Structure and tectonics of the crust and Moho discontinuity of the Gloria Fault and Terceira Rift (S. Miguel) along the Nubia-Eurasia plate boundary

The crustal structure of two ~150 km long segments across two main tectonic plate boundaries in the North Atlantic, the Gloria Fault and the Terceira Rift are presented. The Gloria Fault stands as a seismogenic fracture zone that generates high magnitude earthquakes, such as the M8.4 event in 1941. Vp and Vs waves were recorded during an active seismic refraction experiment using 18 Ocean Bottom Stations. The velocity model allows discrimination of five layers (L1 to L5), L1 for sediments, L2 for upper crust, L3 for lower crust, L4 for a layer of unknown origin and L5 for mantle. Poisson coefficient from Vp/Vs ratio allowed estimation of layers’ densities. We speculate on L4 origin and nature from velocities and densities. Two possible models, L4 corresponds to a mixture of gabbro and peridotite or to hydrated mantle (serpentinized mantle). The Terceira Rift seismic refraction line comprehends data from the S. Miguel Island. Velocities of S waves were not recorded. The model is based in Vp only. A five layer model is proposed, L1 for volcano-sedimentary layer, L2 for upper crust, L3 for lower crust and L5 for the mantle. L4 between L3 and L5 has a lensoid shape and its velocities suggest either a cumulate gabbro underplated layer or hydrated mantle. A south dipping extensional shear zone aligned with the Monaco Graben was identified from the brittle upper crust and across the lower crust, L4 and mantle. This shear zone coincides with a cluster of seismicity located to the south of S. Miguel Island. To the north of S. Miguel seismicity is barely inexistent and a 20 km long recent landslide with a toe thrust is clearly imaged, suggesting northward tilting of the island caused by the extensional shear zone, the south flank of the Terceira Rift.German Research Foundation, DFG, grant Hu698/19-

The geysers geothermal area, California: tomographic images of the depleted steam reservoir and non- double-couple earthquakes

The Geysers geothermal area, California is the world's largest and most intensively exploited steam field, providing about 6% of California's electrical power. The geothermal area is very active seismically, generating about 140 earthquakes per month with M(_D)≥l.2. Non-DC earthquakes have been routinely detected in other geothermal and volcanic areas such as the Hengill-Grensdalur volcanic complex, Iceland but previously went undetected at The Geysers. The steam field is, however, a likely source of non-DC earthquakes because large volumes of steam are extracted and condensate injected during the course of commercial exploitation which might cause cracks or fractures to open and close. Maps of seismic activity through time show conclusively that earthquakes initiate at the onset of production, continue through it and stop when production ceases. Furthermore the volume of steam extracted and/or condensate injected may directly control the rate of seismicity within the geothermal area. A temporary field experiment in April, 1991 recorded about 4000 high-quality earthquakes on three-component digital sensors. Three-dimensional tomographic models of V(_p) and, for the first time at The Geysers, V(_p)/v(_s) were determined using 3906 P-wave and 944 5-wave arrival times from 185 earthquakes. Variations m lithology, temperature and the pore-fluid phase probably produce the variations in V(_p). A strong low in the V(_p)/v(_s) model defines fluid-deficient areas in the steam reservoir and is surrounded by a "halo" of high-V(_p)/v(_s) anomalies. V(_s)/v(_s) can remotely monitor temporal depletion of liquid reserves in the steam reservoir. Well-constrained moment tensor solutions for 30 earthquakes were determined by inverting the polar' ices and amplitude ratios of P- and 5-wave arrivals. Strong evidence for the existence of non-DC earthquakes at The Geysers geothermal area was found. Explosive and implosive events occur in equal numbers and probably reflect source processes involving opening and closing cracks or cavities. The events form a symmetric pattern on source-type plots extending from the postive dipole-to-negative dipole loci, passing through the DC locus. The association with dipole loci rather than crack loci suggests the source process must also involve a compensating flow of fluids, liquid or steam

