Première observation par submersible du rétrochevauchement majeur d'un prisme d'accrétion (fosse de Nankai, Japon sud-ouest)

International audienceDuring the Kaiko-Nankai cruise, several dives were devoted to the exploration of a linear 2000m deep ridge (yukie ridge) located at the trench-slope break of the Eastern Nankai accretionary wedge, off southwest Japan. This ridge is locally one of the two most active venting sites discovery across the prism. Based on the interpretation of seismic lines together with in-situ structural observations, whe show that this ridge is basically an asymmetrical anticline related to the motion along a prominent backthrust (landward verging thurst fault). This backthrust evolves north-eastward to a 5 km wide deformation zone with dominant landward vergence. This backthrust system vanished westward as Zenizu ridge vanishes too and is thus present only opposite the Zenisu intra-oceanic deformed zone. We thus propose to related the development of the backthrust to the presence of an older compressional oceanic ridge buried below the prism. Surprisingly, no significant fluid venting is associated with the outcrop of the main backthrust whereas spectacular seeps (carbonate sementation and biloogical activity) were observed in a strike-slip zone crossing the Yukie anticlinal ridge but none on the northern slope

Normal faulting of the Daiichi-Kashima Seamount in the Japan Trench revealed by the Kaiko I cruise, Leg 3

International audienceA detailed topographic and geophysical survey of the Daiichi-Kashima Seamount area in the southern Japan Trench, northwestern Pacific margin, clearly defines a high-angle normal fault which splits the seamount into two halves. A fan-shaped zone was investigated along 2-4 km spaced, 100 km long subparallel tracks using narrow multi-beam (Seabeam) echo-sounder with simultaneous measurements of gravity, magnetic total field and single-channel seismic reflection records. Vertical displacement of the inboard half was clearly mapped and its normal fault origin was supported. The northern and southern extensions of the normal fault beyond the flank of the seamount were delineated. Materials on the landward trench slope are displaced upward and to sideways away from the colliding seamount. Canyons observed in the upper landward slope terminate at the mid-slope terrace which has been uplifted since start of subduction of the seamount. Most of the landward slope except for the landward walls aside the seamount comprises only a landslide topography in a manner similar to the northern Japan Trench wall. This survey was conducted on R/V "Jean Cbarcot" as a part of the Kaiko I cruise, Leg 3, in July-August 1984 under the auspices of the French-Japanese scientific cooperative program

The Japan Trench and its juncture with the Kuril Trench: cruise results of the Kaiko project, Leg 3

International audienceThis paper presents the results of a detailed survey combining Seabeam mapping, gravity and geomagnetic measurements as well as single-channel seismic reflection observations in the Japan Trench and the juncture with the Kuril Trench during the French-Japanese Kaiko project (northern sector of the Leg 3) on the R/V "Jean Charcot". The main data acquired during the cruise, such as the Seabeam maps, magnetic anomalies pattern, and preliminary interpretations are discussed. These new data cover an area of 18,000 km 2 and provide for the first time a detailed three-dimensional image of the Japan Trench. Combined with the previous results, the data indicate new structural interpretations. A comparative study of Seabeam morphology, single-channel and reprocessed multichannel records lead to the conclusion that along the northern Japan Trench there is little evidence of accretion but, instead, a tectonic erosion of the overriding plate. The tectonic pattern on the oceanic side of the trench is controlled by the creation of new normal faults parallel to the Japan Trench axis, which is a direct consequence of the downward flexure of the Pacific plate. In addition to these new faults, ancient normal faults trending parallel to the N65 ° oceanic magnetic anomalies and oblique to the Japan trench axis are reactivated, so that two directions of normal faulting are observed seaward of the Japan Trench. Only one direction of faulting is observed seaward of the Kuril Trench because of the parallelism between the trench axis and the magnetic anomalies. The convergent front of the Kuril Trench is off~t left-laterally by 20 km relative to those of the Japan Trench. This transform fault and the lower slope of the southernmost Kuril Trench are represented by very steep scarps more than 2 km high. Slightly south of the juncture, the Erimo Seamount riding on the Pacific plate, is now entering the subduction zone. It has been preceded by at least another seamount as revealed by magnetic anomalies across the landward slope of the trench. Deeper future studies will be necessary to discriminate between the two following hypothesis about the origin of the curvature between both trenches: Is it due to the collision of an already subducted chain of seamounts? or does it correspond to one of the failure lines of the America/Eurasia plate boundary

The Lancet NCDI Poverty Commission: bridging a gap in universal health coverage for the poorest billion

For the poorest of our world, non-communicable diseases and injuries (NCDIs) account for more than a third of their burden of disease; this burden includes almost 800000 deaths annually among those aged younger than 40 years, more than HIV, tuberculosis, and maternal deaths combined. • Despite already living in abject poverty, between 19 million and 50 million of the poorest billion spend a catastrophic amount of money each year in direct out-of-pocket costs on health care as a result of NCDIs. • Progressive implementation of affordable, cost-effective, and equitable NCDI interventions between 2020 and 2030 could save the lives of more than 4·6 million of the world’s poorest, including 1·3 million who would otherwise die before the age of 40 years. • To avoid needless death and suffering, and to reduce the risk of catastrophic health spending, essential NCDI services must be financed through pooled, public resources, either from increased domestic funding or external funds. • National governments should set and adjust priorities based on the best available local data on NCDIs and the specific needs of the worst off. • International development assistance for health should be augmented and targeted to ensure that the poorest families affected by NCDIs are included in progress towards universal health care