Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks

无线传感器网络，作为全球未来十大技术之一，集成了传感器技术、嵌入式计算技术、分布式信息处理和自组织网技术，可实时感知、采集、处理、传输网络分布区域内的各种信息数据，在军事国防、生物医疗、环境监测、抢险救灾、防恐反恐、危险区域远程控制等领域具有十分广阔的应用前景。 本文研究分析了无线传感器网络的已有路由协议，并针对大规模的无线传感器网络设计了一种树状路由协议，它根据节点地址信息来形成路由，从而简化了复杂繁冗的路由表查找和维护，节省了不必要的开销，提高了路由效率，实现了快速有效的数据传输。 为支持此路由协议本文提出了一种自适应动态地址分配算——ADAR（AdaptiveDynamicAddre...As one of the ten high technologies in the future, wireless sensor network, which is the integration of micro-sensors, embedded computing, modern network and Ad Hoc technologies, can apperceive, collect, process and transmit various information data within the region. It can be used in military defense, biomedical, environmental monitoring, disaster relief, counter-terrorism, remote control of haz...学位：工学硕士院系专业：信息科学与技术学院通信工程系_通信与信息系统学号：2332007115216

Introduction to "Caribbean geosciences"

International audienceThis special issue includes papers covering various topics of importance in the Caribbean such as geodynamics, environmental evolutions and natural hazards (fig. 1). This collection of articles focuses in particular on geodynamic processes occurring along the Caribbean plate boundaries, on volcanic hazards and on flooding. Given the recently increased societal importance of these subjects, we hope that the regional geological community and the local policy makers and government officials of the Caribbean countries will find this a timely and valuable update regarding research advances on these topics. We decided to publish this issue following the Caribbean Geological Conference, which has been held every 3 years since 1955 and took place in Guadeloupe for its 19th meeting from the 21st to the 24th of March 2011

Eocene to early Miocene evolution of the northern Lesser Antilles volcanic arc – new inputs from geochemistry of the St. Barthelemy island lavas

International audienceThe Lesser Antilles arc, still active nowadays, results from the westward subduction of the North and South American plate beneath the Caribbean plate. Along the Lesser Antilles trench, the volcanic arc regionally shows a north-south dichotomy. To the south the arc emplaced and stayed in a rather steady-state position since the Late Oligocene-Early Miocene period whereas, to the north, remnants of a Eocene-Miocene arc crop out in the forearc location of the present-day active volcanoes. This has been interpreted as a migration of the volcanism (e.g. Legendre et al., 2018). While magmatic products of the three main periods of activity are still present in the southern part of the arc, to the northern part they display on two distinct arc. Petro-geochemical study of the magmatic products from the different volcanic islands can be used as a powerful tool to discuss the geodynamical evolution of the Lesser Antilles arc through time and space. Saint-Barthelemy Island belongs to the northern part of the Lesser Antilles arc, corresponding to the oldest period of the arc activity. Major and trace elements and Sr, Nd, Pb and Hf isotopes have been measured on 24 representative lavas from the Saint Barthelemy island selected in order to cover the variability of differentiation degree and age. Studied samples, ranging from basalt to rhyolite with a majority of andesite, mostly belong to the calc-alkaline series. All samples show significant LREE/HREE enriched patterns normalized to CHUR with an increase of the enrichment factor through time. Middle-Eocene samples exhibit the smallest LREE/HREE enrichment factor combined to the lowest REE content. Extended trace element patterns, normalized to Depleted Mantle, show a marked enrichment in large ion lithophile elements (LILE) and Pb combined to significant negative anomalies in high-field strength elements (HFSE). Such features arc typical of samples formed in subduction zone and support various participation degree of dehydration fluids. Sr-Nd-Pb-Hfinitial isotopes from all studied samples are located in the worldwide arc domain in Nd-Sr, Nd-Hf and Pb-Pb diagrams but yield significant variation which can be interpreted in terms of variations in source components and percentage of fluid participation. At last, comparing Saint Barthelemy samples with synchronous magmatic products of Saint-Martin and Martinique islands outlines the similarity between Saint Barthelemy and Saint-Martin supporting a decoupled evolution of the northern part of the Lesser Antilles arc relative to its southern segment

Eocene to early Miocene evolution of the northern Lesser Antilles volcanic arc – new inputs from geochemistry of the St. Barthelemy island lavas