Seismicity and regional tectonics of the Estremadura, Southwestern Portugal

The RESTE Project was an integrated geophysical-geological study of the Estremadura, southwestern Portugal. The core of the programme consisted of the acquisition and analysis of microearthquake data. This was complemented by an investigation of the structural evolution of the sedimentary basins of the Estremadura. The geological evolution of the Lusitanian Basin was strongly marked by the reactivation of Palaeozoic basement faults, in response to a sequence of tectonic events: opening of the Central Atlantic, opening of the North Atlantic and Alpine convergence between Africa and Eurasia. The current tectonics are regarded as a subdued continuation of the Miocene deformation (Betic Orogeny), and the "tectonic memory" revealed by the Lusitanian and Lower Tagus Basins is explored to characterize the current tectonic processes. Strike-slip tectonics are identified as a dominant feature of several stages of the evolution of the basins, with particular relevance during the Miocene. The technique of "backstripping" is applied to well data, to constrain the history of vertical movement in the basins. This analysis highlighted the pre mature truncation, in the Late Jurassic, of a normal passive-margin evolution. Tectonic unstability caused the structural inversion of areas within the basins, and seems to have inhibited the predictable thermal subsidence. The rifting process, initially taking place at the Lusitanian Basin, jumped westwards in the Late Jurassic. Crustal underplating and the activity of transfer faults are in-voked as possible explanations for the subsequent deformation of the aborted rift. An upper-plate margin configuration is in good agreement with several observations. The tendency for structural inversion continued throughout theCretaceous, and with the onset of the Alpine convergence in the Turonian the control of the tectonic activity seems to have switched from the Atlantic to the Mediterranean. This reinforced the tectonic unstability, marked by magmatic activity and by a regional upwarp that was to last until the Eocene. Of particular interest was the behaviour, during the Late Cretaceous, of the Setúbal Peninsula sub-basin, which seems to have tilted towards the NW as a block, with a hinge line along the present Lower Tagus Valley. When sedimentation was resumed in the Eocene, a pattern of differential vertical movement was established, with some areas continuing to undergo inversion while nearby areas subsided. This pattern characterized the Cainozoic evolution of the basins, and probably still applies to the neotectonic deformation. The activity of strike-slip basement faults, reactivated under the compressive regime caused by the Afro-Eurasian conver-gence, is proposed as the best explanation for the Miocene deformation, with particular relevance for the Lower Tagus Valley. The RESTE Microearthquake Survey is described, and the data acquired with the RESTE network are analysed. The local earthquakes are accurately located, and focal mechanism solutions are obtained for some of them. This information is used to discuss a neotectonic model for the Lower Tagus Valley. In view of their small magnitudes (l.1< M(_L) < 3.8), the focal mechanisms of these events cannot be interpreted directly in terms of the current tectonics. Such small events are usually local readjustments to previous episodes of deformation. However, such features as the along-strike reversal of the polarity of vertical motion or the coexistence at the same region of different types of source mechanism are diagnostic of strike-slip deformation. This model was supported by the occurrence of a macroearthquake (M(_D)=3.8) with an interpreted source mechanism of sinistral strike-slip. The alignment of four hypocentres along the direction of the Lower Tagus Valley, with a compatible orientation of the interpreted nodal planes, supports the existence of a crustal fracture associated with the Valley. The hypocentral depths of the recorded events reach 20 km, showing that the basement faults responsible for the seismicity affect at least the entire upper crust. Since the limited existing data suggest a high level of heat flow in the Lusitanian Basin, the depths reached by the microearthquakes may indicate an abnormally thick seismogenic layer. An investigation of the broad velocity structure of the lithosphere underneath the RESTE Network using the technique of teleseismic tomographic inversion suggested a correlation between Moho undulations and the inversion of areas of the Lusitanian Basin, and this may indicate that the controlling faults cut the entire crust. In order to provide a rationale for the intraplate seismicity of western Portugal, the neotectonics of Iberia are discussed, and a new kinematic model, centred on the idea of continental extrusion, is proposed. According to the model, a continental block formed by Iberia and northern Morocco is being pushed west wards by the convergence between Africa and Eurasia. The resistance offered by the oceanic parts of the plates varies across the East Azores Transform, leading to dextral shear in the Betic Range. The regional stress field induced by the continental convergence can explain the reactivation, in a simple-shear regime, of basement faults of Hercynian orientation, in particular that proposed for the Lower Tagus Valley

