@article{fdi:010083395,
  title = {{T}he {M}w 7.5 {T}adine ({M}ar{\'e}, {L}oyalty {I}slands) earthquake and related tsunami of 5 {D}ecember 2018 : seismotectonic context and numerical modeling},
  author = {{R}oger, {J}. and {P}elletier, {B}ernard and {D}uphil, {M}axime and {L}ef{\`e}vre, {J}{\'e}r{\^o}me and {A}ucan, {J}er{\^o}me and {L}ebellegard, {P}ierre and {T}homas, {B}. and {B}achelier, {C}{\'e}line and {V}arillon, {D}avid},
  editor = {},
  language = {{ENG}},
  abstract = {{O}n 5 {D}ecember 2018, a magnitude {M}w 7.5 earthquake occurred southeast of {M}ar{\'e}, an island of the {L}oyalty {I}slands archipelago, {N}ew {C}aledonia. {T}his earthquake is located at the junction between the plunging {L}oyalty {R}idge and the southern part of the {V}anuatu {A}rc, in a tectonically complex and very active area regularly subjected to strong seismic crises and earthquakes higher than magnitude 7 and up to 8. {W}idely felt in {N}ew {C}aledonia, it was immediately followed by a tsunami warning, confirmed shortly after by a first wave arrival at the {L}oyalty {I}slands tide gauges ({M}are and {L}ifou), and then along the east coast of {G}rande {T}erre of {N}ew {C}aledonia and in several islands of the {V}anuatu {A}rchipelago. {T}wo solutions of the seafloor initial deformation are considered for tsunami generation modeling, one using a non-uniform finite-source model from {USGS} and the other being a uniform slip model built from the {G}lobal {C}entroid {M}oment {T}ensor ({GCMT}) solution, with the geological knowledge of the region and empirical laws establishing relationships between the moment magnitude and the fault plane geometry. {B}oth tsunami generation and propagation are simulated using the {S}emi-implicit {C}ross-scale {H}ydroscience {I}ntegrated {S}ystem {M}odel ({SCHISM}), an open-source modeling code solving the shallow-water equations on an unstructured grid allowing refinement in many critical areas. {T}he results of numerical simulations are compared to tide gauge records, field observations and testimonials from 2018. {C}areful inspection of wave amplitude and wave energy maps for the two simulated scenarios shows clearly that the heterogeneous deformation model is inappropriate, while it raises the importance of the fault plane geometry and azimuth for tsunami amplitude and directivity. {T}he arrival times, wave amplitude and polarities obtained with the uniform slip model are globally coherent, especially in far-field locations ({H}ienghene, {P}oindimie and {P}ort {V}ila). {D}ue to interactions between the tsunami waves and the numerous bathymetric structures like the {L}oyalty and {N}orfolk ridges in the neighborhood of the source, the tsunami propagating toward the south of {G}rande {T}erre and the {I}sle of {P}ines is captured by these structures acting like waveguides, allowing it to propagate to the north-northwest, especially in the {L}oyalty {I}slands and along the east coast of {G}rande {T}erre. {A} similar observation results from the propagation in the {V}anuatu islands, from {A}neityum to {E}fate.},
  keywords = {{SEISME} ; {TRAITEMENT} {DE} {DONNEES} ; {MODELISATION} ; {TSUNAMI} ; {NOUVELLE} {CALEDONIE} ; {LOYAUTE} ; {MARE}},
  booktitle = {},
  journal = {{N}atural {H}azards and {E}arth {S}ystem {S}ciences},
  volume = {21},
  numero = {11},
  pages = {3489--3508},
  ISSN = {1561-8633},
  year = {2021},
  DOI = {10.5194/nhess-21-3489-2021},
  URL = {https://www.documentation.ird.fr/hor/fdi:010083395},
}