International audienceLesser Antilles arc presents three main periods of volcanic activity. The oldest period is occurring during the Eocene-Oligocene, then there has Miocene period, and the last period is occurring from the Plio-Pleistocene to recent. At the southern part of the arc, the magmatic products overlapped the three periods. Whereas at the northern part of the arc, the magmatic products evolve into two distinct branches suggesting a migration of the volcanism. Saint Barthelemy is an island belong to the northern part of the Lesser Antilles arc, illustrating the oldest period activity of the arc. Geochemical study of this key island will permit us to characterize the sources and the potential contamination of the magmas generated in the Lesser Antilles arc from Eocene to Early Miocene. We present new major and trace element and Sr, Nd, Pb and Hf isotope data from lava samples from the Saint Barthelemy island. The samples range from basalt to rhyolites, with mainly andesite and they belong globally calc-alkaline series. The trace element patterns of Saint Barthelemy lavas present enrichment of the large ion lithophile element (LILE) relative to the high field strength elements (HFSE) and anomalies which are typical of subduction zone and of fluid participation. Rare earth element patterns of magmatic rocks from Saint Barthelemy show an increase of LREE/MREE ratios through time. Sr-Nd-Pb isotope variations show all the samples from Saint Barthelemy are located in the Arc worldwide domain in agreement with their origin from a subduction environment. Furthermore, Saint Barthelemy samples show isotopic ratios more similar with the Saint Martin island than Martinique for the same period comforting the distinct evolution of the northern part relative to the southern part of Lesser Antilles arc

The reef platform of Martinique: Interplay between eustasy, tectonic subsidence and volcanism since Late Pleistocene

International audienceReef positions record the interaction between eustasy and tectonics, and have been used worldwide to characterize vertical deformations of upper-plates at different time-scales and constrain the seismic behavior of megathrusts. Along the Lesser Antilles volcanic arc, high-resolution marine geophysical data were collected on the 2–20 km wide eastern Martinique reef platform to reconstruct its stratigraphic and morphologic history, and understand the influence of local normal faulting, volcanism and plate-scale subduction processes on Holocene and Late Pleistocene reef development. The subsiding Martinique platform's stratigraphy is composed of multiple superimposed sea-level highstand deposits separated by subaerial exposure surfaces of sea-level low stands. The carbonate platform consists of two laterally-extensive carbonate units (unit U2 overlying unit U3) that extend to the platform edge to a depth of − 95 m MSL (mean sea level), and form two morphologic terraces, M2 and M3 respectively. The landward portion of unit U2 is partially overlain between 0 and − 60 m MSL by the living reef tract U1. The current reef is composed of a landward fringing reef, a lagoon and a seaward barrier reef, the latter forming a double-bank barrier around the Caravelle Peninsula. In near-shore multi-channel seismic profiles, a distinct reflector at ~− 35 m MSL, probably a subaerial exposure surface E1, separates the reef sequence formed during the last transgression from a Pleistocene fossil reef tract forming unit U2. Offshore of Mount Pelée volcano (Late Pleistocene), the Holocene reef did not develop above unit U2, whose upper surface is incised by channels and apparent sinkholes. During the Holocene transgression, the possibility of excessive turbidity due to volcanic activity may have inhibited reef development in this area. The un-dated unit U2 probably developed 120–130 ka ago during the last interglacial (MIS 5.5) + 6 m MSL highstand as thick, extensive reefs deposited all along the Lesser Antilles arc. Due to subsidence, MIS 5.5 reefs are not represented by onshore facies, except along the southern Sainte Anne Peninsula where normal faulting and uplift balances island-scale subsidence. Based on unit U2's present elevation and assuming an MIS 5.5 age and + 6 m MSL sea level, Martinique has subsided at maximum 0.3 m/ky, likely due to subduction processes that question the coupling state of the megathrust

Seafloor giant polygons associated with underlying polygonal faults in the Caribbean Sea, west of Grenada Basin