Strain partitioning and the seismicity distribution within a transpressive plate boundary : SW Iberia-NW Nubia

Tese de doutoramento, Geologia (Geodinâmica Interna), Universidade de Lisboa, Faculdade de Ciências, 2017The Gulf of Cadiz offshore SW Iberia is an area linked with episodic destructive seismic and tsunamigenic events, such as the M~8.8, 1st November 1755 Lisbon earthquake among others. The association of active faults to this kind of high magnitude event has been extensively studied specially due to the contribution of several international projects for more than two decades. However, the meaning of the persistent small to intermediate magnitude seismicity recognized in this region is still particularly not fully understood. This is, at least, related to the lack of an accurate hypocenter location of these events resulting from an asymmetrical geographical distribution of the permanent seismic network. One of the main purposes of the NEAREST project (Integrated observation from NEAR shore sourcES of Tsunamis: towards an early warning system GOCE, contract n. 037110) was the identification and characterization of seismogenic and tsunamigenic structures in the Gulf of Cadiz area, source region of the Lisbon 1755 earthquake and tsunami. To address this problem 24 broadband Ocean Bottom Seismometers (OBS) and a seafloor multiparametric station GEOSTAR (Geophysical and Oceanographic Station for Abyssal Research) acquired between August 2007 and July 2008 passive seismic data in this region. The results delivered a detailed record of the local seismicity, revealing 3 main clusters of earthquakes, two of them coinciding with the location of the 3 larger instrumental earthquakes in the area: i) the 28th February 1969 (Mw~8.0); ii) the 12th February 2007 (Mw=6.0) and iii) the 17th December 2009 (Mw=5.5). Focal mechanisms show a mixed pattern, mostly strike-slip and reverse dip-slip with a very few normal mechanisms. The results show that of the recorded events are located in the mantle (at depths between 30 and 60 km). This implies the existence of tectonically active structures located much deeper than the ones mapped by Multichannel seismic reflection. A thorough analysis shows that the seismicity clusters are offset with respect to the upper crustal active thrusts. The wide-range solutions of focal mechanisms also imply that the related source processes are complex. This can reflect the interaction of different active geological features, such as faults and rheological boundaries. To understand these new results in the context of the seismotectonics of the Gulf of Cadiz a review of some available geophysical data (reflection and refraction seismic profiles interpretation) in this area is presented as well as novel work on seismic reflection profile IAM GB1 across a rheologic boundary and seismicity cluster. Our study shows that the seismicity clusters are located at faults intersections mapped at the seafloor and shallow crust, suggesting that the crustal tectonic faults are replicated in the lithospheric mantle. These fault interferences are associated with boundaries of lithospheric domains prone to localize stress and seismic strain. Active crustal faults are either locked or move through slow aseismic slip. Frictional slip in crustal faults is probably limited to high magnitude earthquakes. Serpentinization probably induces tectonic decoupling limiting micro-seismicity to depths below the serpentinized layer. It is expected that during highmagnitude events seismic rupture is favored by weakening mechanisms and propagates upwards through the serpentinized layer up to the surface. The results obtained in this work improve our knowledge about the local seismicity and related active faults in the Gulf of Cadiz area, giving a new contribution to access to the seismic hazard in the Nubia-Iberia plate boundary in the Northeast Atlantic Region.O Golfo de Cádis é uma região com uma sismicidade moderada embora se conheça, tanto