In Hog Hole (location 4 in Figure 1b), Philibosian et al (2022) measured their living upper surfaces at elevations ranging between 2 and 16 cm below the annual lowest tide, corresponding to depths of 25-39 cm below MSL, which we express as −0.3 ± 0.1 m relative to MSL (Figure 4a). Subaerial erosion might have planed off the fossil reef and lowered its elevation.…”

Section: Relative Sea-level Estimate Of the Codrington Formationmentioning

confidence: 99%

See 2 more Smart Citations

Interaction Between Climate and Tectonics in the Northern Lesser Antilles Inferred From the Last Interglacial Shoreline on Barbuda Island

Weil-Accardo

Feuillet

Philibosian

et al. 2022

Geochem Geophys Geosyst

Self Cite

View full text Add to dashboard Cite

The Lesser Antilles island arc is located on the eastern border of the Caribbean plate (Figure 1a), where the North and South American plates are subducting below the overriding Caribbean plate at a convergence rate of about 2 cm/yr (DeMets et al., 2000). The historical seismicity catalog, beginning with the first European settlements, mentions only two ≈ Mw 8 likely megathrust earthquakes, occurring 4 years apart, in 1839 and 1843 offshore Martinique and Guadeloupe islands, respectively (Figure 1a) (Feuillard, 1985;Robson, 1964). With its low convergence rate, evidence of weak seismicity from the instrumental record, and lack of major earthquakes since the year 1900, the Lesser Antilles megathrust has often been considered as aseismic (Stein et al., 1982), corroborated by the low plate interface coupling derived from geodetic data (Manaker et al., 2008;Symithe et al., 2015;van Rijsingen et al., 2020). However, deformation patterns within the short time window provided by instrumental records might not be representative of the subduction interface behavior over longer timescales. Moreover, the spatial coverage of geodetic stations is sparse and instruments are often located far from the trench, where they may not be sensitive to small seismogenic fault patches.Several lines of evidence, however, are not consistent with the conclusions of the short-term and sparse geodetic measurements. The existence of emergent and submerged marine terraces in the Guadeloupe archipelago (from the forearc to the arc) highlight a pattern of long-term vertical deformation, which has been interpreted to be linked to plate-scale subduction processes (

show abstract

Section: Downdip Limit Of the Seismogenic Zonesupporting

confidence: 69%

Section: Discussionmentioning

confidence: 99%

Section: Relative Sea-level Estimate Of the Codrington Formationmentioning

confidence: 99%

See 1 more Smart Citation

Interaction Between Climate and Tectonics in the Northern Lesser Antilles Inferred From the Last Interglacial Shoreline on Barbuda Island

Weil-Accardo

Feuillet

Philibosian

et al. 2022

Geochem Geophys Geosyst

Self Cite

View full text Add to dashboard Cite

show abstract

“…The subsidence derived from micro-atolls has been interpreted as the result of interseismic locking of the subduction interface or co-seismic displacements during megathrust earthquakes (Leclerc et al 2015;Weil-Accardo et al 2016;Philibosian et al 2022). However, the agreement between the 'geological' subsidence and the 'geodetic' one, while the subduction interface currently has very low interseismic coupling (i.e.…”

Section: O B S E Rv E D V E Rt I C a L M O T I O N Smentioning

confidence: 99%

“…1; Leclerc et al 2014) and Martinique (Leclerc et al 2015) indicate subsidence at 0.3-0.45 mm yr −1 over the past 125 ka. Recent micro-atoll results north of Martinique, covering ∼25-85 yr in the 20th century and encompassing the region between Marie Galante and Barbuda show subsidence at 0.3-8 mm yr −1 (Philibosian et al 2022). Therefore, at least the central and northern parts of the Lesser Antilles arc have been experiencing tectonic subsidence over this time interval, an observation that has been related to temporal variations in friction of an overall locked plate interface or to the accumulation of coseismic deformation from megathrust earthquakes that would not be fully compensated by opposite interseismic uplift (Leclerc & Feuilet 2019).…”

mentioning

confidence: 99%

Ongoing tectonic subsidence in the Lesser Antilles subduction zone

Rijsingen

Calais

Jolivet

et al. 2022

Geophysical Journal International

View full text Add to dashboard Cite

Summary Geological estimates of vertical motions in the central part of the Lesser Antilles show subsidence on timescales ranging from 125.000 to 100 years, which has been interpreted to be caused by interseismic locking along the subduction megathrust. However, horizontal GNSS velocities show that the Lesser Antilles subduction interface is currently building up little to no elastic strain. Here we present new present-day vertical velocities for the Lesser Antilles islands and explore the link between short- and long-term vertical motions and their underlying processes. We find a geodetic subsidence of the Lesser Antilles island arc at 1-2 mm/yr, consistent with the ∼100-year trend derived from coral micro-atolls. Using elastic dislocation models, we show that a locked or partially-locked subduction interface would produce uplift of the island arc, opposite to the observations, hence supporting a poorly-coupled subduction. We propose that this long-term, margin-wide subsidence is controlled by slab dynamic processes, such as slab rollback. Such processes could also be responsible for the aseismic character of the subduction megathrust.

show abstract

Modeling the potential genesis of tsunamis from below an accretionary prism and their potential impact: a case study along the eastern boundary of the Caribbean Plate

2023

View full text Add to dashboard Cite

20th-century strain accumulation on the Lesser Antilles megathrust based on coral microatolls

Cited by 9 publications

References 27 publications

Interaction Between Climate and Tectonics in the Northern Lesser Antilles Inferred From the Last Interglacial Shoreline on Barbuda Island

Interaction Between Climate and Tectonics in the Northern Lesser Antilles Inferred From the Last Interglacial Shoreline on Barbuda Island

Ongoing tectonic subsidence in the Lesser Antilles subduction zone

Modeling the potential genesis of tsunamis from below an accretionary prism and their potential impact: a case study along the eastern boundary of the Caribbean Plate

Contact Info

Product

Resources

About