A one-kilometer-diameter carbonate/hydrate mound in Mississippi Canyon Block 118 has been chosen to be the site of a multi-sensor, multi-discipline sea-floor observatory. Several surveys have been carried out in preparation for installing the observatory. The resulting data set permits discussing the mound’s structure in some detail. Samples from the water column and intact hydrate outcrops show gas associated with the mound to be thermogenic. Lithologic and bio-geochemical studies have been done on sediment samples from gravity and box cores. Pore-fluid analyses carried out on these cores reveal that microbial sulfate reduction, anaerobic methane oxidation, and methanogenesis are important processes in the upper sediment. These microbial processes control the diffusive flux of methane into the overlying water column. The activity of microbes is also focused within patches near active vents. This is primarily dependent upon an active flux of hydrocarbon-rich fluids. The geochemical evidence suggests that the fluid flux waxes and wanes over time and that the microbial activity is sensitive to such change. Swath bathymetry by AUV combined with sea-floor video provides sub-meter resolution of features on the surface of the mound. Seismic reflection profiling with source-signature processing resolves layer thicknesses within the upper 200-300m of sediment to about a meter. Exploration-scale 3-D seismic imaging shows that a network of faults connects the mound to a salt diapir a few hundred meters below. Analyses of gases from fluid vents and hydrate outcrops imply that the faults act as migration conduits for hydrocarbons from a deep, hot reservoir. Source-signature-processed seismic traces provide normal-incidence reflection coefficients at 30,000 locations over the mound. Picking reflection horizons at each location allows a 3-D model of the mound’s interior to be constructed. This model provides a basis for understanding the movement of fluids within the mound.

En este trabajo se analiza el control de la respuesta sísmica de edificaciones asimétricas, mediante la incorporación de Amortiguadores de Masa Sintonizada (TMD), evaluando distintas distribuciones de estos dispositivos en el último piso para obtener una alternativa de mejora en la respuesta de la estructura con el fin de controlar los efectos torsionales de los dos primeros modos de vibrar producto de las irregularidades en planta. Lo anterior se hace usando un modelo computacional de elementos finitos donde la principal variable es la masa participativa del modo torsional siendo esta la primera forma de vibrar y se obtuvo una reducción hasta de 40% de esa variable. / This paper analyzes the control of the seismic response of asymmetric buildings, through the incorporation of Tuned Mass Damper (TMD), evaluating different distributions of these devices on the top floor to obtain an alternative to improve the response of the structure in order to control the torsional effects of the first two mode of vibrating due to irregularities in the plant. The previous one is done using a finite element computational model where the main variable is the participatory mass of the torsional mode, this being the first way to vibrate and a reduction of up to 40% of that variable was obtained. / Trabajo de investigación