no registo histórico como instrumental, eventos de elevada magnitude. O sismo de 1 de Novembro de 1755 é um exemplo paradigmático com uma magnitude estimada de 8.8 e um tsunami associado com Mt = 8.5. Já o sismo de 28 de Fevereiro de 1969, é o mais importante registado instrumentalmente, teve uma Ms de 7.9, ao qual esteve associado um pequeno tsunami. Mais recentemente, salientam-se os sismos de 12 de Fevereiro de 2007, com Mw=6.0 e o de 17 de Dezembro de 2009, com Mw =5.5 (EMSCEuropean-Mediterranean Seismological Centre). No entanto, a sismicidade nesta região é descrita como de magnitude baixa a intermédia, com uma distribuição em profundidade acima dos 60 km. Correlacionar esta sismicidade com potenciais estruturas sismogénicas no Golfo de Cádis constituiu um dos objectivos do projecto NEAREST (Integrated observation from NEAR shore sourcES of Tsunamis: towards an early warning system GOCE, contract n. 037110). Neste contexto, foram necessárias uma caracterização e localização mais precisas dos eventos sísmicos ocorridos nesta região, até agora limitadas pelos constrangimentos inerentes à distribuição geográfica das estações permanentes terrestres. Por isso, foi desenvolvida uma campanha de aquisição de dados contínuos utilizando uma rede de sismómetros de fundo do mar. A rede sísmica NEAREST operou de modo contínuo num período de 11 meses, entre Agosto de 2007 Julho de 2008, integrando 24 sismómetros de fundo do mar (OBS) e uma estação multiparamétrica- GEOSTAR. Durante as campanhas de colocação e recuperação dos instrumentos, as manipulações dos OBS e GEOSTAR estiveram a cargo do Alfred Wegener Institute for Polarand Marine Research e do Istituto Nazionale di Geofisica e Vulcanologia – INGV, respectivamente. Os OBS foram construídos pela K.U.M. Umwelt- und Meerestechnik Kiel GmbH, Germany e incorporavam sismómetros de banda larga Güralp CMG-40T e um hidrofone. A GEOSTAR é um observatório que integra diversos equipamentos para a recolha de dados geofísicos e oceanográficos em contínuo. Nesta estação estão incluídos um sismómetro de banda larga com 3 componentes e um hidrofone usados nesta campanha. As estações terrestres estão a cargo do Instituto Português do Mar e da Atmosfera (IPMA) e Instituto Dom Luiz (IDL) correspondendo a sismómetros de banda larga também com 3 componentes. Os registos nestas estações foram apenas utilizados para constranger as soluções dos mecanismos focais. Em trabalhos futuros, prevê-se a sua inclusão na localização dos eventos identificados pela rede NEAREST. Durante o período de aquisição foram registados na rede terrestre, para a área delimitada pela rede NEAREST, cerca de 270 sismos locais. Durante o período de funcionamento da rede NEAREST foram identificados cerca de 750 eventos observados em mais de 3 estações. Deste total 590 sismos estavam localizados na área da rede NEAREST. A localização hipocentral foi testada usando diferentes metodologias e modelos de velocidades: a) inversão conjunta das posições hipocentrais e correcções de estações; b) o método das diferenças duplas e c) a inversão conjunta do modelo de velocidades-localizações hipocentrais e correcções de estações. O catálogo final inclui 443 eventos identificados em mais de 6 estações e localizados na área da rede NEAREST. De um modo geral, a maioria dos hipocentros estão localizados a mais de 30 km de profundidade, portanto no manto. As magnitudes locais variam entre 1.2 e 4.8. As localizações epicentrais e hipocentrais baseadas na rede NEAREST divergem das soluções conhecidas para a rede terrestre (providenciadas pelo IPMA), estando deslocadas para SW e sendo mais profundas. A diferença de profundidade pode atingir os 40 km. A campanha do projecto NEAREST permitiu a identificação de uma grande quantidade de eventos não detectada pela rede terrestre. Esta campanha permitiu ainda uma redefinição da distribuição da sismicidade na região, até então considerada difusa. Destes resultados foi possível reconhecer 3 enxames