Discipline: Technology and Engineering
Subcategory: Civil/Mechanical/Manufacturing Engineering
Session: 2
Andrea Salame - Texas Southern University
Co-Author(s): Dr. Juan Horrillo
In recent studies it has became a fact that if a moderate earthquake were to occur in the Gulf of Mexico it could cause submarine landslide that may generate a tsunami. However, the probability is very low for this occurrence. A submarine landslide is a rapid downward movement of ocean sediment on the ocean bottom slope. This causes a Tsunami due to the fact the sediment pushes the water away from the generation area. This wave moves fast and grows faster as they approach the shore. Our submarine landslide experiments will attempt to reproduce a more realistic submarine landslide event to improve and validate our existing numerical model used to construct inundation maps along the US coastline. If the experiment results are taken accurate, it will help us to include in the future better physics to simulate submarine landslide induced-tsunami. Our hypothesis is “How a more realistic submarine landslide affect free surface?” And “How static and dynamic angle of repose of the sediment will play a role in the landslide dynamic and ensued wave?”. The strategies we used to solve for this project is: first, to construct a small scale prototype representing a submerged landslide. Second was using the Continuity equation for incompressible fluid and the equation of motion. These two equations govern both, the landslide flow and its effect in the water. The continuity equation gives us an idea of mass and energy conservation. The glass gems will move and deform the water. The energy and mass of these objects will be conserved. As for Newton’s second law equation, it states that force is dependent on mass and acceleration. Also, an object continues to do whatever it happens to be doing unless a force is exerted upon it. The forces acting on this are the water internal friction and bottom friction. Everything in water will be slowed down by the internal friction and bottom friction. Theses equations give an idea on the outcome form of the experiment. Thirdly, we determined the friction between the glass gem and the bottom of the acrylic. Which helped us get the results of the acrylic glass slope and determined an equilibrium. The last step takes for modeling the submarine landslide was find the static angle of repose of the glass gems in water first. Plastic funnels with wooden handles were utilized to fill the funnel with gem. We slowly brought up the funnel upward giving us the angle repose as gems were finding their own stability. We did this procedure three times and thus we determined an average angle of twenty-six degrees. Then we determine the static and dynamic angle of repose of the gems in air, we poured a substantial number of gems on a sliding platform. We placed the gems on top of the platform carefully and used an iPhone app on the side of the platform to measure the static and dynamic angle of repose. The static angle of repose is determined at the moment is about the gems to fail and the dynamic angle is measured on the failed slope or when the gems reach an equilibrium. We noticed a trend in the dynamic angle of repose after the slope fails. Also, we noticed that the previous experiment that we conducted with the funnel were very close to this one. The averages for the static and dynamic angle of repose were as found static averaging around thirty-three degrees and dynamic around twenty-six degrees. These experiments contributed us to develop our model. Our model contains a winch to change the angle before failure and a control box that contains the circuit for our winch and control switch to change the frequency of the motor generating a micro earthquake. Submarine landslide induced-tsunami is a very complex phenomenon. This work attempts to develop a more realistic (deformable) submarine landslide simulation than the models available in pre existing literature. However, submarine landslide are mainly modeled in laboratory experiments by utilizing rigid landslide; however, they can also be mimicked by using a dam break experimental mechanism. Submarine landslide laboratory experiments are essential for simulation component for the phenomenon. In future experiments to come, our experimental objective is to represent the potential outcome of the deformable submarine landslide. A great idea and effort have been poured to fabricate a control device for that project. The control mechanism, already constructed, will improve substantially the experiment repeatability required for the experiment. Tests for wave generation by submarine landslide and its respective measurements are still in progress. The projects results will facilitate to validate our numerical model( American Tsunami Model) used to develop tsunami maps in the Gulf of Mexico.
Funder Acknowledgement(s): Texas A&M Galveston Oceanus Program
Faculty Advisor: Dr. Juan Horillo, horrillj@tamug.edu
Role: In this research, I contributed everything done in the following abstract. I built the acrylic structure by hand. With carefully measuring each angle, weight and contributing that water shall make adjustments to my land experiment. Conducting other experiments to help further our knowledge of deformable landslide experiment. This project helped me gain opportunity to further the project and eventually bring it to a wave tank.