LAMARCHE , G.

The 29 September 2009 South Pacific tsunami reached the islands of Futuna and Alofi, 650 km to the west of its origin, between 7 and 7:20 am on 30 September, local time. No warning was issued. We measured run-up heights and inundation distances at 41 sites around the islands. The worst impact (4.5 m run-up; 85 m inundation; 3.8 m flow depth)...

Marine Geophysical Researches, v. 24, n. 3-4, p. 311-327, 2003. http://dx.doi.org/10.1007/s11001-004-1945-9

The Matakaoa Debris Flow (MDF) is a 200-km-long mass-transport deposit resulting from the failure of the Matakaoa continental margin, northeast New Zealand, ca. 38-100 ky ago. In this study, high-quality bathymetric and seismic reflection data are used to identify the morpho-structural characters that reflect the kinematics of the MDF, as well...

Four >100 km3 mass-transport deposits (MTDs) identified from their morphology and seismic facies across the Matakaoa Margin and Raukumara fore-arc basin, NE New Zealand, constitute the Matakaoa Submarine Instability Complex (MSIC). MSIC originates from a 45-km-wide, 1100-m-high reentrant in the continental slope. The deposits resulted from...

We first present a synthesis of the Macquarie Ridge Complex (MRC) tectonic structures as well as paleo-reconstruction models of the kinematic evolution of the Pacific-Australia plate boundary south of New Zealand, since the Eocene. We then ascertain the geodynamical conditions that preceded subduction initiation, and identify the nature and...

During the Pleistocene, the Matakaoa Debris Avalanche (MDA) removed ~ 430 km3 of material and formed a 50 km-long re-entrant in the Matakaoa margin, offshore East Cape, New Zealand. In this study, we examine the post-avalanche processes of continental slope reconstruction via the analysis of bathymetry, seismic-reflection data and one sediment...

Multi-proxy studies of trench sediments from Futuna island, in the Wallis and Futuna archipelago, have produced a record of two palaeotsunamis dated to around 1860-2000 BP and c. 470 BP. One of the most useful proxies in this study has been the archaeological data associated with occupations that immediately underlie the deposits associated...

The assessment of sediment transport pathways in carbonate settings is complicated by ecologically sourced sediment. Tracers such as foraminifera have previously been used in these settings to describe the movement of coastal sediments on spatial and temporal scales where traditional grain size methods have limited use. The present study builds...

We investigated the tsunami hazard in the remote French territory of Wallis and Futuna, Southwest Pacific, using the Gerris flow solver to produce numerical models of tsunami generation, propagation and inundation. Wallis consists of the inhabited volcanic island of Uvéa that is surrounded by a lagoon delimited by a barrier reef. Futuna and the...

The recent 29 September 2009 South Pacific and 27 February 2010 Chilean events are a graphic reminder that the tsunami hazard and risk for the Pacific Ocean region should not be forgotten. Pacific Islands Countries (PICs) generally have short (< 150 years) historic records, which means that to understand their tsunami hazard and risk...