de sismicidade, dois destes coincidentes com 3 dos maiores eventos observados no registo instrumental. Tanto os sismos de 28 de Fevereiro de 1969 (Mw~8.0) como 12 de Fevereiro de 2007 (Mw=6.0) na proximidade da Falha da Ferradura e 17 de Dezembro de 2009 (ML=6.0) na região do canhão de São de Vicente. Os mecanismos focais do catálogo NEAREST são consistentes com estes eventos bem como com soluções de tensores de momento publicadas para esta região. No enxame do canhão de São Vicente é onde estão localizados a maioria dos eventos. Os hipocentros encontram-se a profundidades entre os 20 e os 55 km. A distribuição dos epicentros apresenta um alinhamento ≈ NE-SW ao longo do canhão de São Vicente e prolongando-se para o limite NE da Falha da Ferradura. Os mecanismos focais dominantes são de desligamento e oblíquos, combinando movimento de desligamento com uma menor contribuição de movimento inverso. Foram ainda registados raros eventos em falha normal. A compressão máxima é aproximadamente sub-paralela ao SHmax, com uma direcção ≈NW-SE. Os epicentros localizados no enxame a SW da Falha da Ferradura, tem um alinhamento aproximadamente NW-SE, sub-paralelo à direcção de SHmax regional. Neste enxame os hipocentros são mais profundos localizando-se entre os 30 e os 55km. Os mecanismos focais são na sua maioria de desligamento puro existindo alguns eventos em falha inversa e também raras soluções em falha normal. Importa salientar que as soluções de desligamento apresentam frequentemente um plano subparalelo à orientação das falhas de desligamento SWIM (≈WNW-ESE a E-W). A compressão máxima é aproximadamente NW-SE e NNW-SSE, a W e E do enxame de sismicidade, respectivamente. As direcções de SHmax são mais uma vez coincidentes com a direção de compressão máxima. No enxame do Banco do Gorringe maioria dos sismos estão localizados no bordo SW deste relevo submarino, sub-paralelos à falha do Gorringe. Os eventos são menos profundos quando comparados com os outros dois enxames, na sua maioria acima dos 40 km. Os mecanismos focais são na sua maioria de desligamento e em falha inversa. Também neste enxame foram registados alguns sismos em falha normal. A direcção de compressão máxima e o SHmax são NNW-SSE. O facto de estes eventos se localizarem predominantemente no manto constitui um dos principais resultados deste trabalho. Neste contexto, tendo em consideração a profundidade dos eventos sísmicos, a correlação da sismicidade com as estruturas sismogénicas na região do Golfo de Cádis é particularmente complexa. Esta comparação foi desenvolvida com base nos dados de sísmica de reflexão e refração disponíveis. Do nosso estudo resulta que a sismicidade parece estar concentrada em zonas de interferência de falhas localizadas no manto subcrustal litosférico. Estas deverão ser uma replicação do padrão observado a níveis crustais e parecem ser coincidentes com transições entre diferentes domínios litosféricos. Estas zonas de interferência de falhas deverão ser áreas favoráveis à acumulação de tensões e deformação sísmica. As falhas activas crustais deverão estar ou bloqueadas ou movimentar-se de modo assísmico. A movimentação sísmica pode estar associada apenas a sismos de maior magnitude. A existência de níveis serpentinizados no Golfo de Cádis é suportada por dados de sísmica refracção e furos de sondagens profundas. Estes podem funcionar como planos de descolamento para as grandes falhas inversas, acomodando a movimentação asísmica e impedindo a micro-sismicidade de se propagar aos níveis crustais. Durante os sismos de elevada magnitude estes níveis serpentinizados deverão funcionar como zona enfraquecida, de baixo atrito, favorecendo a propagação da ruptura sísmica até à superfície. Os resultados obtidos neste trabalho melhoram o nosso conhecimento sobre a sismicidade e a sua relação com as falhas activas na região do limite de placas litosféricas no Golfo de Cádis, contribuindo para o estudo do risco sísmico associada a sismos devastadores

