Short-Term Consequences of Asteroid Impacts into the Ocean: A Portuguese Case Study

Abstract

Asteroid impacts are a proven global threat, meaning that any location on Earth might be a subject to their consequences. Such collisions are not likely in any person’s lifetime, but their aftermath could be catastrophic. As Earth’s surface is mostly water, a water impact is more probable than a ground impact, and tsunami waves could pose a significant threat. This study expands the knowledge about asteroid impacts in the ocean and their regional environmental consequences. Three asteroids were assumed to impact the Earth: (1) the Apophis asteroid, a 370 m wide asteroid, (2) a 204 m in diameter asteroid representative of the average impactor on the near-Earth objects, and (3) a 5 km in diameter asteroid. We evaluated the consequences of all impacts for a specific case study, where the chosen impact location was the midpoint between Portugal’s mainland, Azores, and Madeira Islands. The cratering process, generated seismic shaking, overpressure, ejected material, induced thermal radiation, and tsunami waves were assessed, along with the global effects. The overpressure mainly causes structural damage. The thermal radiation can be devastating but has a short reach. The tsunami is undoubtedly the most far-reaching and threatening effect of an asteroid impact in the ocean.

Modeling the impact of asteroids over Mexican territory

“…In relation to the latter, there are laboratory simulations that recreate the impacts of NEOs on the Earth's surface, using various materials that act as impactors and as targets, to obtain results on the size of the craters [9,10]. Additionally, there are also works that are related to the impact of bodies in the ocean [11] and its repercussions in coastal areas, as well as the magnitude of the earthquake (measured on the Richter scale) that this impact would cause.…”