International audienceThe initial sediment lithification reactions start with complex interactions involving all components of the sedimentary material (minerals, surface water, decomposing organic matter and living organisms). This is the eogenesis domain (0 to 2000 m below seafloor), covering a burial interval ranging from the interface with the biosphere down to depths where physical compaction processes become predominant. Compared to studies performed on sedimentation (and sedimentary dynamics) and on deep diagenesis (mesogenesis), there is a true lack of data concerning diagenetic processes occurring during eogenesis, in particular concerning siliciclastic diagenesis. However, shallow sediments within the eogenesis domain undergo intense deformation and fracturing. In clay-rich sediments the created faults are organized in polygons due to the volumetric contraction leading to a volume loss during burial. The polygonal fault systems (PFS) have been identified in many basins worldwide, such as in the China Sea, in the Australian Eromanga Basin, in the Lower Congo Basin, in the Danish Central Trough, in the Canadian Atlantic margin and in the Irish Sea. These area are all located in petroleum provinces, either onshore or at water depths ranging from 200 to 1500 m. During the Garanti Cruise in May-June 2017, giant polygons have been identified on the slope of the Caribbean sea, west of Grenada Basin, between 1800 and 2500 m water depth. On seismic profiles the polygonal faults are characterized by an intense dimming of reflections on both edges of the fault planes suggesting that fluids are currently migrating upward. They affect a 700 to 900 m thick interval and they can locally reach the modern seafloor where they form polygons visible on multibeam data. On chirp profiles, the polygons have very steep flanks, defining rectilinear depressions (or furrows) that are 40 m deep compared to the regional slope. Various mechanisms have been referenced in the literature as responsible for polygonal fault initiation and propagation, such as diagenetic transformations or reactivation by sediment loading for instance. Four hypotheses are actually proposed to explain the formation of these polygonal faults: i) syneresis related to colloidal properties of such fine-grained sediments, ii) density inversions and associated hydrofracturing, iii) smectite-rich clays causing residual friction at low burial depth and iv) grain dissolution in incemented media inducing a decrease in horizontal stress that leads to shear failure and shear strain localization. In the Grenada basin it seems that the volumetrical contraction starts very early after deposition suggesting that the smectite-rich clays play a key role in the formation of polygons. This is compatible with the volcano-clastic context in the area where clays may come from the in-situ alteration of volcanic material

Flare-Shaped Acoustic Anomalies in the Water Column Along the Ecuadorian Margin: Relationship with Active Tectonics and Gas Hydrates

International audienceWith hull-mounted multibeam echosounder data, wereport for the first time along the active Ecuadorian margin,acoustic signatures of water column fluid emissions and seep-relatedstructures on the seafloor. In total 17 flare-shaped acousticanomalies were detected from the upper slope (1250 m) to the shelfbreak (140 m). Nearly half of the flare-shaped acoustic anomaliesrise 200–500 m above the seafloor. The base of the flares is generallyassociated with high-reflectivity backscatter patchescontrasting with the neighboring seafloor. We interpret these flaresas caused by fluid escape in the water column, most likely gases.High-resolution seismic profiles show that most flares occur closeto the surface expression of active faults, deformed areas, slopeinstabilities or diapiric structures. In two areas tectonic deformationdisrupts a Bottom Simulating Reflector (BSR), suggesting thatburied frozen gas hydrates are destabilized, thus supplying free gasemissions and related flares. This discovery is important as it opensthe way to determine the nature and origin of the emitted fluids andtheir potential link with the hydrocarbon system of the forearcbasins along the Ecuadorian margin

Quaternary sedimentation and active faulting along the Ecuadorian shelf: preliminary results of the ATACAMES Cruise (2012)

International audienceSelected high-resolution seismic-reflection profiles and multibeam bathymetry acquired along the convergent Ecuador margin during the ATACAMES cruise on onboard the R/V L’Atalante (Jan.15–Feb.18, 2012) allow a preliminary evaluation of the neotectonic development and stratigraphic evolution of the margin based on the sismo-stratigraphic analysis of Quaternary sediment preserved on the margin shelf and upper slope. We present three major preliminary results. (1) The evolution of the Esmeraldas, Guayaquil and Santa Elena canyons. The head of the Esmeraldas canyon is the location of a continuous significant sediment transport. The Guayaquil canyon shows several episodes of deposition and incision. Aggrading sedimentation pattern in the canyon records several changes in relative sea-level. The subsidence of the Gulf of Guayaquil probably contributes to the good preservation of the canyon filling stages. The Santa Elena canyon is controlled by a SW–NE trending normal fault. (2) Variations of sediment accumulation and relative vertical motions are shown along-strike the shelf edge. Offshore the uplifted Manta peninsula, a pronounced subsidence of the shelf edge is documented by sedimentary clinoforms that have deposited in a morphological reentrant, and have migrated upslope testifying of a local subsidence meanwhile the adjacent La Plata Island area underwent uplift. In the Esmeraldas canyon area, a local uplift of the shelf is documented. (3) Two neotectonic fault systems with a possible transcurrent component are imaged across the shelf edge and upper margin slope offshore Jama, and Cape Galera. This possible transcurrent motion could be related to the reactivation of ancient faults of the upper plate by the subduction. These preliminary results indicate that the ATACAMES data set has a strong potential to evaluate the spatial and temporal contribution of tectonic and climate changes on the structural development and stratigraphic evolution of the Ecuador continental margin