Nuevos avances en la RMN anisotrópica y detección de productos naturales marinos bioactivos

Programa Oficial de Doutoramento en Química Ambiental e Fundamental. 5031V01[Resumen] A continuación, se presenta un breve resumen de cada capítulo: Capítulo 1: El uso de RMN anisotrópica en el análisis estructural de moléculas pequeñas quirales se ha expandido en los años recientes. En la actualidad, las Constantes Dipolares Residuales (CDR) pueden ser aplicadas como una herramienta estándar en el mejoramiento eficiente de la determinación de la configuración relativa de compuestos de pequeño tamaño mediante RMN estándar. En la presente tesis doctoral hemos desarrollado otra metodología de RMN anisotrópica basada en medidas de anisotropía de desplazamiento químico residual de protones (1H RCSA) que ha sido aplicada, primero a moléculas modelo, estricnina, estrona, retrorsina y a-santonina, y posteriormente a nuevos productos naturales: a un meroditerpeno aislado del alga parda Sargassum muticum, a las tricloromammindas A y B aisladas del hongo no comestible Tricholoma equestre y, finalmente a un briarano de origen marino aislado de la gorgonia Briareum asbestinum recolectada de la penísula de Yucatán. Toda esta nueva metodología se ha podido realizar a través de la mejora de nuevos dispositivos de compresión y extensión de geles aplicados a tubos de RMN de menos de 5 mm. Este desarrollo de este tipo de dispositivos es una herramienta adicional que puede ser utilizada en el futuro por espectroscopistas en el campo de RMN anisotrópica. Por último, también hemos introducido un nuevo gel deuterado (PMMA-d8) derivado de polimetilmetacrilato deuterado como medio alineante. Capítulo 2: La detección y cuantificación de productos naturales presentes en trazas en mezclas complejas es aún un campo de investigación activo para los químicos. Desde la introducción en el mercado del detector de masas Orbitrap® se iniciado una revolución en las técnicas analíticas de detección. En la presente Tesis Doctoral hemos aprovechado esta tecnología para la detección y, en algunos casos, el aislamiento y la cuantificación de algunos productos naturales de origen marino de interés biológico. Las distintas aproximaciones en las técnicas de LC/HRMS empleadas fueron aplicadas a: La detection y el aislamiento de la producción de sideróforos en varias bacteria marinas patógenas: tipo vancrobactina en tres especies de Vibrio, tipo piscibactina en una cepa mutante de Vibrio alginolyticus, el sideróforo producido por las bacterias Edwardsiella tarda y Photobacterium damselae subsp. damselae. Detección y cuantification de AHLs en tres especies patógenas de Vibrio. Detección de (TTX) en el pez Diodon hystrix recolectado en El Salvador.[Resumo] A continuación amósase un resumo de cada capítulo. Capítulo 1 O uso da RMN anisotrópica na análise estrutural de moléculas pequenas quiraies, expandiuse nos anos recentes. Na actualidade, as Constantes Dipolares Residuais (CDR)poden ser aplicadas como unha ferramenta estándar na millora eficiente da determinación da configuración relativa de compostos de pequeno tamano mediante RMN estándar. Na presente Tese Doutoral desenvolvemos outra metodoloxía de RMN anisotrópica baseada en medidas de anisotropía de desprazamento químico residual de protones (1H RCSA) que foi aplicada, primeiro a moléculas modelo, estricnina, estrona, retrorsina e [alfa]-santonina, e posteriormente a novos produtos naturais: a un meroditerpeno illado do alga parda Sargassum muticum, ás tricloromammindas A e B illadas do fungo non comestible Tricholoma equestre e, finalmente a un briarano de orixe mariña illada da gorgonia Briareum asbestinum colleitada da penísula de Iucatán: Toda esta nova metodoloxía púidose realizar a través da mellora de novos dispositivos de compresión e extensión de xeles aplicados a tubos de RMN de menos de 5 mm. Este desenvolvemento deste tipo de dispositivos é unha ferramenta adicional que pode ser utilizada no futuro por espectroscopistas no campo de RMN anisotrópica. Por último, tamén introducimos un novo xel deuterado (PMMA-d8) derivado de polimetilmetacrilato deuterado como medio alineante. Capítulo 2 A detección e cuantificación de produtos naturais presentes en trazas en mesturas complexas é aínda un campo de investigación activo para os químicos. Desde a introdución no mercado do detector de masas Orbitrap® #iniciar unha revolución nas técnicas analíticas de detección. Na presente Tese Doutoral aproveitamos esta tecnoloxía para a detección e, nalgúns casos, o illamento e a cuantificación dalgúns produtos naturais de orixe mariña de interese biolóxico. As distintas aproximacións nas técnicas de LC/HRMS empregadas foron aplicadas a: A detection e o illamento da produción de sideróforos en varias bacteria mariñas patógenas: tipo vancrobactina en tres especies de Vibrio, tipo piscibactina nunha cepa mutante de Vibrio alginolyticus, o sideróforo producido polas bacterias Edwardsiella tarda e Photobacterium damselae subsp. damselae. Detección e cuantification de AHLs en tres especies patóxenas de Vibrio. Detección de (TTX) no peixe Diodon hystrix colleitado no Salvador.[Abstract] A summary of each chapter shall be presented below. Chapter 1: The use of anisotropic NMR in the structural analysis of chiral small molecules has expanded in recent years. Currently, Residual Dipolar Constants (RDC) can be applied as a standard tool in the efficient improvement of the determination of the relative configuration of small-sized compounds by standard NMR. In the present Thesis dissertation, we have developed another methodology of anisotropic NMR based on measures of anisotropy of residual chemical proton displacement (1H RCSA) that has been applied, firstly to compound-models, strychnine, estrone, retrorsine and [alfa]-santonin, and subsequently to new natural products: to an isolated meroditerpene of the brown alga Sargassum muticum, the trichloromaminades A and B isolated from the non-edible fungus Tricholoma equestre and, finally to a briarane of marine origin isolated from the gorgonian Briareum asbestinum collected from the peninsula of Yucatan (México). Chapter 2: The detection and quantification of natural products present in traces in complex mixtures is still an active field of research for chemists. Since the introduction of the Orbitrap® mass detector into the market, a revolution in analytical detection techniques has begun. In this Doctoral Thesis we have taken advantage of this technology for the detection and, in some cases, the isolation and quantification of natural products of marine origin of biological interest. The different approaches in the LC / HRMS techniques used were applied to: Detection and isolation of siderophore production in several pathogenic marine bacteria: vanchrovatin type in three Vibrio species, piscibactin type in a mutant strain of Vibrio alginolyticus, the siderophore produced by the bacteria Edwardsiella tarda and Photobacterium damselae subsp. damselae Detection and quantification of AHLs in three pathogenic Vibrio species. Detection of TTX in the fish Diodon hystrix collected in El Salvador

Infrared Spectroscopy

This informative and state-of-the-art book on Infrared Spectroscopy is addressed to Researchers in Medicine as well as to Pharmaceutical Industry and Agriculture. It features 7 specialized chapters of MIRS and NIRS covering applications in proteins and biopolymers; food quality research and food safety applications; and medical applications, such as Down syndrome disorders of tooth, probing of brain oxygen, the role of CO2 in blood pressure and diagnosis of metastatic cancer. This book highlights the span of modern Infrared applications

Modern Climatology - Full Text

Climatology, the study of climate, is no longer regarded as a single discipline that treats climate as something that fluctuates only within the unchanging boundaries described by historical statistics. The field has recognized that climate is something that changes continually under the influence of physical and biological forces and so, cannot be understood in isolation but rather, is one that includes diverse scientific disciplines that play their role in understanding a highly complex coupled “whole system” that is the Earth’s climate. The modern era of climatology is echoed in this book. On the one hand it offers a broad synoptic perspective but also considers the regional standpoint as it is this that affects what people need from climatology, albeit water resource managers or engineers etc. Aspects on the topic of climate change – what is often considered a contradiction in terms – is also addressed. It is all too evident these days that what recent work in climatology has revealed carries profound implications for economic and social policy; it is with these in mind that the final chapters consider acumens as to the application of what has been learned to date. This book is divided into four sections that cover sub-disciplines in climatology. The first section contains four chapters that pertain to synoptic climatology, i.e., the study of weather disturbances including hurricanes, monsoon depressions, synoptic waves, and severe thunderstorms; these weather systems directly impact humanity. The second section on regional climatology has four chapters that describe the climate features within physiographically defined areas. The third section is on climate change which involves both past (paleoclimate) and future climate: The first two chapters cover certain facets of paleoclimate while the third is centered towards the signals (observed or otherwise) of climate change. The fourth and final section broaches the sub-discipline that is often referred to as applied climatology; this represents the important goal of all studies in climatology–one that affects modes of living. Here, three chapters are devoted towards the application of climatological research that might have useful application for operational purposes in industrial, manufacturing, agricultural, technological and environmental affairs. Please click here to explore the components of this work.https://digitalcommons.usu.edu/modern_climatology/1014/thumbnail.jp